diff options
Diffstat (limited to 'io_uring')
78 files changed, 24959 insertions, 0 deletions
diff --git a/io_uring/Kconfig b/io_uring/Kconfig new file mode 100644 index 000000000000..4b949c42c0bf --- /dev/null +++ b/io_uring/Kconfig @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# io_uring configuration +# + +config IO_URING_ZCRX + def_bool y + depends on IO_URING + depends on PAGE_POOL + depends on INET + depends on NET_RX_BUSY_POLL diff --git a/io_uring/Makefile b/io_uring/Makefile new file mode 100644 index 000000000000..bc4e4a3fa0a5 --- /dev/null +++ b/io_uring/Makefile @@ -0,0 +1,24 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for io_uring + +ifdef CONFIG_GCOV_PROFILE_URING +GCOV_PROFILE := y +endif + +obj-$(CONFIG_IO_URING) += io_uring.o opdef.o kbuf.o rsrc.o notif.o \ + tctx.o filetable.o rw.o poll.o \ + eventfd.o uring_cmd.o openclose.o \ + sqpoll.o xattr.o nop.o fs.o splice.o \ + sync.o msg_ring.o advise.o openclose.o \ + statx.o timeout.o cancel.o \ + waitid.o register.o truncate.o \ + memmap.o alloc_cache.o query.o +obj-$(CONFIG_IO_URING_ZCRX) += zcrx.o +obj-$(CONFIG_IO_WQ) += io-wq.o +obj-$(CONFIG_FUTEX) += futex.o +obj-$(CONFIG_EPOLL) += epoll.o +obj-$(CONFIG_NET_RX_BUSY_POLL) += napi.o +obj-$(CONFIG_NET) += net.o cmd_net.o +obj-$(CONFIG_PROC_FS) += fdinfo.o +obj-$(CONFIG_IO_URING_MOCK_FILE) += mock_file.o diff --git a/io_uring/advise.c b/io_uring/advise.c new file mode 100644 index 000000000000..0073f74e3658 --- /dev/null +++ b/io_uring/advise.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/io_uring.h> + +#include <uapi/linux/fadvise.h> +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "advise.h" + +struct io_fadvise { + struct file *file; + u64 offset; + u64 len; + u32 advice; +}; + +struct io_madvise { + struct file *file; + u64 addr; + u64 len; + u32 advice; +}; + +int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) + struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise); + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + + ma->addr = READ_ONCE(sqe->addr); + ma->len = READ_ONCE(sqe->off); + if (!ma->len) + ma->len = READ_ONCE(sqe->len); + ma->advice = READ_ONCE(sqe->fadvise_advice); + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +int io_madvise(struct io_kiocb *req, unsigned int issue_flags) +{ +#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) + struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +#else + return -EOPNOTSUPP; +#endif +} + +static bool io_fadvise_force_async(struct io_fadvise *fa) +{ + switch (fa->advice) { + case POSIX_FADV_NORMAL: + case POSIX_FADV_RANDOM: + case POSIX_FADV_SEQUENTIAL: + return false; + default: + return true; + } +} + +int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise); + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + + fa->offset = READ_ONCE(sqe->off); + fa->len = READ_ONCE(sqe->addr); + if (!fa->len) + fa->len = READ_ONCE(sqe->len); + fa->advice = READ_ONCE(sqe->fadvise_advice); + if (io_fadvise_force_async(fa)) + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_fadvise(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK && io_fadvise_force_async(fa)); + + ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/advise.h b/io_uring/advise.h new file mode 100644 index 000000000000..5ece2a045185 --- /dev/null +++ b/io_uring/advise.h @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_madvise(struct io_kiocb *req, unsigned int issue_flags); + +int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_fadvise(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/alloc_cache.c b/io_uring/alloc_cache.c new file mode 100644 index 000000000000..58423888b736 --- /dev/null +++ b/io_uring/alloc_cache.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "alloc_cache.h" + +void io_alloc_cache_free(struct io_alloc_cache *cache, + void (*free)(const void *)) +{ + void *entry; + + if (!cache->entries) + return; + + while ((entry = io_alloc_cache_get(cache)) != NULL) + free(entry); + + kvfree(cache->entries); + cache->entries = NULL; +} + +/* returns false if the cache was initialized properly */ +bool io_alloc_cache_init(struct io_alloc_cache *cache, + unsigned max_nr, unsigned int size, + unsigned int init_bytes) +{ + cache->entries = kvmalloc_array(max_nr, sizeof(void *), GFP_KERNEL); + if (!cache->entries) + return true; + + cache->nr_cached = 0; + cache->max_cached = max_nr; + cache->elem_size = size; + cache->init_clear = init_bytes; + return false; +} + +void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp) +{ + void *obj; + + obj = kmalloc(cache->elem_size, gfp); + if (obj && cache->init_clear) + memset(obj, 0, cache->init_clear); + return obj; +} diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h new file mode 100644 index 000000000000..d33ce159ef33 --- /dev/null +++ b/io_uring/alloc_cache.h @@ -0,0 +1,68 @@ +#ifndef IOU_ALLOC_CACHE_H +#define IOU_ALLOC_CACHE_H + +#include <linux/io_uring_types.h> + +/* + * Don't allow the cache to grow beyond this size. + */ +#define IO_ALLOC_CACHE_MAX 128 + +void io_alloc_cache_free(struct io_alloc_cache *cache, + void (*free)(const void *)); +bool io_alloc_cache_init(struct io_alloc_cache *cache, + unsigned max_nr, unsigned int size, + unsigned int init_bytes); + +void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp); + +static inline bool io_alloc_cache_put(struct io_alloc_cache *cache, + void *entry) +{ + if (cache->nr_cached < cache->max_cached) { + if (!kasan_mempool_poison_object(entry)) + return false; + cache->entries[cache->nr_cached++] = entry; + return true; + } + return false; +} + +static inline void *io_alloc_cache_get(struct io_alloc_cache *cache) +{ + if (cache->nr_cached) { + void *entry = cache->entries[--cache->nr_cached]; + + /* + * If KASAN is enabled, always clear the initial bytes that + * must be zeroed post alloc, in case any of them overlap + * with KASAN storage. + */ +#if defined(CONFIG_KASAN) + kasan_mempool_unpoison_object(entry, cache->elem_size); + if (cache->init_clear) + memset(entry, 0, cache->init_clear); +#endif + return entry; + } + + return NULL; +} + +static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp) +{ + void *obj; + + obj = io_alloc_cache_get(cache); + if (obj) + return obj; + return io_cache_alloc_new(cache, gfp); +} + +static inline void io_cache_free(struct io_alloc_cache *cache, void *obj) +{ + if (!io_alloc_cache_put(cache, obj)) + kfree(obj); +} + +#endif diff --git a/io_uring/cancel.c b/io_uring/cancel.c new file mode 100644 index 000000000000..ca12ac10c0ae --- /dev/null +++ b/io_uring/cancel.c @@ -0,0 +1,656 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/nospec.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "filetable.h" +#include "io_uring.h" +#include "tctx.h" +#include "sqpoll.h" +#include "uring_cmd.h" +#include "poll.h" +#include "timeout.h" +#include "waitid.h" +#include "futex.h" +#include "cancel.h" + +struct io_cancel { + struct file *file; + u64 addr; + u32 flags; + s32 fd; + u8 opcode; +}; + +#define CANCEL_FLAGS (IORING_ASYNC_CANCEL_ALL | IORING_ASYNC_CANCEL_FD | \ + IORING_ASYNC_CANCEL_ANY | IORING_ASYNC_CANCEL_FD_FIXED | \ + IORING_ASYNC_CANCEL_USERDATA | IORING_ASYNC_CANCEL_OP) + +/* + * Returns true if the request matches the criteria outlined by 'cd'. + */ +bool io_cancel_req_match(struct io_kiocb *req, struct io_cancel_data *cd) +{ + bool match_user_data = cd->flags & IORING_ASYNC_CANCEL_USERDATA; + + if (req->ctx != cd->ctx) + return false; + + if (!(cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP))) + match_user_data = true; + + if (cd->flags & IORING_ASYNC_CANCEL_ANY) + goto check_seq; + if (cd->flags & IORING_ASYNC_CANCEL_FD) { + if (req->file != cd->file) + return false; + } + if (cd->flags & IORING_ASYNC_CANCEL_OP) { + if (req->opcode != cd->opcode) + return false; + } + if (match_user_data && req->cqe.user_data != cd->data) + return false; + if (cd->flags & IORING_ASYNC_CANCEL_ALL) { +check_seq: + if (io_cancel_match_sequence(req, cd->seq)) + return false; + } + + return true; +} + +static bool io_cancel_cb(struct io_wq_work *work, void *data) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_cancel_data *cd = data; + + return io_cancel_req_match(req, cd); +} + +static int io_async_cancel_one(struct io_uring_task *tctx, + struct io_cancel_data *cd) +{ + enum io_wq_cancel cancel_ret; + int ret = 0; + bool all; + + if (!tctx || !tctx->io_wq) + return -ENOENT; + + all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY); + cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, cd, all); + switch (cancel_ret) { + case IO_WQ_CANCEL_OK: + ret = 0; + break; + case IO_WQ_CANCEL_RUNNING: + ret = -EALREADY; + break; + case IO_WQ_CANCEL_NOTFOUND: + ret = -ENOENT; + break; + } + + return ret; +} + +int io_try_cancel(struct io_uring_task *tctx, struct io_cancel_data *cd, + unsigned issue_flags) +{ + struct io_ring_ctx *ctx = cd->ctx; + int ret; + + WARN_ON_ONCE(!io_wq_current_is_worker() && tctx != current->io_uring); + + ret = io_async_cancel_one(tctx, cd); + /* + * Fall-through even for -EALREADY, as we may have poll armed + * that need unarming. + */ + if (!ret) + return 0; + + ret = io_poll_cancel(ctx, cd, issue_flags); + if (ret != -ENOENT) + return ret; + + ret = io_waitid_cancel(ctx, cd, issue_flags); + if (ret != -ENOENT) + return ret; + + ret = io_futex_cancel(ctx, cd, issue_flags); + if (ret != -ENOENT) + return ret; + + spin_lock(&ctx->completion_lock); + if (!(cd->flags & IORING_ASYNC_CANCEL_FD)) + ret = io_timeout_cancel(ctx, cd); + spin_unlock(&ctx->completion_lock); + return ret; +} + +int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_cancel *cancel = io_kiocb_to_cmd(req, struct io_cancel); + + if (unlikely(req->flags & REQ_F_BUFFER_SELECT)) + return -EINVAL; + if (sqe->off || sqe->splice_fd_in) + return -EINVAL; + + cancel->addr = READ_ONCE(sqe->addr); + cancel->flags = READ_ONCE(sqe->cancel_flags); + if (cancel->flags & ~CANCEL_FLAGS) + return -EINVAL; + if (cancel->flags & IORING_ASYNC_CANCEL_FD) { + if (cancel->flags & IORING_ASYNC_CANCEL_ANY) + return -EINVAL; + cancel->fd = READ_ONCE(sqe->fd); + } + if (cancel->flags & IORING_ASYNC_CANCEL_OP) { + if (cancel->flags & IORING_ASYNC_CANCEL_ANY) + return -EINVAL; + cancel->opcode = READ_ONCE(sqe->len); + } + + return 0; +} + +static int __io_async_cancel(struct io_cancel_data *cd, + struct io_uring_task *tctx, + unsigned int issue_flags) +{ + bool all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY); + struct io_ring_ctx *ctx = cd->ctx; + struct io_tctx_node *node; + int ret, nr = 0; + + do { + ret = io_try_cancel(tctx, cd, issue_flags); + if (ret == -ENOENT) + break; + if (!all) + return ret; + nr++; + } while (1); + + /* slow path, try all io-wq's */ + io_ring_submit_lock(ctx, issue_flags); + ret = -ENOENT; + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + ret = io_async_cancel_one(node->task->io_uring, cd); + if (ret != -ENOENT) { + if (!all) + break; + nr++; + } + } + io_ring_submit_unlock(ctx, issue_flags); + return all ? nr : ret; +} + +int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_cancel *cancel = io_kiocb_to_cmd(req, struct io_cancel); + struct io_cancel_data cd = { + .ctx = req->ctx, + .data = cancel->addr, + .flags = cancel->flags, + .opcode = cancel->opcode, + .seq = atomic_inc_return(&req->ctx->cancel_seq), + }; + struct io_uring_task *tctx = req->tctx; + int ret; + + if (cd.flags & IORING_ASYNC_CANCEL_FD) { + if (req->flags & REQ_F_FIXED_FILE || + cd.flags & IORING_ASYNC_CANCEL_FD_FIXED) { + req->flags |= REQ_F_FIXED_FILE; + req->file = io_file_get_fixed(req, cancel->fd, + issue_flags); + } else { + req->file = io_file_get_normal(req, cancel->fd); + } + if (!req->file) { + ret = -EBADF; + goto done; + } + cd.file = req->file; + } + + ret = __io_async_cancel(&cd, tctx, issue_flags); +done: + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +static int __io_sync_cancel(struct io_uring_task *tctx, + struct io_cancel_data *cd, int fd) +{ + struct io_ring_ctx *ctx = cd->ctx; + + /* fixed must be grabbed every time since we drop the uring_lock */ + if ((cd->flags & IORING_ASYNC_CANCEL_FD) && + (cd->flags & IORING_ASYNC_CANCEL_FD_FIXED)) { + struct io_rsrc_node *node; + + node = io_rsrc_node_lookup(&ctx->file_table.data, fd); + if (unlikely(!node)) + return -EBADF; + cd->file = io_slot_file(node); + if (!cd->file) + return -EBADF; + } + + return __io_async_cancel(cd, tctx, 0); +} + +int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg) + __must_hold(&ctx->uring_lock) +{ + struct io_cancel_data cd = { + .ctx = ctx, + .seq = atomic_inc_return(&ctx->cancel_seq), + }; + ktime_t timeout = KTIME_MAX; + struct io_uring_sync_cancel_reg sc; + struct file *file = NULL; + DEFINE_WAIT(wait); + int ret, i; + + if (copy_from_user(&sc, arg, sizeof(sc))) + return -EFAULT; + if (sc.flags & ~CANCEL_FLAGS) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(sc.pad); i++) + if (sc.pad[i]) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(sc.pad2); i++) + if (sc.pad2[i]) + return -EINVAL; + + cd.data = sc.addr; + cd.flags = sc.flags; + cd.opcode = sc.opcode; + + /* we can grab a normal file descriptor upfront */ + if ((cd.flags & IORING_ASYNC_CANCEL_FD) && + !(cd.flags & IORING_ASYNC_CANCEL_FD_FIXED)) { + file = fget(sc.fd); + if (!file) + return -EBADF; + cd.file = file; + } + + ret = __io_sync_cancel(current->io_uring, &cd, sc.fd); + + /* found something, done! */ + if (ret != -EALREADY) + goto out; + + if (sc.timeout.tv_sec != -1UL || sc.timeout.tv_nsec != -1UL) { + struct timespec64 ts = { + .tv_sec = sc.timeout.tv_sec, + .tv_nsec = sc.timeout.tv_nsec + }; + + timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns()); + } + + /* + * Keep looking until we get -ENOENT. we'll get woken everytime + * every time a request completes and will retry the cancelation. + */ + do { + cd.seq = atomic_inc_return(&ctx->cancel_seq); + + prepare_to_wait(&ctx->cq_wait, &wait, TASK_INTERRUPTIBLE); + + ret = __io_sync_cancel(current->io_uring, &cd, sc.fd); + + mutex_unlock(&ctx->uring_lock); + if (ret != -EALREADY) + break; + + ret = io_run_task_work_sig(ctx); + if (ret < 0) + break; + ret = schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS); + if (!ret) { + ret = -ETIME; + break; + } + mutex_lock(&ctx->uring_lock); + } while (1); + + finish_wait(&ctx->cq_wait, &wait); + mutex_lock(&ctx->uring_lock); + + if (ret == -ENOENT || ret > 0) + ret = 0; +out: + if (file) + fput(file); + return ret; +} + +bool io_cancel_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + struct hlist_head *list, bool cancel_all, + bool (*cancel)(struct io_kiocb *)) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + bool found = false; + + lockdep_assert_held(&ctx->uring_lock); + + hlist_for_each_entry_safe(req, tmp, list, hash_node) { + if (!io_match_task_safe(req, tctx, cancel_all)) + continue; + hlist_del_init(&req->hash_node); + if (cancel(req)) + found = true; + } + + return found; +} + +int io_cancel_remove(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags, struct hlist_head *list, + bool (*cancel)(struct io_kiocb *)) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + int nr = 0; + + io_ring_submit_lock(ctx, issue_flags); + hlist_for_each_entry_safe(req, tmp, list, hash_node) { + if (!io_cancel_req_match(req, cd)) + continue; + if (cancel(req)) + nr++; + if (!(cd->flags & IORING_ASYNC_CANCEL_ALL)) + break; + } + io_ring_submit_unlock(ctx, issue_flags); + return nr ?: -ENOENT; +} + +static bool io_match_linked(struct io_kiocb *head) +{ + struct io_kiocb *req; + + io_for_each_link(req, head) { + if (req->flags & REQ_F_INFLIGHT) + return true; + } + return false; +} + +/* + * As io_match_task() but protected against racing with linked timeouts. + * User must not hold timeout_lock. + */ +bool io_match_task_safe(struct io_kiocb *head, struct io_uring_task *tctx, + bool cancel_all) +{ + bool matched; + + if (tctx && head->tctx != tctx) + return false; + if (cancel_all) + return true; + + if (head->flags & REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = head->ctx; + + /* protect against races with linked timeouts */ + raw_spin_lock_irq(&ctx->timeout_lock); + matched = io_match_linked(head); + raw_spin_unlock_irq(&ctx->timeout_lock); + } else { + matched = io_match_linked(head); + } + return matched; +} + +void __io_uring_cancel(bool cancel_all) +{ + io_uring_unreg_ringfd(); + io_uring_cancel_generic(cancel_all, NULL); +} + +struct io_task_cancel { + struct io_uring_task *tctx; + bool all; +}; + +static bool io_cancel_task_cb(struct io_wq_work *work, void *data) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_task_cancel *cancel = data; + + return io_match_task_safe(req, cancel->tctx, cancel->all); +} + +static __cold bool io_cancel_defer_files(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, + bool cancel_all) +{ + struct io_defer_entry *de; + LIST_HEAD(list); + + list_for_each_entry_reverse(de, &ctx->defer_list, list) { + if (io_match_task_safe(de->req, tctx, cancel_all)) { + list_cut_position(&list, &ctx->defer_list, &de->list); + break; + } + } + if (list_empty(&list)) + return false; + + while (!list_empty(&list)) { + de = list_first_entry(&list, struct io_defer_entry, list); + list_del_init(&de->list); + ctx->nr_drained -= io_linked_nr(de->req); + io_req_task_queue_fail(de->req, -ECANCELED); + kfree(de); + } + return true; +} + +__cold bool io_cancel_ctx_cb(struct io_wq_work *work, void *data) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + + return req->ctx == data; +} + +static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx) +{ + struct io_tctx_node *node; + enum io_wq_cancel cret; + bool ret = false; + + mutex_lock(&ctx->uring_lock); + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + struct io_uring_task *tctx = node->task->io_uring; + + /* + * io_wq will stay alive while we hold uring_lock, because it's + * killed after ctx nodes, which requires to take the lock. + */ + if (!tctx || !tctx->io_wq) + continue; + cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true); + ret |= (cret != IO_WQ_CANCEL_NOTFOUND); + } + mutex_unlock(&ctx->uring_lock); + + return ret; +} + +__cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, + bool cancel_all, bool is_sqpoll_thread) +{ + struct io_task_cancel cancel = { .tctx = tctx, .all = cancel_all, }; + enum io_wq_cancel cret; + bool ret = false; + + /* set it so io_req_local_work_add() would wake us up */ + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) { + atomic_set(&ctx->cq_wait_nr, 1); + smp_mb(); + } + + /* failed during ring init, it couldn't have issued any requests */ + if (!ctx->rings) + return false; + + if (!tctx) { + ret |= io_uring_try_cancel_iowq(ctx); + } else if (tctx->io_wq) { + /* + * Cancels requests of all rings, not only @ctx, but + * it's fine as the task is in exit/exec. + */ + cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb, + &cancel, true); + ret |= (cret != IO_WQ_CANCEL_NOTFOUND); + } + + /* SQPOLL thread does its own polling */ + if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) || + is_sqpoll_thread) { + while (!wq_list_empty(&ctx->iopoll_list)) { + io_iopoll_try_reap_events(ctx); + ret = true; + cond_resched(); + } + } + + if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) && + io_allowed_defer_tw_run(ctx)) + ret |= io_run_local_work(ctx, INT_MAX, INT_MAX) > 0; + mutex_lock(&ctx->uring_lock); + ret |= io_cancel_defer_files(ctx, tctx, cancel_all); + ret |= io_poll_remove_all(ctx, tctx, cancel_all); + ret |= io_waitid_remove_all(ctx, tctx, cancel_all); + ret |= io_futex_remove_all(ctx, tctx, cancel_all); + ret |= io_uring_try_cancel_uring_cmd(ctx, tctx, cancel_all); + mutex_unlock(&ctx->uring_lock); + ret |= io_kill_timeouts(ctx, tctx, cancel_all); + if (tctx) + ret |= io_run_task_work() > 0; + else + ret |= flush_delayed_work(&ctx->fallback_work); + return ret; +} + +static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked) +{ + if (tracked) + return atomic_read(&tctx->inflight_tracked); + return percpu_counter_sum(&tctx->inflight); +} + +/* + * Find any io_uring ctx that this task has registered or done IO on, and cancel + * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation. + */ +__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_ring_ctx *ctx; + struct io_tctx_node *node; + unsigned long index; + s64 inflight; + DEFINE_WAIT(wait); + + WARN_ON_ONCE(sqd && sqpoll_task_locked(sqd) != current); + + if (!current->io_uring) + return; + if (tctx->io_wq) + io_wq_exit_start(tctx->io_wq); + + atomic_inc(&tctx->in_cancel); + do { + bool loop = false; + + io_uring_drop_tctx_refs(current); + if (!tctx_inflight(tctx, !cancel_all)) + break; + + /* read completions before cancelations */ + inflight = tctx_inflight(tctx, false); + if (!inflight) + break; + + if (!sqd) { + xa_for_each(&tctx->xa, index, node) { + /* sqpoll task will cancel all its requests */ + if (node->ctx->sq_data) + continue; + loop |= io_uring_try_cancel_requests(node->ctx, + current->io_uring, + cancel_all, + false); + } + } else { + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + loop |= io_uring_try_cancel_requests(ctx, + current->io_uring, + cancel_all, + true); + } + + if (loop) { + cond_resched(); + continue; + } + + prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE); + io_run_task_work(); + io_uring_drop_tctx_refs(current); + xa_for_each(&tctx->xa, index, node) { + if (io_local_work_pending(node->ctx)) { + WARN_ON_ONCE(node->ctx->submitter_task && + node->ctx->submitter_task != current); + goto end_wait; + } + } + /* + * If we've seen completions, retry without waiting. This + * avoids a race where a completion comes in before we did + * prepare_to_wait(). + */ + if (inflight == tctx_inflight(tctx, !cancel_all)) + schedule(); +end_wait: + finish_wait(&tctx->wait, &wait); + } while (1); + + io_uring_clean_tctx(tctx); + if (cancel_all) { + /* + * We shouldn't run task_works after cancel, so just leave + * ->in_cancel set for normal exit. + */ + atomic_dec(&tctx->in_cancel); + /* for exec all current's requests should be gone, kill tctx */ + __io_uring_free(current); + } +} diff --git a/io_uring/cancel.h b/io_uring/cancel.h new file mode 100644 index 000000000000..6783961ede1b --- /dev/null +++ b/io_uring/cancel.h @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IORING_CANCEL_H +#define IORING_CANCEL_H + +#include <linux/io_uring_types.h> + +struct io_cancel_data { + struct io_ring_ctx *ctx; + union { + u64 data; + struct file *file; + }; + u8 opcode; + u32 flags; + int seq; +}; + +int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags); + +int io_try_cancel(struct io_uring_task *tctx, struct io_cancel_data *cd, + unsigned int issue_flags); + +int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg); +bool io_cancel_req_match(struct io_kiocb *req, struct io_cancel_data *cd); +bool io_match_task_safe(struct io_kiocb *head, struct io_uring_task *tctx, + bool cancel_all); + +bool io_cancel_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + struct hlist_head *list, bool cancel_all, + bool (*cancel)(struct io_kiocb *)); +int io_cancel_remove(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags, struct hlist_head *list, + bool (*cancel)(struct io_kiocb *)); +__cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, + bool cancel_all, bool is_sqpoll_thread); +__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); +__cold bool io_cancel_ctx_cb(struct io_wq_work *work, void *data); + +static inline bool io_cancel_match_sequence(struct io_kiocb *req, int sequence) +{ + if (req->cancel_seq_set && sequence == req->work.cancel_seq) + return true; + + req->cancel_seq_set = true; + req->work.cancel_seq = sequence; + return false; +} + +#endif diff --git a/io_uring/cmd_net.c b/io_uring/cmd_net.c new file mode 100644 index 000000000000..19d3ce2bd20a --- /dev/null +++ b/io_uring/cmd_net.c @@ -0,0 +1,188 @@ +#include <asm/ioctls.h> +#include <linux/io_uring/net.h> +#include <linux/errqueue.h> +#include <net/sock.h> + +#include "uring_cmd.h" +#include "io_uring.h" + +static inline int io_uring_cmd_getsockopt(struct socket *sock, + struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + const struct io_uring_sqe *sqe = cmd->sqe; + bool compat = !!(issue_flags & IO_URING_F_COMPAT); + int optlen, optname, level, err; + void __user *optval; + + level = READ_ONCE(sqe->level); + if (level != SOL_SOCKET) + return -EOPNOTSUPP; + + optval = u64_to_user_ptr(READ_ONCE(sqe->optval)); + optname = READ_ONCE(sqe->optname); + optlen = READ_ONCE(sqe->optlen); + + err = do_sock_getsockopt(sock, compat, level, optname, + USER_SOCKPTR(optval), + KERNEL_SOCKPTR(&optlen)); + if (err) + return err; + + /* On success, return optlen */ + return optlen; +} + +static inline int io_uring_cmd_setsockopt(struct socket *sock, + struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + const struct io_uring_sqe *sqe = cmd->sqe; + bool compat = !!(issue_flags & IO_URING_F_COMPAT); + int optname, optlen, level; + void __user *optval; + sockptr_t optval_s; + + optval = u64_to_user_ptr(READ_ONCE(sqe->optval)); + optname = READ_ONCE(sqe->optname); + optlen = READ_ONCE(sqe->optlen); + level = READ_ONCE(sqe->level); + optval_s = USER_SOCKPTR(optval); + + return do_sock_setsockopt(sock, compat, level, optname, optval_s, + optlen); +} + +static bool io_process_timestamp_skb(struct io_uring_cmd *cmd, struct sock *sk, + struct sk_buff *skb, unsigned issue_flags) +{ + struct sock_exterr_skb *serr = SKB_EXT_ERR(skb); + struct io_uring_cqe cqe[2]; + struct io_timespec *iots; + struct timespec64 ts; + u32 tstype, tskey; + int ret; + + BUILD_BUG_ON(sizeof(struct io_uring_cqe) != sizeof(struct io_timespec)); + + ret = skb_get_tx_timestamp(skb, sk, &ts); + if (ret < 0) + return false; + + tskey = serr->ee.ee_data; + tstype = serr->ee.ee_info; + + cqe->user_data = 0; + cqe->res = tskey; + cqe->flags = IORING_CQE_F_MORE | ctx_cqe32_flags(cmd_to_io_kiocb(cmd)->ctx); + cqe->flags |= tstype << IORING_TIMESTAMP_TYPE_SHIFT; + if (ret == SOF_TIMESTAMPING_TX_HARDWARE) + cqe->flags |= IORING_CQE_F_TSTAMP_HW; + + iots = (struct io_timespec *)&cqe[1]; + iots->tv_sec = ts.tv_sec; + iots->tv_nsec = ts.tv_nsec; + return io_uring_cmd_post_mshot_cqe32(cmd, issue_flags, cqe); +} + +static int io_uring_cmd_timestamp(struct socket *sock, + struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + struct sock *sk = sock->sk; + struct sk_buff_head *q = &sk->sk_error_queue; + struct sk_buff *skb, *tmp; + struct sk_buff_head list; + int ret; + + if (!(issue_flags & IO_URING_F_CQE32)) + return -EINVAL; + ret = io_cmd_poll_multishot(cmd, issue_flags, EPOLLERR); + if (unlikely(ret)) + return ret; + + if (skb_queue_empty_lockless(q)) + return -EAGAIN; + __skb_queue_head_init(&list); + + scoped_guard(spinlock_irq, &q->lock) { + skb_queue_walk_safe(q, skb, tmp) { + /* don't support skbs with payload */ + if (!skb_has_tx_timestamp(skb, sk) || skb->len) + continue; + __skb_unlink(skb, q); + __skb_queue_tail(&list, skb); + } + } + + while (1) { + skb = skb_peek(&list); + if (!skb) + break; + if (!io_process_timestamp_skb(cmd, sk, skb, issue_flags)) + break; + __skb_dequeue(&list); + consume_skb(skb); + } + + if (!unlikely(skb_queue_empty(&list))) { + scoped_guard(spinlock_irqsave, &q->lock) + skb_queue_splice(&list, q); + } + return -EAGAIN; +} + +static int io_uring_cmd_getsockname(struct socket *sock, + struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + const struct io_uring_sqe *sqe = cmd->sqe; + struct sockaddr __user *uaddr; + unsigned int peer; + int __user *ulen; + + if (sqe->ioprio || sqe->__pad1 || sqe->len || sqe->rw_flags) + return -EINVAL; + + uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + ulen = u64_to_user_ptr(sqe->addr3); + peer = READ_ONCE(sqe->optlen); + if (peer > 1) + return -EINVAL; + return do_getsockname(sock, peer, uaddr, ulen); +} + +int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) +{ + struct socket *sock = cmd->file->private_data; + struct sock *sk = sock->sk; + struct proto *prot = READ_ONCE(sk->sk_prot); + int ret, arg = 0; + + if (!prot || !prot->ioctl) + return -EOPNOTSUPP; + + switch (cmd->cmd_op) { + case SOCKET_URING_OP_SIOCINQ: + ret = prot->ioctl(sk, SIOCINQ, &arg); + if (ret) + return ret; + return arg; + case SOCKET_URING_OP_SIOCOUTQ: + ret = prot->ioctl(sk, SIOCOUTQ, &arg); + if (ret) + return ret; + return arg; + case SOCKET_URING_OP_GETSOCKOPT: + return io_uring_cmd_getsockopt(sock, cmd, issue_flags); + case SOCKET_URING_OP_SETSOCKOPT: + return io_uring_cmd_setsockopt(sock, cmd, issue_flags); + case SOCKET_URING_OP_TX_TIMESTAMP: + return io_uring_cmd_timestamp(sock, cmd, issue_flags); + case SOCKET_URING_OP_GETSOCKNAME: + return io_uring_cmd_getsockname(sock, cmd, issue_flags); + default: + return -EOPNOTSUPP; + } +} +EXPORT_SYMBOL_GPL(io_uring_cmd_sock); diff --git a/io_uring/epoll.c b/io_uring/epoll.c new file mode 100644 index 000000000000..8d4610246ba0 --- /dev/null +++ b/io_uring/epoll.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/uaccess.h> +#include <linux/io_uring.h> +#include <linux/eventpoll.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "epoll.h" + +struct io_epoll { + struct file *file; + int epfd; + int op; + int fd; + struct epoll_event event; +}; + +struct io_epoll_wait { + struct file *file; + int maxevents; + struct epoll_event __user *events; +}; + +int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_epoll *epoll = io_kiocb_to_cmd(req, struct io_epoll); + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + + epoll->epfd = READ_ONCE(sqe->fd); + epoll->op = READ_ONCE(sqe->len); + epoll->fd = READ_ONCE(sqe->off); + + if (ep_op_has_event(epoll->op)) { + struct epoll_event __user *ev; + + ev = u64_to_user_ptr(READ_ONCE(sqe->addr)); + if (copy_from_user(&epoll->event, ev, sizeof(*ev))) + return -EFAULT; + } + + return 0; +} + +int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_epoll *ie = io_kiocb_to_cmd(req, struct io_epoll); + int ret; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + + ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); + if (force_nonblock && ret == -EAGAIN) + return -EAGAIN; + + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_epoll_wait_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait); + + if (sqe->off || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + + iew->maxevents = READ_ONCE(sqe->len); + iew->events = u64_to_user_ptr(READ_ONCE(sqe->addr)); + return 0; +} + +int io_epoll_wait(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait); + int ret; + + ret = epoll_sendevents(req->file, iew->events, iew->maxevents); + if (ret == 0) + return -EAGAIN; + if (ret < 0) + req_set_fail(req); + + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/epoll.h b/io_uring/epoll.h new file mode 100644 index 000000000000..4111997c360b --- /dev/null +++ b/io_uring/epoll.h @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 + +#if defined(CONFIG_EPOLL) +int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags); +int io_epoll_wait_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_epoll_wait(struct io_kiocb *req, unsigned int issue_flags); +#endif diff --git a/io_uring/eventfd.c b/io_uring/eventfd.c new file mode 100644 index 000000000000..78f8ab7db104 --- /dev/null +++ b/io_uring/eventfd.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/eventfd.h> +#include <linux/eventpoll.h> +#include <linux/io_uring.h> +#include <linux/io_uring_types.h> + +#include "io-wq.h" +#include "eventfd.h" + +struct io_ev_fd { + struct eventfd_ctx *cq_ev_fd; + unsigned int eventfd_async; + /* protected by ->completion_lock */ + unsigned last_cq_tail; + refcount_t refs; + atomic_t ops; + struct rcu_head rcu; +}; + +enum { + IO_EVENTFD_OP_SIGNAL_BIT, +}; + +static void io_eventfd_free(struct rcu_head *rcu) +{ + struct io_ev_fd *ev_fd = container_of(rcu, struct io_ev_fd, rcu); + + eventfd_ctx_put(ev_fd->cq_ev_fd); + kfree(ev_fd); +} + +static void io_eventfd_put(struct io_ev_fd *ev_fd) +{ + if (refcount_dec_and_test(&ev_fd->refs)) + call_rcu(&ev_fd->rcu, io_eventfd_free); +} + +static void io_eventfd_do_signal(struct rcu_head *rcu) +{ + struct io_ev_fd *ev_fd = container_of(rcu, struct io_ev_fd, rcu); + + eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE); + io_eventfd_put(ev_fd); +} + +/* + * Returns true if the caller should put the ev_fd reference, false if not. + */ +static bool __io_eventfd_signal(struct io_ev_fd *ev_fd) +{ + if (eventfd_signal_allowed()) { + eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE); + return true; + } + if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops)) { + call_rcu_hurry(&ev_fd->rcu, io_eventfd_do_signal); + return false; + } + return true; +} + +/* + * Trigger if eventfd_async isn't set, or if it's set and the caller is + * an async worker. + */ +static bool io_eventfd_trigger(struct io_ev_fd *ev_fd) +{ + return !ev_fd->eventfd_async || io_wq_current_is_worker(); +} + +void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event) +{ + bool skip = false; + struct io_ev_fd *ev_fd; + + if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) + return; + + guard(rcu)(); + ev_fd = rcu_dereference(ctx->io_ev_fd); + /* + * Check again if ev_fd exists in case an io_eventfd_unregister call + * completed between the NULL check of ctx->io_ev_fd at the start of + * the function and rcu_read_lock. + */ + if (!ev_fd) + return; + if (!io_eventfd_trigger(ev_fd) || !refcount_inc_not_zero(&ev_fd->refs)) + return; + + if (cqe_event) { + /* + * Eventfd should only get triggered when at least one event + * has been posted. Some applications rely on the eventfd + * notification count only changing IFF a new CQE has been + * added to the CQ ring. There's no dependency on 1:1 + * relationship between how many times this function is called + * (and hence the eventfd count) and number of CQEs posted to + * the CQ ring. + */ + spin_lock(&ctx->completion_lock); + skip = ctx->cached_cq_tail == ev_fd->last_cq_tail; + ev_fd->last_cq_tail = ctx->cached_cq_tail; + spin_unlock(&ctx->completion_lock); + } + + if (skip || __io_eventfd_signal(ev_fd)) + io_eventfd_put(ev_fd); +} + +int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned int eventfd_async) +{ + struct io_ev_fd *ev_fd; + __s32 __user *fds = arg; + int fd; + + ev_fd = rcu_dereference_protected(ctx->io_ev_fd, + lockdep_is_held(&ctx->uring_lock)); + if (ev_fd) + return -EBUSY; + + if (copy_from_user(&fd, fds, sizeof(*fds))) + return -EFAULT; + + ev_fd = kmalloc(sizeof(*ev_fd), GFP_KERNEL); + if (!ev_fd) + return -ENOMEM; + + ev_fd->cq_ev_fd = eventfd_ctx_fdget(fd); + if (IS_ERR(ev_fd->cq_ev_fd)) { + int ret = PTR_ERR(ev_fd->cq_ev_fd); + + kfree(ev_fd); + return ret; + } + + spin_lock(&ctx->completion_lock); + ev_fd->last_cq_tail = ctx->cached_cq_tail; + spin_unlock(&ctx->completion_lock); + + ev_fd->eventfd_async = eventfd_async; + ctx->has_evfd = true; + refcount_set(&ev_fd->refs, 1); + atomic_set(&ev_fd->ops, 0); + rcu_assign_pointer(ctx->io_ev_fd, ev_fd); + return 0; +} + +int io_eventfd_unregister(struct io_ring_ctx *ctx) +{ + struct io_ev_fd *ev_fd; + + ev_fd = rcu_dereference_protected(ctx->io_ev_fd, + lockdep_is_held(&ctx->uring_lock)); + if (ev_fd) { + ctx->has_evfd = false; + rcu_assign_pointer(ctx->io_ev_fd, NULL); + io_eventfd_put(ev_fd); + return 0; + } + + return -ENXIO; +} diff --git a/io_uring/eventfd.h b/io_uring/eventfd.h new file mode 100644 index 000000000000..e2f1985c2cf9 --- /dev/null +++ b/io_uring/eventfd.h @@ -0,0 +1,7 @@ + +struct io_ring_ctx; +int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned int eventfd_async); +int io_eventfd_unregister(struct io_ring_ctx *ctx); + +void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event); diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c new file mode 100644 index 000000000000..a87d4e26eee8 --- /dev/null +++ b/io_uring/fdinfo.c @@ -0,0 +1,264 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/nospec.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "filetable.h" +#include "sqpoll.h" +#include "fdinfo.h" +#include "cancel.h" +#include "rsrc.h" +#include "opdef.h" + +#ifdef CONFIG_NET_RX_BUSY_POLL +static __cold void common_tracking_show_fdinfo(struct io_ring_ctx *ctx, + struct seq_file *m, + const char *tracking_strategy) +{ + seq_puts(m, "NAPI:\tenabled\n"); + seq_printf(m, "napi tracking:\t%s\n", tracking_strategy); + seq_printf(m, "napi_busy_poll_dt:\t%llu\n", ctx->napi_busy_poll_dt); + if (ctx->napi_prefer_busy_poll) + seq_puts(m, "napi_prefer_busy_poll:\ttrue\n"); + else + seq_puts(m, "napi_prefer_busy_poll:\tfalse\n"); +} + +static __cold void napi_show_fdinfo(struct io_ring_ctx *ctx, + struct seq_file *m) +{ + unsigned int mode = READ_ONCE(ctx->napi_track_mode); + + switch (mode) { + case IO_URING_NAPI_TRACKING_INACTIVE: + seq_puts(m, "NAPI:\tdisabled\n"); + break; + case IO_URING_NAPI_TRACKING_DYNAMIC: + common_tracking_show_fdinfo(ctx, m, "dynamic"); + break; + case IO_URING_NAPI_TRACKING_STATIC: + common_tracking_show_fdinfo(ctx, m, "static"); + break; + default: + seq_printf(m, "NAPI:\tunknown mode (%u)\n", mode); + } +} +#else +static inline void napi_show_fdinfo(struct io_ring_ctx *ctx, + struct seq_file *m) +{ +} +#endif + +static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) +{ + struct io_overflow_cqe *ocqe; + struct io_rings *r = ctx->rings; + unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1; + unsigned int sq_head = READ_ONCE(r->sq.head); + unsigned int sq_tail = READ_ONCE(r->sq.tail); + unsigned int cq_head = READ_ONCE(r->cq.head); + unsigned int cq_tail = READ_ONCE(r->cq.tail); + unsigned int sq_shift = 0; + unsigned int sq_entries; + int sq_pid = -1, sq_cpu = -1; + u64 sq_total_time = 0, sq_work_time = 0; + unsigned int i; + + if (ctx->flags & IORING_SETUP_SQE128) + sq_shift = 1; + + /* + * we may get imprecise sqe and cqe info if uring is actively running + * since we get cached_sq_head and cached_cq_tail without uring_lock + * and sq_tail and cq_head are changed by userspace. But it's ok since + * we usually use these info when it is stuck. + */ + seq_printf(m, "SqMask:\t0x%x\n", sq_mask); + seq_printf(m, "SqHead:\t%u\n", sq_head); + seq_printf(m, "SqTail:\t%u\n", sq_tail); + seq_printf(m, "CachedSqHead:\t%u\n", data_race(ctx->cached_sq_head)); + seq_printf(m, "CqMask:\t0x%x\n", cq_mask); + seq_printf(m, "CqHead:\t%u\n", cq_head); + seq_printf(m, "CqTail:\t%u\n", cq_tail); + seq_printf(m, "CachedCqTail:\t%u\n", data_race(ctx->cached_cq_tail)); + seq_printf(m, "SQEs:\t%u\n", sq_tail - sq_head); + sq_entries = min(sq_tail - sq_head, ctx->sq_entries); + for (i = 0; i < sq_entries; i++) { + unsigned int entry = i + sq_head; + struct io_uring_sqe *sqe; + unsigned int sq_idx; + bool sqe128 = false; + u8 opcode; + + if (ctx->flags & IORING_SETUP_NO_SQARRAY) + sq_idx = entry & sq_mask; + else + sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]); + if (sq_idx > sq_mask) + continue; + + sqe = &ctx->sq_sqes[sq_idx << sq_shift]; + opcode = READ_ONCE(sqe->opcode); + if (opcode >= IORING_OP_LAST) + continue; + opcode = array_index_nospec(opcode, IORING_OP_LAST); + if (sq_shift) { + sqe128 = true; + } else if (io_issue_defs[opcode].is_128) { + if (!(ctx->flags & IORING_SETUP_SQE_MIXED)) { + seq_printf(m, + "%5u: invalid sqe, 128B entry on non-mixed sq\n", + sq_idx); + break; + } + if ((++sq_head & sq_mask) == 0) { + seq_printf(m, + "%5u: corrupted sqe, wrapping 128B entry\n", + sq_idx); + break; + } + sqe128 = true; + } + seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, " + "addr:0x%llx, rw_flags:0x%x, buf_index:%d " + "user_data:%llu", + sq_idx, io_uring_get_opcode(opcode), sqe->fd, + sqe->flags, (unsigned long long) sqe->off, + (unsigned long long) sqe->addr, sqe->rw_flags, + sqe->buf_index, sqe->user_data); + if (sqe128) { + u64 *sqeb = (void *) (sqe + 1); + int size = sizeof(struct io_uring_sqe) / sizeof(u64); + int j; + + for (j = 0; j < size; j++) { + seq_printf(m, ", e%d:0x%llx", j, + (unsigned long long) *sqeb); + sqeb++; + } + } + seq_printf(m, "\n"); + } + seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head); + while (cq_head < cq_tail) { + struct io_uring_cqe *cqe; + bool cqe32 = false; + + cqe = &r->cqes[(cq_head & cq_mask)]; + if (cqe->flags & IORING_CQE_F_32 || ctx->flags & IORING_SETUP_CQE32) + cqe32 = true; + seq_printf(m, "%5u: user_data:%llu, res:%d, flags:%x", + cq_head & cq_mask, cqe->user_data, cqe->res, + cqe->flags); + if (cqe32) + seq_printf(m, ", extra1:%llu, extra2:%llu\n", + cqe->big_cqe[0], cqe->big_cqe[1]); + seq_printf(m, "\n"); + cq_head++; + if (cqe32) + cq_head++; + } + + if (ctx->flags & IORING_SETUP_SQPOLL) { + struct io_sq_data *sq = ctx->sq_data; + struct task_struct *tsk; + + rcu_read_lock(); + tsk = rcu_dereference(sq->thread); + /* + * sq->thread might be NULL if we raced with the sqpoll + * thread termination. + */ + if (tsk) { + u64 usec; + + get_task_struct(tsk); + rcu_read_unlock(); + usec = io_sq_cpu_usec(tsk); + put_task_struct(tsk); + sq_pid = sq->task_pid; + sq_cpu = sq->sq_cpu; + sq_total_time = usec; + sq_work_time = sq->work_time; + } else { + rcu_read_unlock(); + } + } + + seq_printf(m, "SqThread:\t%d\n", sq_pid); + seq_printf(m, "SqThreadCpu:\t%d\n", sq_cpu); + seq_printf(m, "SqTotalTime:\t%llu\n", sq_total_time); + seq_printf(m, "SqWorkTime:\t%llu\n", sq_work_time); + seq_printf(m, "UserFiles:\t%u\n", ctx->file_table.data.nr); + for (i = 0; i < ctx->file_table.data.nr; i++) { + struct file *f = NULL; + + if (ctx->file_table.data.nodes[i]) + f = io_slot_file(ctx->file_table.data.nodes[i]); + if (f) { + seq_printf(m, "%5u: ", i); + seq_file_path(m, f, " \t\n\\"); + seq_puts(m, "\n"); + } + } + seq_printf(m, "UserBufs:\t%u\n", ctx->buf_table.nr); + for (i = 0; i < ctx->buf_table.nr; i++) { + struct io_mapped_ubuf *buf = NULL; + + if (ctx->buf_table.nodes[i]) + buf = ctx->buf_table.nodes[i]->buf; + if (buf) + seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, buf->len); + else + seq_printf(m, "%5u: <none>\n", i); + } + + seq_puts(m, "PollList:\n"); + for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) { + struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i]; + struct io_kiocb *req; + + hlist_for_each_entry(req, &hb->list, hash_node) + seq_printf(m, " op=%d, task_works=%d\n", req->opcode, + task_work_pending(req->tctx->task)); + } + + seq_puts(m, "CqOverflowList:\n"); + spin_lock(&ctx->completion_lock); + list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) { + struct io_uring_cqe *cqe = &ocqe->cqe; + + seq_printf(m, " user_data=%llu, res=%d, flags=%x\n", + cqe->user_data, cqe->res, cqe->flags); + + } + spin_unlock(&ctx->completion_lock); + napi_show_fdinfo(ctx, m); +} + +/* + * Caller holds a reference to the file already, we don't need to do + * anything else to get an extra reference. + */ +__cold void io_uring_show_fdinfo(struct seq_file *m, struct file *file) +{ + struct io_ring_ctx *ctx = file->private_data; + + /* + * Avoid ABBA deadlock between the seq lock and the io_uring mutex, + * since fdinfo case grabs it in the opposite direction of normal use + * cases. + */ + if (mutex_trylock(&ctx->uring_lock)) { + __io_uring_show_fdinfo(ctx, m); + mutex_unlock(&ctx->uring_lock); + } +} diff --git a/io_uring/fdinfo.h b/io_uring/fdinfo.h new file mode 100644 index 000000000000..6fde48c450e3 --- /dev/null +++ b/io_uring/fdinfo.h @@ -0,0 +1,3 @@ +// SPDX-License-Identifier: GPL-2.0 + +void io_uring_show_fdinfo(struct seq_file *m, struct file *f); diff --git a/io_uring/filetable.c b/io_uring/filetable.c new file mode 100644 index 000000000000..794ef95df293 --- /dev/null +++ b/io_uring/filetable.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/nospec.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "rsrc.h" +#include "filetable.h" + +static int io_file_bitmap_get(struct io_ring_ctx *ctx) +{ + struct io_file_table *table = &ctx->file_table; + unsigned long nr = ctx->file_alloc_end; + int ret; + + if (!table->bitmap) + return -ENFILE; + + do { + ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint); + if (ret != nr) + return ret; + + if (table->alloc_hint == ctx->file_alloc_start) + break; + nr = table->alloc_hint; + table->alloc_hint = ctx->file_alloc_start; + } while (1); + + return -ENFILE; +} + +bool io_alloc_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table, + unsigned nr_files) +{ + if (io_rsrc_data_alloc(&table->data, nr_files)) + return false; + table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT); + if (table->bitmap) + return true; + io_rsrc_data_free(ctx, &table->data); + return false; +} + +void io_free_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table) +{ + io_rsrc_data_free(ctx, &table->data); + bitmap_free(table->bitmap); + table->bitmap = NULL; +} + +static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file, + u32 slot_index) + __must_hold(&ctx->uring_lock) +{ + struct io_rsrc_node *node; + + if (io_is_uring_fops(file)) + return -EBADF; + if (!ctx->file_table.data.nr) + return -ENXIO; + if (slot_index >= ctx->file_table.data.nr) + return -EINVAL; + + node = io_rsrc_node_alloc(ctx, IORING_RSRC_FILE); + if (!node) + return -ENOMEM; + + if (!io_reset_rsrc_node(ctx, &ctx->file_table.data, slot_index)) + io_file_bitmap_set(&ctx->file_table, slot_index); + + ctx->file_table.data.nodes[slot_index] = node; + io_fixed_file_set(node, file); + return 0; +} + +int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file, + unsigned int file_slot) +{ + bool alloc_slot = file_slot == IORING_FILE_INDEX_ALLOC; + int ret; + + if (alloc_slot) { + ret = io_file_bitmap_get(ctx); + if (unlikely(ret < 0)) + return ret; + file_slot = ret; + } else { + file_slot--; + } + + ret = io_install_fixed_file(ctx, file, file_slot); + if (!ret && alloc_slot) + ret = file_slot; + return ret; +} +/* + * Note when io_fixed_fd_install() returns error value, it will ensure + * fput() is called correspondingly. + */ +int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags, + struct file *file, unsigned int file_slot) +{ + struct io_ring_ctx *ctx = req->ctx; + int ret; + + io_ring_submit_lock(ctx, issue_flags); + ret = __io_fixed_fd_install(ctx, file, file_slot); + io_ring_submit_unlock(ctx, issue_flags); + + if (unlikely(ret < 0)) + fput(file); + return ret; +} + +int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset) +{ + struct io_rsrc_node *node; + + if (unlikely(!ctx->file_table.data.nr)) + return -ENXIO; + if (offset >= ctx->file_table.data.nr) + return -EINVAL; + + node = io_rsrc_node_lookup(&ctx->file_table.data, offset); + if (!node) + return -EBADF; + io_reset_rsrc_node(ctx, &ctx->file_table.data, offset); + io_file_bitmap_clear(&ctx->file_table, offset); + return 0; +} + +int io_register_file_alloc_range(struct io_ring_ctx *ctx, + struct io_uring_file_index_range __user *arg) +{ + struct io_uring_file_index_range range; + u32 end; + + if (copy_from_user(&range, arg, sizeof(range))) + return -EFAULT; + if (check_add_overflow(range.off, range.len, &end)) + return -EOVERFLOW; + if (range.resv || end > ctx->file_table.data.nr) + return -EINVAL; + + io_file_table_set_alloc_range(ctx, range.off, range.len); + return 0; +} diff --git a/io_uring/filetable.h b/io_uring/filetable.h new file mode 100644 index 000000000000..7717ea9efd0e --- /dev/null +++ b/io_uring/filetable.h @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_FILE_TABLE_H +#define IOU_FILE_TABLE_H + +#include <linux/file.h> +#include <linux/io_uring_types.h> +#include "rsrc.h" + +bool io_alloc_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table, unsigned nr_files); +void io_free_file_tables(struct io_ring_ctx *ctx, struct io_file_table *table); + +int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags, + struct file *file, unsigned int file_slot); +int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file, + unsigned int file_slot); +int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset); + +int io_register_file_alloc_range(struct io_ring_ctx *ctx, + struct io_uring_file_index_range __user *arg); + +io_req_flags_t io_file_get_flags(struct file *file); + +static inline void io_file_bitmap_clear(struct io_file_table *table, int bit) +{ + WARN_ON_ONCE(!test_bit(bit, table->bitmap)); + __clear_bit(bit, table->bitmap); + table->alloc_hint = bit; +} + +static inline void io_file_bitmap_set(struct io_file_table *table, int bit) +{ + WARN_ON_ONCE(test_bit(bit, table->bitmap)); + __set_bit(bit, table->bitmap); + table->alloc_hint = bit + 1; +} + +#define FFS_NOWAIT 0x1UL +#define FFS_ISREG 0x2UL +#define FFS_MASK ~(FFS_NOWAIT|FFS_ISREG) + +static inline unsigned int io_slot_flags(struct io_rsrc_node *node) +{ + + return (node->file_ptr & ~FFS_MASK) << REQ_F_SUPPORT_NOWAIT_BIT; +} + +static inline struct file *io_slot_file(struct io_rsrc_node *node) +{ + return (struct file *)(node->file_ptr & FFS_MASK); +} + +static inline void io_fixed_file_set(struct io_rsrc_node *node, + struct file *file) +{ + node->file_ptr = (unsigned long)file | + (io_file_get_flags(file) >> REQ_F_SUPPORT_NOWAIT_BIT); +} + +static inline void io_file_table_set_alloc_range(struct io_ring_ctx *ctx, + unsigned off, unsigned len) +{ + ctx->file_alloc_start = off; + ctx->file_alloc_end = off + len; + ctx->file_table.alloc_hint = ctx->file_alloc_start; +} + +#endif diff --git a/io_uring/fs.c b/io_uring/fs.c new file mode 100644 index 000000000000..37079a414eab --- /dev/null +++ b/io_uring/fs.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "../fs/internal.h" + +#include "io_uring.h" +#include "fs.h" + +struct io_rename { + struct file *file; + int old_dfd; + int new_dfd; + struct filename *oldpath; + struct filename *newpath; + int flags; +}; + +struct io_unlink { + struct file *file; + int dfd; + int flags; + struct filename *filename; +}; + +struct io_mkdir { + struct file *file; + int dfd; + umode_t mode; + struct filename *filename; +}; + +struct io_link { + struct file *file; + int old_dfd; + int new_dfd; + struct filename *oldpath; + struct filename *newpath; + int flags; +}; + +int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename); + const char __user *oldf, *newf; + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + ren->old_dfd = READ_ONCE(sqe->fd); + oldf = u64_to_user_ptr(READ_ONCE(sqe->addr)); + newf = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + ren->new_dfd = READ_ONCE(sqe->len); + ren->flags = READ_ONCE(sqe->rename_flags); + + ren->oldpath = getname(oldf); + if (IS_ERR(ren->oldpath)) + return PTR_ERR(ren->oldpath); + + ren->newpath = getname(newf); + if (IS_ERR(ren->newpath)) { + putname(ren->oldpath); + return PTR_ERR(ren->newpath); + } + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_renameat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd, + ren->newpath, ren->flags); + + req->flags &= ~REQ_F_NEED_CLEANUP; + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +void io_renameat_cleanup(struct io_kiocb *req) +{ + struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename); + + putname(ren->oldpath); + putname(ren->newpath); +} + +int io_unlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_unlink *un = io_kiocb_to_cmd(req, struct io_unlink); + const char __user *fname; + + if (sqe->off || sqe->len || sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + un->dfd = READ_ONCE(sqe->fd); + + un->flags = READ_ONCE(sqe->unlink_flags); + if (un->flags & ~AT_REMOVEDIR) + return -EINVAL; + + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + un->filename = getname(fname); + if (IS_ERR(un->filename)) + return PTR_ERR(un->filename); + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_unlink *un = io_kiocb_to_cmd(req, struct io_unlink); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + if (un->flags & AT_REMOVEDIR) + ret = do_rmdir(un->dfd, un->filename); + else + ret = do_unlinkat(un->dfd, un->filename); + + req->flags &= ~REQ_F_NEED_CLEANUP; + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +void io_unlinkat_cleanup(struct io_kiocb *req) +{ + struct io_unlink *ul = io_kiocb_to_cmd(req, struct io_unlink); + + putname(ul->filename); +} + +int io_mkdirat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_mkdir *mkd = io_kiocb_to_cmd(req, struct io_mkdir); + const char __user *fname; + + if (sqe->off || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + mkd->dfd = READ_ONCE(sqe->fd); + mkd->mode = READ_ONCE(sqe->len); + + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + mkd->filename = getname(fname); + if (IS_ERR(mkd->filename)) + return PTR_ERR(mkd->filename); + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_mkdirat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_mkdir *mkd = io_kiocb_to_cmd(req, struct io_mkdir); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_mkdirat(mkd->dfd, mkd->filename, mkd->mode); + + req->flags &= ~REQ_F_NEED_CLEANUP; + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +void io_mkdirat_cleanup(struct io_kiocb *req) +{ + struct io_mkdir *md = io_kiocb_to_cmd(req, struct io_mkdir); + + putname(md->filename); +} + +int io_symlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_link *sl = io_kiocb_to_cmd(req, struct io_link); + const char __user *oldpath, *newpath; + + if (sqe->len || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + sl->new_dfd = READ_ONCE(sqe->fd); + oldpath = u64_to_user_ptr(READ_ONCE(sqe->addr)); + newpath = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + + sl->oldpath = getname(oldpath); + if (IS_ERR(sl->oldpath)) + return PTR_ERR(sl->oldpath); + + sl->newpath = getname(newpath); + if (IS_ERR(sl->newpath)) { + putname(sl->oldpath); + return PTR_ERR(sl->newpath); + } + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_symlinkat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_link *sl = io_kiocb_to_cmd(req, struct io_link); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_symlinkat(sl->oldpath, sl->new_dfd, sl->newpath); + + req->flags &= ~REQ_F_NEED_CLEANUP; + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_link *lnk = io_kiocb_to_cmd(req, struct io_link); + const char __user *oldf, *newf; + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + lnk->old_dfd = READ_ONCE(sqe->fd); + lnk->new_dfd = READ_ONCE(sqe->len); + oldf = u64_to_user_ptr(READ_ONCE(sqe->addr)); + newf = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + lnk->flags = READ_ONCE(sqe->hardlink_flags); + + lnk->oldpath = getname_uflags(oldf, lnk->flags); + if (IS_ERR(lnk->oldpath)) + return PTR_ERR(lnk->oldpath); + + lnk->newpath = getname(newf); + if (IS_ERR(lnk->newpath)) { + putname(lnk->oldpath); + return PTR_ERR(lnk->newpath); + } + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_linkat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_link *lnk = io_kiocb_to_cmd(req, struct io_link); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_linkat(lnk->old_dfd, lnk->oldpath, lnk->new_dfd, + lnk->newpath, lnk->flags); + + req->flags &= ~REQ_F_NEED_CLEANUP; + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +void io_link_cleanup(struct io_kiocb *req) +{ + struct io_link *sl = io_kiocb_to_cmd(req, struct io_link); + + putname(sl->oldpath); + putname(sl->newpath); +} diff --git a/io_uring/fs.h b/io_uring/fs.h new file mode 100644 index 000000000000..0bb5efe3d6bb --- /dev/null +++ b/io_uring/fs.h @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_renameat(struct io_kiocb *req, unsigned int issue_flags); +void io_renameat_cleanup(struct io_kiocb *req); + +int io_unlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags); +void io_unlinkat_cleanup(struct io_kiocb *req); + +int io_mkdirat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_mkdirat(struct io_kiocb *req, unsigned int issue_flags); +void io_mkdirat_cleanup(struct io_kiocb *req); + +int io_symlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_symlinkat(struct io_kiocb *req, unsigned int issue_flags); + +int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_linkat(struct io_kiocb *req, unsigned int issue_flags); +void io_link_cleanup(struct io_kiocb *req); diff --git a/io_uring/futex.c b/io_uring/futex.c new file mode 100644 index 000000000000..11bfff5a80df --- /dev/null +++ b/io_uring/futex.c @@ -0,0 +1,334 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "../kernel/futex/futex.h" +#include "io_uring.h" +#include "alloc_cache.h" +#include "futex.h" + +struct io_futex { + struct file *file; + void __user *uaddr; + unsigned long futex_val; + unsigned long futex_mask; + u32 futex_flags; + unsigned int futex_nr; + bool futexv_unqueued; +}; + +struct io_futex_data { + struct futex_q q; + struct io_kiocb *req; +}; + +struct io_futexv_data { + unsigned long owned; + struct futex_vector futexv[]; +}; + +#define IO_FUTEX_ALLOC_CACHE_MAX 32 + +bool io_futex_cache_init(struct io_ring_ctx *ctx) +{ + return io_alloc_cache_init(&ctx->futex_cache, IO_FUTEX_ALLOC_CACHE_MAX, + sizeof(struct io_futex_data), 0); +} + +void io_futex_cache_free(struct io_ring_ctx *ctx) +{ + io_alloc_cache_free(&ctx->futex_cache, kfree); +} + +static void __io_futex_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + hlist_del_init(&tw_req.req->hash_node); + io_req_task_complete(tw_req, tw); +} + +static void io_futex_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_ring_ctx *ctx = req->ctx; + + io_tw_lock(ctx, tw); + io_cache_free(&ctx->futex_cache, req->async_data); + io_req_async_data_clear(req, 0); + __io_futex_complete(tw_req, tw); +} + +static void io_futexv_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct io_futexv_data *ifd = req->async_data; + + io_tw_lock(req->ctx, tw); + + if (!iof->futexv_unqueued) { + int res; + + res = futex_unqueue_multiple(ifd->futexv, iof->futex_nr); + if (res != -1) + io_req_set_res(req, res, 0); + } + + io_req_async_data_free(req); + __io_futex_complete(tw_req, tw); +} + +static bool io_futexv_claim(struct io_futexv_data *ifd) +{ + if (test_bit(0, &ifd->owned) || test_and_set_bit_lock(0, &ifd->owned)) + return false; + return true; +} + +static bool __io_futex_cancel(struct io_kiocb *req) +{ + /* futex wake already done or in progress */ + if (req->opcode == IORING_OP_FUTEX_WAIT) { + struct io_futex_data *ifd = req->async_data; + + if (!futex_unqueue(&ifd->q)) + return false; + req->io_task_work.func = io_futex_complete; + } else { + struct io_futexv_data *ifd = req->async_data; + + if (!io_futexv_claim(ifd)) + return false; + req->io_task_work.func = io_futexv_complete; + } + + hlist_del_init(&req->hash_node); + io_req_set_res(req, -ECANCELED, 0); + io_req_task_work_add(req); + return true; +} + +int io_futex_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags) +{ + return io_cancel_remove(ctx, cd, issue_flags, &ctx->futex_list, __io_futex_cancel); +} + +bool io_futex_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all) +{ + return io_cancel_remove_all(ctx, tctx, &ctx->futex_list, cancel_all, __io_futex_cancel); +} + +int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + u32 flags; + + if (unlikely(sqe->len || sqe->futex_flags || sqe->buf_index || + sqe->file_index)) + return -EINVAL; + + iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + iof->futex_val = READ_ONCE(sqe->addr2); + iof->futex_mask = READ_ONCE(sqe->addr3); + flags = READ_ONCE(sqe->fd); + + if (flags & ~FUTEX2_VALID_MASK) + return -EINVAL; + + iof->futex_flags = futex2_to_flags(flags); + if (!futex_flags_valid(iof->futex_flags)) + return -EINVAL; + + if (!futex_validate_input(iof->futex_flags, iof->futex_val) || + !futex_validate_input(iof->futex_flags, iof->futex_mask)) + return -EINVAL; + + /* Mark as inflight, so file exit cancelation will find it */ + io_req_track_inflight(req); + return 0; +} + +static void io_futex_wakev_fn(struct wake_q_head *wake_q, struct futex_q *q) +{ + struct io_kiocb *req = q->wake_data; + struct io_futexv_data *ifd = req->async_data; + + if (!io_futexv_claim(ifd)) + return; + if (unlikely(!__futex_wake_mark(q))) + return; + + io_req_set_res(req, 0, 0); + req->io_task_work.func = io_futexv_complete; + io_req_task_work_add(req); +} + +int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct io_futexv_data *ifd; + int ret; + + /* No flags or mask supported for waitv */ + if (unlikely(sqe->fd || sqe->buf_index || sqe->file_index || + sqe->addr2 || sqe->futex_flags || sqe->addr3)) + return -EINVAL; + + iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + iof->futex_nr = READ_ONCE(sqe->len); + if (!iof->futex_nr || iof->futex_nr > FUTEX_WAITV_MAX) + return -EINVAL; + + ifd = kzalloc(struct_size_t(struct io_futexv_data, futexv, iof->futex_nr), + GFP_KERNEL); + if (!ifd) + return -ENOMEM; + + ret = futex_parse_waitv(ifd->futexv, iof->uaddr, iof->futex_nr, + io_futex_wakev_fn, req); + if (ret) { + kfree(ifd); + return ret; + } + + /* Mark as inflight, so file exit cancelation will find it */ + io_req_track_inflight(req); + iof->futexv_unqueued = 0; + req->flags |= REQ_F_ASYNC_DATA; + req->async_data = ifd; + return 0; +} + +static void io_futex_wake_fn(struct wake_q_head *wake_q, struct futex_q *q) +{ + struct io_futex_data *ifd = container_of(q, struct io_futex_data, q); + struct io_kiocb *req = ifd->req; + + if (unlikely(!__futex_wake_mark(q))) + return; + + io_req_set_res(req, 0, 0); + req->io_task_work.func = io_futex_complete; + io_req_task_work_add(req); +} + +int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct io_futexv_data *ifd = req->async_data; + struct io_ring_ctx *ctx = req->ctx; + int ret, woken = -1; + + io_ring_submit_lock(ctx, issue_flags); + + ret = futex_wait_multiple_setup(ifd->futexv, iof->futex_nr, &woken); + + /* + * Error case, ret is < 0. Mark the request as failed. + */ + if (unlikely(ret < 0)) { + io_ring_submit_unlock(ctx, issue_flags); + req_set_fail(req); + io_req_set_res(req, ret, 0); + io_req_async_data_free(req); + return IOU_COMPLETE; + } + + /* + * 0 return means that we successfully setup the waiters, and that + * nobody triggered a wakeup while we were doing so. If the wakeup + * happened post setup, the task_work will be run post this issue and + * under the submission lock. 1 means We got woken while setting up, + * let that side do the completion. Note that + * futex_wait_multiple_setup() will have unqueued all the futexes in + * this case. Mark us as having done that already, since this is + * different from normal wakeup. + */ + if (!ret) { + /* + * If futex_wait_multiple_setup() returns 0 for a + * successful setup, then the task state will not be + * runnable. This is fine for the sync syscall, as + * it'll be blocking unless we already got one of the + * futexes woken, but it obviously won't work for an + * async invocation. Mark us runnable again. + */ + __set_current_state(TASK_RUNNING); + hlist_add_head(&req->hash_node, &ctx->futex_list); + } else { + iof->futexv_unqueued = 1; + if (woken != -1) + io_req_set_res(req, woken, 0); + } + + io_ring_submit_unlock(ctx, issue_flags); + return IOU_ISSUE_SKIP_COMPLETE; +} + +int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct io_ring_ctx *ctx = req->ctx; + struct io_futex_data *ifd = NULL; + int ret; + + if (!iof->futex_mask) { + ret = -EINVAL; + goto done; + } + + io_ring_submit_lock(ctx, issue_flags); + ifd = io_cache_alloc(&ctx->futex_cache, GFP_NOWAIT); + if (!ifd) { + ret = -ENOMEM; + goto done_unlock; + } + + req->flags |= REQ_F_ASYNC_DATA; + req->async_data = ifd; + ifd->q = futex_q_init; + ifd->q.bitset = iof->futex_mask; + ifd->q.wake = io_futex_wake_fn; + ifd->req = req; + + ret = futex_wait_setup(iof->uaddr, iof->futex_val, iof->futex_flags, + &ifd->q, NULL, NULL); + if (!ret) { + hlist_add_head(&req->hash_node, &ctx->futex_list); + io_ring_submit_unlock(ctx, issue_flags); + + return IOU_ISSUE_SKIP_COMPLETE; + } + +done_unlock: + io_ring_submit_unlock(ctx, issue_flags); +done: + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + io_req_async_data_free(req); + return IOU_COMPLETE; +} + +int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + int ret; + + /* + * Strict flags - ensure that waking 0 futexes yields a 0 result. + * See commit 43adf8449510 ("futex: FLAGS_STRICT") for details. + */ + ret = futex_wake(iof->uaddr, FLAGS_STRICT | iof->futex_flags, + iof->futex_val, iof->futex_mask); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/futex.h b/io_uring/futex.h new file mode 100644 index 000000000000..d789fcf715e3 --- /dev/null +++ b/io_uring/futex.h @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "cancel.h" + +int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags); +int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags); +int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags); + +#if defined(CONFIG_FUTEX) +int io_futex_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags); +bool io_futex_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all); +bool io_futex_cache_init(struct io_ring_ctx *ctx); +void io_futex_cache_free(struct io_ring_ctx *ctx); +#else +static inline int io_futex_cancel(struct io_ring_ctx *ctx, + struct io_cancel_data *cd, + unsigned int issue_flags) +{ + return 0; +} +static inline bool io_futex_remove_all(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, bool cancel_all) +{ + return false; +} +static inline bool io_futex_cache_init(struct io_ring_ctx *ctx) +{ + return false; +} +static inline void io_futex_cache_free(struct io_ring_ctx *ctx) +{ +} +#endif diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c new file mode 100644 index 000000000000..cd13d8aac3d2 --- /dev/null +++ b/io_uring/io-wq.c @@ -0,0 +1,1481 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Basic worker thread pool for io_uring + * + * Copyright (C) 2019 Jens Axboe + * + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/sched/signal.h> +#include <linux/percpu.h> +#include <linux/slab.h> +#include <linux/rculist_nulls.h> +#include <linux/cpu.h> +#include <linux/cpuset.h> +#include <linux/task_work.h> +#include <linux/audit.h> +#include <linux/mmu_context.h> +#include <uapi/linux/io_uring.h> + +#include "io-wq.h" +#include "slist.h" +#include "io_uring.h" + +#define WORKER_IDLE_TIMEOUT (5 * HZ) +#define WORKER_INIT_LIMIT 3 + +enum { + IO_WORKER_F_UP = 0, /* up and active */ + IO_WORKER_F_RUNNING = 1, /* account as running */ + IO_WORKER_F_FREE = 2, /* worker on free list */ +}; + +enum { + IO_WQ_BIT_EXIT = 0, /* wq exiting */ +}; + +enum { + IO_ACCT_STALLED_BIT = 0, /* stalled on hash */ +}; + +/* + * One for each thread in a wq pool + */ +struct io_worker { + refcount_t ref; + unsigned long flags; + struct hlist_nulls_node nulls_node; + struct list_head all_list; + struct task_struct *task; + struct io_wq *wq; + struct io_wq_acct *acct; + + struct io_wq_work *cur_work; + raw_spinlock_t lock; + + struct completion ref_done; + + unsigned long create_state; + struct callback_head create_work; + int init_retries; + + union { + struct rcu_head rcu; + struct delayed_work work; + }; +}; + +#if BITS_PER_LONG == 64 +#define IO_WQ_HASH_ORDER 6 +#else +#define IO_WQ_HASH_ORDER 5 +#endif + +#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER) + +struct io_wq_acct { + /** + * Protects access to the worker lists. + */ + raw_spinlock_t workers_lock; + + unsigned nr_workers; + unsigned max_workers; + atomic_t nr_running; + + /** + * The list of free workers. Protected by #workers_lock + * (write) and RCU (read). + */ + struct hlist_nulls_head free_list; + + /** + * The list of all workers. Protected by #workers_lock + * (write) and RCU (read). + */ + struct list_head all_list; + + raw_spinlock_t lock; + struct io_wq_work_list work_list; + unsigned long flags; +}; + +enum { + IO_WQ_ACCT_BOUND, + IO_WQ_ACCT_UNBOUND, + IO_WQ_ACCT_NR, +}; + +/* + * Per io_wq state + */ +struct io_wq { + unsigned long state; + + struct io_wq_hash *hash; + + atomic_t worker_refs; + struct completion worker_done; + + struct hlist_node cpuhp_node; + + struct task_struct *task; + + struct io_wq_acct acct[IO_WQ_ACCT_NR]; + + struct wait_queue_entry wait; + + struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS]; + + cpumask_var_t cpu_mask; +}; + +static enum cpuhp_state io_wq_online; + +struct io_cb_cancel_data { + work_cancel_fn *fn; + void *data; + int nr_running; + int nr_pending; + bool cancel_all; +}; + +static bool create_io_worker(struct io_wq *wq, struct io_wq_acct *acct); +static void io_wq_dec_running(struct io_worker *worker); +static bool io_acct_cancel_pending_work(struct io_wq *wq, + struct io_wq_acct *acct, + struct io_cb_cancel_data *match); +static void create_worker_cb(struct callback_head *cb); +static void io_wq_cancel_tw_create(struct io_wq *wq); + +static inline unsigned int __io_get_work_hash(unsigned int work_flags) +{ + return work_flags >> IO_WQ_HASH_SHIFT; +} + +static inline unsigned int io_get_work_hash(struct io_wq_work *work) +{ + return __io_get_work_hash(atomic_read(&work->flags)); +} + +static bool io_worker_get(struct io_worker *worker) +{ + return refcount_inc_not_zero(&worker->ref); +} + +static void io_worker_release(struct io_worker *worker) +{ + if (refcount_dec_and_test(&worker->ref)) + complete(&worker->ref_done); +} + +static inline struct io_wq_acct *io_get_acct(struct io_wq *wq, bool bound) +{ + return &wq->acct[bound ? IO_WQ_ACCT_BOUND : IO_WQ_ACCT_UNBOUND]; +} + +static inline struct io_wq_acct *io_work_get_acct(struct io_wq *wq, + unsigned int work_flags) +{ + return io_get_acct(wq, !(work_flags & IO_WQ_WORK_UNBOUND)); +} + +static inline struct io_wq_acct *io_wq_get_acct(struct io_worker *worker) +{ + return worker->acct; +} + +static void io_worker_ref_put(struct io_wq *wq) +{ + if (atomic_dec_and_test(&wq->worker_refs)) + complete(&wq->worker_done); +} + +bool io_wq_worker_stopped(void) +{ + struct io_worker *worker = current->worker_private; + + if (WARN_ON_ONCE(!io_wq_current_is_worker())) + return true; + + return test_bit(IO_WQ_BIT_EXIT, &worker->wq->state); +} + +static void io_worker_cancel_cb(struct io_worker *worker) +{ + struct io_wq_acct *acct = io_wq_get_acct(worker); + struct io_wq *wq = worker->wq; + + atomic_dec(&acct->nr_running); + raw_spin_lock(&acct->workers_lock); + acct->nr_workers--; + raw_spin_unlock(&acct->workers_lock); + io_worker_ref_put(wq); + clear_bit_unlock(0, &worker->create_state); + io_worker_release(worker); +} + +static bool io_task_worker_match(struct callback_head *cb, void *data) +{ + struct io_worker *worker; + + if (cb->func != create_worker_cb) + return false; + worker = container_of(cb, struct io_worker, create_work); + return worker == data; +} + +static void io_worker_exit(struct io_worker *worker) +{ + struct io_wq *wq = worker->wq; + struct io_wq_acct *acct = io_wq_get_acct(worker); + + while (1) { + struct callback_head *cb = task_work_cancel_match(wq->task, + io_task_worker_match, worker); + + if (!cb) + break; + io_worker_cancel_cb(worker); + } + + io_worker_release(worker); + wait_for_completion(&worker->ref_done); + + raw_spin_lock(&acct->workers_lock); + if (test_bit(IO_WORKER_F_FREE, &worker->flags)) + hlist_nulls_del_rcu(&worker->nulls_node); + list_del_rcu(&worker->all_list); + raw_spin_unlock(&acct->workers_lock); + io_wq_dec_running(worker); + /* + * this worker is a goner, clear ->worker_private to avoid any + * inc/dec running calls that could happen as part of exit from + * touching 'worker'. + */ + current->worker_private = NULL; + + kfree_rcu(worker, rcu); + io_worker_ref_put(wq); + do_exit(0); +} + +static inline bool __io_acct_run_queue(struct io_wq_acct *acct) +{ + return !test_bit(IO_ACCT_STALLED_BIT, &acct->flags) && + !wq_list_empty(&acct->work_list); +} + +/* + * If there's work to do, returns true with acct->lock acquired. If not, + * returns false with no lock held. + */ +static inline bool io_acct_run_queue(struct io_wq_acct *acct) + __acquires(&acct->lock) +{ + raw_spin_lock(&acct->lock); + if (__io_acct_run_queue(acct)) + return true; + + raw_spin_unlock(&acct->lock); + return false; +} + +/* + * Check head of free list for an available worker. If one isn't available, + * caller must create one. + */ +static bool io_acct_activate_free_worker(struct io_wq_acct *acct) + __must_hold(RCU) +{ + struct hlist_nulls_node *n; + struct io_worker *worker; + + /* + * Iterate free_list and see if we can find an idle worker to + * activate. If a given worker is on the free_list but in the process + * of exiting, keep trying. + */ + hlist_nulls_for_each_entry_rcu(worker, n, &acct->free_list, nulls_node) { + if (!io_worker_get(worker)) + continue; + /* + * If the worker is already running, it's either already + * starting work or finishing work. In either case, if it does + * to go sleep, we'll kick off a new task for this work anyway. + */ + wake_up_process(worker->task); + io_worker_release(worker); + return true; + } + + return false; +} + +/* + * We need a worker. If we find a free one, we're good. If not, and we're + * below the max number of workers, create one. + */ +static bool io_wq_create_worker(struct io_wq *wq, struct io_wq_acct *acct) +{ + /* + * Most likely an attempt to queue unbounded work on an io_wq that + * wasn't setup with any unbounded workers. + */ + if (unlikely(!acct->max_workers)) + pr_warn_once("io-wq is not configured for unbound workers"); + + raw_spin_lock(&acct->workers_lock); + if (acct->nr_workers >= acct->max_workers) { + raw_spin_unlock(&acct->workers_lock); + return true; + } + acct->nr_workers++; + raw_spin_unlock(&acct->workers_lock); + atomic_inc(&acct->nr_running); + atomic_inc(&wq->worker_refs); + return create_io_worker(wq, acct); +} + +static void io_wq_inc_running(struct io_worker *worker) +{ + struct io_wq_acct *acct = io_wq_get_acct(worker); + + atomic_inc(&acct->nr_running); +} + +static void create_worker_cb(struct callback_head *cb) +{ + struct io_worker *worker; + struct io_wq *wq; + + struct io_wq_acct *acct; + bool activated_free_worker, do_create = false; + + worker = container_of(cb, struct io_worker, create_work); + wq = worker->wq; + acct = worker->acct; + + rcu_read_lock(); + activated_free_worker = io_acct_activate_free_worker(acct); + rcu_read_unlock(); + if (activated_free_worker) + goto no_need_create; + + raw_spin_lock(&acct->workers_lock); + + if (acct->nr_workers < acct->max_workers) { + acct->nr_workers++; + do_create = true; + } + raw_spin_unlock(&acct->workers_lock); + if (do_create) { + create_io_worker(wq, acct); + } else { +no_need_create: + atomic_dec(&acct->nr_running); + io_worker_ref_put(wq); + } + clear_bit_unlock(0, &worker->create_state); + io_worker_release(worker); +} + +static bool io_queue_worker_create(struct io_worker *worker, + struct io_wq_acct *acct, + task_work_func_t func) +{ + struct io_wq *wq = worker->wq; + + /* raced with exit, just ignore create call */ + if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) + goto fail; + if (!io_worker_get(worker)) + goto fail; + /* + * create_state manages ownership of create_work/index. We should + * only need one entry per worker, as the worker going to sleep + * will trigger the condition, and waking will clear it once it + * runs the task_work. + */ + if (test_bit(0, &worker->create_state) || + test_and_set_bit_lock(0, &worker->create_state)) + goto fail_release; + + atomic_inc(&wq->worker_refs); + init_task_work(&worker->create_work, func); + if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL)) { + /* + * EXIT may have been set after checking it above, check after + * adding the task_work and remove any creation item if it is + * now set. wq exit does that too, but we can have added this + * work item after we canceled in io_wq_exit_workers(). + */ + if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) + io_wq_cancel_tw_create(wq); + io_worker_ref_put(wq); + return true; + } + io_worker_ref_put(wq); + clear_bit_unlock(0, &worker->create_state); +fail_release: + io_worker_release(worker); +fail: + atomic_dec(&acct->nr_running); + io_worker_ref_put(wq); + return false; +} + +/* Defer if current and next work are both hashed to the same chain */ +static bool io_wq_hash_defer(struct io_wq_work *work, struct io_wq_acct *acct) +{ + unsigned int hash, work_flags; + struct io_wq_work *next; + + lockdep_assert_held(&acct->lock); + + work_flags = atomic_read(&work->flags); + if (!__io_wq_is_hashed(work_flags)) + return false; + + /* should not happen, io_acct_run_queue() said we had work */ + if (wq_list_empty(&acct->work_list)) + return true; + + hash = __io_get_work_hash(work_flags); + next = container_of(acct->work_list.first, struct io_wq_work, list); + work_flags = atomic_read(&next->flags); + if (!__io_wq_is_hashed(work_flags)) + return false; + return hash == __io_get_work_hash(work_flags); +} + +static void io_wq_dec_running(struct io_worker *worker) +{ + struct io_wq_acct *acct = io_wq_get_acct(worker); + struct io_wq *wq = worker->wq; + + if (!test_bit(IO_WORKER_F_UP, &worker->flags)) + return; + + if (!atomic_dec_and_test(&acct->nr_running)) + return; + if (!worker->cur_work) + return; + if (!io_acct_run_queue(acct)) + return; + if (io_wq_hash_defer(worker->cur_work, acct)) { + raw_spin_unlock(&acct->lock); + return; + } + + raw_spin_unlock(&acct->lock); + atomic_inc(&acct->nr_running); + atomic_inc(&wq->worker_refs); + io_queue_worker_create(worker, acct, create_worker_cb); +} + +/* + * Worker will start processing some work. Move it to the busy list, if + * it's currently on the freelist + */ +static void __io_worker_busy(struct io_wq_acct *acct, struct io_worker *worker) +{ + if (test_bit(IO_WORKER_F_FREE, &worker->flags)) { + clear_bit(IO_WORKER_F_FREE, &worker->flags); + raw_spin_lock(&acct->workers_lock); + hlist_nulls_del_init_rcu(&worker->nulls_node); + raw_spin_unlock(&acct->workers_lock); + } +} + +/* + * No work, worker going to sleep. Move to freelist. + */ +static void __io_worker_idle(struct io_wq_acct *acct, struct io_worker *worker) + __must_hold(acct->workers_lock) +{ + if (!test_bit(IO_WORKER_F_FREE, &worker->flags)) { + set_bit(IO_WORKER_F_FREE, &worker->flags); + hlist_nulls_add_head_rcu(&worker->nulls_node, &acct->free_list); + } +} + +static bool io_wait_on_hash(struct io_wq *wq, unsigned int hash) +{ + bool ret = false; + + spin_lock_irq(&wq->hash->wait.lock); + if (list_empty(&wq->wait.entry)) { + __add_wait_queue(&wq->hash->wait, &wq->wait); + if (!test_bit(hash, &wq->hash->map)) { + __set_current_state(TASK_RUNNING); + list_del_init(&wq->wait.entry); + ret = true; + } + } + spin_unlock_irq(&wq->hash->wait.lock); + return ret; +} + +static struct io_wq_work *io_get_next_work(struct io_wq_acct *acct, + struct io_wq *wq) + __must_hold(acct->lock) +{ + struct io_wq_work_node *node, *prev; + struct io_wq_work *work, *tail; + unsigned int stall_hash = -1U; + + wq_list_for_each(node, prev, &acct->work_list) { + unsigned int work_flags; + unsigned int hash; + + work = container_of(node, struct io_wq_work, list); + + /* not hashed, can run anytime */ + work_flags = atomic_read(&work->flags); + if (!__io_wq_is_hashed(work_flags)) { + wq_list_del(&acct->work_list, node, prev); + return work; + } + + hash = __io_get_work_hash(work_flags); + /* all items with this hash lie in [work, tail] */ + tail = wq->hash_tail[hash]; + + /* hashed, can run if not already running */ + if (!test_and_set_bit(hash, &wq->hash->map)) { + wq->hash_tail[hash] = NULL; + wq_list_cut(&acct->work_list, &tail->list, prev); + return work; + } + if (stall_hash == -1U) + stall_hash = hash; + /* fast forward to a next hash, for-each will fix up @prev */ + node = &tail->list; + } + + if (stall_hash != -1U) { + bool unstalled; + + /* + * Set this before dropping the lock to avoid racing with new + * work being added and clearing the stalled bit. + */ + set_bit(IO_ACCT_STALLED_BIT, &acct->flags); + raw_spin_unlock(&acct->lock); + unstalled = io_wait_on_hash(wq, stall_hash); + raw_spin_lock(&acct->lock); + if (unstalled) { + clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + if (wq_has_sleeper(&wq->hash->wait)) + wake_up(&wq->hash->wait); + } + } + + return NULL; +} + +static void io_assign_current_work(struct io_worker *worker, + struct io_wq_work *work) +{ + if (work) { + io_run_task_work(); + cond_resched(); + } + + raw_spin_lock(&worker->lock); + worker->cur_work = work; + raw_spin_unlock(&worker->lock); +} + +/* + * Called with acct->lock held, drops it before returning + */ +static void io_worker_handle_work(struct io_wq_acct *acct, + struct io_worker *worker) + __releases(&acct->lock) +{ + struct io_wq *wq = worker->wq; + bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state); + + do { + struct io_wq_work *work; + + /* + * If we got some work, mark us as busy. If we didn't, but + * the list isn't empty, it means we stalled on hashed work. + * Mark us stalled so we don't keep looking for work when we + * can't make progress, any work completion or insertion will + * clear the stalled flag. + */ + work = io_get_next_work(acct, wq); + if (work) { + /* + * Make sure cancelation can find this, even before + * it becomes the active work. That avoids a window + * where the work has been removed from our general + * work list, but isn't yet discoverable as the + * current work item for this worker. + */ + raw_spin_lock(&worker->lock); + worker->cur_work = work; + raw_spin_unlock(&worker->lock); + } + + raw_spin_unlock(&acct->lock); + + if (!work) + break; + + __io_worker_busy(acct, worker); + + io_assign_current_work(worker, work); + __set_current_state(TASK_RUNNING); + + /* handle a whole dependent link */ + do { + struct io_wq_work *next_hashed, *linked; + unsigned int work_flags = atomic_read(&work->flags); + unsigned int hash = __io_wq_is_hashed(work_flags) + ? __io_get_work_hash(work_flags) + : -1U; + + next_hashed = wq_next_work(work); + + if (do_kill && + (work_flags & IO_WQ_WORK_UNBOUND)) + atomic_or(IO_WQ_WORK_CANCEL, &work->flags); + io_wq_submit_work(work); + io_assign_current_work(worker, NULL); + + linked = io_wq_free_work(work); + work = next_hashed; + if (!work && linked && !io_wq_is_hashed(linked)) { + work = linked; + linked = NULL; + } + io_assign_current_work(worker, work); + if (linked) + io_wq_enqueue(wq, linked); + + if (hash != -1U && !next_hashed) { + /* serialize hash clear with wake_up() */ + spin_lock_irq(&wq->hash->wait.lock); + clear_bit(hash, &wq->hash->map); + clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + spin_unlock_irq(&wq->hash->wait.lock); + if (wq_has_sleeper(&wq->hash->wait)) + wake_up(&wq->hash->wait); + } + } while (work); + + if (!__io_acct_run_queue(acct)) + break; + raw_spin_lock(&acct->lock); + } while (1); +} + +static int io_wq_worker(void *data) +{ + struct io_worker *worker = data; + struct io_wq_acct *acct = io_wq_get_acct(worker); + struct io_wq *wq = worker->wq; + bool exit_mask = false, last_timeout = false; + char buf[TASK_COMM_LEN] = {}; + + set_mask_bits(&worker->flags, 0, + BIT(IO_WORKER_F_UP) | BIT(IO_WORKER_F_RUNNING)); + + snprintf(buf, sizeof(buf), "iou-wrk-%d", wq->task->pid); + set_task_comm(current, buf); + + while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) { + long ret; + + set_current_state(TASK_INTERRUPTIBLE); + + /* + * If we have work to do, io_acct_run_queue() returns with + * the acct->lock held. If not, it will drop it. + */ + while (io_acct_run_queue(acct)) + io_worker_handle_work(acct, worker); + + raw_spin_lock(&acct->workers_lock); + /* + * Last sleep timed out. Exit if we're not the last worker, + * or if someone modified our affinity. + */ + if (last_timeout && (exit_mask || acct->nr_workers > 1)) { + acct->nr_workers--; + raw_spin_unlock(&acct->workers_lock); + __set_current_state(TASK_RUNNING); + break; + } + last_timeout = false; + __io_worker_idle(acct, worker); + raw_spin_unlock(&acct->workers_lock); + if (io_run_task_work()) + continue; + ret = schedule_timeout(WORKER_IDLE_TIMEOUT); + if (signal_pending(current)) { + struct ksignal ksig; + + if (!get_signal(&ksig)) + continue; + break; + } + if (!ret) { + last_timeout = true; + exit_mask = !cpumask_test_cpu(raw_smp_processor_id(), + wq->cpu_mask); + } + } + + if (test_bit(IO_WQ_BIT_EXIT, &wq->state) && io_acct_run_queue(acct)) + io_worker_handle_work(acct, worker); + + io_worker_exit(worker); + return 0; +} + +/* + * Called when a worker is scheduled in. Mark us as currently running. + */ +void io_wq_worker_running(struct task_struct *tsk) +{ + struct io_worker *worker = tsk->worker_private; + + if (!worker) + return; + if (!test_bit(IO_WORKER_F_UP, &worker->flags)) + return; + if (test_bit(IO_WORKER_F_RUNNING, &worker->flags)) + return; + set_bit(IO_WORKER_F_RUNNING, &worker->flags); + io_wq_inc_running(worker); +} + +/* + * Called when worker is going to sleep. If there are no workers currently + * running and we have work pending, wake up a free one or create a new one. + */ +void io_wq_worker_sleeping(struct task_struct *tsk) +{ + struct io_worker *worker = tsk->worker_private; + + if (!worker) + return; + if (!test_bit(IO_WORKER_F_UP, &worker->flags)) + return; + if (!test_bit(IO_WORKER_F_RUNNING, &worker->flags)) + return; + + clear_bit(IO_WORKER_F_RUNNING, &worker->flags); + io_wq_dec_running(worker); +} + +static void io_init_new_worker(struct io_wq *wq, struct io_wq_acct *acct, struct io_worker *worker, + struct task_struct *tsk) +{ + tsk->worker_private = worker; + worker->task = tsk; + set_cpus_allowed_ptr(tsk, wq->cpu_mask); + + raw_spin_lock(&acct->workers_lock); + hlist_nulls_add_head_rcu(&worker->nulls_node, &acct->free_list); + list_add_tail_rcu(&worker->all_list, &acct->all_list); + set_bit(IO_WORKER_F_FREE, &worker->flags); + raw_spin_unlock(&acct->workers_lock); + wake_up_new_task(tsk); +} + +static bool io_wq_work_match_all(struct io_wq_work *work, void *data) +{ + return true; +} + +static inline bool io_should_retry_thread(struct io_worker *worker, long err) +{ + /* + * Prevent perpetual task_work retry, if the task (or its group) is + * exiting. + */ + if (fatal_signal_pending(current)) + return false; + + worker->init_retries++; + switch (err) { + case -EAGAIN: + return worker->init_retries <= WORKER_INIT_LIMIT; + /* Analogous to a fork() syscall, always retry on a restartable error */ + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + return true; + default: + return false; + } +} + +static void queue_create_worker_retry(struct io_worker *worker) +{ + /* + * We only bother retrying because there's a chance that the + * failure to create a worker is due to some temporary condition + * in the forking task (e.g. outstanding signal); give the task + * some time to clear that condition. + */ + schedule_delayed_work(&worker->work, + msecs_to_jiffies(worker->init_retries * 5)); +} + +static void create_worker_cont(struct callback_head *cb) +{ + struct io_worker *worker; + struct task_struct *tsk; + struct io_wq *wq; + struct io_wq_acct *acct; + + worker = container_of(cb, struct io_worker, create_work); + clear_bit_unlock(0, &worker->create_state); + wq = worker->wq; + acct = io_wq_get_acct(worker); + tsk = create_io_thread(io_wq_worker, worker, NUMA_NO_NODE); + if (!IS_ERR(tsk)) { + io_init_new_worker(wq, acct, worker, tsk); + io_worker_release(worker); + return; + } else if (!io_should_retry_thread(worker, PTR_ERR(tsk))) { + atomic_dec(&acct->nr_running); + raw_spin_lock(&acct->workers_lock); + acct->nr_workers--; + if (!acct->nr_workers) { + struct io_cb_cancel_data match = { + .fn = io_wq_work_match_all, + .cancel_all = true, + }; + + raw_spin_unlock(&acct->workers_lock); + while (io_acct_cancel_pending_work(wq, acct, &match)) + ; + } else { + raw_spin_unlock(&acct->workers_lock); + } + io_worker_ref_put(wq); + kfree(worker); + return; + } + + /* re-create attempts grab a new worker ref, drop the existing one */ + io_worker_release(worker); + queue_create_worker_retry(worker); +} + +static void io_workqueue_create(struct work_struct *work) +{ + struct io_worker *worker = container_of(work, struct io_worker, + work.work); + struct io_wq_acct *acct = io_wq_get_acct(worker); + + if (!io_queue_worker_create(worker, acct, create_worker_cont)) + kfree(worker); +} + +static bool create_io_worker(struct io_wq *wq, struct io_wq_acct *acct) +{ + struct io_worker *worker; + struct task_struct *tsk; + + __set_current_state(TASK_RUNNING); + + worker = kzalloc(sizeof(*worker), GFP_KERNEL); + if (!worker) { +fail: + atomic_dec(&acct->nr_running); + raw_spin_lock(&acct->workers_lock); + acct->nr_workers--; + raw_spin_unlock(&acct->workers_lock); + io_worker_ref_put(wq); + return false; + } + + refcount_set(&worker->ref, 1); + worker->wq = wq; + worker->acct = acct; + raw_spin_lock_init(&worker->lock); + init_completion(&worker->ref_done); + + tsk = create_io_thread(io_wq_worker, worker, NUMA_NO_NODE); + if (!IS_ERR(tsk)) { + io_init_new_worker(wq, acct, worker, tsk); + } else if (!io_should_retry_thread(worker, PTR_ERR(tsk))) { + kfree(worker); + goto fail; + } else { + INIT_DELAYED_WORK(&worker->work, io_workqueue_create); + queue_create_worker_retry(worker); + } + + return true; +} + +/* + * Iterate the passed in list and call the specific function for each + * worker that isn't exiting + */ +static bool io_acct_for_each_worker(struct io_wq_acct *acct, + bool (*func)(struct io_worker *, void *), + void *data) +{ + struct io_worker *worker; + bool ret = false; + + list_for_each_entry_rcu(worker, &acct->all_list, all_list) { + if (io_worker_get(worker)) { + /* no task if node is/was offline */ + if (worker->task) + ret = func(worker, data); + io_worker_release(worker); + if (ret) + break; + } + } + + return ret; +} + +static bool io_wq_for_each_worker(struct io_wq *wq, + bool (*func)(struct io_worker *, void *), + void *data) +{ + for (int i = 0; i < IO_WQ_ACCT_NR; i++) { + if (!io_acct_for_each_worker(&wq->acct[i], func, data)) + return false; + } + + return true; +} + +static bool io_wq_worker_wake(struct io_worker *worker, void *data) +{ + __set_notify_signal(worker->task); + wake_up_process(worker->task); + return false; +} + +static void io_run_cancel(struct io_wq_work *work, struct io_wq *wq) +{ + do { + atomic_or(IO_WQ_WORK_CANCEL, &work->flags); + io_wq_submit_work(work); + work = io_wq_free_work(work); + } while (work); +} + +static void io_wq_insert_work(struct io_wq *wq, struct io_wq_acct *acct, + struct io_wq_work *work, unsigned int work_flags) +{ + unsigned int hash; + struct io_wq_work *tail; + + if (!__io_wq_is_hashed(work_flags)) { +append: + wq_list_add_tail(&work->list, &acct->work_list); + return; + } + + hash = __io_get_work_hash(work_flags); + tail = wq->hash_tail[hash]; + wq->hash_tail[hash] = work; + if (!tail) + goto append; + + wq_list_add_after(&work->list, &tail->list, &acct->work_list); +} + +static bool io_wq_work_match_item(struct io_wq_work *work, void *data) +{ + return work == data; +} + +void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work) +{ + unsigned int work_flags = atomic_read(&work->flags); + struct io_wq_acct *acct = io_work_get_acct(wq, work_flags); + struct io_cb_cancel_data match = { + .fn = io_wq_work_match_item, + .data = work, + .cancel_all = false, + }; + bool do_create; + + /* + * If io-wq is exiting for this task, or if the request has explicitly + * been marked as one that should not get executed, cancel it here. + */ + if (test_bit(IO_WQ_BIT_EXIT, &wq->state) || + (work_flags & IO_WQ_WORK_CANCEL)) { + io_run_cancel(work, wq); + return; + } + + raw_spin_lock(&acct->lock); + io_wq_insert_work(wq, acct, work, work_flags); + clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + raw_spin_unlock(&acct->lock); + + rcu_read_lock(); + do_create = !io_acct_activate_free_worker(acct); + rcu_read_unlock(); + + if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running))) { + bool did_create; + + did_create = io_wq_create_worker(wq, acct); + if (likely(did_create)) + return; + + raw_spin_lock(&acct->workers_lock); + if (acct->nr_workers) { + raw_spin_unlock(&acct->workers_lock); + return; + } + raw_spin_unlock(&acct->workers_lock); + + /* fatal condition, failed to create the first worker */ + io_acct_cancel_pending_work(wq, acct, &match); + } +} + +/* + * Work items that hash to the same value will not be done in parallel. + * Used to limit concurrent writes, generally hashed by inode. + */ +void io_wq_hash_work(struct io_wq_work *work, void *val) +{ + unsigned int bit; + + bit = hash_ptr(val, IO_WQ_HASH_ORDER); + atomic_or(IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT), &work->flags); +} + +static bool __io_wq_worker_cancel(struct io_worker *worker, + struct io_cb_cancel_data *match, + struct io_wq_work *work) +{ + if (work && match->fn(work, match->data)) { + atomic_or(IO_WQ_WORK_CANCEL, &work->flags); + __set_notify_signal(worker->task); + return true; + } + + return false; +} + +static bool io_wq_worker_cancel(struct io_worker *worker, void *data) +{ + struct io_cb_cancel_data *match = data; + + /* + * Hold the lock to avoid ->cur_work going out of scope, caller + * may dereference the passed in work. + */ + raw_spin_lock(&worker->lock); + if (__io_wq_worker_cancel(worker, match, worker->cur_work)) + match->nr_running++; + raw_spin_unlock(&worker->lock); + + return match->nr_running && !match->cancel_all; +} + +static inline void io_wq_remove_pending(struct io_wq *wq, + struct io_wq_acct *acct, + struct io_wq_work *work, + struct io_wq_work_node *prev) +{ + unsigned int hash = io_get_work_hash(work); + struct io_wq_work *prev_work = NULL; + + if (io_wq_is_hashed(work) && work == wq->hash_tail[hash]) { + if (prev) + prev_work = container_of(prev, struct io_wq_work, list); + if (prev_work && io_get_work_hash(prev_work) == hash) + wq->hash_tail[hash] = prev_work; + else + wq->hash_tail[hash] = NULL; + } + wq_list_del(&acct->work_list, &work->list, prev); +} + +static bool io_acct_cancel_pending_work(struct io_wq *wq, + struct io_wq_acct *acct, + struct io_cb_cancel_data *match) +{ + struct io_wq_work_node *node, *prev; + struct io_wq_work *work; + + raw_spin_lock(&acct->lock); + wq_list_for_each(node, prev, &acct->work_list) { + work = container_of(node, struct io_wq_work, list); + if (!match->fn(work, match->data)) + continue; + io_wq_remove_pending(wq, acct, work, prev); + raw_spin_unlock(&acct->lock); + io_run_cancel(work, wq); + match->nr_pending++; + /* not safe to continue after unlock */ + return true; + } + raw_spin_unlock(&acct->lock); + + return false; +} + +static void io_wq_cancel_pending_work(struct io_wq *wq, + struct io_cb_cancel_data *match) +{ + int i; +retry: + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + struct io_wq_acct *acct = io_get_acct(wq, i == 0); + + if (io_acct_cancel_pending_work(wq, acct, match)) { + if (match->cancel_all) + goto retry; + break; + } + } +} + +static void io_acct_cancel_running_work(struct io_wq_acct *acct, + struct io_cb_cancel_data *match) +{ + raw_spin_lock(&acct->workers_lock); + io_acct_for_each_worker(acct, io_wq_worker_cancel, match); + raw_spin_unlock(&acct->workers_lock); +} + +static void io_wq_cancel_running_work(struct io_wq *wq, + struct io_cb_cancel_data *match) +{ + rcu_read_lock(); + + for (int i = 0; i < IO_WQ_ACCT_NR; i++) + io_acct_cancel_running_work(&wq->acct[i], match); + + rcu_read_unlock(); +} + +enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, + void *data, bool cancel_all) +{ + struct io_cb_cancel_data match = { + .fn = cancel, + .data = data, + .cancel_all = cancel_all, + }; + + /* + * First check pending list, if we're lucky we can just remove it + * from there. CANCEL_OK means that the work is returned as-new, + * no completion will be posted for it. + * + * Then check if a free (going busy) or busy worker has the work + * currently running. If we find it there, we'll return CANCEL_RUNNING + * as an indication that we attempt to signal cancellation. The + * completion will run normally in this case. + * + * Do both of these while holding the acct->workers_lock, to ensure that + * we'll find a work item regardless of state. + */ + io_wq_cancel_pending_work(wq, &match); + if (match.nr_pending && !match.cancel_all) + return IO_WQ_CANCEL_OK; + + io_wq_cancel_running_work(wq, &match); + if (match.nr_running && !match.cancel_all) + return IO_WQ_CANCEL_RUNNING; + + if (match.nr_running) + return IO_WQ_CANCEL_RUNNING; + if (match.nr_pending) + return IO_WQ_CANCEL_OK; + return IO_WQ_CANCEL_NOTFOUND; +} + +static int io_wq_hash_wake(struct wait_queue_entry *wait, unsigned mode, + int sync, void *key) +{ + struct io_wq *wq = container_of(wait, struct io_wq, wait); + int i; + + list_del_init(&wait->entry); + + rcu_read_lock(); + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + struct io_wq_acct *acct = &wq->acct[i]; + + if (test_and_clear_bit(IO_ACCT_STALLED_BIT, &acct->flags)) + io_acct_activate_free_worker(acct); + } + rcu_read_unlock(); + return 1; +} + +struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) +{ + int ret, i; + struct io_wq *wq; + + if (WARN_ON_ONCE(!bounded)) + return ERR_PTR(-EINVAL); + + wq = kzalloc(sizeof(struct io_wq), GFP_KERNEL); + if (!wq) + return ERR_PTR(-ENOMEM); + + refcount_inc(&data->hash->refs); + wq->hash = data->hash; + + ret = -ENOMEM; + + if (!alloc_cpumask_var(&wq->cpu_mask, GFP_KERNEL)) + goto err; + cpuset_cpus_allowed(data->task, wq->cpu_mask); + wq->acct[IO_WQ_ACCT_BOUND].max_workers = bounded; + wq->acct[IO_WQ_ACCT_UNBOUND].max_workers = + task_rlimit(current, RLIMIT_NPROC); + INIT_LIST_HEAD(&wq->wait.entry); + wq->wait.func = io_wq_hash_wake; + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + struct io_wq_acct *acct = &wq->acct[i]; + + atomic_set(&acct->nr_running, 0); + + raw_spin_lock_init(&acct->workers_lock); + INIT_HLIST_NULLS_HEAD(&acct->free_list, 0); + INIT_LIST_HEAD(&acct->all_list); + + INIT_WQ_LIST(&acct->work_list); + raw_spin_lock_init(&acct->lock); + } + + wq->task = get_task_struct(data->task); + atomic_set(&wq->worker_refs, 1); + init_completion(&wq->worker_done); + ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node); + if (ret) { + put_task_struct(wq->task); + goto err; + } + + return wq; +err: + io_wq_put_hash(data->hash); + free_cpumask_var(wq->cpu_mask); + kfree(wq); + return ERR_PTR(ret); +} + +static bool io_task_work_match(struct callback_head *cb, void *data) +{ + struct io_worker *worker; + + if (cb->func != create_worker_cb && cb->func != create_worker_cont) + return false; + worker = container_of(cb, struct io_worker, create_work); + return worker->wq == data; +} + +void io_wq_exit_start(struct io_wq *wq) +{ + set_bit(IO_WQ_BIT_EXIT, &wq->state); +} + +static void io_wq_cancel_tw_create(struct io_wq *wq) +{ + struct callback_head *cb; + + while ((cb = task_work_cancel_match(wq->task, io_task_work_match, wq)) != NULL) { + struct io_worker *worker; + + worker = container_of(cb, struct io_worker, create_work); + io_worker_cancel_cb(worker); + /* + * Only the worker continuation helper has worker allocated and + * hence needs freeing. + */ + if (cb->func == create_worker_cont) + kfree(worker); + } +} + +static void io_wq_exit_workers(struct io_wq *wq) +{ + if (!wq->task) + return; + + io_wq_cancel_tw_create(wq); + + rcu_read_lock(); + io_wq_for_each_worker(wq, io_wq_worker_wake, NULL); + rcu_read_unlock(); + io_worker_ref_put(wq); + wait_for_completion(&wq->worker_done); + + spin_lock_irq(&wq->hash->wait.lock); + list_del_init(&wq->wait.entry); + spin_unlock_irq(&wq->hash->wait.lock); + + put_task_struct(wq->task); + wq->task = NULL; +} + +static void io_wq_destroy(struct io_wq *wq) +{ + struct io_cb_cancel_data match = { + .fn = io_wq_work_match_all, + .cancel_all = true, + }; + + cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node); + io_wq_cancel_pending_work(wq, &match); + free_cpumask_var(wq->cpu_mask); + io_wq_put_hash(wq->hash); + kfree(wq); +} + +void io_wq_put_and_exit(struct io_wq *wq) +{ + WARN_ON_ONCE(!test_bit(IO_WQ_BIT_EXIT, &wq->state)); + + io_wq_exit_workers(wq); + io_wq_destroy(wq); +} + +struct online_data { + unsigned int cpu; + bool online; +}; + +static bool io_wq_worker_affinity(struct io_worker *worker, void *data) +{ + struct online_data *od = data; + + if (od->online) + cpumask_set_cpu(od->cpu, worker->wq->cpu_mask); + else + cpumask_clear_cpu(od->cpu, worker->wq->cpu_mask); + return false; +} + +static int __io_wq_cpu_online(struct io_wq *wq, unsigned int cpu, bool online) +{ + struct online_data od = { + .cpu = cpu, + .online = online + }; + + rcu_read_lock(); + io_wq_for_each_worker(wq, io_wq_worker_affinity, &od); + rcu_read_unlock(); + return 0; +} + +static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node) +{ + struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node); + + return __io_wq_cpu_online(wq, cpu, true); +} + +static int io_wq_cpu_offline(unsigned int cpu, struct hlist_node *node) +{ + struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node); + + return __io_wq_cpu_online(wq, cpu, false); +} + +int io_wq_cpu_affinity(struct io_uring_task *tctx, cpumask_var_t mask) +{ + cpumask_var_t allowed_mask; + int ret = 0; + + if (!tctx || !tctx->io_wq) + return -EINVAL; + + if (!alloc_cpumask_var(&allowed_mask, GFP_KERNEL)) + return -ENOMEM; + + rcu_read_lock(); + cpuset_cpus_allowed(tctx->io_wq->task, allowed_mask); + if (mask) { + if (cpumask_subset(mask, allowed_mask)) + cpumask_copy(tctx->io_wq->cpu_mask, mask); + else + ret = -EINVAL; + } else { + cpumask_copy(tctx->io_wq->cpu_mask, allowed_mask); + } + rcu_read_unlock(); + + free_cpumask_var(allowed_mask); + return ret; +} + +/* + * Set max number of unbounded workers, returns old value. If new_count is 0, + * then just return the old value. + */ +int io_wq_max_workers(struct io_wq *wq, int *new_count) +{ + struct io_wq_acct *acct; + int prev[IO_WQ_ACCT_NR]; + int i; + + BUILD_BUG_ON((int) IO_WQ_ACCT_BOUND != (int) IO_WQ_BOUND); + BUILD_BUG_ON((int) IO_WQ_ACCT_UNBOUND != (int) IO_WQ_UNBOUND); + BUILD_BUG_ON((int) IO_WQ_ACCT_NR != 2); + + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + if (new_count[i] > task_rlimit(current, RLIMIT_NPROC)) + new_count[i] = task_rlimit(current, RLIMIT_NPROC); + } + + for (i = 0; i < IO_WQ_ACCT_NR; i++) + prev[i] = 0; + + rcu_read_lock(); + + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + acct = &wq->acct[i]; + raw_spin_lock(&acct->workers_lock); + prev[i] = max_t(int, acct->max_workers, prev[i]); + if (new_count[i]) + acct->max_workers = new_count[i]; + raw_spin_unlock(&acct->workers_lock); + } + rcu_read_unlock(); + + for (i = 0; i < IO_WQ_ACCT_NR; i++) + new_count[i] = prev[i]; + + return 0; +} + +static __init int io_wq_init(void) +{ + int ret; + + ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online", + io_wq_cpu_online, io_wq_cpu_offline); + if (ret < 0) + return ret; + io_wq_online = ret; + return 0; +} +subsys_initcall(io_wq_init); diff --git a/io_uring/io-wq.h b/io_uring/io-wq.h new file mode 100644 index 000000000000..774abab54732 --- /dev/null +++ b/io_uring/io-wq.h @@ -0,0 +1,84 @@ +#ifndef INTERNAL_IO_WQ_H +#define INTERNAL_IO_WQ_H + +#include <linux/refcount.h> +#include <linux/io_uring_types.h> + +struct io_wq; + +enum { + IO_WQ_WORK_CANCEL = 1, + IO_WQ_WORK_HASHED = 2, + IO_WQ_WORK_UNBOUND = 4, + IO_WQ_WORK_CONCURRENT = 16, + + IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */ +}; + +enum io_wq_cancel { + IO_WQ_CANCEL_OK, /* cancelled before started */ + IO_WQ_CANCEL_RUNNING, /* found, running, and attempted cancelled */ + IO_WQ_CANCEL_NOTFOUND, /* work not found */ +}; + +struct io_wq_hash { + refcount_t refs; + unsigned long map; + struct wait_queue_head wait; +}; + +static inline void io_wq_put_hash(struct io_wq_hash *hash) +{ + if (refcount_dec_and_test(&hash->refs)) + kfree(hash); +} + +struct io_wq_data { + struct io_wq_hash *hash; + struct task_struct *task; +}; + +struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data); +void io_wq_exit_start(struct io_wq *wq); +void io_wq_put_and_exit(struct io_wq *wq); + +void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work); +void io_wq_hash_work(struct io_wq_work *work, void *val); + +int io_wq_cpu_affinity(struct io_uring_task *tctx, cpumask_var_t mask); +int io_wq_max_workers(struct io_wq *wq, int *new_count); +bool io_wq_worker_stopped(void); + +static inline bool __io_wq_is_hashed(unsigned int work_flags) +{ + return work_flags & IO_WQ_WORK_HASHED; +} + +static inline bool io_wq_is_hashed(struct io_wq_work *work) +{ + return __io_wq_is_hashed(atomic_read(&work->flags)); +} + +typedef bool (work_cancel_fn)(struct io_wq_work *, void *); + +enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, + void *data, bool cancel_all); + +#if defined(CONFIG_IO_WQ) +extern void io_wq_worker_sleeping(struct task_struct *); +extern void io_wq_worker_running(struct task_struct *); +#else +static inline void io_wq_worker_sleeping(struct task_struct *tsk) +{ +} +static inline void io_wq_worker_running(struct task_struct *tsk) +{ +} +#endif + +static inline bool io_wq_current_is_worker(void) +{ + return in_task() && (current->flags & PF_IO_WORKER) && + current->worker_private; +} +#endif diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c new file mode 100644 index 000000000000..5d130c578435 --- /dev/null +++ b/io_uring/io_uring.c @@ -0,0 +1,3865 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Shared application/kernel submission and completion ring pairs, for + * supporting fast/efficient IO. + * + * A note on the read/write ordering memory barriers that are matched between + * the application and kernel side. + * + * After the application reads the CQ ring tail, it must use an + * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses + * before writing the tail (using smp_load_acquire to read the tail will + * do). It also needs a smp_mb() before updating CQ head (ordering the + * entry load(s) with the head store), pairing with an implicit barrier + * through a control-dependency in io_get_cqe (smp_store_release to + * store head will do). Failure to do so could lead to reading invalid + * CQ entries. + * + * Likewise, the application must use an appropriate smp_wmb() before + * writing the SQ tail (ordering SQ entry stores with the tail store), + * which pairs with smp_load_acquire in io_get_sqring (smp_store_release + * to store the tail will do). And it needs a barrier ordering the SQ + * head load before writing new SQ entries (smp_load_acquire to read + * head will do). + * + * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application + * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after* + * updating the SQ tail; a full memory barrier smp_mb() is needed + * between. + * + * Also see the examples in the liburing library: + * + * git://git.kernel.org/pub/scm/linux/kernel/git/axboe/liburing.git + * + * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens + * from data shared between the kernel and application. This is done both + * for ordering purposes, but also to ensure that once a value is loaded from + * data that the application could potentially modify, it remains stable. + * + * Copyright (C) 2018-2019 Jens Axboe + * Copyright (c) 2018-2019 Christoph Hellwig + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/syscalls.h> +#include <net/compat.h> +#include <linux/refcount.h> +#include <linux/uio.h> +#include <linux/bits.h> + +#include <linux/sched/signal.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/percpu.h> +#include <linux/slab.h> +#include <linux/bvec.h> +#include <linux/net.h> +#include <net/sock.h> +#include <linux/anon_inodes.h> +#include <linux/sched/mm.h> +#include <linux/uaccess.h> +#include <linux/nospec.h> +#include <linux/fsnotify.h> +#include <linux/fadvise.h> +#include <linux/task_work.h> +#include <linux/io_uring.h> +#include <linux/io_uring/cmd.h> +#include <linux/audit.h> +#include <linux/security.h> +#include <linux/jump_label.h> +#include <asm/shmparam.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io-wq.h" + +#include "filetable.h" +#include "io_uring.h" +#include "opdef.h" +#include "refs.h" +#include "tctx.h" +#include "register.h" +#include "sqpoll.h" +#include "fdinfo.h" +#include "kbuf.h" +#include "rsrc.h" +#include "cancel.h" +#include "net.h" +#include "notif.h" +#include "waitid.h" +#include "futex.h" +#include "napi.h" +#include "uring_cmd.h" +#include "msg_ring.h" +#include "memmap.h" +#include "zcrx.h" + +#include "timeout.h" +#include "poll.h" +#include "rw.h" +#include "alloc_cache.h" +#include "eventfd.h" + +#define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \ + IOSQE_IO_HARDLINK | IOSQE_ASYNC) + +#define IO_REQ_LINK_FLAGS (REQ_F_LINK | REQ_F_HARDLINK) + +#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \ + REQ_F_INFLIGHT | REQ_F_CREDS | REQ_F_ASYNC_DATA) + +#define IO_REQ_CLEAN_SLOW_FLAGS (REQ_F_REFCOUNT | IO_REQ_LINK_FLAGS | \ + REQ_F_REISSUE | REQ_F_POLLED | \ + IO_REQ_CLEAN_FLAGS) + +#define IO_TCTX_REFS_CACHE_NR (1U << 10) + +#define IO_COMPL_BATCH 32 +#define IO_REQ_ALLOC_BATCH 8 +#define IO_LOCAL_TW_DEFAULT_MAX 20 + +/* requests with any of those set should undergo io_disarm_next() */ +#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL) + +/* + * No waiters. It's larger than any valid value of the tw counter + * so that tests against ->cq_wait_nr would fail and skip wake_up(). + */ +#define IO_CQ_WAKE_INIT (-1U) +/* Forced wake up if there is a waiter regardless of ->cq_wait_nr */ +#define IO_CQ_WAKE_FORCE (IO_CQ_WAKE_INIT >> 1) + +static void io_queue_sqe(struct io_kiocb *req, unsigned int extra_flags); +static void __io_req_caches_free(struct io_ring_ctx *ctx); + +static __read_mostly DEFINE_STATIC_KEY_FALSE(io_key_has_sqarray); + +struct kmem_cache *req_cachep; +static struct workqueue_struct *iou_wq __ro_after_init; + +static int __read_mostly sysctl_io_uring_disabled; +static int __read_mostly sysctl_io_uring_group = -1; + +#ifdef CONFIG_SYSCTL +static const struct ctl_table kernel_io_uring_disabled_table[] = { + { + .procname = "io_uring_disabled", + .data = &sysctl_io_uring_disabled, + .maxlen = sizeof(sysctl_io_uring_disabled), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_TWO, + }, + { + .procname = "io_uring_group", + .data = &sysctl_io_uring_group, + .maxlen = sizeof(gid_t), + .mode = 0644, + .proc_handler = proc_dointvec, + }, +}; +#endif + +static void io_poison_cached_req(struct io_kiocb *req) +{ + req->ctx = IO_URING_PTR_POISON; + req->tctx = IO_URING_PTR_POISON; + req->file = IO_URING_PTR_POISON; + req->creds = IO_URING_PTR_POISON; + req->io_task_work.func = IO_URING_PTR_POISON; + req->apoll = IO_URING_PTR_POISON; +} + +static void io_poison_req(struct io_kiocb *req) +{ + io_poison_cached_req(req); + req->async_data = IO_URING_PTR_POISON; + req->kbuf = IO_URING_PTR_POISON; + req->comp_list.next = IO_URING_PTR_POISON; + req->file_node = IO_URING_PTR_POISON; + req->link = IO_URING_PTR_POISON; +} + +static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) +{ + return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head); +} + +static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx) +{ + return READ_ONCE(ctx->rings->cq.tail) - READ_ONCE(ctx->rings->cq.head); +} + +static inline void req_fail_link_node(struct io_kiocb *req, int res) +{ + req_set_fail(req); + io_req_set_res(req, res, 0); +} + +static inline void io_req_add_to_cache(struct io_kiocb *req, struct io_ring_ctx *ctx) +{ + if (IS_ENABLED(CONFIG_KASAN)) + io_poison_cached_req(req); + wq_stack_add_head(&req->comp_list, &ctx->submit_state.free_list); +} + +static __cold void io_ring_ctx_ref_free(struct percpu_ref *ref) +{ + struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); + + complete(&ctx->ref_comp); +} + +/* + * Terminate the request if either of these conditions are true: + * + * 1) It's being executed by the original task, but that task is marked + * with PF_EXITING as it's exiting. + * 2) PF_KTHREAD is set, in which case the invoker of the task_work is + * our fallback task_work. + * 3) The ring has been closed and is going away. + */ +static inline bool io_should_terminate_tw(struct io_ring_ctx *ctx) +{ + return (current->flags & (PF_EXITING | PF_KTHREAD)) || percpu_ref_is_dying(&ctx->refs); +} + +static __cold void io_fallback_req_func(struct work_struct *work) +{ + struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, + fallback_work.work); + struct llist_node *node = llist_del_all(&ctx->fallback_llist); + struct io_kiocb *req, *tmp; + struct io_tw_state ts = {}; + + percpu_ref_get(&ctx->refs); + mutex_lock(&ctx->uring_lock); + ts.cancel = io_should_terminate_tw(ctx); + llist_for_each_entry_safe(req, tmp, node, io_task_work.node) + req->io_task_work.func((struct io_tw_req){req}, ts); + io_submit_flush_completions(ctx); + mutex_unlock(&ctx->uring_lock); + percpu_ref_put(&ctx->refs); +} + +static int io_alloc_hash_table(struct io_hash_table *table, unsigned bits) +{ + unsigned int hash_buckets; + int i; + + do { + hash_buckets = 1U << bits; + table->hbs = kvmalloc_array(hash_buckets, sizeof(table->hbs[0]), + GFP_KERNEL_ACCOUNT); + if (table->hbs) + break; + if (bits == 1) + return -ENOMEM; + bits--; + } while (1); + + table->hash_bits = bits; + for (i = 0; i < hash_buckets; i++) + INIT_HLIST_HEAD(&table->hbs[i].list); + return 0; +} + +static void io_free_alloc_caches(struct io_ring_ctx *ctx) +{ + io_alloc_cache_free(&ctx->apoll_cache, kfree); + io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free); + io_alloc_cache_free(&ctx->rw_cache, io_rw_cache_free); + io_alloc_cache_free(&ctx->cmd_cache, io_cmd_cache_free); + io_futex_cache_free(ctx); + io_rsrc_cache_free(ctx); +} + +static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) +{ + struct io_ring_ctx *ctx; + int hash_bits; + bool ret; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return NULL; + + xa_init(&ctx->io_bl_xa); + + /* + * Use 5 bits less than the max cq entries, that should give us around + * 32 entries per hash list if totally full and uniformly spread, but + * don't keep too many buckets to not overconsume memory. + */ + hash_bits = ilog2(p->cq_entries) - 5; + hash_bits = clamp(hash_bits, 1, 8); + if (io_alloc_hash_table(&ctx->cancel_table, hash_bits)) + goto err; + if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, + 0, GFP_KERNEL)) + goto err; + + ctx->flags = p->flags; + ctx->hybrid_poll_time = LLONG_MAX; + atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT); + init_waitqueue_head(&ctx->sqo_sq_wait); + INIT_LIST_HEAD(&ctx->sqd_list); + INIT_LIST_HEAD(&ctx->cq_overflow_list); + ret = io_alloc_cache_init(&ctx->apoll_cache, IO_POLL_ALLOC_CACHE_MAX, + sizeof(struct async_poll), 0); + ret |= io_alloc_cache_init(&ctx->netmsg_cache, IO_ALLOC_CACHE_MAX, + sizeof(struct io_async_msghdr), + offsetof(struct io_async_msghdr, clear)); + ret |= io_alloc_cache_init(&ctx->rw_cache, IO_ALLOC_CACHE_MAX, + sizeof(struct io_async_rw), + offsetof(struct io_async_rw, clear)); + ret |= io_alloc_cache_init(&ctx->cmd_cache, IO_ALLOC_CACHE_MAX, + sizeof(struct io_async_cmd), + sizeof(struct io_async_cmd)); + ret |= io_futex_cache_init(ctx); + ret |= io_rsrc_cache_init(ctx); + if (ret) + goto free_ref; + init_completion(&ctx->ref_comp); + xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1); + mutex_init(&ctx->uring_lock); + init_waitqueue_head(&ctx->cq_wait); + init_waitqueue_head(&ctx->poll_wq); + spin_lock_init(&ctx->completion_lock); + raw_spin_lock_init(&ctx->timeout_lock); + INIT_WQ_LIST(&ctx->iopoll_list); + INIT_LIST_HEAD(&ctx->defer_list); + INIT_LIST_HEAD(&ctx->timeout_list); + INIT_LIST_HEAD(&ctx->ltimeout_list); + init_llist_head(&ctx->work_llist); + INIT_LIST_HEAD(&ctx->tctx_list); + ctx->submit_state.free_list.next = NULL; + INIT_HLIST_HEAD(&ctx->waitid_list); + xa_init_flags(&ctx->zcrx_ctxs, XA_FLAGS_ALLOC); +#ifdef CONFIG_FUTEX + INIT_HLIST_HEAD(&ctx->futex_list); +#endif + INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func); + INIT_WQ_LIST(&ctx->submit_state.compl_reqs); + INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd); + io_napi_init(ctx); + mutex_init(&ctx->mmap_lock); + + return ctx; + +free_ref: + percpu_ref_exit(&ctx->refs); +err: + io_free_alloc_caches(ctx); + kvfree(ctx->cancel_table.hbs); + xa_destroy(&ctx->io_bl_xa); + kfree(ctx); + return NULL; +} + +static void io_clean_op(struct io_kiocb *req) +{ + if (unlikely(req->flags & REQ_F_BUFFER_SELECTED)) + io_kbuf_drop_legacy(req); + + if (req->flags & REQ_F_NEED_CLEANUP) { + const struct io_cold_def *def = &io_cold_defs[req->opcode]; + + if (def->cleanup) + def->cleanup(req); + } + if (req->flags & REQ_F_INFLIGHT) + atomic_dec(&req->tctx->inflight_tracked); + if (req->flags & REQ_F_CREDS) + put_cred(req->creds); + if (req->flags & REQ_F_ASYNC_DATA) { + kfree(req->async_data); + req->async_data = NULL; + } + req->flags &= ~IO_REQ_CLEAN_FLAGS; +} + +/* + * Mark the request as inflight, so that file cancelation will find it. + * Can be used if the file is an io_uring instance, or if the request itself + * relies on ->mm being alive for the duration of the request. + */ +inline void io_req_track_inflight(struct io_kiocb *req) +{ + if (!(req->flags & REQ_F_INFLIGHT)) { + req->flags |= REQ_F_INFLIGHT; + atomic_inc(&req->tctx->inflight_tracked); + } +} + +static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req) +{ + if (WARN_ON_ONCE(!req->link)) + return NULL; + + req->flags &= ~REQ_F_ARM_LTIMEOUT; + req->flags |= REQ_F_LINK_TIMEOUT; + + /* linked timeouts should have two refs once prep'ed */ + io_req_set_refcount(req); + __io_req_set_refcount(req->link, 2); + return req->link; +} + +static void io_prep_async_work(struct io_kiocb *req) +{ + const struct io_issue_def *def = &io_issue_defs[req->opcode]; + struct io_ring_ctx *ctx = req->ctx; + + if (!(req->flags & REQ_F_CREDS)) { + req->flags |= REQ_F_CREDS; + req->creds = get_current_cred(); + } + + req->work.list.next = NULL; + atomic_set(&req->work.flags, 0); + if (req->flags & REQ_F_FORCE_ASYNC) + atomic_or(IO_WQ_WORK_CONCURRENT, &req->work.flags); + + if (req->file && !(req->flags & REQ_F_FIXED_FILE)) + req->flags |= io_file_get_flags(req->file); + + if (req->file && (req->flags & REQ_F_ISREG)) { + bool should_hash = def->hash_reg_file; + + /* don't serialize this request if the fs doesn't need it */ + if (should_hash && (req->file->f_flags & O_DIRECT) && + (req->file->f_op->fop_flags & FOP_DIO_PARALLEL_WRITE)) + should_hash = false; + if (should_hash || (ctx->flags & IORING_SETUP_IOPOLL)) + io_wq_hash_work(&req->work, file_inode(req->file)); + } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) { + if (def->unbound_nonreg_file) + atomic_or(IO_WQ_WORK_UNBOUND, &req->work.flags); + } +} + +static void io_prep_async_link(struct io_kiocb *req) +{ + struct io_kiocb *cur; + + if (req->flags & REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = req->ctx; + + raw_spin_lock_irq(&ctx->timeout_lock); + io_for_each_link(cur, req) + io_prep_async_work(cur); + raw_spin_unlock_irq(&ctx->timeout_lock); + } else { + io_for_each_link(cur, req) + io_prep_async_work(cur); + } +} + +static void io_queue_iowq(struct io_kiocb *req) +{ + struct io_uring_task *tctx = req->tctx; + + BUG_ON(!tctx); + + if ((current->flags & PF_KTHREAD) || !tctx->io_wq) { + io_req_task_queue_fail(req, -ECANCELED); + return; + } + + /* init ->work of the whole link before punting */ + io_prep_async_link(req); + + /* + * Not expected to happen, but if we do have a bug where this _can_ + * happen, catch it here and ensure the request is marked as + * canceled. That will make io-wq go through the usual work cancel + * procedure rather than attempt to run this request (or create a new + * worker for it). + */ + if (WARN_ON_ONCE(!same_thread_group(tctx->task, current))) + atomic_or(IO_WQ_WORK_CANCEL, &req->work.flags); + + trace_io_uring_queue_async_work(req, io_wq_is_hashed(&req->work)); + io_wq_enqueue(tctx->io_wq, &req->work); +} + +static void io_req_queue_iowq_tw(struct io_tw_req tw_req, io_tw_token_t tw) +{ + io_queue_iowq(tw_req.req); +} + +void io_req_queue_iowq(struct io_kiocb *req) +{ + req->io_task_work.func = io_req_queue_iowq_tw; + io_req_task_work_add(req); +} + +unsigned io_linked_nr(struct io_kiocb *req) +{ + struct io_kiocb *tmp; + unsigned nr = 0; + + io_for_each_link(tmp, req) + nr++; + return nr; +} + +static __cold noinline void io_queue_deferred(struct io_ring_ctx *ctx) +{ + bool drain_seen = false, first = true; + + lockdep_assert_held(&ctx->uring_lock); + __io_req_caches_free(ctx); + + while (!list_empty(&ctx->defer_list)) { + struct io_defer_entry *de = list_first_entry(&ctx->defer_list, + struct io_defer_entry, list); + + drain_seen |= de->req->flags & REQ_F_IO_DRAIN; + if ((drain_seen || first) && ctx->nr_req_allocated != ctx->nr_drained) + return; + + list_del_init(&de->list); + ctx->nr_drained -= io_linked_nr(de->req); + io_req_task_queue(de->req); + kfree(de); + first = false; + } +} + +void __io_commit_cqring_flush(struct io_ring_ctx *ctx) +{ + if (ctx->poll_activated) + io_poll_wq_wake(ctx); + if (ctx->off_timeout_used) + io_flush_timeouts(ctx); + if (ctx->has_evfd) + io_eventfd_signal(ctx, true); +} + +static inline void __io_cq_lock(struct io_ring_ctx *ctx) +{ + if (!ctx->lockless_cq) + spin_lock(&ctx->completion_lock); +} + +static inline void io_cq_lock(struct io_ring_ctx *ctx) + __acquires(ctx->completion_lock) +{ + spin_lock(&ctx->completion_lock); +} + +static inline void __io_cq_unlock_post(struct io_ring_ctx *ctx) +{ + io_commit_cqring(ctx); + if (!ctx->task_complete) { + if (!ctx->lockless_cq) + spin_unlock(&ctx->completion_lock); + /* IOPOLL rings only need to wake up if it's also SQPOLL */ + if (!ctx->syscall_iopoll) + io_cqring_wake(ctx); + } + io_commit_cqring_flush(ctx); +} + +static void io_cq_unlock_post(struct io_ring_ctx *ctx) + __releases(ctx->completion_lock) +{ + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); + io_cqring_wake(ctx); + io_commit_cqring_flush(ctx); +} + +static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool dying) +{ + lockdep_assert_held(&ctx->uring_lock); + + /* don't abort if we're dying, entries must get freed */ + if (!dying && __io_cqring_events(ctx) == ctx->cq_entries) + return; + + io_cq_lock(ctx); + while (!list_empty(&ctx->cq_overflow_list)) { + size_t cqe_size = sizeof(struct io_uring_cqe); + struct io_uring_cqe *cqe; + struct io_overflow_cqe *ocqe; + bool is_cqe32 = false; + + ocqe = list_first_entry(&ctx->cq_overflow_list, + struct io_overflow_cqe, list); + if (ocqe->cqe.flags & IORING_CQE_F_32 || + ctx->flags & IORING_SETUP_CQE32) { + is_cqe32 = true; + cqe_size <<= 1; + } + if (ctx->flags & IORING_SETUP_CQE32) + is_cqe32 = false; + + if (!dying) { + if (!io_get_cqe_overflow(ctx, &cqe, true, is_cqe32)) + break; + memcpy(cqe, &ocqe->cqe, cqe_size); + } + list_del(&ocqe->list); + kfree(ocqe); + + /* + * For silly syzbot cases that deliberately overflow by huge + * amounts, check if we need to resched and drop and + * reacquire the locks if so. Nothing real would ever hit this. + * Ideally we'd have a non-posting unlock for this, but hard + * to care for a non-real case. + */ + if (need_resched()) { + ctx->cqe_sentinel = ctx->cqe_cached; + io_cq_unlock_post(ctx); + mutex_unlock(&ctx->uring_lock); + cond_resched(); + mutex_lock(&ctx->uring_lock); + io_cq_lock(ctx); + } + } + + if (list_empty(&ctx->cq_overflow_list)) { + clear_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq); + atomic_andnot(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags); + } + io_cq_unlock_post(ctx); +} + +static void io_cqring_overflow_kill(struct io_ring_ctx *ctx) +{ + if (ctx->rings) + __io_cqring_overflow_flush(ctx, true); +} + +static void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx) +{ + mutex_lock(&ctx->uring_lock); + __io_cqring_overflow_flush(ctx, false); + mutex_unlock(&ctx->uring_lock); +} + +/* must to be called somewhat shortly after putting a request */ +static inline void io_put_task(struct io_kiocb *req) +{ + struct io_uring_task *tctx = req->tctx; + + if (likely(tctx->task == current)) { + tctx->cached_refs++; + } else { + percpu_counter_sub(&tctx->inflight, 1); + if (unlikely(atomic_read(&tctx->in_cancel))) + wake_up(&tctx->wait); + put_task_struct(tctx->task); + } +} + +void io_task_refs_refill(struct io_uring_task *tctx) +{ + unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR; + + percpu_counter_add(&tctx->inflight, refill); + refcount_add(refill, ¤t->usage); + tctx->cached_refs += refill; +} + +__cold void io_uring_drop_tctx_refs(struct task_struct *task) +{ + struct io_uring_task *tctx = task->io_uring; + unsigned int refs = tctx->cached_refs; + + if (refs) { + tctx->cached_refs = 0; + percpu_counter_sub(&tctx->inflight, refs); + put_task_struct_many(task, refs); + } +} + +static __cold bool io_cqring_add_overflow(struct io_ring_ctx *ctx, + struct io_overflow_cqe *ocqe) +{ + lockdep_assert_held(&ctx->completion_lock); + + if (!ocqe) { + struct io_rings *r = ctx->rings; + + /* + * If we're in ring overflow flush mode, or in task cancel mode, + * or cannot allocate an overflow entry, then we need to drop it + * on the floor. + */ + WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1); + set_bit(IO_CHECK_CQ_DROPPED_BIT, &ctx->check_cq); + return false; + } + if (list_empty(&ctx->cq_overflow_list)) { + set_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq); + atomic_or(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags); + + } + list_add_tail(&ocqe->list, &ctx->cq_overflow_list); + return true; +} + +static struct io_overflow_cqe *io_alloc_ocqe(struct io_ring_ctx *ctx, + struct io_cqe *cqe, + struct io_big_cqe *big_cqe, gfp_t gfp) +{ + struct io_overflow_cqe *ocqe; + size_t ocq_size = sizeof(struct io_overflow_cqe); + bool is_cqe32 = false; + + if (cqe->flags & IORING_CQE_F_32 || ctx->flags & IORING_SETUP_CQE32) { + is_cqe32 = true; + ocq_size += sizeof(struct io_uring_cqe); + } + + ocqe = kzalloc(ocq_size, gfp | __GFP_ACCOUNT); + trace_io_uring_cqe_overflow(ctx, cqe->user_data, cqe->res, cqe->flags, ocqe); + if (ocqe) { + ocqe->cqe.user_data = cqe->user_data; + ocqe->cqe.res = cqe->res; + ocqe->cqe.flags = cqe->flags; + if (is_cqe32 && big_cqe) { + ocqe->cqe.big_cqe[0] = big_cqe->extra1; + ocqe->cqe.big_cqe[1] = big_cqe->extra2; + } + } + if (big_cqe) + big_cqe->extra1 = big_cqe->extra2 = 0; + return ocqe; +} + +/* + * Fill an empty dummy CQE, in case alignment is off for posting a 32b CQE + * because the ring is a single 16b entry away from wrapping. + */ +static bool io_fill_nop_cqe(struct io_ring_ctx *ctx, unsigned int off) +{ + if (__io_cqring_events(ctx) < ctx->cq_entries) { + struct io_uring_cqe *cqe = &ctx->rings->cqes[off]; + + cqe->user_data = 0; + cqe->res = 0; + cqe->flags = IORING_CQE_F_SKIP; + ctx->cached_cq_tail++; + return true; + } + return false; +} + +/* + * writes to the cq entry need to come after reading head; the + * control dependency is enough as we're using WRITE_ONCE to + * fill the cq entry + */ +bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow, bool cqe32) +{ + struct io_rings *rings = ctx->rings; + unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1); + unsigned int free, queued, len; + + /* + * Posting into the CQ when there are pending overflowed CQEs may break + * ordering guarantees, which will affect links, F_MORE users and more. + * Force overflow the completion. + */ + if (!overflow && (ctx->check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))) + return false; + + /* + * Post dummy CQE if a 32b CQE is needed and there's only room for a + * 16b CQE before the ring wraps. + */ + if (cqe32 && off + 1 == ctx->cq_entries) { + if (!io_fill_nop_cqe(ctx, off)) + return false; + off = 0; + } + + /* userspace may cheat modifying the tail, be safe and do min */ + queued = min(__io_cqring_events(ctx), ctx->cq_entries); + free = ctx->cq_entries - queued; + /* we need a contiguous range, limit based on the current array offset */ + len = min(free, ctx->cq_entries - off); + if (len < (cqe32 + 1)) + return false; + + if (ctx->flags & IORING_SETUP_CQE32) { + off <<= 1; + len <<= 1; + } + + ctx->cqe_cached = &rings->cqes[off]; + ctx->cqe_sentinel = ctx->cqe_cached + len; + return true; +} + +static bool io_fill_cqe_aux32(struct io_ring_ctx *ctx, + struct io_uring_cqe src_cqe[2]) +{ + struct io_uring_cqe *cqe; + + if (WARN_ON_ONCE(!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED)))) + return false; + if (unlikely(!io_get_cqe(ctx, &cqe, true))) + return false; + + memcpy(cqe, src_cqe, 2 * sizeof(*cqe)); + trace_io_uring_complete(ctx, NULL, cqe); + return true; +} + +static bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, + u32 cflags) +{ + bool cqe32 = cflags & IORING_CQE_F_32; + struct io_uring_cqe *cqe; + + if (likely(io_get_cqe(ctx, &cqe, cqe32))) { + WRITE_ONCE(cqe->user_data, user_data); + WRITE_ONCE(cqe->res, res); + WRITE_ONCE(cqe->flags, cflags); + + if (cqe32) { + WRITE_ONCE(cqe->big_cqe[0], 0); + WRITE_ONCE(cqe->big_cqe[1], 0); + } + + trace_io_uring_complete(ctx, NULL, cqe); + return true; + } + return false; +} + +static inline struct io_cqe io_init_cqe(u64 user_data, s32 res, u32 cflags) +{ + return (struct io_cqe) { .user_data = user_data, .res = res, .flags = cflags }; +} + +static __cold void io_cqe_overflow(struct io_ring_ctx *ctx, struct io_cqe *cqe, + struct io_big_cqe *big_cqe) +{ + struct io_overflow_cqe *ocqe; + + ocqe = io_alloc_ocqe(ctx, cqe, big_cqe, GFP_KERNEL); + spin_lock(&ctx->completion_lock); + io_cqring_add_overflow(ctx, ocqe); + spin_unlock(&ctx->completion_lock); +} + +static __cold bool io_cqe_overflow_locked(struct io_ring_ctx *ctx, + struct io_cqe *cqe, + struct io_big_cqe *big_cqe) +{ + struct io_overflow_cqe *ocqe; + + ocqe = io_alloc_ocqe(ctx, cqe, big_cqe, GFP_ATOMIC); + return io_cqring_add_overflow(ctx, ocqe); +} + +bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags) +{ + bool filled; + + io_cq_lock(ctx); + filled = io_fill_cqe_aux(ctx, user_data, res, cflags); + if (unlikely(!filled)) { + struct io_cqe cqe = io_init_cqe(user_data, res, cflags); + + filled = io_cqe_overflow_locked(ctx, &cqe, NULL); + } + io_cq_unlock_post(ctx); + return filled; +} + +/* + * Must be called from inline task_work so we know a flush will happen later, + * and obviously with ctx->uring_lock held (tw always has that). + */ +void io_add_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags) +{ + lockdep_assert_held(&ctx->uring_lock); + lockdep_assert(ctx->lockless_cq); + + if (!io_fill_cqe_aux(ctx, user_data, res, cflags)) { + struct io_cqe cqe = io_init_cqe(user_data, res, cflags); + + io_cqe_overflow(ctx, &cqe, NULL); + } + ctx->submit_state.cq_flush = true; +} + +/* + * A helper for multishot requests posting additional CQEs. + * Should only be used from a task_work including IO_URING_F_MULTISHOT. + */ +bool io_req_post_cqe(struct io_kiocb *req, s32 res, u32 cflags) +{ + struct io_ring_ctx *ctx = req->ctx; + bool posted; + + /* + * If multishot has already posted deferred completions, ensure that + * those are flushed first before posting this one. If not, CQEs + * could get reordered. + */ + if (!wq_list_empty(&ctx->submit_state.compl_reqs)) + __io_submit_flush_completions(ctx); + + lockdep_assert(!io_wq_current_is_worker()); + lockdep_assert_held(&ctx->uring_lock); + + if (!ctx->lockless_cq) { + spin_lock(&ctx->completion_lock); + posted = io_fill_cqe_aux(ctx, req->cqe.user_data, res, cflags); + spin_unlock(&ctx->completion_lock); + } else { + posted = io_fill_cqe_aux(ctx, req->cqe.user_data, res, cflags); + } + + ctx->submit_state.cq_flush = true; + return posted; +} + +/* + * A helper for multishot requests posting additional CQEs. + * Should only be used from a task_work including IO_URING_F_MULTISHOT. + */ +bool io_req_post_cqe32(struct io_kiocb *req, struct io_uring_cqe cqe[2]) +{ + struct io_ring_ctx *ctx = req->ctx; + bool posted; + + lockdep_assert(!io_wq_current_is_worker()); + lockdep_assert_held(&ctx->uring_lock); + + cqe[0].user_data = req->cqe.user_data; + if (!ctx->lockless_cq) { + spin_lock(&ctx->completion_lock); + posted = io_fill_cqe_aux32(ctx, cqe); + spin_unlock(&ctx->completion_lock); + } else { + posted = io_fill_cqe_aux32(ctx, cqe); + } + + ctx->submit_state.cq_flush = true; + return posted; +} + +static void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + bool completed = true; + + /* + * All execution paths but io-wq use the deferred completions by + * passing IO_URING_F_COMPLETE_DEFER and thus should not end up here. + */ + if (WARN_ON_ONCE(!(issue_flags & IO_URING_F_IOWQ))) + return; + + /* + * Handle special CQ sync cases via task_work. DEFER_TASKRUN requires + * the submitter task context, IOPOLL protects with uring_lock. + */ + if (ctx->lockless_cq || (req->flags & REQ_F_REISSUE)) { +defer_complete: + req->io_task_work.func = io_req_task_complete; + io_req_task_work_add(req); + return; + } + + io_cq_lock(ctx); + if (!(req->flags & REQ_F_CQE_SKIP)) + completed = io_fill_cqe_req(ctx, req); + io_cq_unlock_post(ctx); + + if (!completed) + goto defer_complete; + + /* + * We don't free the request here because we know it's called from + * io-wq only, which holds a reference, so it cannot be the last put. + */ + req_ref_put(req); +} + +void io_req_defer_failed(struct io_kiocb *req, s32 res) + __must_hold(&ctx->uring_lock) +{ + const struct io_cold_def *def = &io_cold_defs[req->opcode]; + + lockdep_assert_held(&req->ctx->uring_lock); + + req_set_fail(req); + io_req_set_res(req, res, io_put_kbuf(req, res, NULL)); + if (def->fail) + def->fail(req); + io_req_complete_defer(req); +} + +/* + * A request might get retired back into the request caches even before opcode + * handlers and io_issue_sqe() are done with it, e.g. inline completion path. + * Because of that, io_alloc_req() should be called only under ->uring_lock + * and with extra caution to not get a request that is still worked on. + */ +__cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx) + __must_hold(&ctx->uring_lock) +{ + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO; + void *reqs[IO_REQ_ALLOC_BATCH]; + int ret; + + ret = kmem_cache_alloc_bulk(req_cachep, gfp, ARRAY_SIZE(reqs), reqs); + + /* + * Bulk alloc is all-or-nothing. If we fail to get a batch, + * retry single alloc to be on the safe side. + */ + if (unlikely(ret <= 0)) { + reqs[0] = kmem_cache_alloc(req_cachep, gfp); + if (!reqs[0]) + return false; + ret = 1; + } + + percpu_ref_get_many(&ctx->refs, ret); + ctx->nr_req_allocated += ret; + + while (ret--) { + struct io_kiocb *req = reqs[ret]; + + io_req_add_to_cache(req, ctx); + } + return true; +} + +__cold void io_free_req(struct io_kiocb *req) +{ + /* refs were already put, restore them for io_req_task_complete() */ + req->flags &= ~REQ_F_REFCOUNT; + /* we only want to free it, don't post CQEs */ + req->flags |= REQ_F_CQE_SKIP; + req->io_task_work.func = io_req_task_complete; + io_req_task_work_add(req); +} + +static void __io_req_find_next_prep(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + + spin_lock(&ctx->completion_lock); + io_disarm_next(req); + spin_unlock(&ctx->completion_lock); +} + +static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req) +{ + struct io_kiocb *nxt; + + /* + * If LINK is set, we have dependent requests in this chain. If we + * didn't fail this request, queue the first one up, moving any other + * dependencies to the next request. In case of failure, fail the rest + * of the chain. + */ + if (unlikely(req->flags & IO_DISARM_MASK)) + __io_req_find_next_prep(req); + nxt = req->link; + req->link = NULL; + return nxt; +} + +static void ctx_flush_and_put(struct io_ring_ctx *ctx, io_tw_token_t tw) +{ + if (!ctx) + return; + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) + atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); + + io_submit_flush_completions(ctx); + mutex_unlock(&ctx->uring_lock); + percpu_ref_put(&ctx->refs); +} + +/* + * Run queued task_work, returning the number of entries processed in *count. + * If more entries than max_entries are available, stop processing once this + * is reached and return the rest of the list. + */ +struct llist_node *io_handle_tw_list(struct llist_node *node, + unsigned int *count, + unsigned int max_entries) +{ + struct io_ring_ctx *ctx = NULL; + struct io_tw_state ts = { }; + + do { + struct llist_node *next = node->next; + struct io_kiocb *req = container_of(node, struct io_kiocb, + io_task_work.node); + + if (req->ctx != ctx) { + ctx_flush_and_put(ctx, ts); + ctx = req->ctx; + mutex_lock(&ctx->uring_lock); + percpu_ref_get(&ctx->refs); + ts.cancel = io_should_terminate_tw(ctx); + } + INDIRECT_CALL_2(req->io_task_work.func, + io_poll_task_func, io_req_rw_complete, + (struct io_tw_req){req}, ts); + node = next; + (*count)++; + if (unlikely(need_resched())) { + ctx_flush_and_put(ctx, ts); + ctx = NULL; + cond_resched(); + } + } while (node && *count < max_entries); + + ctx_flush_and_put(ctx, ts); + return node; +} + +static __cold void __io_fallback_tw(struct llist_node *node, bool sync) +{ + struct io_ring_ctx *last_ctx = NULL; + struct io_kiocb *req; + + while (node) { + req = container_of(node, struct io_kiocb, io_task_work.node); + node = node->next; + if (last_ctx != req->ctx) { + if (last_ctx) { + if (sync) + flush_delayed_work(&last_ctx->fallback_work); + percpu_ref_put(&last_ctx->refs); + } + last_ctx = req->ctx; + percpu_ref_get(&last_ctx->refs); + } + if (llist_add(&req->io_task_work.node, &last_ctx->fallback_llist)) + schedule_delayed_work(&last_ctx->fallback_work, 1); + } + + if (last_ctx) { + if (sync) + flush_delayed_work(&last_ctx->fallback_work); + percpu_ref_put(&last_ctx->refs); + } +} + +static void io_fallback_tw(struct io_uring_task *tctx, bool sync) +{ + struct llist_node *node = llist_del_all(&tctx->task_list); + + __io_fallback_tw(node, sync); +} + +struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, + unsigned int max_entries, + unsigned int *count) +{ + struct llist_node *node; + + node = llist_del_all(&tctx->task_list); + if (node) { + node = llist_reverse_order(node); + node = io_handle_tw_list(node, count, max_entries); + } + + /* relaxed read is enough as only the task itself sets ->in_cancel */ + if (unlikely(atomic_read(&tctx->in_cancel))) + io_uring_drop_tctx_refs(current); + + trace_io_uring_task_work_run(tctx, *count); + return node; +} + +void tctx_task_work(struct callback_head *cb) +{ + struct io_uring_task *tctx; + struct llist_node *ret; + unsigned int count = 0; + + tctx = container_of(cb, struct io_uring_task, task_work); + ret = tctx_task_work_run(tctx, UINT_MAX, &count); + /* can't happen */ + WARN_ON_ONCE(ret); +} + +static void io_req_local_work_add(struct io_kiocb *req, unsigned flags) +{ + struct io_ring_ctx *ctx = req->ctx; + unsigned nr_wait, nr_tw, nr_tw_prev; + struct llist_node *head; + + /* See comment above IO_CQ_WAKE_INIT */ + BUILD_BUG_ON(IO_CQ_WAKE_FORCE <= IORING_MAX_CQ_ENTRIES); + + /* + * We don't know how many requests there are in the link and whether + * they can even be queued lazily, fall back to non-lazy. + */ + if (req->flags & IO_REQ_LINK_FLAGS) + flags &= ~IOU_F_TWQ_LAZY_WAKE; + + guard(rcu)(); + + head = READ_ONCE(ctx->work_llist.first); + do { + nr_tw_prev = 0; + if (head) { + struct io_kiocb *first_req = container_of(head, + struct io_kiocb, + io_task_work.node); + /* + * Might be executed at any moment, rely on + * SLAB_TYPESAFE_BY_RCU to keep it alive. + */ + nr_tw_prev = READ_ONCE(first_req->nr_tw); + } + + /* + * Theoretically, it can overflow, but that's fine as one of + * previous adds should've tried to wake the task. + */ + nr_tw = nr_tw_prev + 1; + if (!(flags & IOU_F_TWQ_LAZY_WAKE)) + nr_tw = IO_CQ_WAKE_FORCE; + + req->nr_tw = nr_tw; + req->io_task_work.node.next = head; + } while (!try_cmpxchg(&ctx->work_llist.first, &head, + &req->io_task_work.node)); + + /* + * cmpxchg implies a full barrier, which pairs with the barrier + * in set_current_state() on the io_cqring_wait() side. It's used + * to ensure that either we see updated ->cq_wait_nr, or waiters + * going to sleep will observe the work added to the list, which + * is similar to the wait/wawke task state sync. + */ + + if (!head) { + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) + atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); + if (ctx->has_evfd) + io_eventfd_signal(ctx, false); + } + + nr_wait = atomic_read(&ctx->cq_wait_nr); + /* not enough or no one is waiting */ + if (nr_tw < nr_wait) + return; + /* the previous add has already woken it up */ + if (nr_tw_prev >= nr_wait) + return; + wake_up_state(ctx->submitter_task, TASK_INTERRUPTIBLE); +} + +static void io_req_normal_work_add(struct io_kiocb *req) +{ + struct io_uring_task *tctx = req->tctx; + struct io_ring_ctx *ctx = req->ctx; + + /* task_work already pending, we're done */ + if (!llist_add(&req->io_task_work.node, &tctx->task_list)) + return; + + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) + atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); + + /* SQPOLL doesn't need the task_work added, it'll run it itself */ + if (ctx->flags & IORING_SETUP_SQPOLL) { + __set_notify_signal(tctx->task); + return; + } + + if (likely(!task_work_add(tctx->task, &tctx->task_work, ctx->notify_method))) + return; + + io_fallback_tw(tctx, false); +} + +void __io_req_task_work_add(struct io_kiocb *req, unsigned flags) +{ + if (req->ctx->flags & IORING_SETUP_DEFER_TASKRUN) + io_req_local_work_add(req, flags); + else + io_req_normal_work_add(req); +} + +void io_req_task_work_add_remote(struct io_kiocb *req, unsigned flags) +{ + if (WARN_ON_ONCE(!(req->ctx->flags & IORING_SETUP_DEFER_TASKRUN))) + return; + __io_req_task_work_add(req, flags); +} + +static void __cold io_move_task_work_from_local(struct io_ring_ctx *ctx) +{ + struct llist_node *node = llist_del_all(&ctx->work_llist); + + __io_fallback_tw(node, false); + node = llist_del_all(&ctx->retry_llist); + __io_fallback_tw(node, false); +} + +static bool io_run_local_work_continue(struct io_ring_ctx *ctx, int events, + int min_events) +{ + if (!io_local_work_pending(ctx)) + return false; + if (events < min_events) + return true; + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) + atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); + return false; +} + +static int __io_run_local_work_loop(struct llist_node **node, + io_tw_token_t tw, + int events) +{ + int ret = 0; + + while (*node) { + struct llist_node *next = (*node)->next; + struct io_kiocb *req = container_of(*node, struct io_kiocb, + io_task_work.node); + INDIRECT_CALL_2(req->io_task_work.func, + io_poll_task_func, io_req_rw_complete, + (struct io_tw_req){req}, tw); + *node = next; + if (++ret >= events) + break; + } + + return ret; +} + +static int __io_run_local_work(struct io_ring_ctx *ctx, io_tw_token_t tw, + int min_events, int max_events) +{ + struct llist_node *node; + unsigned int loops = 0; + int ret = 0; + + if (WARN_ON_ONCE(ctx->submitter_task != current)) + return -EEXIST; + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) + atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); +again: + tw.cancel = io_should_terminate_tw(ctx); + min_events -= ret; + ret = __io_run_local_work_loop(&ctx->retry_llist.first, tw, max_events); + if (ctx->retry_llist.first) + goto retry_done; + + /* + * llists are in reverse order, flip it back the right way before + * running the pending items. + */ + node = llist_reverse_order(llist_del_all(&ctx->work_llist)); + ret += __io_run_local_work_loop(&node, tw, max_events - ret); + ctx->retry_llist.first = node; + loops++; + + if (io_run_local_work_continue(ctx, ret, min_events)) + goto again; +retry_done: + io_submit_flush_completions(ctx); + if (io_run_local_work_continue(ctx, ret, min_events)) + goto again; + + trace_io_uring_local_work_run(ctx, ret, loops); + return ret; +} + +static inline int io_run_local_work_locked(struct io_ring_ctx *ctx, + int min_events) +{ + struct io_tw_state ts = {}; + + if (!io_local_work_pending(ctx)) + return 0; + return __io_run_local_work(ctx, ts, min_events, + max(IO_LOCAL_TW_DEFAULT_MAX, min_events)); +} + +int io_run_local_work(struct io_ring_ctx *ctx, int min_events, int max_events) +{ + struct io_tw_state ts = {}; + int ret; + + mutex_lock(&ctx->uring_lock); + ret = __io_run_local_work(ctx, ts, min_events, max_events); + mutex_unlock(&ctx->uring_lock); + return ret; +} + +static void io_req_task_cancel(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + + io_tw_lock(req->ctx, tw); + io_req_defer_failed(req, req->cqe.res); +} + +void io_req_task_submit(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_ring_ctx *ctx = req->ctx; + + io_tw_lock(ctx, tw); + if (unlikely(tw.cancel)) + io_req_defer_failed(req, -EFAULT); + else if (req->flags & REQ_F_FORCE_ASYNC) + io_queue_iowq(req); + else + io_queue_sqe(req, 0); +} + +void io_req_task_queue_fail(struct io_kiocb *req, int ret) +{ + io_req_set_res(req, ret, 0); + req->io_task_work.func = io_req_task_cancel; + io_req_task_work_add(req); +} + +void io_req_task_queue(struct io_kiocb *req) +{ + req->io_task_work.func = io_req_task_submit; + io_req_task_work_add(req); +} + +void io_queue_next(struct io_kiocb *req) +{ + struct io_kiocb *nxt = io_req_find_next(req); + + if (nxt) + io_req_task_queue(nxt); +} + +static inline void io_req_put_rsrc_nodes(struct io_kiocb *req) +{ + if (req->file_node) { + io_put_rsrc_node(req->ctx, req->file_node); + req->file_node = NULL; + } + if (req->flags & REQ_F_BUF_NODE) + io_put_rsrc_node(req->ctx, req->buf_node); +} + +static void io_free_batch_list(struct io_ring_ctx *ctx, + struct io_wq_work_node *node) + __must_hold(&ctx->uring_lock) +{ + do { + struct io_kiocb *req = container_of(node, struct io_kiocb, + comp_list); + + if (unlikely(req->flags & IO_REQ_CLEAN_SLOW_FLAGS)) { + if (req->flags & REQ_F_REISSUE) { + node = req->comp_list.next; + req->flags &= ~REQ_F_REISSUE; + io_queue_iowq(req); + continue; + } + if (req->flags & REQ_F_REFCOUNT) { + node = req->comp_list.next; + if (!req_ref_put_and_test(req)) + continue; + } + if ((req->flags & REQ_F_POLLED) && req->apoll) { + struct async_poll *apoll = req->apoll; + + if (apoll->double_poll) + kfree(apoll->double_poll); + io_cache_free(&ctx->apoll_cache, apoll); + req->flags &= ~REQ_F_POLLED; + } + if (req->flags & IO_REQ_LINK_FLAGS) + io_queue_next(req); + if (unlikely(req->flags & IO_REQ_CLEAN_FLAGS)) + io_clean_op(req); + } + io_put_file(req); + io_req_put_rsrc_nodes(req); + io_put_task(req); + + node = req->comp_list.next; + io_req_add_to_cache(req, ctx); + } while (node); +} + +void __io_submit_flush_completions(struct io_ring_ctx *ctx) + __must_hold(&ctx->uring_lock) +{ + struct io_submit_state *state = &ctx->submit_state; + struct io_wq_work_node *node; + + __io_cq_lock(ctx); + __wq_list_for_each(node, &state->compl_reqs) { + struct io_kiocb *req = container_of(node, struct io_kiocb, + comp_list); + + /* + * Requests marked with REQUEUE should not post a CQE, they + * will go through the io-wq retry machinery and post one + * later. + */ + if (!(req->flags & (REQ_F_CQE_SKIP | REQ_F_REISSUE)) && + unlikely(!io_fill_cqe_req(ctx, req))) { + if (ctx->lockless_cq) + io_cqe_overflow(ctx, &req->cqe, &req->big_cqe); + else + io_cqe_overflow_locked(ctx, &req->cqe, &req->big_cqe); + } + } + __io_cq_unlock_post(ctx); + + if (!wq_list_empty(&state->compl_reqs)) { + io_free_batch_list(ctx, state->compl_reqs.first); + INIT_WQ_LIST(&state->compl_reqs); + } + + if (unlikely(ctx->drain_active)) + io_queue_deferred(ctx); + + ctx->submit_state.cq_flush = false; +} + +static unsigned io_cqring_events(struct io_ring_ctx *ctx) +{ + /* See comment at the top of this file */ + smp_rmb(); + return __io_cqring_events(ctx); +} + +/* + * We can't just wait for polled events to come to us, we have to actively + * find and complete them. + */ +__cold void io_iopoll_try_reap_events(struct io_ring_ctx *ctx) +{ + if (!(ctx->flags & IORING_SETUP_IOPOLL)) + return; + + mutex_lock(&ctx->uring_lock); + while (!wq_list_empty(&ctx->iopoll_list)) { + /* let it sleep and repeat later if can't complete a request */ + if (io_do_iopoll(ctx, true) == 0) + break; + /* + * Ensure we allow local-to-the-cpu processing to take place, + * in this case we need to ensure that we reap all events. + * Also let task_work, etc. to progress by releasing the mutex + */ + if (need_resched()) { + mutex_unlock(&ctx->uring_lock); + cond_resched(); + mutex_lock(&ctx->uring_lock); + } + } + mutex_unlock(&ctx->uring_lock); + + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) + io_move_task_work_from_local(ctx); +} + +static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned int min_events) +{ + unsigned int nr_events = 0; + unsigned long check_cq; + + min_events = min(min_events, ctx->cq_entries); + + lockdep_assert_held(&ctx->uring_lock); + + if (!io_allowed_run_tw(ctx)) + return -EEXIST; + + check_cq = READ_ONCE(ctx->check_cq); + if (unlikely(check_cq)) { + if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT)) + __io_cqring_overflow_flush(ctx, false); + /* + * Similarly do not spin if we have not informed the user of any + * dropped CQE. + */ + if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) + return -EBADR; + } + /* + * Don't enter poll loop if we already have events pending. + * If we do, we can potentially be spinning for commands that + * already triggered a CQE (eg in error). + */ + if (io_cqring_events(ctx)) + return 0; + + do { + int ret = 0; + + /* + * If a submit got punted to a workqueue, we can have the + * application entering polling for a command before it gets + * issued. That app will hold the uring_lock for the duration + * of the poll right here, so we need to take a breather every + * now and then to ensure that the issue has a chance to add + * the poll to the issued list. Otherwise we can spin here + * forever, while the workqueue is stuck trying to acquire the + * very same mutex. + */ + if (wq_list_empty(&ctx->iopoll_list) || + io_task_work_pending(ctx)) { + u32 tail = ctx->cached_cq_tail; + + (void) io_run_local_work_locked(ctx, min_events); + + if (task_work_pending(current) || + wq_list_empty(&ctx->iopoll_list)) { + mutex_unlock(&ctx->uring_lock); + io_run_task_work(); + mutex_lock(&ctx->uring_lock); + } + /* some requests don't go through iopoll_list */ + if (tail != ctx->cached_cq_tail || + wq_list_empty(&ctx->iopoll_list)) + break; + } + ret = io_do_iopoll(ctx, !min_events); + if (unlikely(ret < 0)) + return ret; + + if (task_sigpending(current)) + return -EINTR; + if (need_resched()) + break; + + nr_events += ret; + } while (nr_events < min_events); + + return 0; +} + +void io_req_task_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + io_req_complete_defer(tw_req.req); +} + +/* + * After the iocb has been issued, it's safe to be found on the poll list. + * Adding the kiocb to the list AFTER submission ensures that we don't + * find it from a io_do_iopoll() thread before the issuer is done + * accessing the kiocb cookie. + */ +static void io_iopoll_req_issued(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + const bool needs_lock = issue_flags & IO_URING_F_UNLOCKED; + + /* workqueue context doesn't hold uring_lock, grab it now */ + if (unlikely(needs_lock)) + mutex_lock(&ctx->uring_lock); + + /* + * Track whether we have multiple files in our lists. This will impact + * how we do polling eventually, not spinning if we're on potentially + * different devices. + */ + if (wq_list_empty(&ctx->iopoll_list)) { + ctx->poll_multi_queue = false; + } else if (!ctx->poll_multi_queue) { + struct io_kiocb *list_req; + + list_req = container_of(ctx->iopoll_list.first, struct io_kiocb, + comp_list); + if (list_req->file != req->file) + ctx->poll_multi_queue = true; + } + + /* + * For fast devices, IO may have already completed. If it has, add + * it to the front so we find it first. + */ + if (READ_ONCE(req->iopoll_completed)) + wq_list_add_head(&req->comp_list, &ctx->iopoll_list); + else + wq_list_add_tail(&req->comp_list, &ctx->iopoll_list); + + if (unlikely(needs_lock)) { + /* + * If IORING_SETUP_SQPOLL is enabled, sqes are either handle + * in sq thread task context or in io worker task context. If + * current task context is sq thread, we don't need to check + * whether should wake up sq thread. + */ + if ((ctx->flags & IORING_SETUP_SQPOLL) && + wq_has_sleeper(&ctx->sq_data->wait)) + wake_up(&ctx->sq_data->wait); + + mutex_unlock(&ctx->uring_lock); + } +} + +io_req_flags_t io_file_get_flags(struct file *file) +{ + io_req_flags_t res = 0; + + BUILD_BUG_ON(REQ_F_ISREG_BIT != REQ_F_SUPPORT_NOWAIT_BIT + 1); + + if (S_ISREG(file_inode(file)->i_mode)) + res |= REQ_F_ISREG; + if ((file->f_flags & O_NONBLOCK) || (file->f_mode & FMODE_NOWAIT)) + res |= REQ_F_SUPPORT_NOWAIT; + return res; +} + +static __cold void io_drain_req(struct io_kiocb *req) + __must_hold(&ctx->uring_lock) +{ + struct io_ring_ctx *ctx = req->ctx; + bool drain = req->flags & IOSQE_IO_DRAIN; + struct io_defer_entry *de; + + de = kmalloc(sizeof(*de), GFP_KERNEL_ACCOUNT); + if (!de) { + io_req_defer_failed(req, -ENOMEM); + return; + } + + io_prep_async_link(req); + trace_io_uring_defer(req); + de->req = req; + + ctx->nr_drained += io_linked_nr(req); + list_add_tail(&de->list, &ctx->defer_list); + io_queue_deferred(ctx); + if (!drain && list_empty(&ctx->defer_list)) + ctx->drain_active = false; +} + +static bool io_assign_file(struct io_kiocb *req, const struct io_issue_def *def, + unsigned int issue_flags) +{ + if (req->file || !def->needs_file) + return true; + + if (req->flags & REQ_F_FIXED_FILE) + req->file = io_file_get_fixed(req, req->cqe.fd, issue_flags); + else + req->file = io_file_get_normal(req, req->cqe.fd); + + return !!req->file; +} + +#define REQ_ISSUE_SLOW_FLAGS (REQ_F_CREDS | REQ_F_ARM_LTIMEOUT) + +static inline int __io_issue_sqe(struct io_kiocb *req, + unsigned int issue_flags, + const struct io_issue_def *def) +{ + const struct cred *creds = NULL; + struct io_kiocb *link = NULL; + int ret; + + if (unlikely(req->flags & REQ_ISSUE_SLOW_FLAGS)) { + if ((req->flags & REQ_F_CREDS) && req->creds != current_cred()) + creds = override_creds(req->creds); + if (req->flags & REQ_F_ARM_LTIMEOUT) + link = __io_prep_linked_timeout(req); + } + + if (!def->audit_skip) + audit_uring_entry(req->opcode); + + ret = def->issue(req, issue_flags); + + if (!def->audit_skip) + audit_uring_exit(!ret, ret); + + if (unlikely(creds || link)) { + if (creds) + revert_creds(creds); + if (link) + io_queue_linked_timeout(link); + } + + return ret; +} + +static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) +{ + const struct io_issue_def *def = &io_issue_defs[req->opcode]; + int ret; + + if (unlikely(!io_assign_file(req, def, issue_flags))) + return -EBADF; + + ret = __io_issue_sqe(req, issue_flags, def); + + if (ret == IOU_COMPLETE) { + if (issue_flags & IO_URING_F_COMPLETE_DEFER) + io_req_complete_defer(req); + else + io_req_complete_post(req, issue_flags); + + return 0; + } + + if (ret == IOU_ISSUE_SKIP_COMPLETE) { + ret = 0; + + /* If the op doesn't have a file, we're not polling for it */ + if ((req->ctx->flags & IORING_SETUP_IOPOLL) && def->iopoll_queue) + io_iopoll_req_issued(req, issue_flags); + } + return ret; +} + +int io_poll_issue(struct io_kiocb *req, io_tw_token_t tw) +{ + const unsigned int issue_flags = IO_URING_F_NONBLOCK | + IO_URING_F_MULTISHOT | + IO_URING_F_COMPLETE_DEFER; + int ret; + + io_tw_lock(req->ctx, tw); + + WARN_ON_ONCE(!req->file); + if (WARN_ON_ONCE(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EFAULT; + + ret = __io_issue_sqe(req, issue_flags, &io_issue_defs[req->opcode]); + + WARN_ON_ONCE(ret == IOU_ISSUE_SKIP_COMPLETE); + return ret; +} + +struct io_wq_work *io_wq_free_work(struct io_wq_work *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_kiocb *nxt = NULL; + + if (req_ref_put_and_test_atomic(req)) { + if (req->flags & IO_REQ_LINK_FLAGS) + nxt = io_req_find_next(req); + io_free_req(req); + } + return nxt ? &nxt->work : NULL; +} + +void io_wq_submit_work(struct io_wq_work *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + const struct io_issue_def *def = &io_issue_defs[req->opcode]; + unsigned int issue_flags = IO_URING_F_UNLOCKED | IO_URING_F_IOWQ; + bool needs_poll = false; + int ret = 0, err = -ECANCELED; + + /* one will be dropped by io_wq_free_work() after returning to io-wq */ + if (!(req->flags & REQ_F_REFCOUNT)) + __io_req_set_refcount(req, 2); + else + req_ref_get(req); + + /* either cancelled or io-wq is dying, so don't touch tctx->iowq */ + if (atomic_read(&work->flags) & IO_WQ_WORK_CANCEL) { +fail: + io_req_task_queue_fail(req, err); + return; + } + if (!io_assign_file(req, def, issue_flags)) { + err = -EBADF; + atomic_or(IO_WQ_WORK_CANCEL, &work->flags); + goto fail; + } + + /* + * If DEFER_TASKRUN is set, it's only allowed to post CQEs from the + * submitter task context. Final request completions are handed to the + * right context, however this is not the case of auxiliary CQEs, + * which is the main mean of operation for multishot requests. + * Don't allow any multishot execution from io-wq. It's more restrictive + * than necessary and also cleaner. + */ + if (req->flags & (REQ_F_MULTISHOT|REQ_F_APOLL_MULTISHOT)) { + err = -EBADFD; + if (!io_file_can_poll(req)) + goto fail; + if (req->file->f_flags & O_NONBLOCK || + req->file->f_mode & FMODE_NOWAIT) { + err = -ECANCELED; + if (io_arm_poll_handler(req, issue_flags) != IO_APOLL_OK) + goto fail; + return; + } else { + req->flags &= ~(REQ_F_APOLL_MULTISHOT|REQ_F_MULTISHOT); + } + } + + if (req->flags & REQ_F_FORCE_ASYNC) { + bool opcode_poll = def->pollin || def->pollout; + + if (opcode_poll && io_file_can_poll(req)) { + needs_poll = true; + issue_flags |= IO_URING_F_NONBLOCK; + } + } + + do { + ret = io_issue_sqe(req, issue_flags); + if (ret != -EAGAIN) + break; + + /* + * If REQ_F_NOWAIT is set, then don't wait or retry with + * poll. -EAGAIN is final for that case. + */ + if (req->flags & REQ_F_NOWAIT) + break; + + /* + * We can get EAGAIN for iopolled IO even though we're + * forcing a sync submission from here, since we can't + * wait for request slots on the block side. + */ + if (!needs_poll) { + if (!(req->ctx->flags & IORING_SETUP_IOPOLL)) + break; + if (io_wq_worker_stopped()) + break; + cond_resched(); + continue; + } + + if (io_arm_poll_handler(req, issue_flags) == IO_APOLL_OK) + return; + /* aborted or ready, in either case retry blocking */ + needs_poll = false; + issue_flags &= ~IO_URING_F_NONBLOCK; + } while (1); + + /* avoid locking problems by failing it from a clean context */ + if (ret) + io_req_task_queue_fail(req, ret); +} + +inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd, + unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_rsrc_node *node; + struct file *file = NULL; + + io_ring_submit_lock(ctx, issue_flags); + node = io_rsrc_node_lookup(&ctx->file_table.data, fd); + if (node) { + node->refs++; + req->file_node = node; + req->flags |= io_slot_flags(node); + file = io_slot_file(node); + } + io_ring_submit_unlock(ctx, issue_flags); + return file; +} + +struct file *io_file_get_normal(struct io_kiocb *req, int fd) +{ + struct file *file = fget(fd); + + trace_io_uring_file_get(req, fd); + + /* we don't allow fixed io_uring files */ + if (file && io_is_uring_fops(file)) + io_req_track_inflight(req); + return file; +} + +static int io_req_sqe_copy(struct io_kiocb *req, unsigned int issue_flags) +{ + const struct io_cold_def *def = &io_cold_defs[req->opcode]; + + if (req->flags & REQ_F_SQE_COPIED) + return 0; + req->flags |= REQ_F_SQE_COPIED; + if (!def->sqe_copy) + return 0; + if (WARN_ON_ONCE(!(issue_flags & IO_URING_F_INLINE))) + return -EFAULT; + def->sqe_copy(req); + return 0; +} + +static void io_queue_async(struct io_kiocb *req, unsigned int issue_flags, int ret) + __must_hold(&req->ctx->uring_lock) +{ + if (ret != -EAGAIN || (req->flags & REQ_F_NOWAIT)) { +fail: + io_req_defer_failed(req, ret); + return; + } + + ret = io_req_sqe_copy(req, issue_flags); + if (unlikely(ret)) + goto fail; + + switch (io_arm_poll_handler(req, 0)) { + case IO_APOLL_READY: + io_req_task_queue(req); + break; + case IO_APOLL_ABORTED: + io_queue_iowq(req); + break; + case IO_APOLL_OK: + break; + } +} + +static inline void io_queue_sqe(struct io_kiocb *req, unsigned int extra_flags) + __must_hold(&req->ctx->uring_lock) +{ + unsigned int issue_flags = IO_URING_F_NONBLOCK | + IO_URING_F_COMPLETE_DEFER | extra_flags; + int ret; + + ret = io_issue_sqe(req, issue_flags); + + /* + * We async punt it if the file wasn't marked NOWAIT, or if the file + * doesn't support non-blocking read/write attempts + */ + if (unlikely(ret)) + io_queue_async(req, issue_flags, ret); +} + +static void io_queue_sqe_fallback(struct io_kiocb *req) + __must_hold(&req->ctx->uring_lock) +{ + if (unlikely(req->flags & REQ_F_FAIL)) { + /* + * We don't submit, fail them all, for that replace hardlinks + * with normal links. Extra REQ_F_LINK is tolerated. + */ + req->flags &= ~REQ_F_HARDLINK; + req->flags |= REQ_F_LINK; + io_req_defer_failed(req, req->cqe.res); + } else { + /* can't fail with IO_URING_F_INLINE */ + io_req_sqe_copy(req, IO_URING_F_INLINE); + if (unlikely(req->ctx->drain_active)) + io_drain_req(req); + else + io_queue_iowq(req); + } +} + +/* + * Check SQE restrictions (opcode and flags). + * + * Returns 'true' if SQE is allowed, 'false' otherwise. + */ +static inline bool io_check_restriction(struct io_ring_ctx *ctx, + struct io_kiocb *req, + unsigned int sqe_flags) +{ + if (!test_bit(req->opcode, ctx->restrictions.sqe_op)) + return false; + + if ((sqe_flags & ctx->restrictions.sqe_flags_required) != + ctx->restrictions.sqe_flags_required) + return false; + + if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed | + ctx->restrictions.sqe_flags_required)) + return false; + + return true; +} + +static void io_init_drain(struct io_ring_ctx *ctx) +{ + struct io_kiocb *head = ctx->submit_state.link.head; + + ctx->drain_active = true; + if (head) { + /* + * If we need to drain a request in the middle of a link, drain + * the head request and the next request/link after the current + * link. Considering sequential execution of links, + * REQ_F_IO_DRAIN will be maintained for every request of our + * link. + */ + head->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC; + ctx->drain_next = true; + } +} + +static __cold int io_init_fail_req(struct io_kiocb *req, int err) +{ + /* ensure per-opcode data is cleared if we fail before prep */ + memset(&req->cmd.data, 0, sizeof(req->cmd.data)); + return err; +} + +static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, + const struct io_uring_sqe *sqe, unsigned int *left) + __must_hold(&ctx->uring_lock) +{ + const struct io_issue_def *def; + unsigned int sqe_flags; + int personality; + u8 opcode; + + req->ctx = ctx; + req->opcode = opcode = READ_ONCE(sqe->opcode); + /* same numerical values with corresponding REQ_F_*, safe to copy */ + sqe_flags = READ_ONCE(sqe->flags); + req->flags = (__force io_req_flags_t) sqe_flags; + req->cqe.user_data = READ_ONCE(sqe->user_data); + req->file = NULL; + req->tctx = current->io_uring; + req->cancel_seq_set = false; + req->async_data = NULL; + + if (unlikely(opcode >= IORING_OP_LAST)) { + req->opcode = 0; + return io_init_fail_req(req, -EINVAL); + } + opcode = array_index_nospec(opcode, IORING_OP_LAST); + + def = &io_issue_defs[opcode]; + if (def->is_128 && !(ctx->flags & IORING_SETUP_SQE128)) { + /* + * A 128b op on a non-128b SQ requires mixed SQE support as + * well as 2 contiguous entries. + */ + if (!(ctx->flags & IORING_SETUP_SQE_MIXED) || *left < 2 || + !(ctx->cached_sq_head & (ctx->sq_entries - 1))) + return io_init_fail_req(req, -EINVAL); + /* + * A 128b operation on a mixed SQ uses two entries, so we have + * to increment the head and cached refs, and decrement what's + * left. + */ + current->io_uring->cached_refs++; + ctx->cached_sq_head++; + (*left)--; + } + + if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) { + /* enforce forwards compatibility on users */ + if (sqe_flags & ~SQE_VALID_FLAGS) + return io_init_fail_req(req, -EINVAL); + if (sqe_flags & IOSQE_BUFFER_SELECT) { + if (!def->buffer_select) + return io_init_fail_req(req, -EOPNOTSUPP); + req->buf_index = READ_ONCE(sqe->buf_group); + } + if (sqe_flags & IOSQE_CQE_SKIP_SUCCESS) + ctx->drain_disabled = true; + if (sqe_flags & IOSQE_IO_DRAIN) { + if (ctx->drain_disabled) + return io_init_fail_req(req, -EOPNOTSUPP); + io_init_drain(ctx); + } + } + if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) { + if (ctx->restricted && !io_check_restriction(ctx, req, sqe_flags)) + return io_init_fail_req(req, -EACCES); + /* knock it to the slow queue path, will be drained there */ + if (ctx->drain_active) + req->flags |= REQ_F_FORCE_ASYNC; + /* if there is no link, we're at "next" request and need to drain */ + if (unlikely(ctx->drain_next) && !ctx->submit_state.link.head) { + ctx->drain_next = false; + ctx->drain_active = true; + req->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC; + } + } + + if (!def->ioprio && sqe->ioprio) + return io_init_fail_req(req, -EINVAL); + if (!def->iopoll && (ctx->flags & IORING_SETUP_IOPOLL)) + return io_init_fail_req(req, -EINVAL); + + if (def->needs_file) { + struct io_submit_state *state = &ctx->submit_state; + + req->cqe.fd = READ_ONCE(sqe->fd); + + /* + * Plug now if we have more than 2 IO left after this, and the + * target is potentially a read/write to block based storage. + */ + if (state->need_plug && def->plug) { + state->plug_started = true; + state->need_plug = false; + blk_start_plug_nr_ios(&state->plug, state->submit_nr); + } + } + + personality = READ_ONCE(sqe->personality); + if (personality) { + int ret; + + req->creds = xa_load(&ctx->personalities, personality); + if (!req->creds) + return io_init_fail_req(req, -EINVAL); + get_cred(req->creds); + ret = security_uring_override_creds(req->creds); + if (ret) { + put_cred(req->creds); + return io_init_fail_req(req, ret); + } + req->flags |= REQ_F_CREDS; + } + + return def->prep(req, sqe); +} + +static __cold int io_submit_fail_init(const struct io_uring_sqe *sqe, + struct io_kiocb *req, int ret) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_submit_link *link = &ctx->submit_state.link; + struct io_kiocb *head = link->head; + + trace_io_uring_req_failed(sqe, req, ret); + + /* + * Avoid breaking links in the middle as it renders links with SQPOLL + * unusable. Instead of failing eagerly, continue assembling the link if + * applicable and mark the head with REQ_F_FAIL. The link flushing code + * should find the flag and handle the rest. + */ + req_fail_link_node(req, ret); + if (head && !(head->flags & REQ_F_FAIL)) + req_fail_link_node(head, -ECANCELED); + + if (!(req->flags & IO_REQ_LINK_FLAGS)) { + if (head) { + link->last->link = req; + link->head = NULL; + req = head; + } + io_queue_sqe_fallback(req); + return ret; + } + + if (head) + link->last->link = req; + else + link->head = req; + link->last = req; + return 0; +} + +static inline int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, + const struct io_uring_sqe *sqe, unsigned int *left) + __must_hold(&ctx->uring_lock) +{ + struct io_submit_link *link = &ctx->submit_state.link; + int ret; + + ret = io_init_req(ctx, req, sqe, left); + if (unlikely(ret)) + return io_submit_fail_init(sqe, req, ret); + + trace_io_uring_submit_req(req); + + /* + * If we already have a head request, queue this one for async + * submittal once the head completes. If we don't have a head but + * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be + * submitted sync once the chain is complete. If none of those + * conditions are true (normal request), then just queue it. + */ + if (unlikely(link->head)) { + trace_io_uring_link(req, link->last); + io_req_sqe_copy(req, IO_URING_F_INLINE); + link->last->link = req; + link->last = req; + + if (req->flags & IO_REQ_LINK_FLAGS) + return 0; + /* last request of the link, flush it */ + req = link->head; + link->head = NULL; + if (req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)) + goto fallback; + + } else if (unlikely(req->flags & (IO_REQ_LINK_FLAGS | + REQ_F_FORCE_ASYNC | REQ_F_FAIL))) { + if (req->flags & IO_REQ_LINK_FLAGS) { + link->head = req; + link->last = req; + } else { +fallback: + io_queue_sqe_fallback(req); + } + return 0; + } + + io_queue_sqe(req, IO_URING_F_INLINE); + return 0; +} + +/* + * Batched submission is done, ensure local IO is flushed out. + */ +static void io_submit_state_end(struct io_ring_ctx *ctx) +{ + struct io_submit_state *state = &ctx->submit_state; + + if (unlikely(state->link.head)) + io_queue_sqe_fallback(state->link.head); + /* flush only after queuing links as they can generate completions */ + io_submit_flush_completions(ctx); + if (state->plug_started) + blk_finish_plug(&state->plug); +} + +/* + * Start submission side cache. + */ +static void io_submit_state_start(struct io_submit_state *state, + unsigned int max_ios) +{ + state->plug_started = false; + state->need_plug = max_ios > 2; + state->submit_nr = max_ios; + /* set only head, no need to init link_last in advance */ + state->link.head = NULL; +} + +static void io_commit_sqring(struct io_ring_ctx *ctx) +{ + struct io_rings *rings = ctx->rings; + + /* + * Ensure any loads from the SQEs are done at this point, + * since once we write the new head, the application could + * write new data to them. + */ + smp_store_release(&rings->sq.head, ctx->cached_sq_head); +} + +/* + * Fetch an sqe, if one is available. Note this returns a pointer to memory + * that is mapped by userspace. This means that care needs to be taken to + * ensure that reads are stable, as we cannot rely on userspace always + * being a good citizen. If members of the sqe are validated and then later + * used, it's important that those reads are done through READ_ONCE() to + * prevent a re-load down the line. + */ +static bool io_get_sqe(struct io_ring_ctx *ctx, const struct io_uring_sqe **sqe) +{ + unsigned mask = ctx->sq_entries - 1; + unsigned head = ctx->cached_sq_head++ & mask; + + if (static_branch_unlikely(&io_key_has_sqarray) && + (!(ctx->flags & IORING_SETUP_NO_SQARRAY))) { + head = READ_ONCE(ctx->sq_array[head]); + if (unlikely(head >= ctx->sq_entries)) { + WRITE_ONCE(ctx->rings->sq_dropped, + READ_ONCE(ctx->rings->sq_dropped) + 1); + return false; + } + head = array_index_nospec(head, ctx->sq_entries); + } + + /* + * The cached sq head (or cq tail) serves two purposes: + * + * 1) allows us to batch the cost of updating the user visible + * head updates. + * 2) allows the kernel side to track the head on its own, even + * though the application is the one updating it. + */ + + /* double index for 128-byte SQEs, twice as long */ + if (ctx->flags & IORING_SETUP_SQE128) + head <<= 1; + *sqe = &ctx->sq_sqes[head]; + return true; +} + +int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) + __must_hold(&ctx->uring_lock) +{ + unsigned int entries = io_sqring_entries(ctx); + unsigned int left; + int ret; + + entries = min(nr, entries); + if (unlikely(!entries)) + return 0; + + ret = left = entries; + io_get_task_refs(left); + io_submit_state_start(&ctx->submit_state, left); + + do { + const struct io_uring_sqe *sqe; + struct io_kiocb *req; + + if (unlikely(!io_alloc_req(ctx, &req))) + break; + if (unlikely(!io_get_sqe(ctx, &sqe))) { + io_req_add_to_cache(req, ctx); + break; + } + + /* + * Continue submitting even for sqe failure if the + * ring was setup with IORING_SETUP_SUBMIT_ALL + */ + if (unlikely(io_submit_sqe(ctx, req, sqe, &left)) && + !(ctx->flags & IORING_SETUP_SUBMIT_ALL)) { + left--; + break; + } + } while (--left); + + if (unlikely(left)) { + ret -= left; + /* try again if it submitted nothing and can't allocate a req */ + if (!ret && io_req_cache_empty(ctx)) + ret = -EAGAIN; + current->io_uring->cached_refs += left; + } + + io_submit_state_end(ctx); + /* Commit SQ ring head once we've consumed and submitted all SQEs */ + io_commit_sqring(ctx); + return ret; +} + +static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, + int wake_flags, void *key) +{ + struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, wq); + + /* + * Cannot safely flush overflowed CQEs from here, ensure we wake up + * the task, and the next invocation will do it. + */ + if (io_should_wake(iowq) || io_has_work(iowq->ctx)) + return autoremove_wake_function(curr, mode, wake_flags, key); + return -1; +} + +int io_run_task_work_sig(struct io_ring_ctx *ctx) +{ + if (io_local_work_pending(ctx)) { + __set_current_state(TASK_RUNNING); + if (io_run_local_work(ctx, INT_MAX, IO_LOCAL_TW_DEFAULT_MAX) > 0) + return 0; + } + if (io_run_task_work() > 0) + return 0; + if (task_sigpending(current)) + return -EINTR; + return 0; +} + +static bool current_pending_io(void) +{ + struct io_uring_task *tctx = current->io_uring; + + if (!tctx) + return false; + return percpu_counter_read_positive(&tctx->inflight); +} + +static enum hrtimer_restart io_cqring_timer_wakeup(struct hrtimer *timer) +{ + struct io_wait_queue *iowq = container_of(timer, struct io_wait_queue, t); + + WRITE_ONCE(iowq->hit_timeout, 1); + iowq->min_timeout = 0; + wake_up_process(iowq->wq.private); + return HRTIMER_NORESTART; +} + +/* + * Doing min_timeout portion. If we saw any timeouts, events, or have work, + * wake up. If not, and we have a normal timeout, switch to that and keep + * sleeping. + */ +static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer) +{ + struct io_wait_queue *iowq = container_of(timer, struct io_wait_queue, t); + struct io_ring_ctx *ctx = iowq->ctx; + + /* no general timeout, or shorter (or equal), we are done */ + if (iowq->timeout == KTIME_MAX || + ktime_compare(iowq->min_timeout, iowq->timeout) >= 0) + goto out_wake; + /* work we may need to run, wake function will see if we need to wake */ + if (io_has_work(ctx)) + goto out_wake; + /* got events since we started waiting, min timeout is done */ + if (iowq->cq_min_tail != READ_ONCE(ctx->rings->cq.tail)) + goto out_wake; + /* if we have any events and min timeout expired, we're done */ + if (io_cqring_events(ctx)) + goto out_wake; + + /* + * If using deferred task_work running and application is waiting on + * more than one request, ensure we reset it now where we are switching + * to normal sleeps. Any request completion post min_wait should wake + * the task and return. + */ + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) { + atomic_set(&ctx->cq_wait_nr, 1); + smp_mb(); + if (!llist_empty(&ctx->work_llist)) + goto out_wake; + } + + hrtimer_update_function(&iowq->t, io_cqring_timer_wakeup); + hrtimer_set_expires(timer, iowq->timeout); + return HRTIMER_RESTART; +out_wake: + return io_cqring_timer_wakeup(timer); +} + +static int io_cqring_schedule_timeout(struct io_wait_queue *iowq, + clockid_t clock_id, ktime_t start_time) +{ + ktime_t timeout; + + if (iowq->min_timeout) { + timeout = ktime_add_ns(iowq->min_timeout, start_time); + hrtimer_setup_on_stack(&iowq->t, io_cqring_min_timer_wakeup, clock_id, + HRTIMER_MODE_ABS); + } else { + timeout = iowq->timeout; + hrtimer_setup_on_stack(&iowq->t, io_cqring_timer_wakeup, clock_id, + HRTIMER_MODE_ABS); + } + + hrtimer_set_expires_range_ns(&iowq->t, timeout, 0); + hrtimer_start_expires(&iowq->t, HRTIMER_MODE_ABS); + + if (!READ_ONCE(iowq->hit_timeout)) + schedule(); + + hrtimer_cancel(&iowq->t); + destroy_hrtimer_on_stack(&iowq->t); + __set_current_state(TASK_RUNNING); + + return READ_ONCE(iowq->hit_timeout) ? -ETIME : 0; +} + +struct ext_arg { + size_t argsz; + struct timespec64 ts; + const sigset_t __user *sig; + ktime_t min_time; + bool ts_set; + bool iowait; +}; + +static int __io_cqring_wait_schedule(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq, + struct ext_arg *ext_arg, + ktime_t start_time) +{ + int ret = 0; + + /* + * Mark us as being in io_wait if we have pending requests, so cpufreq + * can take into account that the task is waiting for IO - turns out + * to be important for low QD IO. + */ + if (ext_arg->iowait && current_pending_io()) + current->in_iowait = 1; + if (iowq->timeout != KTIME_MAX || iowq->min_timeout) + ret = io_cqring_schedule_timeout(iowq, ctx->clockid, start_time); + else + schedule(); + current->in_iowait = 0; + return ret; +} + +/* If this returns > 0, the caller should retry */ +static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq, + struct ext_arg *ext_arg, + ktime_t start_time) +{ + if (unlikely(READ_ONCE(ctx->check_cq))) + return 1; + if (unlikely(io_local_work_pending(ctx))) + return 1; + if (unlikely(task_work_pending(current))) + return 1; + if (unlikely(task_sigpending(current))) + return -EINTR; + if (unlikely(io_should_wake(iowq))) + return 0; + + return __io_cqring_wait_schedule(ctx, iowq, ext_arg, start_time); +} + +/* + * Wait until events become available, if we don't already have some. The + * application must reap them itself, as they reside on the shared cq ring. + */ +static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags, + struct ext_arg *ext_arg) +{ + struct io_wait_queue iowq; + struct io_rings *rings = ctx->rings; + ktime_t start_time; + int ret; + + min_events = min_t(int, min_events, ctx->cq_entries); + + if (!io_allowed_run_tw(ctx)) + return -EEXIST; + if (io_local_work_pending(ctx)) + io_run_local_work(ctx, min_events, + max(IO_LOCAL_TW_DEFAULT_MAX, min_events)); + io_run_task_work(); + + if (unlikely(test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq))) + io_cqring_do_overflow_flush(ctx); + if (__io_cqring_events_user(ctx) >= min_events) + return 0; + + init_waitqueue_func_entry(&iowq.wq, io_wake_function); + iowq.wq.private = current; + INIT_LIST_HEAD(&iowq.wq.entry); + iowq.ctx = ctx; + iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events; + iowq.cq_min_tail = READ_ONCE(ctx->rings->cq.tail); + iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); + iowq.hit_timeout = 0; + iowq.min_timeout = ext_arg->min_time; + iowq.timeout = KTIME_MAX; + start_time = io_get_time(ctx); + + if (ext_arg->ts_set) { + iowq.timeout = timespec64_to_ktime(ext_arg->ts); + if (!(flags & IORING_ENTER_ABS_TIMER)) + iowq.timeout = ktime_add(iowq.timeout, start_time); + } + + if (ext_arg->sig) { +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = set_compat_user_sigmask((const compat_sigset_t __user *)ext_arg->sig, + ext_arg->argsz); + else +#endif + ret = set_user_sigmask(ext_arg->sig, ext_arg->argsz); + + if (ret) + return ret; + } + + io_napi_busy_loop(ctx, &iowq); + + trace_io_uring_cqring_wait(ctx, min_events); + do { + unsigned long check_cq; + int nr_wait; + + /* if min timeout has been hit, don't reset wait count */ + if (!iowq.hit_timeout) + nr_wait = (int) iowq.cq_tail - + READ_ONCE(ctx->rings->cq.tail); + else + nr_wait = 1; + + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) { + atomic_set(&ctx->cq_wait_nr, nr_wait); + set_current_state(TASK_INTERRUPTIBLE); + } else { + prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq, + TASK_INTERRUPTIBLE); + } + + ret = io_cqring_wait_schedule(ctx, &iowq, ext_arg, start_time); + __set_current_state(TASK_RUNNING); + atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT); + + /* + * Run task_work after scheduling and before io_should_wake(). + * If we got woken because of task_work being processed, run it + * now rather than let the caller do another wait loop. + */ + if (io_local_work_pending(ctx)) + io_run_local_work(ctx, nr_wait, nr_wait); + io_run_task_work(); + + /* + * Non-local task_work will be run on exit to userspace, but + * if we're using DEFER_TASKRUN, then we could have waited + * with a timeout for a number of requests. If the timeout + * hits, we could have some requests ready to process. Ensure + * this break is _after_ we have run task_work, to avoid + * deferring running potentially pending requests until the + * next time we wait for events. + */ + if (ret < 0) + break; + + check_cq = READ_ONCE(ctx->check_cq); + if (unlikely(check_cq)) { + /* let the caller flush overflows, retry */ + if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT)) + io_cqring_do_overflow_flush(ctx); + if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) { + ret = -EBADR; + break; + } + } + + if (io_should_wake(&iowq)) { + ret = 0; + break; + } + cond_resched(); + } while (1); + + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + finish_wait(&ctx->cq_wait, &iowq.wq); + restore_saved_sigmask_unless(ret == -EINTR); + + return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; +} + +static void io_rings_free(struct io_ring_ctx *ctx) +{ + io_free_region(ctx->user, &ctx->sq_region); + io_free_region(ctx->user, &ctx->ring_region); + ctx->rings = NULL; + ctx->sq_sqes = NULL; +} + +static int rings_size(unsigned int flags, unsigned int sq_entries, + unsigned int cq_entries, struct io_rings_layout *rl) +{ + struct io_rings *rings; + size_t sqe_size; + size_t off; + + if (flags & IORING_SETUP_CQE_MIXED) { + if (cq_entries < 2) + return -EOVERFLOW; + } + if (flags & IORING_SETUP_SQE_MIXED) { + if (sq_entries < 2) + return -EOVERFLOW; + } + + rl->sq_array_offset = SIZE_MAX; + + sqe_size = sizeof(struct io_uring_sqe); + if (flags & IORING_SETUP_SQE128) + sqe_size *= 2; + + rl->sq_size = array_size(sqe_size, sq_entries); + if (rl->sq_size == SIZE_MAX) + return -EOVERFLOW; + + off = struct_size(rings, cqes, cq_entries); + if (flags & IORING_SETUP_CQE32) + off = size_mul(off, 2); + if (off == SIZE_MAX) + return -EOVERFLOW; + +#ifdef CONFIG_SMP + off = ALIGN(off, SMP_CACHE_BYTES); + if (off == 0) + return -EOVERFLOW; +#endif + + if (!(flags & IORING_SETUP_NO_SQARRAY)) { + size_t sq_array_size; + + rl->sq_array_offset = off; + + sq_array_size = array_size(sizeof(u32), sq_entries); + off = size_add(off, sq_array_size); + if (off == SIZE_MAX) + return -EOVERFLOW; + } + + rl->rings_size = off; + return 0; +} + +static __cold void __io_req_caches_free(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req; + int nr = 0; + + while (!io_req_cache_empty(ctx)) { + req = io_extract_req(ctx); + io_poison_req(req); + kmem_cache_free(req_cachep, req); + nr++; + } + if (nr) { + ctx->nr_req_allocated -= nr; + percpu_ref_put_many(&ctx->refs, nr); + } +} + +static __cold void io_req_caches_free(struct io_ring_ctx *ctx) +{ + guard(mutex)(&ctx->uring_lock); + __io_req_caches_free(ctx); +} + +static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx) +{ + io_sq_thread_finish(ctx); + + mutex_lock(&ctx->uring_lock); + io_sqe_buffers_unregister(ctx); + io_sqe_files_unregister(ctx); + io_unregister_zcrx_ifqs(ctx); + io_cqring_overflow_kill(ctx); + io_eventfd_unregister(ctx); + io_free_alloc_caches(ctx); + io_destroy_buffers(ctx); + io_free_region(ctx->user, &ctx->param_region); + mutex_unlock(&ctx->uring_lock); + if (ctx->sq_creds) + put_cred(ctx->sq_creds); + if (ctx->submitter_task) + put_task_struct(ctx->submitter_task); + + WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list)); + + if (ctx->mm_account) { + mmdrop(ctx->mm_account); + ctx->mm_account = NULL; + } + io_rings_free(ctx); + + if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) + static_branch_dec(&io_key_has_sqarray); + + percpu_ref_exit(&ctx->refs); + free_uid(ctx->user); + io_req_caches_free(ctx); + + WARN_ON_ONCE(ctx->nr_req_allocated); + + if (ctx->hash_map) + io_wq_put_hash(ctx->hash_map); + io_napi_free(ctx); + kvfree(ctx->cancel_table.hbs); + xa_destroy(&ctx->io_bl_xa); + kfree(ctx); +} + +static __cold void io_activate_pollwq_cb(struct callback_head *cb) +{ + struct io_ring_ctx *ctx = container_of(cb, struct io_ring_ctx, + poll_wq_task_work); + + mutex_lock(&ctx->uring_lock); + ctx->poll_activated = true; + mutex_unlock(&ctx->uring_lock); + + /* + * Wake ups for some events between start of polling and activation + * might've been lost due to loose synchronisation. + */ + wake_up_all(&ctx->poll_wq); + percpu_ref_put(&ctx->refs); +} + +__cold void io_activate_pollwq(struct io_ring_ctx *ctx) +{ + spin_lock(&ctx->completion_lock); + /* already activated or in progress */ + if (ctx->poll_activated || ctx->poll_wq_task_work.func) + goto out; + if (WARN_ON_ONCE(!ctx->task_complete)) + goto out; + if (!ctx->submitter_task) + goto out; + /* + * with ->submitter_task only the submitter task completes requests, we + * only need to sync with it, which is done by injecting a tw + */ + init_task_work(&ctx->poll_wq_task_work, io_activate_pollwq_cb); + percpu_ref_get(&ctx->refs); + if (task_work_add(ctx->submitter_task, &ctx->poll_wq_task_work, TWA_SIGNAL)) + percpu_ref_put(&ctx->refs); +out: + spin_unlock(&ctx->completion_lock); +} + +static __poll_t io_uring_poll(struct file *file, poll_table *wait) +{ + struct io_ring_ctx *ctx = file->private_data; + __poll_t mask = 0; + + if (unlikely(!ctx->poll_activated)) + io_activate_pollwq(ctx); + /* + * provides mb() which pairs with barrier from wq_has_sleeper + * call in io_commit_cqring + */ + poll_wait(file, &ctx->poll_wq, wait); + + if (!io_sqring_full(ctx)) + mask |= EPOLLOUT | EPOLLWRNORM; + + /* + * Don't flush cqring overflow list here, just do a simple check. + * Otherwise there could possible be ABBA deadlock: + * CPU0 CPU1 + * ---- ---- + * lock(&ctx->uring_lock); + * lock(&ep->mtx); + * lock(&ctx->uring_lock); + * lock(&ep->mtx); + * + * Users may get EPOLLIN meanwhile seeing nothing in cqring, this + * pushes them to do the flush. + */ + + if (__io_cqring_events_user(ctx) || io_has_work(ctx)) + mask |= EPOLLIN | EPOLLRDNORM; + + return mask; +} + +struct io_tctx_exit { + struct callback_head task_work; + struct completion completion; + struct io_ring_ctx *ctx; +}; + +static __cold void io_tctx_exit_cb(struct callback_head *cb) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_exit *work; + + work = container_of(cb, struct io_tctx_exit, task_work); + /* + * When @in_cancel, we're in cancellation and it's racy to remove the + * node. It'll be removed by the end of cancellation, just ignore it. + * tctx can be NULL if the queueing of this task_work raced with + * work cancelation off the exec path. + */ + if (tctx && !atomic_read(&tctx->in_cancel)) + io_uring_del_tctx_node((unsigned long)work->ctx); + complete(&work->completion); +} + +static __cold void io_ring_exit_work(struct work_struct *work) +{ + struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work); + unsigned long timeout = jiffies + HZ * 60 * 5; + unsigned long interval = HZ / 20; + struct io_tctx_exit exit; + struct io_tctx_node *node; + int ret; + + /* + * If we're doing polled IO and end up having requests being + * submitted async (out-of-line), then completions can come in while + * we're waiting for refs to drop. We need to reap these manually, + * as nobody else will be looking for them. + */ + do { + if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) { + mutex_lock(&ctx->uring_lock); + io_cqring_overflow_kill(ctx); + mutex_unlock(&ctx->uring_lock); + } + + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) + io_move_task_work_from_local(ctx); + + /* The SQPOLL thread never reaches this path */ + while (io_uring_try_cancel_requests(ctx, NULL, true, false)) + cond_resched(); + + if (ctx->sq_data) { + struct io_sq_data *sqd = ctx->sq_data; + struct task_struct *tsk; + + io_sq_thread_park(sqd); + tsk = sqpoll_task_locked(sqd); + if (tsk && tsk->io_uring && tsk->io_uring->io_wq) + io_wq_cancel_cb(tsk->io_uring->io_wq, + io_cancel_ctx_cb, ctx, true); + io_sq_thread_unpark(sqd); + } + + io_req_caches_free(ctx); + + if (WARN_ON_ONCE(time_after(jiffies, timeout))) { + /* there is little hope left, don't run it too often */ + interval = HZ * 60; + } + /* + * This is really an uninterruptible wait, as it has to be + * complete. But it's also run from a kworker, which doesn't + * take signals, so it's fine to make it interruptible. This + * avoids scenarios where we knowingly can wait much longer + * on completions, for example if someone does a SIGSTOP on + * a task that needs to finish task_work to make this loop + * complete. That's a synthetic situation that should not + * cause a stuck task backtrace, and hence a potential panic + * on stuck tasks if that is enabled. + */ + } while (!wait_for_completion_interruptible_timeout(&ctx->ref_comp, interval)); + + init_completion(&exit.completion); + init_task_work(&exit.task_work, io_tctx_exit_cb); + exit.ctx = ctx; + + mutex_lock(&ctx->uring_lock); + while (!list_empty(&ctx->tctx_list)) { + WARN_ON_ONCE(time_after(jiffies, timeout)); + + node = list_first_entry(&ctx->tctx_list, struct io_tctx_node, + ctx_node); + /* don't spin on a single task if cancellation failed */ + list_rotate_left(&ctx->tctx_list); + ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL); + if (WARN_ON_ONCE(ret)) + continue; + + mutex_unlock(&ctx->uring_lock); + /* + * See comment above for + * wait_for_completion_interruptible_timeout() on why this + * wait is marked as interruptible. + */ + wait_for_completion_interruptible(&exit.completion); + mutex_lock(&ctx->uring_lock); + } + mutex_unlock(&ctx->uring_lock); + spin_lock(&ctx->completion_lock); + spin_unlock(&ctx->completion_lock); + + /* pairs with RCU read section in io_req_local_work_add() */ + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) + synchronize_rcu(); + + io_ring_ctx_free(ctx); +} + +static __cold void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) +{ + unsigned long index; + struct creds *creds; + + mutex_lock(&ctx->uring_lock); + percpu_ref_kill(&ctx->refs); + xa_for_each(&ctx->personalities, index, creds) + io_unregister_personality(ctx, index); + mutex_unlock(&ctx->uring_lock); + + flush_delayed_work(&ctx->fallback_work); + + INIT_WORK(&ctx->exit_work, io_ring_exit_work); + /* + * Use system_dfl_wq to avoid spawning tons of event kworkers + * if we're exiting a ton of rings at the same time. It just adds + * noise and overhead, there's no discernable change in runtime + * over using system_percpu_wq. + */ + queue_work(iou_wq, &ctx->exit_work); +} + +static int io_uring_release(struct inode *inode, struct file *file) +{ + struct io_ring_ctx *ctx = file->private_data; + + file->private_data = NULL; + io_ring_ctx_wait_and_kill(ctx); + return 0; +} + +static struct io_uring_reg_wait *io_get_ext_arg_reg(struct io_ring_ctx *ctx, + const struct io_uring_getevents_arg __user *uarg) +{ + unsigned long size = sizeof(struct io_uring_reg_wait); + unsigned long offset = (uintptr_t)uarg; + unsigned long end; + + if (unlikely(offset % sizeof(long))) + return ERR_PTR(-EFAULT); + + /* also protects from NULL ->cq_wait_arg as the size would be 0 */ + if (unlikely(check_add_overflow(offset, size, &end) || + end > ctx->cq_wait_size)) + return ERR_PTR(-EFAULT); + + offset = array_index_nospec(offset, ctx->cq_wait_size - size); + return ctx->cq_wait_arg + offset; +} + +static int io_validate_ext_arg(struct io_ring_ctx *ctx, unsigned flags, + const void __user *argp, size_t argsz) +{ + struct io_uring_getevents_arg arg; + + if (!(flags & IORING_ENTER_EXT_ARG)) + return 0; + if (flags & IORING_ENTER_EXT_ARG_REG) + return -EINVAL; + if (argsz != sizeof(arg)) + return -EINVAL; + if (copy_from_user(&arg, argp, sizeof(arg))) + return -EFAULT; + return 0; +} + +static int io_get_ext_arg(struct io_ring_ctx *ctx, unsigned flags, + const void __user *argp, struct ext_arg *ext_arg) +{ + const struct io_uring_getevents_arg __user *uarg = argp; + struct io_uring_getevents_arg arg; + + ext_arg->iowait = !(flags & IORING_ENTER_NO_IOWAIT); + + /* + * If EXT_ARG isn't set, then we have no timespec and the argp pointer + * is just a pointer to the sigset_t. + */ + if (!(flags & IORING_ENTER_EXT_ARG)) { + ext_arg->sig = (const sigset_t __user *) argp; + return 0; + } + + if (flags & IORING_ENTER_EXT_ARG_REG) { + struct io_uring_reg_wait *w; + + if (ext_arg->argsz != sizeof(struct io_uring_reg_wait)) + return -EINVAL; + w = io_get_ext_arg_reg(ctx, argp); + if (IS_ERR(w)) + return PTR_ERR(w); + + if (w->flags & ~IORING_REG_WAIT_TS) + return -EINVAL; + ext_arg->min_time = READ_ONCE(w->min_wait_usec) * NSEC_PER_USEC; + ext_arg->sig = u64_to_user_ptr(READ_ONCE(w->sigmask)); + ext_arg->argsz = READ_ONCE(w->sigmask_sz); + if (w->flags & IORING_REG_WAIT_TS) { + ext_arg->ts.tv_sec = READ_ONCE(w->ts.tv_sec); + ext_arg->ts.tv_nsec = READ_ONCE(w->ts.tv_nsec); + ext_arg->ts_set = true; + } + return 0; + } + + /* + * EXT_ARG is set - ensure we agree on the size of it and copy in our + * timespec and sigset_t pointers if good. + */ + if (ext_arg->argsz != sizeof(arg)) + return -EINVAL; +#ifdef CONFIG_64BIT + if (!user_access_begin(uarg, sizeof(*uarg))) + return -EFAULT; + unsafe_get_user(arg.sigmask, &uarg->sigmask, uaccess_end); + unsafe_get_user(arg.sigmask_sz, &uarg->sigmask_sz, uaccess_end); + unsafe_get_user(arg.min_wait_usec, &uarg->min_wait_usec, uaccess_end); + unsafe_get_user(arg.ts, &uarg->ts, uaccess_end); + user_access_end(); +#else + if (copy_from_user(&arg, uarg, sizeof(arg))) + return -EFAULT; +#endif + ext_arg->min_time = arg.min_wait_usec * NSEC_PER_USEC; + ext_arg->sig = u64_to_user_ptr(arg.sigmask); + ext_arg->argsz = arg.sigmask_sz; + if (arg.ts) { + if (get_timespec64(&ext_arg->ts, u64_to_user_ptr(arg.ts))) + return -EFAULT; + ext_arg->ts_set = true; + } + return 0; +#ifdef CONFIG_64BIT +uaccess_end: + user_access_end(); + return -EFAULT; +#endif +} + +SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, + u32, min_complete, u32, flags, const void __user *, argp, + size_t, argsz) +{ + struct io_ring_ctx *ctx; + struct file *file; + long ret; + + if (unlikely(flags & ~IORING_ENTER_FLAGS)) + return -EINVAL; + + /* + * Ring fd has been registered via IORING_REGISTER_RING_FDS, we + * need only dereference our task private array to find it. + */ + if (flags & IORING_ENTER_REGISTERED_RING) { + struct io_uring_task *tctx = current->io_uring; + + if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) + return -EINVAL; + fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); + file = tctx->registered_rings[fd]; + if (unlikely(!file)) + return -EBADF; + } else { + file = fget(fd); + if (unlikely(!file)) + return -EBADF; + ret = -EOPNOTSUPP; + if (unlikely(!io_is_uring_fops(file))) + goto out; + } + + ctx = file->private_data; + ret = -EBADFD; + if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED)) + goto out; + + /* + * For SQ polling, the thread will do all submissions and completions. + * Just return the requested submit count, and wake the thread if + * we were asked to. + */ + ret = 0; + if (ctx->flags & IORING_SETUP_SQPOLL) { + if (unlikely(ctx->sq_data->thread == NULL)) { + ret = -EOWNERDEAD; + goto out; + } + if (flags & IORING_ENTER_SQ_WAKEUP) + wake_up(&ctx->sq_data->wait); + if (flags & IORING_ENTER_SQ_WAIT) + io_sqpoll_wait_sq(ctx); + + ret = to_submit; + } else if (to_submit) { + ret = io_uring_add_tctx_node(ctx); + if (unlikely(ret)) + goto out; + + mutex_lock(&ctx->uring_lock); + ret = io_submit_sqes(ctx, to_submit); + if (ret != to_submit) { + mutex_unlock(&ctx->uring_lock); + goto out; + } + if (flags & IORING_ENTER_GETEVENTS) { + if (ctx->syscall_iopoll) + goto iopoll_locked; + /* + * Ignore errors, we'll soon call io_cqring_wait() and + * it should handle ownership problems if any. + */ + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) + (void)io_run_local_work_locked(ctx, min_complete); + } + mutex_unlock(&ctx->uring_lock); + } + + if (flags & IORING_ENTER_GETEVENTS) { + int ret2; + + if (ctx->syscall_iopoll) { + /* + * We disallow the app entering submit/complete with + * polling, but we still need to lock the ring to + * prevent racing with polled issue that got punted to + * a workqueue. + */ + mutex_lock(&ctx->uring_lock); +iopoll_locked: + ret2 = io_validate_ext_arg(ctx, flags, argp, argsz); + if (likely(!ret2)) + ret2 = io_iopoll_check(ctx, min_complete); + mutex_unlock(&ctx->uring_lock); + } else { + struct ext_arg ext_arg = { .argsz = argsz }; + + ret2 = io_get_ext_arg(ctx, flags, argp, &ext_arg); + if (likely(!ret2)) + ret2 = io_cqring_wait(ctx, min_complete, flags, + &ext_arg); + } + + if (!ret) { + ret = ret2; + + /* + * EBADR indicates that one or more CQE were dropped. + * Once the user has been informed we can clear the bit + * as they are obviously ok with those drops. + */ + if (unlikely(ret2 == -EBADR)) + clear_bit(IO_CHECK_CQ_DROPPED_BIT, + &ctx->check_cq); + } + } +out: + if (!(flags & IORING_ENTER_REGISTERED_RING)) + fput(file); + return ret; +} + +static const struct file_operations io_uring_fops = { + .release = io_uring_release, + .mmap = io_uring_mmap, + .get_unmapped_area = io_uring_get_unmapped_area, +#ifndef CONFIG_MMU + .mmap_capabilities = io_uring_nommu_mmap_capabilities, +#endif + .poll = io_uring_poll, +#ifdef CONFIG_PROC_FS + .show_fdinfo = io_uring_show_fdinfo, +#endif +}; + +bool io_is_uring_fops(struct file *file) +{ + return file->f_op == &io_uring_fops; +} + +static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx, + struct io_ctx_config *config) +{ + struct io_uring_params *p = &config->p; + struct io_rings_layout *rl = &config->layout; + struct io_uring_region_desc rd; + struct io_rings *rings; + int ret; + + /* make sure these are sane, as we already accounted them */ + ctx->sq_entries = p->sq_entries; + ctx->cq_entries = p->cq_entries; + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(rl->rings_size); + if (ctx->flags & IORING_SETUP_NO_MMAP) { + rd.user_addr = p->cq_off.user_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &ctx->ring_region, &rd, IORING_OFF_CQ_RING); + if (ret) + return ret; + ctx->rings = rings = io_region_get_ptr(&ctx->ring_region); + if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) + ctx->sq_array = (u32 *)((char *)rings + rl->sq_array_offset); + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(rl->sq_size); + if (ctx->flags & IORING_SETUP_NO_MMAP) { + rd.user_addr = p->sq_off.user_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &ctx->sq_region, &rd, IORING_OFF_SQES); + if (ret) { + io_rings_free(ctx); + return ret; + } + ctx->sq_sqes = io_region_get_ptr(&ctx->sq_region); + + memset(rings, 0, sizeof(*rings)); + WRITE_ONCE(rings->sq_ring_mask, ctx->sq_entries - 1); + WRITE_ONCE(rings->cq_ring_mask, ctx->cq_entries - 1); + WRITE_ONCE(rings->sq_ring_entries, ctx->sq_entries); + WRITE_ONCE(rings->cq_ring_entries, ctx->cq_entries); + return 0; +} + +static int io_uring_install_fd(struct file *file) +{ + int fd; + + fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC); + if (fd < 0) + return fd; + fd_install(fd, file); + return fd; +} + +/* + * Allocate an anonymous fd, this is what constitutes the application + * visible backing of an io_uring instance. The application mmaps this + * fd to gain access to the SQ/CQ ring details. + */ +static struct file *io_uring_get_file(struct io_ring_ctx *ctx) +{ + /* Create a new inode so that the LSM can block the creation. */ + return anon_inode_create_getfile("[io_uring]", &io_uring_fops, ctx, + O_RDWR | O_CLOEXEC, NULL); +} + +static int io_uring_sanitise_params(struct io_uring_params *p) +{ + unsigned flags = p->flags; + + if (flags & ~IORING_SETUP_FLAGS) + return -EINVAL; + + /* There is no way to mmap rings without a real fd */ + if ((flags & IORING_SETUP_REGISTERED_FD_ONLY) && + !(flags & IORING_SETUP_NO_MMAP)) + return -EINVAL; + + if (flags & IORING_SETUP_SQPOLL) { + /* IPI related flags don't make sense with SQPOLL */ + if (flags & (IORING_SETUP_COOP_TASKRUN | + IORING_SETUP_TASKRUN_FLAG | + IORING_SETUP_DEFER_TASKRUN)) + return -EINVAL; + } + + if (flags & IORING_SETUP_TASKRUN_FLAG) { + if (!(flags & (IORING_SETUP_COOP_TASKRUN | + IORING_SETUP_DEFER_TASKRUN))) + return -EINVAL; + } + + /* HYBRID_IOPOLL only valid with IOPOLL */ + if ((flags & IORING_SETUP_HYBRID_IOPOLL) && !(flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + + /* + * For DEFER_TASKRUN we require the completion task to be the same as + * the submission task. This implies that there is only one submitter. + */ + if ((flags & IORING_SETUP_DEFER_TASKRUN) && + !(flags & IORING_SETUP_SINGLE_ISSUER)) + return -EINVAL; + + /* + * Nonsensical to ask for CQE32 and mixed CQE support, it's not + * supported to post 16b CQEs on a ring setup with CQE32. + */ + if ((flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED)) == + (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED)) + return -EINVAL; + /* + * Nonsensical to ask for SQE128 and mixed SQE support, it's not + * supported to post 64b SQEs on a ring setup with SQE128. + */ + if ((flags & (IORING_SETUP_SQE128|IORING_SETUP_SQE_MIXED)) == + (IORING_SETUP_SQE128|IORING_SETUP_SQE_MIXED)) + return -EINVAL; + + return 0; +} + +static int io_uring_fill_params(struct io_uring_params *p) +{ + unsigned entries = p->sq_entries; + + if (!entries) + return -EINVAL; + if (entries > IORING_MAX_ENTRIES) { + if (!(p->flags & IORING_SETUP_CLAMP)) + return -EINVAL; + entries = IORING_MAX_ENTRIES; + } + + /* + * Use twice as many entries for the CQ ring. It's possible for the + * application to drive a higher depth than the size of the SQ ring, + * since the sqes are only used at submission time. This allows for + * some flexibility in overcommitting a bit. If the application has + * set IORING_SETUP_CQSIZE, it will have passed in the desired number + * of CQ ring entries manually. + */ + p->sq_entries = roundup_pow_of_two(entries); + if (p->flags & IORING_SETUP_CQSIZE) { + /* + * If IORING_SETUP_CQSIZE is set, we do the same roundup + * to a power-of-two, if it isn't already. We do NOT impose + * any cq vs sq ring sizing. + */ + if (!p->cq_entries) + return -EINVAL; + if (p->cq_entries > IORING_MAX_CQ_ENTRIES) { + if (!(p->flags & IORING_SETUP_CLAMP)) + return -EINVAL; + p->cq_entries = IORING_MAX_CQ_ENTRIES; + } + p->cq_entries = roundup_pow_of_two(p->cq_entries); + if (p->cq_entries < p->sq_entries) + return -EINVAL; + } else { + p->cq_entries = 2 * p->sq_entries; + } + + return 0; +} + +int io_prepare_config(struct io_ctx_config *config) +{ + struct io_uring_params *p = &config->p; + int ret; + + ret = io_uring_sanitise_params(p); + if (ret) + return ret; + + ret = io_uring_fill_params(p); + if (ret) + return ret; + + ret = rings_size(p->flags, p->sq_entries, p->cq_entries, + &config->layout); + if (ret) + return ret; + + p->sq_off.head = offsetof(struct io_rings, sq.head); + p->sq_off.tail = offsetof(struct io_rings, sq.tail); + p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); + p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); + p->sq_off.flags = offsetof(struct io_rings, sq_flags); + p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); + p->sq_off.resv1 = 0; + if (!(p->flags & IORING_SETUP_NO_MMAP)) + p->sq_off.user_addr = 0; + + p->cq_off.head = offsetof(struct io_rings, cq.head); + p->cq_off.tail = offsetof(struct io_rings, cq.tail); + p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); + p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); + p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); + p->cq_off.cqes = offsetof(struct io_rings, cqes); + p->cq_off.flags = offsetof(struct io_rings, cq_flags); + p->cq_off.resv1 = 0; + if (!(p->flags & IORING_SETUP_NO_MMAP)) + p->cq_off.user_addr = 0; + if (!(p->flags & IORING_SETUP_NO_SQARRAY)) + p->sq_off.array = config->layout.sq_array_offset; + + return 0; +} + +static __cold int io_uring_create(struct io_ctx_config *config) +{ + struct io_uring_params *p = &config->p; + struct io_ring_ctx *ctx; + struct io_uring_task *tctx; + struct file *file; + int ret; + + ret = io_prepare_config(config); + if (ret) + return ret; + + ctx = io_ring_ctx_alloc(p); + if (!ctx) + return -ENOMEM; + + ctx->clockid = CLOCK_MONOTONIC; + ctx->clock_offset = 0; + + if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) + static_branch_inc(&io_key_has_sqarray); + + if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) && + !(ctx->flags & IORING_SETUP_IOPOLL) && + !(ctx->flags & IORING_SETUP_SQPOLL)) + ctx->task_complete = true; + + if (ctx->task_complete || (ctx->flags & IORING_SETUP_IOPOLL)) + ctx->lockless_cq = true; + + /* + * lazy poll_wq activation relies on ->task_complete for synchronisation + * purposes, see io_activate_pollwq() + */ + if (!ctx->task_complete) + ctx->poll_activated = true; + + /* + * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user + * space applications don't need to do io completion events + * polling again, they can rely on io_sq_thread to do polling + * work, which can reduce cpu usage and uring_lock contention. + */ + if (ctx->flags & IORING_SETUP_IOPOLL && + !(ctx->flags & IORING_SETUP_SQPOLL)) + ctx->syscall_iopoll = 1; + + ctx->compat = in_compat_syscall(); + if (!ns_capable_noaudit(&init_user_ns, CAP_IPC_LOCK)) + ctx->user = get_uid(current_user()); + + /* + * For SQPOLL, we just need a wakeup, always. For !SQPOLL, if + * COOP_TASKRUN is set, then IPIs are never needed by the app. + */ + if (ctx->flags & (IORING_SETUP_SQPOLL|IORING_SETUP_COOP_TASKRUN)) + ctx->notify_method = TWA_SIGNAL_NO_IPI; + else + ctx->notify_method = TWA_SIGNAL; + + /* + * This is just grabbed for accounting purposes. When a process exits, + * the mm is exited and dropped before the files, hence we need to hang + * on to this mm purely for the purposes of being able to unaccount + * memory (locked/pinned vm). It's not used for anything else. + */ + mmgrab(current->mm); + ctx->mm_account = current->mm; + + ret = io_allocate_scq_urings(ctx, config); + if (ret) + goto err; + + ret = io_sq_offload_create(ctx, p); + if (ret) + goto err; + + p->features = IORING_FEAT_FLAGS; + + if (copy_to_user(config->uptr, p, sizeof(*p))) { + ret = -EFAULT; + goto err; + } + + if (ctx->flags & IORING_SETUP_SINGLE_ISSUER + && !(ctx->flags & IORING_SETUP_R_DISABLED)) { + /* + * Unlike io_register_enable_rings(), don't need WRITE_ONCE() + * since ctx isn't yet accessible from other tasks + */ + ctx->submitter_task = get_task_struct(current); + } + + file = io_uring_get_file(ctx); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto err; + } + + ret = __io_uring_add_tctx_node(ctx); + if (ret) + goto err_fput; + tctx = current->io_uring; + + /* + * Install ring fd as the very last thing, so we don't risk someone + * having closed it before we finish setup + */ + if (p->flags & IORING_SETUP_REGISTERED_FD_ONLY) + ret = io_ring_add_registered_file(tctx, file, 0, IO_RINGFD_REG_MAX); + else + ret = io_uring_install_fd(file); + if (ret < 0) + goto err_fput; + + trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); + return ret; +err: + io_ring_ctx_wait_and_kill(ctx); + return ret; +err_fput: + fput(file); + return ret; +} + +/* + * Sets up an aio uring context, and returns the fd. Applications asks for a + * ring size, we return the actual sq/cq ring sizes (among other things) in the + * params structure passed in. + */ +static long io_uring_setup(u32 entries, struct io_uring_params __user *params) +{ + struct io_ctx_config config; + + memset(&config, 0, sizeof(config)); + + if (copy_from_user(&config.p, params, sizeof(config.p))) + return -EFAULT; + + if (!mem_is_zero(&config.p.resv, sizeof(config.p.resv))) + return -EINVAL; + + config.p.sq_entries = entries; + config.uptr = params; + return io_uring_create(&config); +} + +static inline int io_uring_allowed(void) +{ + int disabled = READ_ONCE(sysctl_io_uring_disabled); + kgid_t io_uring_group; + + if (disabled == 2) + return -EPERM; + + if (disabled == 0 || capable(CAP_SYS_ADMIN)) + goto allowed_lsm; + + io_uring_group = make_kgid(&init_user_ns, sysctl_io_uring_group); + if (!gid_valid(io_uring_group)) + return -EPERM; + + if (!in_group_p(io_uring_group)) + return -EPERM; + +allowed_lsm: + return security_uring_allowed(); +} + +SYSCALL_DEFINE2(io_uring_setup, u32, entries, + struct io_uring_params __user *, params) +{ + int ret; + + ret = io_uring_allowed(); + if (ret) + return ret; + + return io_uring_setup(entries, params); +} + +static int __init io_uring_init(void) +{ + struct kmem_cache_args kmem_args = { + .useroffset = offsetof(struct io_kiocb, cmd.data), + .usersize = sizeof_field(struct io_kiocb, cmd.data), + .freeptr_offset = offsetof(struct io_kiocb, work), + .use_freeptr_offset = true, + }; + +#define __BUILD_BUG_VERIFY_OFFSET_SIZE(stype, eoffset, esize, ename) do { \ + BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \ + BUILD_BUG_ON(sizeof_field(stype, ename) != esize); \ +} while (0) + +#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \ + __BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, sizeof(etype), ename) +#define BUILD_BUG_SQE_ELEM_SIZE(eoffset, esize, ename) \ + __BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, esize, ename) + BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64); + BUILD_BUG_SQE_ELEM(0, __u8, opcode); + BUILD_BUG_SQE_ELEM(1, __u8, flags); + BUILD_BUG_SQE_ELEM(2, __u16, ioprio); + BUILD_BUG_SQE_ELEM(4, __s32, fd); + BUILD_BUG_SQE_ELEM(8, __u64, off); + BUILD_BUG_SQE_ELEM(8, __u64, addr2); + BUILD_BUG_SQE_ELEM(8, __u32, cmd_op); + BUILD_BUG_SQE_ELEM(12, __u32, __pad1); + BUILD_BUG_SQE_ELEM(16, __u64, addr); + BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in); + BUILD_BUG_SQE_ELEM(24, __u32, len); + BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags); + BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags); + BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags); + BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags); + BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events); + BUILD_BUG_SQE_ELEM(28, __u32, poll32_events); + BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags); + BUILD_BUG_SQE_ELEM(28, __u32, msg_flags); + BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags); + BUILD_BUG_SQE_ELEM(28, __u32, accept_flags); + BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags); + BUILD_BUG_SQE_ELEM(28, __u32, open_flags); + BUILD_BUG_SQE_ELEM(28, __u32, statx_flags); + BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice); + BUILD_BUG_SQE_ELEM(28, __u32, splice_flags); + BUILD_BUG_SQE_ELEM(28, __u32, rename_flags); + BUILD_BUG_SQE_ELEM(28, __u32, unlink_flags); + BUILD_BUG_SQE_ELEM(28, __u32, hardlink_flags); + BUILD_BUG_SQE_ELEM(28, __u32, xattr_flags); + BUILD_BUG_SQE_ELEM(28, __u32, msg_ring_flags); + BUILD_BUG_SQE_ELEM(32, __u64, user_data); + BUILD_BUG_SQE_ELEM(40, __u16, buf_index); + BUILD_BUG_SQE_ELEM(40, __u16, buf_group); + BUILD_BUG_SQE_ELEM(42, __u16, personality); + BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); + BUILD_BUG_SQE_ELEM(44, __u32, file_index); + BUILD_BUG_SQE_ELEM(44, __u16, addr_len); + BUILD_BUG_SQE_ELEM(44, __u8, write_stream); + BUILD_BUG_SQE_ELEM(45, __u8, __pad4[0]); + BUILD_BUG_SQE_ELEM(46, __u16, __pad3[0]); + BUILD_BUG_SQE_ELEM(48, __u64, addr3); + BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd); + BUILD_BUG_SQE_ELEM(48, __u64, attr_ptr); + BUILD_BUG_SQE_ELEM(56, __u64, attr_type_mask); + BUILD_BUG_SQE_ELEM(56, __u64, __pad2); + + BUILD_BUG_ON(sizeof(struct io_uring_files_update) != + sizeof(struct io_uring_rsrc_update)); + BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) > + sizeof(struct io_uring_rsrc_update2)); + + /* ->buf_index is u16 */ + BUILD_BUG_ON(offsetof(struct io_uring_buf_ring, bufs) != 0); + BUILD_BUG_ON(offsetof(struct io_uring_buf, resv) != + offsetof(struct io_uring_buf_ring, tail)); + + /* should fit into one byte */ + BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8)); + BUILD_BUG_ON(SQE_COMMON_FLAGS >= (1 << 8)); + BUILD_BUG_ON((SQE_VALID_FLAGS | SQE_COMMON_FLAGS) != SQE_VALID_FLAGS); + + BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof_field(struct io_kiocb, flags)); + + BUILD_BUG_ON(sizeof(atomic_t) != sizeof(u32)); + + /* top 8bits are for internal use */ + BUILD_BUG_ON((IORING_URING_CMD_MASK & 0xff000000) != 0); + + io_uring_optable_init(); + + /* imu->dir is u8 */ + BUILD_BUG_ON((IO_IMU_DEST | IO_IMU_SOURCE) > U8_MAX); + + /* + * Allow user copy in the per-command field, which starts after the + * file in io_kiocb and until the opcode field. The openat2 handling + * requires copying in user memory into the io_kiocb object in that + * range, and HARDENED_USERCOPY will complain if we haven't + * correctly annotated this range. + */ + req_cachep = kmem_cache_create("io_kiocb", sizeof(struct io_kiocb), &kmem_args, + SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT | + SLAB_TYPESAFE_BY_RCU); + + iou_wq = alloc_workqueue("iou_exit", WQ_UNBOUND, 64); + BUG_ON(!iou_wq); + +#ifdef CONFIG_SYSCTL + register_sysctl_init("kernel", kernel_io_uring_disabled_table); +#endif + + return 0; +}; +__initcall(io_uring_init); diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h new file mode 100644 index 000000000000..a790c16854d3 --- /dev/null +++ b/io_uring/io_uring.h @@ -0,0 +1,616 @@ +#ifndef IOU_CORE_H +#define IOU_CORE_H + +#include <linux/errno.h> +#include <linux/lockdep.h> +#include <linux/resume_user_mode.h> +#include <linux/kasan.h> +#include <linux/poll.h> +#include <linux/io_uring_types.h> +#include <uapi/linux/eventpoll.h> +#include "alloc_cache.h" +#include "io-wq.h" +#include "slist.h" +#include "opdef.h" + +#ifndef CREATE_TRACE_POINTS +#include <trace/events/io_uring.h> +#endif + +struct io_rings_layout { + /* size of CQ + headers + SQ offset array */ + size_t rings_size; + size_t sq_size; + + size_t sq_array_offset; +}; + +struct io_ctx_config { + struct io_uring_params p; + struct io_rings_layout layout; + struct io_uring_params __user *uptr; +}; + +#define IORING_FEAT_FLAGS (IORING_FEAT_SINGLE_MMAP |\ + IORING_FEAT_NODROP |\ + IORING_FEAT_SUBMIT_STABLE |\ + IORING_FEAT_RW_CUR_POS |\ + IORING_FEAT_CUR_PERSONALITY |\ + IORING_FEAT_FAST_POLL |\ + IORING_FEAT_POLL_32BITS |\ + IORING_FEAT_SQPOLL_NONFIXED |\ + IORING_FEAT_EXT_ARG |\ + IORING_FEAT_NATIVE_WORKERS |\ + IORING_FEAT_RSRC_TAGS |\ + IORING_FEAT_CQE_SKIP |\ + IORING_FEAT_LINKED_FILE |\ + IORING_FEAT_REG_REG_RING |\ + IORING_FEAT_RECVSEND_BUNDLE |\ + IORING_FEAT_MIN_TIMEOUT |\ + IORING_FEAT_RW_ATTR |\ + IORING_FEAT_NO_IOWAIT) + +#define IORING_SETUP_FLAGS (IORING_SETUP_IOPOLL |\ + IORING_SETUP_SQPOLL |\ + IORING_SETUP_SQ_AFF |\ + IORING_SETUP_CQSIZE |\ + IORING_SETUP_CLAMP |\ + IORING_SETUP_ATTACH_WQ |\ + IORING_SETUP_R_DISABLED |\ + IORING_SETUP_SUBMIT_ALL |\ + IORING_SETUP_COOP_TASKRUN |\ + IORING_SETUP_TASKRUN_FLAG |\ + IORING_SETUP_SQE128 |\ + IORING_SETUP_CQE32 |\ + IORING_SETUP_SINGLE_ISSUER |\ + IORING_SETUP_DEFER_TASKRUN |\ + IORING_SETUP_NO_MMAP |\ + IORING_SETUP_REGISTERED_FD_ONLY |\ + IORING_SETUP_NO_SQARRAY |\ + IORING_SETUP_HYBRID_IOPOLL |\ + IORING_SETUP_CQE_MIXED |\ + IORING_SETUP_SQE_MIXED) + +#define IORING_ENTER_FLAGS (IORING_ENTER_GETEVENTS |\ + IORING_ENTER_SQ_WAKEUP |\ + IORING_ENTER_SQ_WAIT |\ + IORING_ENTER_EXT_ARG |\ + IORING_ENTER_REGISTERED_RING |\ + IORING_ENTER_ABS_TIMER |\ + IORING_ENTER_EXT_ARG_REG |\ + IORING_ENTER_NO_IOWAIT) + + +#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE |\ + IOSQE_IO_DRAIN |\ + IOSQE_IO_LINK |\ + IOSQE_IO_HARDLINK |\ + IOSQE_ASYNC |\ + IOSQE_BUFFER_SELECT |\ + IOSQE_CQE_SKIP_SUCCESS) + +enum { + IOU_COMPLETE = 0, + + IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED, + + /* + * The request has more work to do and should be retried. io_uring will + * attempt to wait on the file for eligible opcodes, but otherwise + * it'll be handed to iowq for blocking execution. It works for normal + * requests as well as for the multi shot mode. + */ + IOU_RETRY = -EAGAIN, + + /* + * Requeue the task_work to restart operations on this request. The + * actual value isn't important, should just be not an otherwise + * valid error code, yet less than -MAX_ERRNO and valid internally. + */ + IOU_REQUEUE = -3072, +}; + +struct io_defer_entry { + struct list_head list; + struct io_kiocb *req; +}; + +struct io_wait_queue { + struct wait_queue_entry wq; + struct io_ring_ctx *ctx; + unsigned cq_tail; + unsigned cq_min_tail; + unsigned nr_timeouts; + int hit_timeout; + ktime_t min_timeout; + ktime_t timeout; + struct hrtimer t; + +#ifdef CONFIG_NET_RX_BUSY_POLL + ktime_t napi_busy_poll_dt; + bool napi_prefer_busy_poll; +#endif +}; + +static inline bool io_should_wake(struct io_wait_queue *iowq) +{ + struct io_ring_ctx *ctx = iowq->ctx; + int dist = READ_ONCE(ctx->rings->cq.tail) - (int) iowq->cq_tail; + + /* + * Wake up if we have enough events, or if a timeout occurred since we + * started waiting. For timeouts, we always want to return to userspace, + * regardless of event count. + */ + return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; +} + +#define IORING_MAX_ENTRIES 32768 +#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) + +int io_prepare_config(struct io_ctx_config *config); + +bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow, bool cqe32); +int io_run_task_work_sig(struct io_ring_ctx *ctx); +int io_run_local_work(struct io_ring_ctx *ctx, int min_events, int max_events); +void io_req_defer_failed(struct io_kiocb *req, s32 res); +bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); +void io_add_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); +bool io_req_post_cqe(struct io_kiocb *req, s32 res, u32 cflags); +bool io_req_post_cqe32(struct io_kiocb *req, struct io_uring_cqe src_cqe[2]); +void __io_commit_cqring_flush(struct io_ring_ctx *ctx); + +unsigned io_linked_nr(struct io_kiocb *req); +void io_req_track_inflight(struct io_kiocb *req); +struct file *io_file_get_normal(struct io_kiocb *req, int fd); +struct file *io_file_get_fixed(struct io_kiocb *req, int fd, + unsigned issue_flags); + +void __io_req_task_work_add(struct io_kiocb *req, unsigned flags); +void io_req_task_work_add_remote(struct io_kiocb *req, unsigned flags); +void io_req_task_queue(struct io_kiocb *req); +void io_req_task_complete(struct io_tw_req tw_req, io_tw_token_t tw); +void io_req_task_queue_fail(struct io_kiocb *req, int ret); +void io_req_task_submit(struct io_tw_req tw_req, io_tw_token_t tw); +struct llist_node *io_handle_tw_list(struct llist_node *node, unsigned int *count, unsigned int max_entries); +struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, unsigned int max_entries, unsigned int *count); +void tctx_task_work(struct callback_head *cb); +__cold void io_uring_drop_tctx_refs(struct task_struct *task); + +int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file, + int start, int end); +void io_req_queue_iowq(struct io_kiocb *req); + +int io_poll_issue(struct io_kiocb *req, io_tw_token_t tw); +int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr); +int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin); +__cold void io_iopoll_try_reap_events(struct io_ring_ctx *ctx); +void __io_submit_flush_completions(struct io_ring_ctx *ctx); + +struct io_wq_work *io_wq_free_work(struct io_wq_work *work); +void io_wq_submit_work(struct io_wq_work *work); + +void io_free_req(struct io_kiocb *req); +void io_queue_next(struct io_kiocb *req); +void io_task_refs_refill(struct io_uring_task *tctx); +bool __io_alloc_req_refill(struct io_ring_ctx *ctx); + +void io_activate_pollwq(struct io_ring_ctx *ctx); + +static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx) +{ +#if defined(CONFIG_PROVE_LOCKING) + lockdep_assert(in_task()); + + if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) + lockdep_assert_held(&ctx->uring_lock); + + if (ctx->flags & IORING_SETUP_IOPOLL) { + lockdep_assert_held(&ctx->uring_lock); + } else if (!ctx->task_complete) { + lockdep_assert_held(&ctx->completion_lock); + } else if (ctx->submitter_task) { + /* + * ->submitter_task may be NULL and we can still post a CQE, + * if the ring has been setup with IORING_SETUP_R_DISABLED. + * Not from an SQE, as those cannot be submitted, but via + * updating tagged resources. + */ + if (!percpu_ref_is_dying(&ctx->refs)) + lockdep_assert(current == ctx->submitter_task); + } +#endif +} + +static inline bool io_is_compat(struct io_ring_ctx *ctx) +{ + return IS_ENABLED(CONFIG_COMPAT) && unlikely(ctx->compat); +} + +static inline void io_req_task_work_add(struct io_kiocb *req) +{ + __io_req_task_work_add(req, 0); +} + +static inline void io_submit_flush_completions(struct io_ring_ctx *ctx) +{ + if (!wq_list_empty(&ctx->submit_state.compl_reqs) || + ctx->submit_state.cq_flush) + __io_submit_flush_completions(ctx); +} + +#define io_for_each_link(pos, head) \ + for (pos = (head); pos; pos = pos->link) + +static inline bool io_get_cqe_overflow(struct io_ring_ctx *ctx, + struct io_uring_cqe **ret, + bool overflow, bool cqe32) +{ + io_lockdep_assert_cq_locked(ctx); + + if (unlikely(ctx->cqe_sentinel - ctx->cqe_cached < (cqe32 + 1))) { + if (unlikely(!io_cqe_cache_refill(ctx, overflow, cqe32))) + return false; + } + *ret = ctx->cqe_cached; + ctx->cached_cq_tail++; + ctx->cqe_cached++; + if (ctx->flags & IORING_SETUP_CQE32) { + ctx->cqe_cached++; + } else if (cqe32 && ctx->flags & IORING_SETUP_CQE_MIXED) { + ctx->cqe_cached++; + ctx->cached_cq_tail++; + } + WARN_ON_ONCE(ctx->cqe_cached > ctx->cqe_sentinel); + return true; +} + +static inline bool io_get_cqe(struct io_ring_ctx *ctx, struct io_uring_cqe **ret, + bool cqe32) +{ + return io_get_cqe_overflow(ctx, ret, false, cqe32); +} + +static inline bool io_defer_get_uncommited_cqe(struct io_ring_ctx *ctx, + struct io_uring_cqe **cqe_ret) +{ + io_lockdep_assert_cq_locked(ctx); + + ctx->submit_state.cq_flush = true; + return io_get_cqe(ctx, cqe_ret, ctx->flags & IORING_SETUP_CQE_MIXED); +} + +static __always_inline bool io_fill_cqe_req(struct io_ring_ctx *ctx, + struct io_kiocb *req) +{ + bool is_cqe32 = req->cqe.flags & IORING_CQE_F_32; + struct io_uring_cqe *cqe; + + /* + * If we can't get a cq entry, userspace overflowed the submission + * (by quite a lot). + */ + if (unlikely(!io_get_cqe(ctx, &cqe, is_cqe32))) + return false; + + memcpy(cqe, &req->cqe, sizeof(*cqe)); + if (ctx->flags & IORING_SETUP_CQE32 || is_cqe32) { + memcpy(cqe->big_cqe, &req->big_cqe, sizeof(*cqe)); + memset(&req->big_cqe, 0, sizeof(req->big_cqe)); + } + + if (trace_io_uring_complete_enabled()) + trace_io_uring_complete(req->ctx, req, cqe); + return true; +} + +static inline void req_set_fail(struct io_kiocb *req) +{ + req->flags |= REQ_F_FAIL; + if (req->flags & REQ_F_CQE_SKIP) { + req->flags &= ~REQ_F_CQE_SKIP; + req->flags |= REQ_F_SKIP_LINK_CQES; + } +} + +static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags) +{ + req->cqe.res = res; + req->cqe.flags = cflags; +} + +static inline u32 ctx_cqe32_flags(struct io_ring_ctx *ctx) +{ + if (ctx->flags & IORING_SETUP_CQE_MIXED) + return IORING_CQE_F_32; + return 0; +} + +static inline void io_req_set_res32(struct io_kiocb *req, s32 res, u32 cflags, + __u64 extra1, __u64 extra2) +{ + req->cqe.res = res; + req->cqe.flags = cflags | ctx_cqe32_flags(req->ctx); + req->big_cqe.extra1 = extra1; + req->big_cqe.extra2 = extra2; +} + +static inline void *io_uring_alloc_async_data(struct io_alloc_cache *cache, + struct io_kiocb *req) +{ + if (cache) { + req->async_data = io_cache_alloc(cache, GFP_KERNEL); + } else { + const struct io_issue_def *def = &io_issue_defs[req->opcode]; + + WARN_ON_ONCE(!def->async_size); + req->async_data = kmalloc(def->async_size, GFP_KERNEL); + } + if (req->async_data) + req->flags |= REQ_F_ASYNC_DATA; + return req->async_data; +} + +static inline bool req_has_async_data(struct io_kiocb *req) +{ + return req->flags & REQ_F_ASYNC_DATA; +} + +static inline void io_req_async_data_clear(struct io_kiocb *req, + io_req_flags_t extra_flags) +{ + req->flags &= ~(REQ_F_ASYNC_DATA|extra_flags); + req->async_data = NULL; +} + +static inline void io_req_async_data_free(struct io_kiocb *req) +{ + kfree(req->async_data); + io_req_async_data_clear(req, 0); +} + +static inline void io_put_file(struct io_kiocb *req) +{ + if (!(req->flags & REQ_F_FIXED_FILE) && req->file) + fput(req->file); +} + +static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx, + unsigned issue_flags) +{ + lockdep_assert_held(&ctx->uring_lock); + if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) + mutex_unlock(&ctx->uring_lock); +} + +static inline void io_ring_submit_lock(struct io_ring_ctx *ctx, + unsigned issue_flags) +{ + /* + * "Normal" inline submissions always hold the uring_lock, since we + * grab it from the system call. Same is true for the SQPOLL offload. + * The only exception is when we've detached the request and issue it + * from an async worker thread, grab the lock for that case. + */ + if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) + mutex_lock(&ctx->uring_lock); + lockdep_assert_held(&ctx->uring_lock); +} + +static inline void io_commit_cqring(struct io_ring_ctx *ctx) +{ + /* order cqe stores with ring update */ + smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); +} + +static inline void __io_wq_wake(struct wait_queue_head *wq) +{ + /* + * + * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter + * set in the mask so that if we recurse back into our own poll + * waitqueue handlers, we know we have a dependency between eventfd or + * epoll and should terminate multishot poll at that point. + */ + if (wq_has_sleeper(wq)) + __wake_up(wq, TASK_NORMAL, 0, poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); +} + +static inline void io_poll_wq_wake(struct io_ring_ctx *ctx) +{ + __io_wq_wake(&ctx->poll_wq); +} + +static inline void io_cqring_wake(struct io_ring_ctx *ctx) +{ + /* + * Trigger waitqueue handler on all waiters on our waitqueue. This + * won't necessarily wake up all the tasks, io_should_wake() will make + * that decision. + */ + + __io_wq_wake(&ctx->cq_wait); +} + +static inline bool io_sqring_full(struct io_ring_ctx *ctx) +{ + struct io_rings *r = ctx->rings; + + /* + * SQPOLL must use the actual sqring head, as using the cached_sq_head + * is race prone if the SQPOLL thread has grabbed entries but not yet + * committed them to the ring. For !SQPOLL, this doesn't matter, but + * since this helper is just used for SQPOLL sqring waits (or POLLOUT), + * just read the actual sqring head unconditionally. + */ + return READ_ONCE(r->sq.tail) - READ_ONCE(r->sq.head) == ctx->sq_entries; +} + +static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) +{ + struct io_rings *rings = ctx->rings; + unsigned int entries; + + /* make sure SQ entry isn't read before tail */ + entries = smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; + return min(entries, ctx->sq_entries); +} + +static inline int io_run_task_work(void) +{ + bool ret = false; + + /* + * Always check-and-clear the task_work notification signal. With how + * signaling works for task_work, we can find it set with nothing to + * run. We need to clear it for that case, like get_signal() does. + */ + if (test_thread_flag(TIF_NOTIFY_SIGNAL)) + clear_notify_signal(); + /* + * PF_IO_WORKER never returns to userspace, so check here if we have + * notify work that needs processing. + */ + if (current->flags & PF_IO_WORKER) { + if (test_thread_flag(TIF_NOTIFY_RESUME)) { + __set_current_state(TASK_RUNNING); + resume_user_mode_work(NULL); + } + if (current->io_uring) { + unsigned int count = 0; + + __set_current_state(TASK_RUNNING); + tctx_task_work_run(current->io_uring, UINT_MAX, &count); + if (count) + ret = true; + } + } + if (task_work_pending(current)) { + __set_current_state(TASK_RUNNING); + task_work_run(); + ret = true; + } + + return ret; +} + +static inline bool io_local_work_pending(struct io_ring_ctx *ctx) +{ + return !llist_empty(&ctx->work_llist) || !llist_empty(&ctx->retry_llist); +} + +static inline bool io_task_work_pending(struct io_ring_ctx *ctx) +{ + return task_work_pending(current) || io_local_work_pending(ctx); +} + +static inline void io_tw_lock(struct io_ring_ctx *ctx, io_tw_token_t tw) +{ + lockdep_assert_held(&ctx->uring_lock); +} + +/* + * Don't complete immediately but use deferred completion infrastructure. + * Protected by ->uring_lock and can only be used either with + * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex. + */ +static inline void io_req_complete_defer(struct io_kiocb *req) + __must_hold(&req->ctx->uring_lock) +{ + struct io_submit_state *state = &req->ctx->submit_state; + + lockdep_assert_held(&req->ctx->uring_lock); + + wq_list_add_tail(&req->comp_list, &state->compl_reqs); +} + +static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx) +{ + if (unlikely(ctx->off_timeout_used || + ctx->has_evfd || ctx->poll_activated)) + __io_commit_cqring_flush(ctx); +} + +static inline void io_get_task_refs(int nr) +{ + struct io_uring_task *tctx = current->io_uring; + + tctx->cached_refs -= nr; + if (unlikely(tctx->cached_refs < 0)) + io_task_refs_refill(tctx); +} + +static inline bool io_req_cache_empty(struct io_ring_ctx *ctx) +{ + return !ctx->submit_state.free_list.next; +} + +extern struct kmem_cache *req_cachep; + +static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req; + + req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list); + wq_stack_extract(&ctx->submit_state.free_list); + return req; +} + +static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req) +{ + if (unlikely(io_req_cache_empty(ctx))) { + if (!__io_alloc_req_refill(ctx)) + return false; + } + *req = io_extract_req(ctx); + return true; +} + +static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx) +{ + return likely(ctx->submitter_task == current); +} + +static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) +{ + return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || + ctx->submitter_task == current); +} + +static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) +{ + io_req_set_res(req, res, 0); + req->io_task_work.func = io_req_task_complete; + io_req_task_work_add(req); +} + +static inline bool io_file_can_poll(struct io_kiocb *req) +{ + if (req->flags & REQ_F_CAN_POLL) + return true; + if (req->file && file_can_poll(req->file)) { + req->flags |= REQ_F_CAN_POLL; + return true; + } + return false; +} + +static inline ktime_t io_get_time(struct io_ring_ctx *ctx) +{ + if (ctx->clockid == CLOCK_MONOTONIC) + return ktime_get(); + + return ktime_get_with_offset(ctx->clock_offset); +} + +enum { + IO_CHECK_CQ_OVERFLOW_BIT, + IO_CHECK_CQ_DROPPED_BIT, +}; + +static inline bool io_has_work(struct io_ring_ctx *ctx) +{ + return test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq) || + io_local_work_pending(ctx); +} +#endif diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c new file mode 100644 index 000000000000..796d131107dd --- /dev/null +++ b/io_uring/kbuf.c @@ -0,0 +1,739 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/poll.h> +#include <linux/vmalloc.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "opdef.h" +#include "kbuf.h" +#include "memmap.h" + +/* BIDs are addressed by a 16-bit field in a CQE */ +#define MAX_BIDS_PER_BGID (1 << 16) + +/* Mapped buffer ring, return io_uring_buf from head */ +#define io_ring_head_to_buf(br, head, mask) &(br)->bufs[(head) & (mask)] + +struct io_provide_buf { + struct file *file; + __u64 addr; + __u32 len; + __u32 bgid; + __u32 nbufs; + __u16 bid; +}; + +static bool io_kbuf_inc_commit(struct io_buffer_list *bl, int len) +{ + while (len) { + struct io_uring_buf *buf; + u32 buf_len, this_len; + + buf = io_ring_head_to_buf(bl->buf_ring, bl->head, bl->mask); + buf_len = READ_ONCE(buf->len); + this_len = min_t(u32, len, buf_len); + buf_len -= this_len; + /* Stop looping for invalid buffer length of 0 */ + if (buf_len || !this_len) { + WRITE_ONCE(buf->addr, READ_ONCE(buf->addr) + this_len); + WRITE_ONCE(buf->len, buf_len); + return false; + } + WRITE_ONCE(buf->len, 0); + bl->head++; + len -= this_len; + } + return true; +} + +bool io_kbuf_commit(struct io_kiocb *req, + struct io_buffer_list *bl, int len, int nr) +{ + if (unlikely(!(req->flags & REQ_F_BUFFERS_COMMIT))) + return true; + + req->flags &= ~REQ_F_BUFFERS_COMMIT; + + if (unlikely(len < 0)) + return true; + if (bl->flags & IOBL_INC) + return io_kbuf_inc_commit(bl, len); + bl->head += nr; + return true; +} + +static inline struct io_buffer_list *io_buffer_get_list(struct io_ring_ctx *ctx, + unsigned int bgid) +{ + lockdep_assert_held(&ctx->uring_lock); + + return xa_load(&ctx->io_bl_xa, bgid); +} + +static int io_buffer_add_list(struct io_ring_ctx *ctx, + struct io_buffer_list *bl, unsigned int bgid) +{ + /* + * Store buffer group ID and finally mark the list as visible. + * The normal lookup doesn't care about the visibility as we're + * always under the ->uring_lock, but lookups from mmap do. + */ + bl->bgid = bgid; + guard(mutex)(&ctx->mmap_lock); + return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL)); +} + +void io_kbuf_drop_legacy(struct io_kiocb *req) +{ + if (WARN_ON_ONCE(!(req->flags & REQ_F_BUFFER_SELECTED))) + return; + req->flags &= ~REQ_F_BUFFER_SELECTED; + kfree(req->kbuf); + req->kbuf = NULL; +} + +bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_buffer_list *bl; + struct io_buffer *buf; + + io_ring_submit_lock(ctx, issue_flags); + + buf = req->kbuf; + bl = io_buffer_get_list(ctx, buf->bgid); + list_add(&buf->list, &bl->buf_list); + bl->nbufs++; + req->flags &= ~REQ_F_BUFFER_SELECTED; + + io_ring_submit_unlock(ctx, issue_flags); + return true; +} + +static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len, + struct io_buffer_list *bl) +{ + if (!list_empty(&bl->buf_list)) { + struct io_buffer *kbuf; + + kbuf = list_first_entry(&bl->buf_list, struct io_buffer, list); + list_del(&kbuf->list); + bl->nbufs--; + if (*len == 0 || *len > kbuf->len) + *len = kbuf->len; + if (list_empty(&bl->buf_list)) + req->flags |= REQ_F_BL_EMPTY; + req->flags |= REQ_F_BUFFER_SELECTED; + req->kbuf = kbuf; + req->buf_index = kbuf->bid; + return u64_to_user_ptr(kbuf->addr); + } + return NULL; +} + +static int io_provided_buffers_select(struct io_kiocb *req, size_t *len, + struct io_buffer_list *bl, + struct iovec *iov) +{ + void __user *buf; + + buf = io_provided_buffer_select(req, len, bl); + if (unlikely(!buf)) + return -ENOBUFS; + + iov[0].iov_base = buf; + iov[0].iov_len = *len; + return 1; +} + +static bool io_should_commit(struct io_kiocb *req, unsigned int issue_flags) +{ + /* + * If we came in unlocked, we have no choice but to consume the + * buffer here, otherwise nothing ensures that the buffer won't + * get used by others. This does mean it'll be pinned until the + * IO completes, coming in unlocked means we're being called from + * io-wq context and there may be further retries in async hybrid + * mode. For the locked case, the caller must call commit when + * the transfer completes (or if we get -EAGAIN and must poll of + * retry). + */ + if (issue_flags & IO_URING_F_UNLOCKED) + return true; + + /* uring_cmd commits kbuf upfront, no need to auto-commit */ + if (!io_file_can_poll(req) && req->opcode != IORING_OP_URING_CMD) + return true; + return false; +} + +static struct io_br_sel io_ring_buffer_select(struct io_kiocb *req, size_t *len, + struct io_buffer_list *bl, + unsigned int issue_flags) +{ + struct io_uring_buf_ring *br = bl->buf_ring; + __u16 tail, head = bl->head; + struct io_br_sel sel = { }; + struct io_uring_buf *buf; + u32 buf_len; + + tail = smp_load_acquire(&br->tail); + if (unlikely(tail == head)) + return sel; + + if (head + 1 == tail) + req->flags |= REQ_F_BL_EMPTY; + + buf = io_ring_head_to_buf(br, head, bl->mask); + buf_len = READ_ONCE(buf->len); + if (*len == 0 || *len > buf_len) + *len = buf_len; + req->flags |= REQ_F_BUFFER_RING | REQ_F_BUFFERS_COMMIT; + req->buf_index = READ_ONCE(buf->bid); + sel.buf_list = bl; + sel.addr = u64_to_user_ptr(READ_ONCE(buf->addr)); + + if (io_should_commit(req, issue_flags)) { + io_kbuf_commit(req, sel.buf_list, *len, 1); + sel.buf_list = NULL; + } + return sel; +} + +struct io_br_sel io_buffer_select(struct io_kiocb *req, size_t *len, + unsigned buf_group, unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_br_sel sel = { }; + struct io_buffer_list *bl; + + io_ring_submit_lock(req->ctx, issue_flags); + + bl = io_buffer_get_list(ctx, buf_group); + if (likely(bl)) { + if (bl->flags & IOBL_BUF_RING) + sel = io_ring_buffer_select(req, len, bl, issue_flags); + else + sel.addr = io_provided_buffer_select(req, len, bl); + } + io_ring_submit_unlock(req->ctx, issue_flags); + return sel; +} + +/* cap it at a reasonable 256, will be one page even for 4K */ +#define PEEK_MAX_IMPORT 256 + +static int io_ring_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg, + struct io_buffer_list *bl) +{ + struct io_uring_buf_ring *br = bl->buf_ring; + struct iovec *iov = arg->iovs; + int nr_iovs = arg->nr_iovs; + __u16 nr_avail, tail, head; + struct io_uring_buf *buf; + + tail = smp_load_acquire(&br->tail); + head = bl->head; + nr_avail = min_t(__u16, tail - head, UIO_MAXIOV); + if (unlikely(!nr_avail)) + return -ENOBUFS; + + buf = io_ring_head_to_buf(br, head, bl->mask); + if (arg->max_len) { + u32 len = READ_ONCE(buf->len); + size_t needed; + + if (unlikely(!len)) + return -ENOBUFS; + needed = (arg->max_len + len - 1) / len; + needed = min_not_zero(needed, (size_t) PEEK_MAX_IMPORT); + if (nr_avail > needed) + nr_avail = needed; + } + + /* + * only alloc a bigger array if we know we have data to map, eg not + * a speculative peek operation. + */ + if (arg->mode & KBUF_MODE_EXPAND && nr_avail > nr_iovs && arg->max_len) { + iov = kmalloc_array(nr_avail, sizeof(struct iovec), GFP_KERNEL); + if (unlikely(!iov)) + return -ENOMEM; + if (arg->mode & KBUF_MODE_FREE) + kfree(arg->iovs); + arg->iovs = iov; + nr_iovs = nr_avail; + } else if (nr_avail < nr_iovs) { + nr_iovs = nr_avail; + } + + /* set it to max, if not set, so we can use it unconditionally */ + if (!arg->max_len) + arg->max_len = INT_MAX; + + req->buf_index = READ_ONCE(buf->bid); + do { + u32 len = READ_ONCE(buf->len); + + /* truncate end piece, if needed, for non partial buffers */ + if (len > arg->max_len) { + len = arg->max_len; + if (!(bl->flags & IOBL_INC)) { + arg->partial_map = 1; + if (iov != arg->iovs) + break; + WRITE_ONCE(buf->len, len); + } + } + + iov->iov_base = u64_to_user_ptr(READ_ONCE(buf->addr)); + iov->iov_len = len; + iov++; + + arg->out_len += len; + arg->max_len -= len; + if (!arg->max_len) + break; + + buf = io_ring_head_to_buf(br, ++head, bl->mask); + } while (--nr_iovs); + + if (head == tail) + req->flags |= REQ_F_BL_EMPTY; + + req->flags |= REQ_F_BUFFER_RING; + return iov - arg->iovs; +} + +int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg, + struct io_br_sel *sel, unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + int ret = -ENOENT; + + io_ring_submit_lock(ctx, issue_flags); + sel->buf_list = io_buffer_get_list(ctx, arg->buf_group); + if (unlikely(!sel->buf_list)) + goto out_unlock; + + if (sel->buf_list->flags & IOBL_BUF_RING) { + ret = io_ring_buffers_peek(req, arg, sel->buf_list); + /* + * Don't recycle these buffers if we need to go through poll. + * Nobody else can use them anyway, and holding on to provided + * buffers for a send/write operation would happen on the app + * side anyway with normal buffers. Besides, we already + * committed them, they cannot be put back in the queue. + */ + if (ret > 0) { + req->flags |= REQ_F_BUFFERS_COMMIT | REQ_F_BL_NO_RECYCLE; + io_kbuf_commit(req, sel->buf_list, arg->out_len, ret); + } + } else { + ret = io_provided_buffers_select(req, &arg->out_len, sel->buf_list, arg->iovs); + } +out_unlock: + if (issue_flags & IO_URING_F_UNLOCKED) { + sel->buf_list = NULL; + mutex_unlock(&ctx->uring_lock); + } + return ret; +} + +int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg, + struct io_br_sel *sel) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_buffer_list *bl; + int ret; + + lockdep_assert_held(&ctx->uring_lock); + + bl = io_buffer_get_list(ctx, arg->buf_group); + if (unlikely(!bl)) + return -ENOENT; + + if (bl->flags & IOBL_BUF_RING) { + ret = io_ring_buffers_peek(req, arg, bl); + if (ret > 0) + req->flags |= REQ_F_BUFFERS_COMMIT; + sel->buf_list = bl; + return ret; + } + + /* don't support multiple buffer selections for legacy */ + sel->buf_list = NULL; + return io_provided_buffers_select(req, &arg->max_len, bl, arg->iovs); +} + +static inline bool __io_put_kbuf_ring(struct io_kiocb *req, + struct io_buffer_list *bl, int len, int nr) +{ + bool ret = true; + + if (bl) + ret = io_kbuf_commit(req, bl, len, nr); + + req->flags &= ~REQ_F_BUFFER_RING; + return ret; +} + +unsigned int __io_put_kbufs(struct io_kiocb *req, struct io_buffer_list *bl, + int len, int nbufs) +{ + unsigned int ret; + + ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT); + + if (unlikely(!(req->flags & REQ_F_BUFFER_RING))) { + io_kbuf_drop_legacy(req); + return ret; + } + + if (!__io_put_kbuf_ring(req, bl, len, nbufs)) + ret |= IORING_CQE_F_BUF_MORE; + return ret; +} + +static int io_remove_buffers_legacy(struct io_ring_ctx *ctx, + struct io_buffer_list *bl, + unsigned long nbufs) +{ + unsigned long i = 0; + struct io_buffer *nxt; + + /* protects io_buffers_cache */ + lockdep_assert_held(&ctx->uring_lock); + WARN_ON_ONCE(bl->flags & IOBL_BUF_RING); + + for (i = 0; i < nbufs && !list_empty(&bl->buf_list); i++) { + nxt = list_first_entry(&bl->buf_list, struct io_buffer, list); + list_del(&nxt->list); + bl->nbufs--; + kfree(nxt); + cond_resched(); + } + return i; +} + +static void io_put_bl(struct io_ring_ctx *ctx, struct io_buffer_list *bl) +{ + if (bl->flags & IOBL_BUF_RING) + io_free_region(ctx->user, &bl->region); + else + io_remove_buffers_legacy(ctx, bl, -1U); + + kfree(bl); +} + +void io_destroy_buffers(struct io_ring_ctx *ctx) +{ + struct io_buffer_list *bl; + + while (1) { + unsigned long index = 0; + + scoped_guard(mutex, &ctx->mmap_lock) { + bl = xa_find(&ctx->io_bl_xa, &index, ULONG_MAX, XA_PRESENT); + if (bl) + xa_erase(&ctx->io_bl_xa, bl->bgid); + } + if (!bl) + break; + io_put_bl(ctx, bl); + } +} + +static void io_destroy_bl(struct io_ring_ctx *ctx, struct io_buffer_list *bl) +{ + scoped_guard(mutex, &ctx->mmap_lock) + WARN_ON_ONCE(xa_erase(&ctx->io_bl_xa, bl->bgid) != bl); + io_put_bl(ctx, bl); +} + +int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf); + u64 tmp; + + if (sqe->rw_flags || sqe->addr || sqe->len || sqe->off || + sqe->splice_fd_in) + return -EINVAL; + + tmp = READ_ONCE(sqe->fd); + if (!tmp || tmp > MAX_BIDS_PER_BGID) + return -EINVAL; + + memset(p, 0, sizeof(*p)); + p->nbufs = tmp; + p->bgid = READ_ONCE(sqe->buf_group); + return 0; +} + +int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + unsigned long size, tmp_check; + struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf); + u64 tmp; + + if (sqe->rw_flags || sqe->splice_fd_in) + return -EINVAL; + + tmp = READ_ONCE(sqe->fd); + if (!tmp || tmp > MAX_BIDS_PER_BGID) + return -E2BIG; + p->nbufs = tmp; + p->addr = READ_ONCE(sqe->addr); + p->len = READ_ONCE(sqe->len); + if (!p->len) + return -EINVAL; + + if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs, + &size)) + return -EOVERFLOW; + if (check_add_overflow((unsigned long)p->addr, size, &tmp_check)) + return -EOVERFLOW; + if (!access_ok(u64_to_user_ptr(p->addr), size)) + return -EFAULT; + + p->bgid = READ_ONCE(sqe->buf_group); + tmp = READ_ONCE(sqe->off); + if (tmp > USHRT_MAX) + return -E2BIG; + if (tmp + p->nbufs > MAX_BIDS_PER_BGID) + return -EINVAL; + p->bid = tmp; + return 0; +} + +static int io_add_buffers(struct io_ring_ctx *ctx, struct io_provide_buf *pbuf, + struct io_buffer_list *bl) +{ + struct io_buffer *buf; + u64 addr = pbuf->addr; + int ret = -ENOMEM, i, bid = pbuf->bid; + + for (i = 0; i < pbuf->nbufs; i++) { + /* + * Nonsensical to have more than sizeof(bid) buffers in a + * buffer list, as the application then has no way of knowing + * which duplicate bid refers to what buffer. + */ + if (bl->nbufs == USHRT_MAX) { + ret = -EOVERFLOW; + break; + } + buf = kmalloc(sizeof(*buf), GFP_KERNEL_ACCOUNT); + if (!buf) + break; + + list_add_tail(&buf->list, &bl->buf_list); + bl->nbufs++; + buf->addr = addr; + buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT); + buf->bid = bid; + buf->bgid = pbuf->bgid; + addr += pbuf->len; + bid++; + cond_resched(); + } + + return i ? 0 : ret; +} + +static int __io_manage_buffers_legacy(struct io_kiocb *req, + struct io_buffer_list *bl) +{ + struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf); + int ret; + + if (!bl) { + if (req->opcode != IORING_OP_PROVIDE_BUFFERS) + return -ENOENT; + bl = kzalloc(sizeof(*bl), GFP_KERNEL_ACCOUNT); + if (!bl) + return -ENOMEM; + + INIT_LIST_HEAD(&bl->buf_list); + ret = io_buffer_add_list(req->ctx, bl, p->bgid); + if (ret) { + kfree(bl); + return ret; + } + } + /* can't use provide/remove buffers command on mapped buffers */ + if (bl->flags & IOBL_BUF_RING) + return -EINVAL; + if (req->opcode == IORING_OP_PROVIDE_BUFFERS) + return io_add_buffers(req->ctx, p, bl); + return io_remove_buffers_legacy(req->ctx, bl, p->nbufs); +} + +int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf); + struct io_ring_ctx *ctx = req->ctx; + struct io_buffer_list *bl; + int ret; + + io_ring_submit_lock(ctx, issue_flags); + bl = io_buffer_get_list(ctx, p->bgid); + ret = __io_manage_buffers_legacy(req, bl); + io_ring_submit_unlock(ctx, issue_flags); + + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) +{ + struct io_uring_buf_reg reg; + struct io_buffer_list *bl; + struct io_uring_region_desc rd; + struct io_uring_buf_ring *br; + unsigned long mmap_offset; + unsigned long ring_size; + int ret; + + lockdep_assert_held(&ctx->uring_lock); + + if (copy_from_user(®, arg, sizeof(reg))) + return -EFAULT; + if (!mem_is_zero(reg.resv, sizeof(reg.resv))) + return -EINVAL; + if (reg.flags & ~(IOU_PBUF_RING_MMAP | IOU_PBUF_RING_INC)) + return -EINVAL; + if (!is_power_of_2(reg.ring_entries)) + return -EINVAL; + /* cannot disambiguate full vs empty due to head/tail size */ + if (reg.ring_entries >= 65536) + return -EINVAL; + + bl = io_buffer_get_list(ctx, reg.bgid); + if (bl) { + /* if mapped buffer ring OR classic exists, don't allow */ + if (bl->flags & IOBL_BUF_RING || !list_empty(&bl->buf_list)) + return -EEXIST; + io_destroy_bl(ctx, bl); + } + + bl = kzalloc(sizeof(*bl), GFP_KERNEL_ACCOUNT); + if (!bl) + return -ENOMEM; + + mmap_offset = (unsigned long)reg.bgid << IORING_OFF_PBUF_SHIFT; + ring_size = flex_array_size(br, bufs, reg.ring_entries); + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(ring_size); + if (!(reg.flags & IOU_PBUF_RING_MMAP)) { + rd.user_addr = reg.ring_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &bl->region, &rd, mmap_offset); + if (ret) + goto fail; + br = io_region_get_ptr(&bl->region); + +#ifdef SHM_COLOUR + /* + * On platforms that have specific aliasing requirements, SHM_COLOUR + * is set and we must guarantee that the kernel and user side align + * nicely. We cannot do that if IOU_PBUF_RING_MMAP isn't set and + * the application mmap's the provided ring buffer. Fail the request + * if we, by chance, don't end up with aligned addresses. The app + * should use IOU_PBUF_RING_MMAP instead, and liburing will handle + * this transparently. + */ + if (!(reg.flags & IOU_PBUF_RING_MMAP) && + ((reg.ring_addr | (unsigned long)br) & (SHM_COLOUR - 1))) { + ret = -EINVAL; + goto fail; + } +#endif + + bl->nr_entries = reg.ring_entries; + bl->mask = reg.ring_entries - 1; + bl->flags |= IOBL_BUF_RING; + bl->buf_ring = br; + if (reg.flags & IOU_PBUF_RING_INC) + bl->flags |= IOBL_INC; + io_buffer_add_list(ctx, bl, reg.bgid); + return 0; +fail: + io_free_region(ctx->user, &bl->region); + kfree(bl); + return ret; +} + +int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) +{ + struct io_uring_buf_reg reg; + struct io_buffer_list *bl; + + lockdep_assert_held(&ctx->uring_lock); + + if (copy_from_user(®, arg, sizeof(reg))) + return -EFAULT; + if (!mem_is_zero(reg.resv, sizeof(reg.resv)) || reg.flags) + return -EINVAL; + + bl = io_buffer_get_list(ctx, reg.bgid); + if (!bl) + return -ENOENT; + if (!(bl->flags & IOBL_BUF_RING)) + return -EINVAL; + + scoped_guard(mutex, &ctx->mmap_lock) + xa_erase(&ctx->io_bl_xa, bl->bgid); + + io_put_bl(ctx, bl); + return 0; +} + +int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg) +{ + struct io_uring_buf_status buf_status; + struct io_buffer_list *bl; + + if (copy_from_user(&buf_status, arg, sizeof(buf_status))) + return -EFAULT; + if (!mem_is_zero(buf_status.resv, sizeof(buf_status.resv))) + return -EINVAL; + + bl = io_buffer_get_list(ctx, buf_status.buf_group); + if (!bl) + return -ENOENT; + if (!(bl->flags & IOBL_BUF_RING)) + return -EINVAL; + + buf_status.head = bl->head; + if (copy_to_user(arg, &buf_status, sizeof(buf_status))) + return -EFAULT; + + return 0; +} + +struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx, + unsigned int bgid) +{ + struct io_buffer_list *bl; + + lockdep_assert_held(&ctx->mmap_lock); + + bl = xa_load(&ctx->io_bl_xa, bgid); + if (!bl || !(bl->flags & IOBL_BUF_RING)) + return NULL; + return &bl->region; +} diff --git a/io_uring/kbuf.h b/io_uring/kbuf.h new file mode 100644 index 000000000000..bf15e26520d3 --- /dev/null +++ b/io_uring/kbuf.h @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_KBUF_H +#define IOU_KBUF_H + +#include <uapi/linux/io_uring.h> +#include <linux/io_uring_types.h> + +enum { + /* ring mapped provided buffers */ + IOBL_BUF_RING = 1, + /* buffers are consumed incrementally rather than always fully */ + IOBL_INC = 2, +}; + +struct io_buffer_list { + /* + * If the IOBL_BUF_RING flag is set, then buf_ring is used. If not, then + * these are classic provided buffers and ->buf_list is used. + */ + union { + struct list_head buf_list; + struct io_uring_buf_ring *buf_ring; + }; + /* count of classic/legacy buffers in buffer list */ + int nbufs; + + __u16 bgid; + + /* below is for ring provided buffers */ + __u16 nr_entries; + __u16 head; + __u16 mask; + + __u16 flags; + + struct io_mapped_region region; +}; + +struct io_buffer { + struct list_head list; + __u64 addr; + __u32 len; + __u16 bid; + __u16 bgid; +}; + +enum { + /* can alloc a bigger vec */ + KBUF_MODE_EXPAND = 1, + /* if bigger vec allocated, free old one */ + KBUF_MODE_FREE = 2, +}; + +struct buf_sel_arg { + struct iovec *iovs; + size_t out_len; + size_t max_len; + unsigned short nr_iovs; + unsigned short mode; + unsigned short buf_group; + unsigned short partial_map; +}; + +struct io_br_sel io_buffer_select(struct io_kiocb *req, size_t *len, + unsigned buf_group, unsigned int issue_flags); +int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg, + struct io_br_sel *sel, unsigned int issue_flags); +int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg, + struct io_br_sel *sel); +void io_destroy_buffers(struct io_ring_ctx *ctx); + +int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags); + +int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); +int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); +int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg); + +bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags); +void io_kbuf_drop_legacy(struct io_kiocb *req); + +unsigned int __io_put_kbufs(struct io_kiocb *req, struct io_buffer_list *bl, + int len, int nbufs); +bool io_kbuf_commit(struct io_kiocb *req, + struct io_buffer_list *bl, int len, int nr); + +struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx, + unsigned int bgid); + +static inline bool io_kbuf_recycle_ring(struct io_kiocb *req, + struct io_buffer_list *bl) +{ + if (bl) { + req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT); + return true; + } + return false; +} + +static inline bool io_do_buffer_select(struct io_kiocb *req) +{ + if (!(req->flags & REQ_F_BUFFER_SELECT)) + return false; + return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)); +} + +static inline bool io_kbuf_recycle(struct io_kiocb *req, struct io_buffer_list *bl, + unsigned issue_flags) +{ + if (req->flags & REQ_F_BL_NO_RECYCLE) + return false; + if (req->flags & REQ_F_BUFFER_RING) + return io_kbuf_recycle_ring(req, bl); + if (req->flags & REQ_F_BUFFER_SELECTED) + return io_kbuf_recycle_legacy(req, issue_flags); + return false; +} + +static inline unsigned int io_put_kbuf(struct io_kiocb *req, int len, + struct io_buffer_list *bl) +{ + if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED))) + return 0; + return __io_put_kbufs(req, bl, len, 1); +} + +static inline unsigned int io_put_kbufs(struct io_kiocb *req, int len, + struct io_buffer_list *bl, int nbufs) +{ + if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED))) + return 0; + return __io_put_kbufs(req, bl, len, nbufs); +} +#endif diff --git a/io_uring/memmap.c b/io_uring/memmap.c new file mode 100644 index 000000000000..18e574776ef6 --- /dev/null +++ b/io_uring/memmap.c @@ -0,0 +1,396 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/io_uring.h> +#include <linux/io_uring_types.h> +#include <asm/shmparam.h> + +#include "memmap.h" +#include "kbuf.h" +#include "rsrc.h" +#include "zcrx.h" + +static bool io_mem_alloc_compound(struct page **pages, int nr_pages, + size_t size, gfp_t gfp) +{ + struct page *page; + int i, order; + + order = get_order(size); + if (order > MAX_PAGE_ORDER) + return false; + else if (order) + gfp |= __GFP_COMP; + + page = alloc_pages(gfp, order); + if (!page) + return false; + + for (i = 0; i < nr_pages; i++) + pages[i] = page + i; + + return true; +} + +struct page **io_pin_pages(unsigned long uaddr, unsigned long len, int *npages) +{ + unsigned long start, end, nr_pages; + struct page **pages; + int ret; + + if (check_add_overflow(uaddr, len, &end)) + return ERR_PTR(-EOVERFLOW); + if (check_add_overflow(end, PAGE_SIZE - 1, &end)) + return ERR_PTR(-EOVERFLOW); + + end = end >> PAGE_SHIFT; + start = uaddr >> PAGE_SHIFT; + nr_pages = end - start; + if (WARN_ON_ONCE(!nr_pages)) + return ERR_PTR(-EINVAL); + if (WARN_ON_ONCE(nr_pages > INT_MAX)) + return ERR_PTR(-EOVERFLOW); + + pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); + if (!pages) + return ERR_PTR(-ENOMEM); + + ret = pin_user_pages_fast(uaddr, nr_pages, FOLL_WRITE | FOLL_LONGTERM, + pages); + /* success, mapped all pages */ + if (ret == nr_pages) { + *npages = nr_pages; + return pages; + } + + /* partial map, or didn't map anything */ + if (ret >= 0) { + /* if we did partial map, release any pages we did get */ + if (ret) + unpin_user_pages(pages, ret); + ret = -EFAULT; + } + kvfree(pages); + return ERR_PTR(ret); +} + +enum { + /* memory was vmap'ed for the kernel, freeing the region vunmap's it */ + IO_REGION_F_VMAP = 1, + /* memory is provided by user and pinned by the kernel */ + IO_REGION_F_USER_PROVIDED = 2, + /* only the first page in the array is ref'ed */ + IO_REGION_F_SINGLE_REF = 4, +}; + +void io_free_region(struct user_struct *user, struct io_mapped_region *mr) +{ + if (mr->pages) { + long nr_refs = mr->nr_pages; + + if (mr->flags & IO_REGION_F_SINGLE_REF) + nr_refs = 1; + + if (mr->flags & IO_REGION_F_USER_PROVIDED) + unpin_user_pages(mr->pages, nr_refs); + else + release_pages(mr->pages, nr_refs); + + kvfree(mr->pages); + } + if ((mr->flags & IO_REGION_F_VMAP) && mr->ptr) + vunmap(mr->ptr); + if (mr->nr_pages && user) + __io_unaccount_mem(user, mr->nr_pages); + + memset(mr, 0, sizeof(*mr)); +} + +static int io_region_init_ptr(struct io_mapped_region *mr) +{ + struct io_imu_folio_data ifd; + void *ptr; + + if (io_check_coalesce_buffer(mr->pages, mr->nr_pages, &ifd)) { + if (ifd.nr_folios == 1 && !PageHighMem(mr->pages[0])) { + mr->ptr = page_address(mr->pages[0]); + return 0; + } + } + ptr = vmap(mr->pages, mr->nr_pages, VM_MAP, PAGE_KERNEL); + if (!ptr) + return -ENOMEM; + + mr->ptr = ptr; + mr->flags |= IO_REGION_F_VMAP; + return 0; +} + +static int io_region_pin_pages(struct io_mapped_region *mr, + struct io_uring_region_desc *reg) +{ + size_t size = io_region_size(mr); + struct page **pages; + int nr_pages; + + pages = io_pin_pages(reg->user_addr, size, &nr_pages); + if (IS_ERR(pages)) + return PTR_ERR(pages); + if (WARN_ON_ONCE(nr_pages != mr->nr_pages)) + return -EFAULT; + + mr->pages = pages; + mr->flags |= IO_REGION_F_USER_PROVIDED; + return 0; +} + +static int io_region_allocate_pages(struct io_mapped_region *mr, + struct io_uring_region_desc *reg, + unsigned long mmap_offset) +{ + gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN; + size_t size = io_region_size(mr); + unsigned long nr_allocated; + struct page **pages; + + pages = kvmalloc_array(mr->nr_pages, sizeof(*pages), gfp); + if (!pages) + return -ENOMEM; + + if (io_mem_alloc_compound(pages, mr->nr_pages, size, gfp)) { + mr->flags |= IO_REGION_F_SINGLE_REF; + goto done; + } + + nr_allocated = alloc_pages_bulk_node(gfp, NUMA_NO_NODE, + mr->nr_pages, pages); + if (nr_allocated != mr->nr_pages) { + if (nr_allocated) + release_pages(pages, nr_allocated); + kvfree(pages); + return -ENOMEM; + } +done: + reg->mmap_offset = mmap_offset; + mr->pages = pages; + return 0; +} + +int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr, + struct io_uring_region_desc *reg, + unsigned long mmap_offset) +{ + int nr_pages, ret; + u64 end; + + if (WARN_ON_ONCE(mr->pages || mr->ptr || mr->nr_pages)) + return -EFAULT; + if (memchr_inv(®->__resv, 0, sizeof(reg->__resv))) + return -EINVAL; + if (reg->flags & ~IORING_MEM_REGION_TYPE_USER) + return -EINVAL; + /* user_addr should be set IFF it's a user memory backed region */ + if ((reg->flags & IORING_MEM_REGION_TYPE_USER) != !!reg->user_addr) + return -EFAULT; + if (!reg->size || reg->mmap_offset || reg->id) + return -EINVAL; + if ((reg->size >> PAGE_SHIFT) > INT_MAX) + return -E2BIG; + if ((reg->user_addr | reg->size) & ~PAGE_MASK) + return -EINVAL; + if (check_add_overflow(reg->user_addr, reg->size, &end)) + return -EOVERFLOW; + + nr_pages = reg->size >> PAGE_SHIFT; + if (ctx->user) { + ret = __io_account_mem(ctx->user, nr_pages); + if (ret) + return ret; + } + mr->nr_pages = nr_pages; + + if (reg->flags & IORING_MEM_REGION_TYPE_USER) + ret = io_region_pin_pages(mr, reg); + else + ret = io_region_allocate_pages(mr, reg, mmap_offset); + if (ret) + goto out_free; + + ret = io_region_init_ptr(mr); + if (ret) + goto out_free; + return 0; +out_free: + io_free_region(ctx->user, mr); + return ret; +} + +static struct io_mapped_region *io_mmap_get_region(struct io_ring_ctx *ctx, + loff_t pgoff) +{ + loff_t offset = pgoff << PAGE_SHIFT; + unsigned int id; + + + switch (offset & IORING_OFF_MMAP_MASK) { + case IORING_OFF_SQ_RING: + case IORING_OFF_CQ_RING: + return &ctx->ring_region; + case IORING_OFF_SQES: + return &ctx->sq_region; + case IORING_OFF_PBUF_RING: + id = (offset & ~IORING_OFF_MMAP_MASK) >> IORING_OFF_PBUF_SHIFT; + return io_pbuf_get_region(ctx, id); + case IORING_MAP_OFF_PARAM_REGION: + return &ctx->param_region; + case IORING_MAP_OFF_ZCRX_REGION: + id = (offset & ~IORING_OFF_MMAP_MASK) >> IORING_OFF_ZCRX_SHIFT; + return io_zcrx_get_region(ctx, id); + } + return NULL; +} + +static void *io_region_validate_mmap(struct io_ring_ctx *ctx, + struct io_mapped_region *mr) +{ + lockdep_assert_held(&ctx->mmap_lock); + + if (!io_region_is_set(mr)) + return ERR_PTR(-EINVAL); + if (mr->flags & IO_REGION_F_USER_PROVIDED) + return ERR_PTR(-EINVAL); + + return io_region_get_ptr(mr); +} + +static void *io_uring_validate_mmap_request(struct file *file, loff_t pgoff, + size_t sz) +{ + struct io_ring_ctx *ctx = file->private_data; + struct io_mapped_region *region; + + region = io_mmap_get_region(ctx, pgoff); + if (!region) + return ERR_PTR(-EINVAL); + return io_region_validate_mmap(ctx, region); +} + +#ifdef CONFIG_MMU + +static int io_region_mmap(struct io_ring_ctx *ctx, + struct io_mapped_region *mr, + struct vm_area_struct *vma, + unsigned max_pages) +{ + unsigned long nr_pages = min(mr->nr_pages, max_pages); + + vm_flags_set(vma, VM_DONTEXPAND); + return vm_insert_pages(vma, vma->vm_start, mr->pages, &nr_pages); +} + +__cold int io_uring_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct io_ring_ctx *ctx = file->private_data; + size_t sz = vma->vm_end - vma->vm_start; + long offset = vma->vm_pgoff << PAGE_SHIFT; + unsigned int page_limit = UINT_MAX; + struct io_mapped_region *region; + void *ptr; + + guard(mutex)(&ctx->mmap_lock); + + ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + + switch (offset & IORING_OFF_MMAP_MASK) { + case IORING_OFF_SQ_RING: + case IORING_OFF_CQ_RING: + page_limit = (sz + PAGE_SIZE - 1) >> PAGE_SHIFT; + break; + } + + region = io_mmap_get_region(ctx, vma->vm_pgoff); + return io_region_mmap(ctx, region, vma, page_limit); +} + +unsigned long io_uring_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + struct io_ring_ctx *ctx = filp->private_data; + void *ptr; + + /* + * Do not allow to map to user-provided address to avoid breaking the + * aliasing rules. Userspace is not able to guess the offset address of + * kernel kmalloc()ed memory area. + */ + if (addr) + return -EINVAL; + + guard(mutex)(&ctx->mmap_lock); + + ptr = io_uring_validate_mmap_request(filp, pgoff, len); + if (IS_ERR(ptr)) + return -ENOMEM; + + /* + * Some architectures have strong cache aliasing requirements. + * For such architectures we need a coherent mapping which aliases + * kernel memory *and* userspace memory. To achieve that: + * - use a NULL file pointer to reference physical memory, and + * - use the kernel virtual address of the shared io_uring context + * (instead of the userspace-provided address, which has to be 0UL + * anyway). + * - use the same pgoff which the get_unmapped_area() uses to + * calculate the page colouring. + * For architectures without such aliasing requirements, the + * architecture will return any suitable mapping because addr is 0. + */ + filp = NULL; + flags |= MAP_SHARED; + pgoff = 0; /* has been translated to ptr above */ +#ifdef SHM_COLOUR + addr = (uintptr_t) ptr; + pgoff = addr >> PAGE_SHIFT; +#else + addr = 0UL; +#endif + return mm_get_unmapped_area(filp, addr, len, pgoff, flags); +} + +#else /* !CONFIG_MMU */ + +int io_uring_mmap(struct file *file, struct vm_area_struct *vma) +{ + return is_nommu_shared_mapping(vma->vm_flags) ? 0 : -EINVAL; +} + +unsigned int io_uring_nommu_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE; +} + +unsigned long io_uring_get_unmapped_area(struct file *file, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + struct io_ring_ctx *ctx = file->private_data; + void *ptr; + + guard(mutex)(&ctx->mmap_lock); + + ptr = io_uring_validate_mmap_request(file, pgoff, len); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + + return (unsigned long) ptr; +} + +#endif /* !CONFIG_MMU */ diff --git a/io_uring/memmap.h b/io_uring/memmap.h new file mode 100644 index 000000000000..a39d9e518905 --- /dev/null +++ b/io_uring/memmap.h @@ -0,0 +1,51 @@ +#ifndef IO_URING_MEMMAP_H +#define IO_URING_MEMMAP_H + +#define IORING_MAP_OFF_PARAM_REGION 0x20000000ULL +#define IORING_MAP_OFF_ZCRX_REGION 0x30000000ULL + +#define IORING_OFF_ZCRX_SHIFT 16 + +struct page **io_pin_pages(unsigned long uaddr, unsigned long len, int *npages); + +#ifndef CONFIG_MMU +unsigned int io_uring_nommu_mmap_capabilities(struct file *file); +#endif +unsigned long io_uring_get_unmapped_area(struct file *file, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags); +int io_uring_mmap(struct file *file, struct vm_area_struct *vma); + +void io_free_region(struct user_struct *user, struct io_mapped_region *mr); +int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr, + struct io_uring_region_desc *reg, + unsigned long mmap_offset); + +static inline void *io_region_get_ptr(struct io_mapped_region *mr) +{ + return mr->ptr; +} + +static inline bool io_region_is_set(struct io_mapped_region *mr) +{ + return !!mr->nr_pages; +} + +static inline void io_region_publish(struct io_ring_ctx *ctx, + struct io_mapped_region *src_region, + struct io_mapped_region *dst_region) +{ + /* + * Once published mmap can find it without holding only the ->mmap_lock + * and not ->uring_lock. + */ + guard(mutex)(&ctx->mmap_lock); + *dst_region = *src_region; +} + +static inline size_t io_region_size(struct io_mapped_region *mr) +{ + return (size_t) mr->nr_pages << PAGE_SHIFT; +} + +#endif diff --git a/io_uring/mock_file.c b/io_uring/mock_file.c new file mode 100644 index 000000000000..3ffac8f72974 --- /dev/null +++ b/io_uring/mock_file.c @@ -0,0 +1,350 @@ +#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/anon_inodes.h> +#include <linux/ktime.h> +#include <linux/hrtimer.h> +#include <linux/poll.h> + +#include <linux/io_uring/cmd.h> +#include <linux/io_uring_types.h> +#include <uapi/linux/io_uring/mock_file.h> + +struct io_mock_iocb { + struct kiocb *iocb; + struct hrtimer timer; + int res; +}; + +struct io_mock_file { + size_t size; + u64 rw_delay_ns; + bool pollable; + struct wait_queue_head poll_wq; +}; + +#define IO_VALID_COPY_CMD_FLAGS IORING_MOCK_COPY_FROM + +static int io_copy_regbuf(struct iov_iter *reg_iter, void __user *ubuf) +{ + size_t ret, copied = 0; + size_t buflen = PAGE_SIZE; + void *tmp_buf; + + tmp_buf = kzalloc(buflen, GFP_KERNEL); + if (!tmp_buf) + return -ENOMEM; + + while (iov_iter_count(reg_iter)) { + size_t len = min(iov_iter_count(reg_iter), buflen); + + if (iov_iter_rw(reg_iter) == ITER_SOURCE) { + ret = copy_from_iter(tmp_buf, len, reg_iter); + if (ret <= 0) + break; + if (copy_to_user(ubuf, tmp_buf, ret)) + break; + } else { + if (copy_from_user(tmp_buf, ubuf, len)) + break; + ret = copy_to_iter(tmp_buf, len, reg_iter); + if (ret <= 0) + break; + } + ubuf += ret; + copied += ret; + } + + kfree(tmp_buf); + return copied; +} + +static int io_cmd_copy_regbuf(struct io_uring_cmd *cmd, unsigned int issue_flags) +{ + const struct io_uring_sqe *sqe = cmd->sqe; + const struct iovec __user *iovec; + unsigned flags, iovec_len; + struct iov_iter iter; + void __user *ubuf; + int dir, ret; + + ubuf = u64_to_user_ptr(READ_ONCE(sqe->addr3)); + iovec = u64_to_user_ptr(READ_ONCE(sqe->addr)); + iovec_len = READ_ONCE(sqe->len); + flags = READ_ONCE(sqe->file_index); + + if (unlikely(sqe->ioprio || sqe->__pad1)) + return -EINVAL; + if (flags & ~IO_VALID_COPY_CMD_FLAGS) + return -EINVAL; + + dir = (flags & IORING_MOCK_COPY_FROM) ? ITER_SOURCE : ITER_DEST; + ret = io_uring_cmd_import_fixed_vec(cmd, iovec, iovec_len, dir, &iter, + issue_flags); + if (ret) + return ret; + ret = io_copy_regbuf(&iter, ubuf); + return ret ? ret : -EFAULT; +} + +static int io_mock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) +{ + switch (cmd->cmd_op) { + case IORING_MOCK_CMD_COPY_REGBUF: + return io_cmd_copy_regbuf(cmd, issue_flags); + } + return -ENOTSUPP; +} + +static enum hrtimer_restart io_mock_rw_timer_expired(struct hrtimer *timer) +{ + struct io_mock_iocb *mio = container_of(timer, struct io_mock_iocb, timer); + struct kiocb *iocb = mio->iocb; + + WRITE_ONCE(iocb->private, NULL); + iocb->ki_complete(iocb, mio->res); + kfree(mio); + return HRTIMER_NORESTART; +} + +static ssize_t io_mock_delay_rw(struct kiocb *iocb, size_t len) +{ + struct io_mock_file *mf = iocb->ki_filp->private_data; + struct io_mock_iocb *mio; + + mio = kzalloc(sizeof(*mio), GFP_KERNEL); + if (!mio) + return -ENOMEM; + + mio->iocb = iocb; + mio->res = len; + hrtimer_setup(&mio->timer, io_mock_rw_timer_expired, + CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_start(&mio->timer, ns_to_ktime(mf->rw_delay_ns), + HRTIMER_MODE_REL); + return -EIOCBQUEUED; +} + +static ssize_t io_mock_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct io_mock_file *mf = iocb->ki_filp->private_data; + size_t len = iov_iter_count(to); + size_t nr_zeroed; + + if (iocb->ki_pos + len > mf->size) + return -EINVAL; + nr_zeroed = iov_iter_zero(len, to); + if (!mf->rw_delay_ns || nr_zeroed != len) + return nr_zeroed; + + return io_mock_delay_rw(iocb, len); +} + +static ssize_t io_mock_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct io_mock_file *mf = iocb->ki_filp->private_data; + size_t len = iov_iter_count(from); + + if (iocb->ki_pos + len > mf->size) + return -EINVAL; + if (!mf->rw_delay_ns) { + iov_iter_advance(from, len); + return len; + } + + return io_mock_delay_rw(iocb, len); +} + +static loff_t io_mock_llseek(struct file *file, loff_t offset, int whence) +{ + struct io_mock_file *mf = file->private_data; + + return fixed_size_llseek(file, offset, whence, mf->size); +} + +static __poll_t io_mock_poll(struct file *file, struct poll_table_struct *pt) +{ + struct io_mock_file *mf = file->private_data; + __poll_t mask = 0; + + poll_wait(file, &mf->poll_wq, pt); + + mask |= EPOLLOUT | EPOLLWRNORM; + mask |= EPOLLIN | EPOLLRDNORM; + return mask; +} + +static int io_mock_release(struct inode *inode, struct file *file) +{ + struct io_mock_file *mf = file->private_data; + + kfree(mf); + return 0; +} + +static const struct file_operations io_mock_fops = { + .owner = THIS_MODULE, + .release = io_mock_release, + .uring_cmd = io_mock_cmd, + .read_iter = io_mock_read_iter, + .write_iter = io_mock_write_iter, + .llseek = io_mock_llseek, +}; + +static const struct file_operations io_mock_poll_fops = { + .owner = THIS_MODULE, + .release = io_mock_release, + .uring_cmd = io_mock_cmd, + .read_iter = io_mock_read_iter, + .write_iter = io_mock_write_iter, + .llseek = io_mock_llseek, + .poll = io_mock_poll, +}; + +#define IO_VALID_CREATE_FLAGS (IORING_MOCK_CREATE_F_SUPPORT_NOWAIT | \ + IORING_MOCK_CREATE_F_POLL) + +static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flags) +{ + const struct file_operations *fops = &io_mock_fops; + const struct io_uring_sqe *sqe = cmd->sqe; + struct io_uring_mock_create mc, __user *uarg; + struct file *file; + struct io_mock_file *mf __free(kfree) = NULL; + size_t uarg_size; + + /* + * It's a testing only driver that allows exercising edge cases + * that wouldn't be possible to hit otherwise. + */ + add_taint(TAINT_TEST, LOCKDEP_STILL_OK); + + uarg = u64_to_user_ptr(READ_ONCE(sqe->addr)); + uarg_size = READ_ONCE(sqe->len); + + if (sqe->ioprio || sqe->__pad1 || sqe->addr3 || sqe->file_index) + return -EINVAL; + if (uarg_size != sizeof(mc)) + return -EINVAL; + + memset(&mc, 0, sizeof(mc)); + if (copy_from_user(&mc, uarg, uarg_size)) + return -EFAULT; + if (!mem_is_zero(mc.__resv, sizeof(mc.__resv))) + return -EINVAL; + if (mc.flags & ~IO_VALID_CREATE_FLAGS) + return -EINVAL; + if (mc.file_size > SZ_1G) + return -EINVAL; + if (mc.rw_delay_ns > NSEC_PER_SEC) + return -EINVAL; + + mf = kzalloc(sizeof(*mf), GFP_KERNEL_ACCOUNT); + if (!mf) + return -ENOMEM; + + init_waitqueue_head(&mf->poll_wq); + mf->size = mc.file_size; + mf->rw_delay_ns = mc.rw_delay_ns; + if (mc.flags & IORING_MOCK_CREATE_F_POLL) { + fops = &io_mock_poll_fops; + mf->pollable = true; + } + + FD_PREPARE(fdf, O_RDWR | O_CLOEXEC, + anon_inode_create_getfile("[io_uring_mock]", fops, mf, + O_RDWR | O_CLOEXEC, NULL)); + if (fdf.err) + return fdf.err; + + retain_and_null_ptr(mf); + file = fd_prepare_file(fdf); + file->f_mode |= FMODE_READ | FMODE_CAN_READ | FMODE_WRITE | + FMODE_CAN_WRITE | FMODE_LSEEK; + if (mc.flags & IORING_MOCK_CREATE_F_SUPPORT_NOWAIT) + file->f_mode |= FMODE_NOWAIT; + + mc.out_fd = fd_prepare_fd(fdf); + if (copy_to_user(uarg, &mc, uarg_size)) + return -EFAULT; + + fd_publish(fdf); + return 0; +} + +static int io_probe_mock(struct io_uring_cmd *cmd) +{ + const struct io_uring_sqe *sqe = cmd->sqe; + struct io_uring_mock_probe mp, __user *uarg; + size_t uarg_size; + + uarg = u64_to_user_ptr(READ_ONCE(sqe->addr)); + uarg_size = READ_ONCE(sqe->len); + + if (sqe->ioprio || sqe->__pad1 || sqe->addr3 || sqe->file_index || + uarg_size != sizeof(mp)) + return -EINVAL; + + memset(&mp, 0, sizeof(mp)); + if (copy_from_user(&mp, uarg, uarg_size)) + return -EFAULT; + if (!mem_is_zero(&mp, sizeof(mp))) + return -EINVAL; + + mp.features = IORING_MOCK_FEAT_END; + + if (copy_to_user(uarg, &mp, uarg_size)) + return -EFAULT; + return 0; +} + +static int iou_mock_mgr_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + switch (cmd->cmd_op) { + case IORING_MOCK_MGR_CMD_PROBE: + return io_probe_mock(cmd); + case IORING_MOCK_MGR_CMD_CREATE: + return io_create_mock_file(cmd, issue_flags); + } + return -EOPNOTSUPP; +} + +static const struct file_operations iou_mock_dev_fops = { + .owner = THIS_MODULE, + .uring_cmd = iou_mock_mgr_cmd, +}; + +static struct miscdevice iou_mock_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "io_uring_mock", + .fops = &iou_mock_dev_fops, +}; + +static int __init io_mock_init(void) +{ + int ret; + + ret = misc_register(&iou_mock_miscdev); + if (ret < 0) { + pr_err("Could not initialize io_uring mock device\n"); + return ret; + } + return 0; +} + +static void __exit io_mock_exit(void) +{ + misc_deregister(&iou_mock_miscdev); +} + +module_init(io_mock_init) +module_exit(io_mock_exit) + +MODULE_AUTHOR("Pavel Begunkov <asml.silence@gmail.com>"); +MODULE_DESCRIPTION("io_uring mock file"); +MODULE_LICENSE("GPL"); diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c new file mode 100644 index 000000000000..7063ea7964e7 --- /dev/null +++ b/io_uring/msg_ring.c @@ -0,0 +1,338 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/nospec.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "rsrc.h" +#include "filetable.h" +#include "msg_ring.h" + +/* All valid masks for MSG_RING */ +#define IORING_MSG_RING_MASK (IORING_MSG_RING_CQE_SKIP | \ + IORING_MSG_RING_FLAGS_PASS) + +struct io_msg { + struct file *file; + struct file *src_file; + struct callback_head tw; + u64 user_data; + u32 len; + u32 cmd; + u32 src_fd; + union { + u32 dst_fd; + u32 cqe_flags; + }; + u32 flags; +}; + +static void io_double_unlock_ctx(struct io_ring_ctx *octx) +{ + mutex_unlock(&octx->uring_lock); +} + +static int io_lock_external_ctx(struct io_ring_ctx *octx, + unsigned int issue_flags) +{ + /* + * To ensure proper ordering between the two ctxs, we can only + * attempt a trylock on the target. If that fails and we already have + * the source ctx lock, punt to io-wq. + */ + if (!(issue_flags & IO_URING_F_UNLOCKED)) { + if (!mutex_trylock(&octx->uring_lock)) + return -EAGAIN; + return 0; + } + mutex_lock(&octx->uring_lock); + return 0; +} + +void io_msg_ring_cleanup(struct io_kiocb *req) +{ + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + + if (WARN_ON_ONCE(!msg->src_file)) + return; + + fput(msg->src_file); + msg->src_file = NULL; +} + +static inline bool io_msg_need_remote(struct io_ring_ctx *target_ctx) +{ + return target_ctx->task_complete; +} + +static void io_msg_tw_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_ring_ctx *ctx = req->ctx; + + io_add_aux_cqe(ctx, req->cqe.user_data, req->cqe.res, req->cqe.flags); + kfree_rcu(req, rcu_head); + percpu_ref_put(&ctx->refs); +} + +static int io_msg_remote_post(struct io_ring_ctx *ctx, struct io_kiocb *req, + int res, u32 cflags, u64 user_data) +{ + if (!READ_ONCE(ctx->submitter_task)) { + kfree_rcu(req, rcu_head); + return -EOWNERDEAD; + } + req->opcode = IORING_OP_NOP; + req->cqe.user_data = user_data; + io_req_set_res(req, res, cflags); + percpu_ref_get(&ctx->refs); + req->ctx = ctx; + req->tctx = NULL; + req->io_task_work.func = io_msg_tw_complete; + io_req_task_work_add_remote(req, IOU_F_TWQ_LAZY_WAKE); + return 0; +} + +static int io_msg_data_remote(struct io_ring_ctx *target_ctx, + struct io_msg *msg) +{ + struct io_kiocb *target; + u32 flags = 0; + + target = kmem_cache_alloc(req_cachep, GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO) ; + if (unlikely(!target)) + return -ENOMEM; + + if (msg->flags & IORING_MSG_RING_FLAGS_PASS) + flags = msg->cqe_flags; + + return io_msg_remote_post(target_ctx, target, msg->len, flags, + msg->user_data); +} + +static int __io_msg_ring_data(struct io_ring_ctx *target_ctx, + struct io_msg *msg, unsigned int issue_flags) +{ + u32 flags = 0; + int ret; + + if (msg->src_fd || msg->flags & ~IORING_MSG_RING_FLAGS_PASS) + return -EINVAL; + if (!(msg->flags & IORING_MSG_RING_FLAGS_PASS) && msg->dst_fd) + return -EINVAL; + if (target_ctx->flags & IORING_SETUP_R_DISABLED) + return -EBADFD; + + if (io_msg_need_remote(target_ctx)) + return io_msg_data_remote(target_ctx, msg); + + if (msg->flags & IORING_MSG_RING_FLAGS_PASS) + flags = msg->cqe_flags; + + ret = -EOVERFLOW; + if (target_ctx->flags & IORING_SETUP_IOPOLL) { + if (unlikely(io_lock_external_ctx(target_ctx, issue_flags))) + return -EAGAIN; + } + if (io_post_aux_cqe(target_ctx, msg->user_data, msg->len, flags)) + ret = 0; + if (target_ctx->flags & IORING_SETUP_IOPOLL) + io_double_unlock_ctx(target_ctx); + return ret; +} + +static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *target_ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + + return __io_msg_ring_data(target_ctx, msg, issue_flags); +} + +static int io_msg_grab_file(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + struct io_ring_ctx *ctx = req->ctx; + struct io_rsrc_node *node; + int ret = -EBADF; + + io_ring_submit_lock(ctx, issue_flags); + node = io_rsrc_node_lookup(&ctx->file_table.data, msg->src_fd); + if (node) { + msg->src_file = io_slot_file(node); + if (msg->src_file) + get_file(msg->src_file); + req->flags |= REQ_F_NEED_CLEANUP; + ret = 0; + } + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} + +static int io_msg_install_complete(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *target_ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + struct file *src_file = msg->src_file; + int ret; + + if (unlikely(io_lock_external_ctx(target_ctx, issue_flags))) + return -EAGAIN; + + ret = __io_fixed_fd_install(target_ctx, src_file, msg->dst_fd); + if (ret < 0) + goto out_unlock; + + msg->src_file = NULL; + req->flags &= ~REQ_F_NEED_CLEANUP; + + if (msg->flags & IORING_MSG_RING_CQE_SKIP) + goto out_unlock; + /* + * If this fails, the target still received the file descriptor but + * wasn't notified of the fact. This means that if this request + * completes with -EOVERFLOW, then the sender must ensure that a + * later IORING_OP_MSG_RING delivers the message. + */ + if (!io_post_aux_cqe(target_ctx, msg->user_data, ret, 0)) + ret = -EOVERFLOW; +out_unlock: + io_double_unlock_ctx(target_ctx); + return ret; +} + +static void io_msg_tw_fd_complete(struct callback_head *head) +{ + struct io_msg *msg = container_of(head, struct io_msg, tw); + struct io_kiocb *req = cmd_to_io_kiocb(msg); + int ret = -EOWNERDEAD; + + if (!(current->flags & PF_EXITING)) + ret = io_msg_install_complete(req, IO_URING_F_UNLOCKED); + if (ret < 0) + req_set_fail(req); + io_req_queue_tw_complete(req, ret); +} + +static int io_msg_fd_remote(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + struct task_struct *task = READ_ONCE(ctx->submitter_task); + + if (unlikely(!task)) + return -EOWNERDEAD; + + init_task_work(&msg->tw, io_msg_tw_fd_complete); + if (task_work_add(task, &msg->tw, TWA_SIGNAL)) + return -EOWNERDEAD; + + return IOU_ISSUE_SKIP_COMPLETE; +} + +static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *target_ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + struct io_ring_ctx *ctx = req->ctx; + + if (msg->len) + return -EINVAL; + if (target_ctx == ctx) + return -EINVAL; + if (target_ctx->flags & IORING_SETUP_R_DISABLED) + return -EBADFD; + if (!msg->src_file) { + int ret = io_msg_grab_file(req, issue_flags); + if (unlikely(ret)) + return ret; + } + + if (io_msg_need_remote(target_ctx)) + return io_msg_fd_remote(req); + return io_msg_install_complete(req, issue_flags); +} + +static int __io_msg_ring_prep(struct io_msg *msg, const struct io_uring_sqe *sqe) +{ + if (unlikely(sqe->buf_index || sqe->personality)) + return -EINVAL; + + msg->src_file = NULL; + msg->user_data = READ_ONCE(sqe->off); + msg->len = READ_ONCE(sqe->len); + msg->cmd = READ_ONCE(sqe->addr); + msg->src_fd = READ_ONCE(sqe->addr3); + msg->dst_fd = READ_ONCE(sqe->file_index); + msg->flags = READ_ONCE(sqe->msg_ring_flags); + if (msg->flags & ~IORING_MSG_RING_MASK) + return -EINVAL; + + return 0; +} + +int io_msg_ring_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_msg_ring_prep(io_kiocb_to_cmd(req, struct io_msg), sqe); +} + +int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + int ret; + + ret = -EBADFD; + if (!io_is_uring_fops(req->file)) + goto done; + + switch (msg->cmd) { + case IORING_MSG_DATA: + ret = io_msg_ring_data(req, issue_flags); + break; + case IORING_MSG_SEND_FD: + ret = io_msg_send_fd(req, issue_flags); + break; + default: + ret = -EINVAL; + break; + } + +done: + if (ret < 0) { + if (ret == -EAGAIN || ret == IOU_ISSUE_SKIP_COMPLETE) + return ret; + req_set_fail(req); + } + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_uring_sync_msg_ring(struct io_uring_sqe *sqe) +{ + struct io_msg io_msg = { }; + int ret; + + ret = __io_msg_ring_prep(&io_msg, sqe); + if (unlikely(ret)) + return ret; + + /* + * Only data sending supported, not IORING_MSG_SEND_FD as that one + * doesn't make sense without a source ring to send files from. + */ + if (io_msg.cmd != IORING_MSG_DATA) + return -EINVAL; + + CLASS(fd, f)(sqe->fd); + if (fd_empty(f)) + return -EBADF; + if (!io_is_uring_fops(fd_file(f))) + return -EBADFD; + return __io_msg_ring_data(fd_file(f)->private_data, + &io_msg, IO_URING_F_UNLOCKED); +} diff --git a/io_uring/msg_ring.h b/io_uring/msg_ring.h new file mode 100644 index 000000000000..32236d2fb778 --- /dev/null +++ b/io_uring/msg_ring.h @@ -0,0 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_uring_sync_msg_ring(struct io_uring_sqe *sqe); +int io_msg_ring_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags); +void io_msg_ring_cleanup(struct io_kiocb *req); diff --git a/io_uring/napi.c b/io_uring/napi.c new file mode 100644 index 000000000000..4a10de03e426 --- /dev/null +++ b/io_uring/napi.c @@ -0,0 +1,396 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "io_uring.h" +#include "napi.h" + +#ifdef CONFIG_NET_RX_BUSY_POLL + +/* Timeout for cleanout of stale entries. */ +#define NAPI_TIMEOUT (60 * SEC_CONVERSION) + +struct io_napi_entry { + unsigned int napi_id; + struct list_head list; + + unsigned long timeout; + struct hlist_node node; + + struct rcu_head rcu; +}; + +static struct io_napi_entry *io_napi_hash_find(struct hlist_head *hash_list, + unsigned int napi_id) +{ + struct io_napi_entry *e; + + hlist_for_each_entry_rcu(e, hash_list, node) { + if (e->napi_id != napi_id) + continue; + return e; + } + + return NULL; +} + +static inline ktime_t net_to_ktime(unsigned long t) +{ + /* napi approximating usecs, reverse busy_loop_current_time */ + return ns_to_ktime(t << 10); +} + +int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id) +{ + struct hlist_head *hash_list; + struct io_napi_entry *e; + + /* Non-NAPI IDs can be rejected. */ + if (!napi_id_valid(napi_id)) + return -EINVAL; + + hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))]; + + scoped_guard(rcu) { + e = io_napi_hash_find(hash_list, napi_id); + if (e) { + WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT); + return -EEXIST; + } + } + + e = kmalloc(sizeof(*e), GFP_NOWAIT); + if (!e) + return -ENOMEM; + + e->napi_id = napi_id; + e->timeout = jiffies + NAPI_TIMEOUT; + + /* + * guard(spinlock) is not used to manually unlock it before calling + * kfree() + */ + spin_lock(&ctx->napi_lock); + if (unlikely(io_napi_hash_find(hash_list, napi_id))) { + spin_unlock(&ctx->napi_lock); + kfree(e); + return -EEXIST; + } + + hlist_add_tail_rcu(&e->node, hash_list); + list_add_tail_rcu(&e->list, &ctx->napi_list); + spin_unlock(&ctx->napi_lock); + return 0; +} + +static int __io_napi_del_id(struct io_ring_ctx *ctx, unsigned int napi_id) +{ + struct hlist_head *hash_list; + struct io_napi_entry *e; + + /* Non-NAPI IDs can be rejected. */ + if (!napi_id_valid(napi_id)) + return -EINVAL; + + hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))]; + guard(spinlock)(&ctx->napi_lock); + e = io_napi_hash_find(hash_list, napi_id); + if (!e) + return -ENOENT; + + list_del_rcu(&e->list); + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + return 0; +} + +static void __io_napi_remove_stale(struct io_ring_ctx *ctx) +{ + struct io_napi_entry *e; + + guard(spinlock)(&ctx->napi_lock); + /* + * list_for_each_entry_safe() is not required as long as: + * 1. list_del_rcu() does not reset the deleted node next pointer + * 2. kfree_rcu() delays the memory freeing until the next quiescent + * state + */ + list_for_each_entry(e, &ctx->napi_list, list) { + if (time_after(jiffies, READ_ONCE(e->timeout))) { + list_del_rcu(&e->list); + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + } + } +} + +static inline void io_napi_remove_stale(struct io_ring_ctx *ctx, bool is_stale) +{ + if (is_stale) + __io_napi_remove_stale(ctx); +} + +static inline bool io_napi_busy_loop_timeout(ktime_t start_time, + ktime_t bp) +{ + if (bp) { + ktime_t end_time = ktime_add(start_time, bp); + ktime_t now = net_to_ktime(busy_loop_current_time()); + + return ktime_after(now, end_time); + } + + return true; +} + +static bool io_napi_busy_loop_should_end(void *data, + unsigned long start_time) +{ + struct io_wait_queue *iowq = data; + + if (signal_pending(current)) + return true; + if (io_should_wake(iowq) || io_has_work(iowq->ctx)) + return true; + if (io_napi_busy_loop_timeout(net_to_ktime(start_time), + iowq->napi_busy_poll_dt)) + return true; + + return false; +} + +/* + * never report stale entries + */ +static bool static_tracking_do_busy_loop(struct io_ring_ctx *ctx, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg) +{ + struct io_napi_entry *e; + + list_for_each_entry_rcu(e, &ctx->napi_list, list) + napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg, + ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET); + return false; +} + +static bool +dynamic_tracking_do_busy_loop(struct io_ring_ctx *ctx, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg) +{ + struct io_napi_entry *e; + bool is_stale = false; + + list_for_each_entry_rcu(e, &ctx->napi_list, list) { + napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg, + ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET); + + if (time_after(jiffies, READ_ONCE(e->timeout))) + is_stale = true; + } + + return is_stale; +} + +static inline bool +__io_napi_do_busy_loop(struct io_ring_ctx *ctx, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg) +{ + if (READ_ONCE(ctx->napi_track_mode) == IO_URING_NAPI_TRACKING_STATIC) + return static_tracking_do_busy_loop(ctx, loop_end, loop_end_arg); + return dynamic_tracking_do_busy_loop(ctx, loop_end, loop_end_arg); +} + +static void io_napi_blocking_busy_loop(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq) +{ + unsigned long start_time = busy_loop_current_time(); + bool (*loop_end)(void *, unsigned long) = NULL; + void *loop_end_arg = NULL; + bool is_stale = false; + + /* Singular lists use a different napi loop end check function and are + * only executed once. + */ + if (list_is_singular(&ctx->napi_list)) { + loop_end = io_napi_busy_loop_should_end; + loop_end_arg = iowq; + } + + scoped_guard(rcu) { + do { + is_stale = __io_napi_do_busy_loop(ctx, loop_end, + loop_end_arg); + } while (!io_napi_busy_loop_should_end(iowq, start_time) && + !loop_end_arg); + } + + io_napi_remove_stale(ctx, is_stale); +} + +/* + * io_napi_init() - Init napi settings + * @ctx: pointer to io-uring context structure + * + * Init napi settings in the io-uring context. + */ +void io_napi_init(struct io_ring_ctx *ctx) +{ + u64 sys_dt = READ_ONCE(sysctl_net_busy_poll) * NSEC_PER_USEC; + + INIT_LIST_HEAD(&ctx->napi_list); + spin_lock_init(&ctx->napi_lock); + ctx->napi_prefer_busy_poll = false; + ctx->napi_busy_poll_dt = ns_to_ktime(sys_dt); + ctx->napi_track_mode = IO_URING_NAPI_TRACKING_INACTIVE; +} + +/* + * io_napi_free() - Deallocate napi + * @ctx: pointer to io-uring context structure + * + * Free the napi list and the hash table in the io-uring context. + */ +void io_napi_free(struct io_ring_ctx *ctx) +{ + struct io_napi_entry *e; + + guard(spinlock)(&ctx->napi_lock); + list_for_each_entry(e, &ctx->napi_list, list) { + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + } + INIT_LIST_HEAD_RCU(&ctx->napi_list); +} + +static int io_napi_register_napi(struct io_ring_ctx *ctx, + struct io_uring_napi *napi) +{ + switch (napi->op_param) { + case IO_URING_NAPI_TRACKING_DYNAMIC: + case IO_URING_NAPI_TRACKING_STATIC: + break; + default: + return -EINVAL; + } + /* clean the napi list for new settings */ + io_napi_free(ctx); + WRITE_ONCE(ctx->napi_track_mode, napi->op_param); + WRITE_ONCE(ctx->napi_busy_poll_dt, napi->busy_poll_to * NSEC_PER_USEC); + WRITE_ONCE(ctx->napi_prefer_busy_poll, !!napi->prefer_busy_poll); + return 0; +} + +/* + * io_napi_register() - Register napi with io-uring + * @ctx: pointer to io-uring context structure + * @arg: pointer to io_uring_napi structure + * + * Register napi in the io-uring context. + */ +int io_register_napi(struct io_ring_ctx *ctx, void __user *arg) +{ + const struct io_uring_napi curr = { + .busy_poll_to = ktime_to_us(ctx->napi_busy_poll_dt), + .prefer_busy_poll = ctx->napi_prefer_busy_poll, + .op_param = ctx->napi_track_mode + }; + struct io_uring_napi napi; + + if (ctx->flags & IORING_SETUP_IOPOLL) + return -EINVAL; + if (copy_from_user(&napi, arg, sizeof(napi))) + return -EFAULT; + if (napi.pad[0] || napi.pad[1] || napi.resv) + return -EINVAL; + + if (copy_to_user(arg, &curr, sizeof(curr))) + return -EFAULT; + + switch (napi.opcode) { + case IO_URING_NAPI_REGISTER_OP: + return io_napi_register_napi(ctx, &napi); + case IO_URING_NAPI_STATIC_ADD_ID: + if (curr.op_param != IO_URING_NAPI_TRACKING_STATIC) + return -EINVAL; + return __io_napi_add_id(ctx, napi.op_param); + case IO_URING_NAPI_STATIC_DEL_ID: + if (curr.op_param != IO_URING_NAPI_TRACKING_STATIC) + return -EINVAL; + return __io_napi_del_id(ctx, napi.op_param); + default: + return -EINVAL; + } +} + +/* + * io_napi_unregister() - Unregister napi with io-uring + * @ctx: pointer to io-uring context structure + * @arg: pointer to io_uring_napi structure + * + * Unregister napi. If arg has been specified copy the busy poll timeout and + * prefer busy poll setting to the passed in structure. + */ +int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg) +{ + const struct io_uring_napi curr = { + .busy_poll_to = ktime_to_us(ctx->napi_busy_poll_dt), + .prefer_busy_poll = ctx->napi_prefer_busy_poll + }; + + if (arg && copy_to_user(arg, &curr, sizeof(curr))) + return -EFAULT; + + WRITE_ONCE(ctx->napi_busy_poll_dt, 0); + WRITE_ONCE(ctx->napi_prefer_busy_poll, false); + WRITE_ONCE(ctx->napi_track_mode, IO_URING_NAPI_TRACKING_INACTIVE); + return 0; +} + +/* + * __io_napi_busy_loop() - execute busy poll loop + * @ctx: pointer to io-uring context structure + * @iowq: pointer to io wait queue + * + * Execute the busy poll loop and merge the spliced off list. + */ +void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) +{ + if (ctx->flags & IORING_SETUP_SQPOLL) + return; + + iowq->napi_busy_poll_dt = READ_ONCE(ctx->napi_busy_poll_dt); + if (iowq->timeout != KTIME_MAX) { + ktime_t dt = ktime_sub(iowq->timeout, io_get_time(ctx)); + + iowq->napi_busy_poll_dt = min_t(u64, iowq->napi_busy_poll_dt, dt); + } + + iowq->napi_prefer_busy_poll = READ_ONCE(ctx->napi_prefer_busy_poll); + io_napi_blocking_busy_loop(ctx, iowq); +} + +/* + * io_napi_sqpoll_busy_poll() - busy poll loop for sqpoll + * @ctx: pointer to io-uring context structure + * + * Splice of the napi list and execute the napi busy poll loop. + */ +int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx) +{ + bool is_stale = false; + + if (!READ_ONCE(ctx->napi_busy_poll_dt)) + return 0; + if (list_empty_careful(&ctx->napi_list)) + return 0; + + scoped_guard(rcu) { + is_stale = __io_napi_do_busy_loop(ctx, NULL, NULL); + } + + io_napi_remove_stale(ctx, is_stale); + return 1; +} + +#endif diff --git a/io_uring/napi.h b/io_uring/napi.h new file mode 100644 index 000000000000..fa742f42e09b --- /dev/null +++ b/io_uring/napi.h @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef IOU_NAPI_H +#define IOU_NAPI_H + +#include <linux/kernel.h> +#include <linux/io_uring.h> +#include <net/busy_poll.h> + +#ifdef CONFIG_NET_RX_BUSY_POLL + +void io_napi_init(struct io_ring_ctx *ctx); +void io_napi_free(struct io_ring_ctx *ctx); + +int io_register_napi(struct io_ring_ctx *ctx, void __user *arg); +int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg); + +int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id); + +void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq); +int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx); + +static inline bool io_napi(struct io_ring_ctx *ctx) +{ + return !list_empty(&ctx->napi_list); +} + +static inline void io_napi_busy_loop(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq) +{ + if (!io_napi(ctx)) + return; + __io_napi_busy_loop(ctx, iowq); +} + +/* + * io_napi_add() - Add napi id to the busy poll list + * @req: pointer to io_kiocb request + * + * Add the napi id of the socket to the napi busy poll list and hash table. + */ +static inline void io_napi_add(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + struct socket *sock; + + if (READ_ONCE(ctx->napi_track_mode) != IO_URING_NAPI_TRACKING_DYNAMIC) + return; + + sock = sock_from_file(req->file); + if (sock && sock->sk) + __io_napi_add_id(ctx, READ_ONCE(sock->sk->sk_napi_id)); +} + +#else + +static inline void io_napi_init(struct io_ring_ctx *ctx) +{ +} +static inline void io_napi_free(struct io_ring_ctx *ctx) +{ +} +static inline int io_register_napi(struct io_ring_ctx *ctx, void __user *arg) +{ + return -EOPNOTSUPP; +} +static inline int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg) +{ + return -EOPNOTSUPP; +} +static inline bool io_napi(struct io_ring_ctx *ctx) +{ + return false; +} +static inline void io_napi_add(struct io_kiocb *req) +{ +} +static inline void io_napi_busy_loop(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq) +{ +} +static inline int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx) +{ + return 0; +} +#endif /* CONFIG_NET_RX_BUSY_POLL */ + +#endif diff --git a/io_uring/net.c b/io_uring/net.c new file mode 100644 index 000000000000..519ea055b761 --- /dev/null +++ b/io_uring/net.c @@ -0,0 +1,1897 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/net.h> +#include <linux/compat.h> +#include <net/compat.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "filetable.h" +#include "io_uring.h" +#include "kbuf.h" +#include "alloc_cache.h" +#include "net.h" +#include "notif.h" +#include "rsrc.h" +#include "zcrx.h" + +struct io_shutdown { + struct file *file; + int how; +}; + +struct io_accept { + struct file *file; + struct sockaddr __user *addr; + int __user *addr_len; + int flags; + int iou_flags; + u32 file_slot; + unsigned long nofile; +}; + +struct io_socket { + struct file *file; + int domain; + int type; + int protocol; + int flags; + u32 file_slot; + unsigned long nofile; +}; + +struct io_connect { + struct file *file; + struct sockaddr __user *addr; + int addr_len; + bool in_progress; + bool seen_econnaborted; +}; + +struct io_bind { + struct file *file; + int addr_len; +}; + +struct io_listen { + struct file *file; + int backlog; +}; + +struct io_sr_msg { + struct file *file; + union { + struct compat_msghdr __user *umsg_compat; + struct user_msghdr __user *umsg; + void __user *buf; + }; + int len; + unsigned done_io; + unsigned msg_flags; + unsigned nr_multishot_loops; + u16 flags; + /* initialised and used only by !msg send variants */ + u16 buf_group; + /* per-invocation mshot limit */ + unsigned mshot_len; + /* overall mshot byte limit */ + unsigned mshot_total_len; + void __user *msg_control; + /* used only for send zerocopy */ + struct io_kiocb *notif; +}; + +/* + * The UAPI flags are the lower 8 bits, as that's all sqe->ioprio will hold + * anyway. Use the upper 8 bits for internal uses. + */ +enum sr_retry_flags { + IORING_RECV_RETRY = (1U << 15), + IORING_RECV_PARTIAL_MAP = (1U << 14), + IORING_RECV_MSHOT_CAP = (1U << 13), + IORING_RECV_MSHOT_LIM = (1U << 12), + IORING_RECV_MSHOT_DONE = (1U << 11), + + IORING_RECV_RETRY_CLEAR = IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP, + IORING_RECV_NO_RETRY = IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP | + IORING_RECV_MSHOT_CAP | IORING_RECV_MSHOT_DONE, +}; + +/* + * Number of times we'll try and do receives if there's more data. If we + * exceed this limit, then add us to the back of the queue and retry from + * there. This helps fairness between flooding clients. + */ +#define MULTISHOT_MAX_RETRY 32 + +struct io_recvzc { + struct file *file; + u16 flags; + u32 len; + struct io_zcrx_ifq *ifq; +}; + +static int io_sg_from_iter_iovec(struct sk_buff *skb, + struct iov_iter *from, size_t length); +static int io_sg_from_iter(struct sk_buff *skb, + struct iov_iter *from, size_t length); + +int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown); + + if (unlikely(sqe->off || sqe->addr || sqe->rw_flags || + sqe->buf_index || sqe->splice_fd_in)) + return -EINVAL; + + shutdown->how = READ_ONCE(sqe->len); + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_shutdown(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown); + struct socket *sock; + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + ret = __sys_shutdown_sock(sock, shutdown->how); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +static bool io_net_retry(struct socket *sock, int flags) +{ + if (!(flags & MSG_WAITALL)) + return false; + return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET; +} + +static void io_netmsg_iovec_free(struct io_async_msghdr *kmsg) +{ + if (kmsg->vec.iovec) + io_vec_free(&kmsg->vec); +} + +static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_async_msghdr *hdr = req->async_data; + + /* can't recycle, ensure we free the iovec if we have one */ + if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) { + io_netmsg_iovec_free(hdr); + return; + } + + /* Let normal cleanup path reap it if we fail adding to the cache */ + io_alloc_cache_vec_kasan(&hdr->vec); + if (hdr->vec.nr > IO_VEC_CACHE_SOFT_CAP) + io_vec_free(&hdr->vec); + + if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr)) + io_req_async_data_clear(req, REQ_F_NEED_CLEANUP); +} + +static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_async_msghdr *hdr; + + hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req); + if (!hdr) + return NULL; + + /* If the async data was cached, we might have an iov cached inside. */ + if (hdr->vec.iovec) + req->flags |= REQ_F_NEED_CLEANUP; + return hdr; +} + +static inline void io_mshot_prep_retry(struct io_kiocb *req, + struct io_async_msghdr *kmsg) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + + req->flags &= ~REQ_F_BL_EMPTY; + sr->done_io = 0; + sr->flags &= ~IORING_RECV_RETRY_CLEAR; + sr->len = sr->mshot_len; +} + +static int io_net_import_vec(struct io_kiocb *req, struct io_async_msghdr *iomsg, + const struct iovec __user *uiov, unsigned uvec_seg, + int ddir) +{ + struct iovec *iov; + int ret, nr_segs; + + if (iomsg->vec.iovec) { + nr_segs = iomsg->vec.nr; + iov = iomsg->vec.iovec; + } else { + nr_segs = 1; + iov = &iomsg->fast_iov; + } + + ret = __import_iovec(ddir, uiov, uvec_seg, nr_segs, &iov, + &iomsg->msg.msg_iter, io_is_compat(req->ctx)); + if (unlikely(ret < 0)) + return ret; + + if (iov) { + req->flags |= REQ_F_NEED_CLEANUP; + io_vec_reset_iovec(&iomsg->vec, iov, iomsg->msg.msg_iter.nr_segs); + } + return 0; +} + +static int io_compat_msg_copy_hdr(struct io_kiocb *req, + struct io_async_msghdr *iomsg, + struct compat_msghdr *msg, int ddir, + struct sockaddr __user **save_addr) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct compat_iovec __user *uiov; + int ret; + + if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg))) + return -EFAULT; + + ret = __get_compat_msghdr(&iomsg->msg, msg, save_addr); + if (ret) + return ret; + + uiov = compat_ptr(msg->msg_iov); + if (req->flags & REQ_F_BUFFER_SELECT) { + if (msg->msg_iovlen == 0) { + sr->len = 0; + } else if (msg->msg_iovlen > 1) { + return -EINVAL; + } else { + struct compat_iovec tmp_iov; + + if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov))) + return -EFAULT; + sr->len = tmp_iov.iov_len; + } + } + return 0; +} + +static int io_copy_msghdr_from_user(struct user_msghdr *msg, + struct user_msghdr __user *umsg) +{ + if (!user_access_begin(umsg, sizeof(*umsg))) + return -EFAULT; + unsafe_get_user(msg->msg_name, &umsg->msg_name, ua_end); + unsafe_get_user(msg->msg_namelen, &umsg->msg_namelen, ua_end); + unsafe_get_user(msg->msg_iov, &umsg->msg_iov, ua_end); + unsafe_get_user(msg->msg_iovlen, &umsg->msg_iovlen, ua_end); + unsafe_get_user(msg->msg_control, &umsg->msg_control, ua_end); + unsafe_get_user(msg->msg_controllen, &umsg->msg_controllen, ua_end); + user_access_end(); + return 0; +ua_end: + user_access_end(); + return -EFAULT; +} + +static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg, + struct user_msghdr *msg, int ddir, + struct sockaddr __user **save_addr) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct user_msghdr __user *umsg = sr->umsg; + int ret; + + iomsg->msg.msg_name = &iomsg->addr; + iomsg->msg.msg_iter.nr_segs = 0; + + if (io_is_compat(req->ctx)) { + struct compat_msghdr cmsg; + + ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ddir, save_addr); + if (ret) + return ret; + + memset(msg, 0, sizeof(*msg)); + msg->msg_namelen = cmsg.msg_namelen; + msg->msg_controllen = cmsg.msg_controllen; + msg->msg_iov = compat_ptr(cmsg.msg_iov); + msg->msg_iovlen = cmsg.msg_iovlen; + return 0; + } + + ret = io_copy_msghdr_from_user(msg, umsg); + if (unlikely(ret)) + return ret; + + msg->msg_flags = 0; + + ret = __copy_msghdr(&iomsg->msg, msg, save_addr); + if (ret) + return ret; + + if (req->flags & REQ_F_BUFFER_SELECT) { + if (msg->msg_iovlen == 0) { + sr->len = 0; + } else if (msg->msg_iovlen > 1) { + return -EINVAL; + } else { + struct iovec __user *uiov = msg->msg_iov; + struct iovec tmp_iov; + + if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov))) + return -EFAULT; + sr->len = tmp_iov.iov_len; + } + } + return 0; +} + +void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req) +{ + struct io_async_msghdr *io = req->async_data; + + io_netmsg_iovec_free(io); +} + +static int io_send_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + void __user *addr; + u16 addr_len; + int ret; + + sr->buf = u64_to_user_ptr(READ_ONCE(sqe->addr)); + + if (READ_ONCE(sqe->__pad3[0])) + return -EINVAL; + + kmsg->msg.msg_name = NULL; + kmsg->msg.msg_namelen = 0; + kmsg->msg.msg_control = NULL; + kmsg->msg.msg_controllen = 0; + kmsg->msg.msg_ubuf = NULL; + + addr = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + addr_len = READ_ONCE(sqe->addr_len); + if (addr) { + ret = move_addr_to_kernel(addr, addr_len, &kmsg->addr); + if (unlikely(ret < 0)) + return ret; + kmsg->msg.msg_name = &kmsg->addr; + kmsg->msg.msg_namelen = addr_len; + } + if (sr->flags & IORING_RECVSEND_FIXED_BUF) { + req->flags |= REQ_F_IMPORT_BUFFER; + return 0; + } + if (req->flags & REQ_F_BUFFER_SELECT) + return 0; + + if (sr->flags & IORING_SEND_VECTORIZED) + return io_net_import_vec(req, kmsg, sr->buf, sr->len, ITER_SOURCE); + + return import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter); +} + +static int io_sendmsg_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct user_msghdr msg; + int ret; + + sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); + ret = io_msg_copy_hdr(req, kmsg, &msg, ITER_SOURCE, NULL); + if (unlikely(ret)) + return ret; + /* save msg_control as sys_sendmsg() overwrites it */ + sr->msg_control = kmsg->msg.msg_control_user; + + if (sr->flags & IORING_RECVSEND_FIXED_BUF) { + kmsg->msg.msg_iter.nr_segs = msg.msg_iovlen; + return io_prep_reg_iovec(req, &kmsg->vec, msg.msg_iov, + msg.msg_iovlen); + } + if (req->flags & REQ_F_BUFFER_SELECT) + return 0; + return io_net_import_vec(req, kmsg, msg.msg_iov, msg.msg_iovlen, ITER_SOURCE); +} + +#define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE | IORING_SEND_VECTORIZED) + +int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + + sr->done_io = 0; + sr->len = READ_ONCE(sqe->len); + sr->flags = READ_ONCE(sqe->ioprio); + if (sr->flags & ~SENDMSG_FLAGS) + return -EINVAL; + sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL; + if (sr->msg_flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + if (req->flags & REQ_F_BUFFER_SELECT) + sr->buf_group = req->buf_index; + if (sr->flags & IORING_RECVSEND_BUNDLE) { + if (req->opcode == IORING_OP_SENDMSG) + return -EINVAL; + sr->msg_flags |= MSG_WAITALL; + req->flags |= REQ_F_MULTISHOT; + } + + if (io_is_compat(req->ctx)) + sr->msg_flags |= MSG_CMSG_COMPAT; + + if (unlikely(!io_msg_alloc_async(req))) + return -ENOMEM; + if (req->opcode != IORING_OP_SENDMSG) + return io_send_setup(req, sqe); + if (unlikely(sqe->addr2 || sqe->file_index)) + return -EINVAL; + return io_sendmsg_setup(req, sqe); +} + +static void io_req_msg_cleanup(struct io_kiocb *req, + unsigned int issue_flags) +{ + io_netmsg_recycle(req, issue_flags); +} + +/* + * For bundle completions, we need to figure out how many segments we consumed. + * A bundle could be using a single ITER_UBUF if that's all we mapped, or it + * could be using an ITER_IOVEC. If the latter, then if we consumed all of + * the segments, then it's a trivial questiont o answer. If we have residual + * data in the iter, then loop the segments to figure out how much we + * transferred. + */ +static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret) +{ + struct iovec *iov; + int nbufs; + + /* no data is always zero segments, and a ubuf is always 1 segment */ + if (ret <= 0) + return 0; + if (iter_is_ubuf(&kmsg->msg.msg_iter)) + return 1; + + iov = kmsg->vec.iovec; + if (!iov) + iov = &kmsg->fast_iov; + + /* if all data was transferred, it's basic pointer math */ + if (!iov_iter_count(&kmsg->msg.msg_iter)) + return iter_iov(&kmsg->msg.msg_iter) - iov; + + /* short transfer, count segments */ + nbufs = 0; + do { + int this_len = min_t(int, iov[nbufs].iov_len, ret); + + nbufs++; + ret -= this_len; + } while (ret); + + return nbufs; +} + +static int io_net_kbuf_recyle(struct io_kiocb *req, struct io_buffer_list *bl, + struct io_async_msghdr *kmsg, int len) +{ + req->flags |= REQ_F_BL_NO_RECYCLE; + if (req->flags & REQ_F_BUFFERS_COMMIT) + io_kbuf_commit(req, bl, len, io_bundle_nbufs(kmsg, len)); + return IOU_RETRY; +} + +static inline bool io_send_finish(struct io_kiocb *req, + struct io_async_msghdr *kmsg, + struct io_br_sel *sel) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + bool bundle_finished = sel->val <= 0; + unsigned int cflags; + + if (!(sr->flags & IORING_RECVSEND_BUNDLE)) { + cflags = io_put_kbuf(req, sel->val, sel->buf_list); + goto finish; + } + + cflags = io_put_kbufs(req, sel->val, sel->buf_list, io_bundle_nbufs(kmsg, sel->val)); + + if (bundle_finished || req->flags & REQ_F_BL_EMPTY) + goto finish; + + /* + * Fill CQE for this receive and see if we should keep trying to + * receive from this socket. + */ + if (io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) { + io_mshot_prep_retry(req, kmsg); + return false; + } + + /* Otherwise stop bundle and use the current result. */ +finish: + io_req_set_res(req, sel->val, cflags); + sel->val = IOU_COMPLETE; + return true; +} + +int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct socket *sock; + unsigned flags; + int min_ret = 0; + int ret; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + if (!(req->flags & REQ_F_POLLED) && + (sr->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + flags = sr->msg_flags; + if (issue_flags & IO_URING_F_NONBLOCK) + flags |= MSG_DONTWAIT; + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + + kmsg->msg.msg_control_user = sr->msg_control; + + ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); + + if (ret < min_ret) { + if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK)) + return -EAGAIN; + if (ret > 0 && io_net_retry(sock, flags)) { + kmsg->msg.msg_controllen = 0; + kmsg->msg.msg_control = NULL; + sr->done_io += ret; + return -EAGAIN; + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } + io_req_msg_cleanup(req, issue_flags); + if (ret >= 0) + ret += sr->done_io; + else if (sr->done_io) + ret = sr->done_io; + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +static int io_send_select_buffer(struct io_kiocb *req, unsigned int issue_flags, + struct io_br_sel *sel, struct io_async_msghdr *kmsg) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct buf_sel_arg arg = { + .iovs = &kmsg->fast_iov, + .max_len = min_not_zero(sr->len, INT_MAX), + .nr_iovs = 1, + .buf_group = sr->buf_group, + }; + int ret; + + if (kmsg->vec.iovec) { + arg.nr_iovs = kmsg->vec.nr; + arg.iovs = kmsg->vec.iovec; + arg.mode = KBUF_MODE_FREE; + } + + if (!(sr->flags & IORING_RECVSEND_BUNDLE)) + arg.nr_iovs = 1; + else + arg.mode |= KBUF_MODE_EXPAND; + + ret = io_buffers_select(req, &arg, sel, issue_flags); + if (unlikely(ret < 0)) + return ret; + + if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) { + kmsg->vec.nr = ret; + kmsg->vec.iovec = arg.iovs; + req->flags |= REQ_F_NEED_CLEANUP; + } + sr->len = arg.out_len; + + if (ret == 1) { + sr->buf = arg.iovs[0].iov_base; + ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, + &kmsg->msg.msg_iter); + if (unlikely(ret)) + return ret; + } else { + iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE, + arg.iovs, ret, arg.out_len); + } + + return 0; +} + +int io_send(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct io_br_sel sel = { }; + struct socket *sock; + unsigned flags; + int min_ret = 0; + int ret; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + if (!(req->flags & REQ_F_POLLED) && + (sr->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + flags = sr->msg_flags; + if (issue_flags & IO_URING_F_NONBLOCK) + flags |= MSG_DONTWAIT; + +retry_bundle: + sel.buf_list = NULL; + if (io_do_buffer_select(req)) { + ret = io_send_select_buffer(req, issue_flags, &sel, kmsg); + if (ret) + return ret; + } + + /* + * If MSG_WAITALL is set, or this is a bundle send, then we need + * the full amount. If just bundle is set, if we do a short send + * then we complete the bundle sequence rather than continue on. + */ + if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + + flags &= ~MSG_INTERNAL_SENDMSG_FLAGS; + kmsg->msg.msg_flags = flags; + ret = sock_sendmsg(sock, &kmsg->msg); + if (ret < min_ret) { + if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK)) + return -EAGAIN; + + if (ret > 0 && io_net_retry(sock, flags)) { + sr->len -= ret; + sr->buf += ret; + sr->done_io += ret; + return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret); + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } + if (ret >= 0) + ret += sr->done_io; + else if (sr->done_io) + ret = sr->done_io; + + sel.val = ret; + if (!io_send_finish(req, kmsg, &sel)) + goto retry_bundle; + + io_req_msg_cleanup(req, issue_flags); + return sel.val; +} + +static int io_recvmsg_mshot_prep(struct io_kiocb *req, + struct io_async_msghdr *iomsg, + int namelen, size_t controllen) +{ + if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) == + (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) { + int hdr; + + if (unlikely(namelen < 0)) + return -EOVERFLOW; + if (check_add_overflow(sizeof(struct io_uring_recvmsg_out), + namelen, &hdr)) + return -EOVERFLOW; + if (check_add_overflow(hdr, controllen, &hdr)) + return -EOVERFLOW; + + iomsg->namelen = namelen; + iomsg->controllen = controllen; + return 0; + } + + return 0; +} + +static int io_recvmsg_copy_hdr(struct io_kiocb *req, + struct io_async_msghdr *iomsg) +{ + struct user_msghdr msg; + int ret; + + ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST, &iomsg->uaddr); + if (unlikely(ret)) + return ret; + + if (!(req->flags & REQ_F_BUFFER_SELECT)) { + ret = io_net_import_vec(req, iomsg, msg.msg_iov, msg.msg_iovlen, + ITER_DEST); + if (unlikely(ret)) + return ret; + } + return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen, + msg.msg_controllen); +} + +static int io_recvmsg_prep_setup(struct io_kiocb *req) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg; + + kmsg = io_msg_alloc_async(req); + if (unlikely(!kmsg)) + return -ENOMEM; + + if (req->opcode == IORING_OP_RECV) { + kmsg->msg.msg_name = NULL; + kmsg->msg.msg_namelen = 0; + kmsg->msg.msg_inq = 0; + kmsg->msg.msg_control = NULL; + kmsg->msg.msg_get_inq = 1; + kmsg->msg.msg_controllen = 0; + kmsg->msg.msg_iocb = NULL; + kmsg->msg.msg_ubuf = NULL; + + if (req->flags & REQ_F_BUFFER_SELECT) + return 0; + return import_ubuf(ITER_DEST, sr->buf, sr->len, + &kmsg->msg.msg_iter); + } + + return io_recvmsg_copy_hdr(req, kmsg); +} + +#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \ + IORING_RECVSEND_BUNDLE) + +int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + + sr->done_io = 0; + + if (unlikely(sqe->addr2)) + return -EINVAL; + + sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); + sr->len = READ_ONCE(sqe->len); + sr->flags = READ_ONCE(sqe->ioprio); + if (sr->flags & ~RECVMSG_FLAGS) + return -EINVAL; + sr->msg_flags = READ_ONCE(sqe->msg_flags); + if (sr->msg_flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + if (sr->msg_flags & MSG_ERRQUEUE) + req->flags |= REQ_F_CLEAR_POLLIN; + if (req->flags & REQ_F_BUFFER_SELECT) + sr->buf_group = req->buf_index; + sr->mshot_total_len = sr->mshot_len = 0; + if (sr->flags & IORING_RECV_MULTISHOT) { + if (!(req->flags & REQ_F_BUFFER_SELECT)) + return -EINVAL; + if (sr->msg_flags & MSG_WAITALL) + return -EINVAL; + if (req->opcode == IORING_OP_RECV) { + sr->mshot_len = sr->len; + sr->mshot_total_len = READ_ONCE(sqe->optlen); + if (sr->mshot_total_len) + sr->flags |= IORING_RECV_MSHOT_LIM; + } else if (sqe->optlen) { + return -EINVAL; + } + req->flags |= REQ_F_APOLL_MULTISHOT; + } else if (sqe->optlen) { + return -EINVAL; + } + + if (sr->flags & IORING_RECVSEND_BUNDLE) { + if (req->opcode == IORING_OP_RECVMSG) + return -EINVAL; + } + + if (io_is_compat(req->ctx)) + sr->msg_flags |= MSG_CMSG_COMPAT; + + sr->nr_multishot_loops = 0; + return io_recvmsg_prep_setup(req); +} + +/* bits to clear in old and inherit in new cflags on bundle retry */ +#define CQE_F_MASK (IORING_CQE_F_SOCK_NONEMPTY|IORING_CQE_F_MORE) + +/* + * Finishes io_recv and io_recvmsg. + * + * Returns true if it is actually finished, or false if it should run + * again (for multishot). + */ +static inline bool io_recv_finish(struct io_kiocb *req, + struct io_async_msghdr *kmsg, + struct io_br_sel *sel, bool mshot_finished, + unsigned issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + unsigned int cflags = 0; + + if (kmsg->msg.msg_inq > 0) + cflags |= IORING_CQE_F_SOCK_NONEMPTY; + + if (sel->val > 0 && sr->flags & IORING_RECV_MSHOT_LIM) { + /* + * If sr->len hits zero, the limit has been reached. Mark + * mshot as finished, and flag MSHOT_DONE as well to prevent + * a potential bundle from being retried. + */ + sr->mshot_total_len -= min_t(int, sel->val, sr->mshot_total_len); + if (!sr->mshot_total_len) { + sr->flags |= IORING_RECV_MSHOT_DONE; + mshot_finished = true; + } + } + + if (sr->flags & IORING_RECVSEND_BUNDLE) { + size_t this_ret = sel->val - sr->done_io; + + cflags |= io_put_kbufs(req, this_ret, sel->buf_list, io_bundle_nbufs(kmsg, this_ret)); + if (sr->flags & IORING_RECV_RETRY) + cflags = req->cqe.flags | (cflags & CQE_F_MASK); + if (sr->mshot_len && sel->val >= sr->mshot_len) + sr->flags |= IORING_RECV_MSHOT_CAP; + /* bundle with no more immediate buffers, we're done */ + if (req->flags & REQ_F_BL_EMPTY) + goto finish; + /* + * If more is available AND it was a full transfer, retry and + * append to this one + */ + if (!(sr->flags & IORING_RECV_NO_RETRY) && + kmsg->msg.msg_inq > 1 && this_ret > 0 && + !iov_iter_count(&kmsg->msg.msg_iter)) { + req->cqe.flags = cflags & ~CQE_F_MASK; + sr->len = kmsg->msg.msg_inq; + sr->done_io += this_ret; + sr->flags |= IORING_RECV_RETRY; + return false; + } + } else { + cflags |= io_put_kbuf(req, sel->val, sel->buf_list); + } + + /* + * Fill CQE for this receive and see if we should keep trying to + * receive from this socket. + */ + if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished && + io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) { + sel->val = IOU_RETRY; + io_mshot_prep_retry(req, kmsg); + /* Known not-empty or unknown state, retry */ + if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) { + if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY && + !(sr->flags & IORING_RECV_MSHOT_CAP)) { + return false; + } + /* mshot retries exceeded, force a requeue */ + sr->nr_multishot_loops = 0; + sr->flags &= ~IORING_RECV_MSHOT_CAP; + if (issue_flags & IO_URING_F_MULTISHOT) + sel->val = IOU_REQUEUE; + } + return true; + } + + /* Finish the request / stop multishot. */ +finish: + io_req_set_res(req, sel->val, cflags); + sel->val = IOU_COMPLETE; + io_req_msg_cleanup(req, issue_flags); + return true; +} + +static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg, + struct io_sr_msg *sr, void __user **buf, + size_t *len) +{ + unsigned long ubuf = (unsigned long) *buf; + unsigned long hdr; + + hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen + + kmsg->controllen; + if (*len < hdr) + return -EFAULT; + + if (kmsg->controllen) { + unsigned long control = ubuf + hdr - kmsg->controllen; + + kmsg->msg.msg_control_user = (void __user *) control; + kmsg->msg.msg_controllen = kmsg->controllen; + } + + sr->buf = *buf; /* stash for later copy */ + *buf = (void __user *) (ubuf + hdr); + kmsg->payloadlen = *len = *len - hdr; + return 0; +} + +struct io_recvmsg_multishot_hdr { + struct io_uring_recvmsg_out msg; + struct sockaddr_storage addr; +}; + +static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io, + struct io_async_msghdr *kmsg, + unsigned int flags, bool *finished) +{ + int err; + int copy_len; + struct io_recvmsg_multishot_hdr hdr; + + if (kmsg->namelen) + kmsg->msg.msg_name = &hdr.addr; + kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT); + kmsg->msg.msg_namelen = 0; + + if (sock->file->f_flags & O_NONBLOCK) + flags |= MSG_DONTWAIT; + + err = sock_recvmsg(sock, &kmsg->msg, flags); + *finished = err <= 0; + if (err < 0) + return err; + + hdr.msg = (struct io_uring_recvmsg_out) { + .controllen = kmsg->controllen - kmsg->msg.msg_controllen, + .flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT + }; + + hdr.msg.payloadlen = err; + if (err > kmsg->payloadlen) + err = kmsg->payloadlen; + + copy_len = sizeof(struct io_uring_recvmsg_out); + if (kmsg->msg.msg_namelen > kmsg->namelen) + copy_len += kmsg->namelen; + else + copy_len += kmsg->msg.msg_namelen; + + /* + * "fromlen shall refer to the value before truncation.." + * 1003.1g + */ + hdr.msg.namelen = kmsg->msg.msg_namelen; + + /* ensure that there is no gap between hdr and sockaddr_storage */ + BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) != + sizeof(struct io_uring_recvmsg_out)); + if (copy_to_user(io->buf, &hdr, copy_len)) { + *finished = true; + return -EFAULT; + } + + return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen + + kmsg->controllen + err; +} + +int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct io_br_sel sel = { }; + struct socket *sock; + unsigned flags; + int ret, min_ret = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + bool mshot_finished = true; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + if (!(req->flags & REQ_F_POLLED) && + (sr->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + flags = sr->msg_flags; + if (force_nonblock) + flags |= MSG_DONTWAIT; + +retry_multishot: + sel.buf_list = NULL; + if (io_do_buffer_select(req)) { + size_t len = sr->len; + + sel = io_buffer_select(req, &len, sr->buf_group, issue_flags); + if (!sel.addr) + return -ENOBUFS; + + if (req->flags & REQ_F_APOLL_MULTISHOT) { + ret = io_recvmsg_prep_multishot(kmsg, sr, &sel.addr, &len); + if (ret) { + io_kbuf_recycle(req, sel.buf_list, issue_flags); + return ret; + } + } + + iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, sel.addr, len); + } + + kmsg->msg.msg_get_inq = 1; + kmsg->msg.msg_inq = -1; + if (req->flags & REQ_F_APOLL_MULTISHOT) { + ret = io_recvmsg_multishot(sock, sr, kmsg, flags, + &mshot_finished); + } else { + /* disable partial retry for recvmsg with cmsg attached */ + if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + + ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg, + kmsg->uaddr, flags); + } + + if (ret < min_ret) { + if (ret == -EAGAIN && force_nonblock) { + io_kbuf_recycle(req, sel.buf_list, issue_flags); + return IOU_RETRY; + } + if (ret > 0 && io_net_retry(sock, flags)) { + sr->done_io += ret; + return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret); + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) { + req_set_fail(req); + } + + if (ret > 0) + ret += sr->done_io; + else if (sr->done_io) + ret = sr->done_io; + else + io_kbuf_recycle(req, sel.buf_list, issue_flags); + + sel.val = ret; + if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags)) + goto retry_multishot; + + return sel.val; +} + +static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg, + struct io_br_sel *sel, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + int ret; + + /* + * If the ring isn't locked, then don't use the peek interface + * to grab multiple buffers as we will lock/unlock between + * this selection and posting the buffers. + */ + if (!(issue_flags & IO_URING_F_UNLOCKED) && + sr->flags & IORING_RECVSEND_BUNDLE) { + struct buf_sel_arg arg = { + .iovs = &kmsg->fast_iov, + .nr_iovs = 1, + .mode = KBUF_MODE_EXPAND, + .buf_group = sr->buf_group, + }; + + if (kmsg->vec.iovec) { + arg.nr_iovs = kmsg->vec.nr; + arg.iovs = kmsg->vec.iovec; + arg.mode |= KBUF_MODE_FREE; + } + + if (sel->val) + arg.max_len = sel->val; + else if (kmsg->msg.msg_inq > 1) + arg.max_len = min_not_zero(sel->val, (ssize_t) kmsg->msg.msg_inq); + + /* if mshot limited, ensure we don't go over */ + if (sr->flags & IORING_RECV_MSHOT_LIM) + arg.max_len = min_not_zero(arg.max_len, sr->mshot_total_len); + ret = io_buffers_peek(req, &arg, sel); + if (unlikely(ret < 0)) + return ret; + + if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) { + kmsg->vec.nr = ret; + kmsg->vec.iovec = arg.iovs; + req->flags |= REQ_F_NEED_CLEANUP; + } + if (arg.partial_map) + sr->flags |= IORING_RECV_PARTIAL_MAP; + + /* special case 1 vec, can be a fast path */ + if (ret == 1) { + sr->buf = arg.iovs[0].iov_base; + sr->len = arg.iovs[0].iov_len; + goto map_ubuf; + } + iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret, + arg.out_len); + } else { + size_t len = sel->val; + + *sel = io_buffer_select(req, &len, sr->buf_group, issue_flags); + if (!sel->addr) + return -ENOBUFS; + sr->buf = sel->addr; + sr->len = len; +map_ubuf: + ret = import_ubuf(ITER_DEST, sr->buf, sr->len, + &kmsg->msg.msg_iter); + if (unlikely(ret)) + return ret; + } + + return 0; +} + +int io_recv(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct io_br_sel sel; + struct socket *sock; + unsigned flags; + int ret, min_ret = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + bool mshot_finished; + + if (!(req->flags & REQ_F_POLLED) && + (sr->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + flags = sr->msg_flags; + if (force_nonblock) + flags |= MSG_DONTWAIT; + +retry_multishot: + sel.buf_list = NULL; + if (io_do_buffer_select(req)) { + sel.val = sr->len; + ret = io_recv_buf_select(req, kmsg, &sel, issue_flags); + if (unlikely(ret < 0)) { + kmsg->msg.msg_inq = -1; + goto out_free; + } + sr->buf = NULL; + } + + kmsg->msg.msg_flags = 0; + kmsg->msg.msg_inq = -1; + + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + + ret = sock_recvmsg(sock, &kmsg->msg, flags); + if (ret < min_ret) { + if (ret == -EAGAIN && force_nonblock) { + io_kbuf_recycle(req, sel.buf_list, issue_flags); + return IOU_RETRY; + } + if (ret > 0 && io_net_retry(sock, flags)) { + sr->len -= ret; + sr->buf += ret; + sr->done_io += ret; + return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret); + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) { +out_free: + req_set_fail(req); + } + + mshot_finished = ret <= 0; + if (ret > 0) + ret += sr->done_io; + else if (sr->done_io) + ret = sr->done_io; + else + io_kbuf_recycle(req, sel.buf_list, issue_flags); + + sel.val = ret; + if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags)) + goto retry_multishot; + + return sel.val; +} + +int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc); + unsigned ifq_idx; + + if (unlikely(sqe->addr2 || sqe->addr || sqe->addr3)) + return -EINVAL; + + ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx); + zc->ifq = xa_load(&req->ctx->zcrx_ctxs, ifq_idx); + if (!zc->ifq) + return -EINVAL; + + zc->len = READ_ONCE(sqe->len); + zc->flags = READ_ONCE(sqe->ioprio); + if (READ_ONCE(sqe->msg_flags)) + return -EINVAL; + if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)) + return -EINVAL; + /* multishot required */ + if (!(zc->flags & IORING_RECV_MULTISHOT)) + return -EINVAL; + /* All data completions are posted as aux CQEs. */ + req->flags |= REQ_F_APOLL_MULTISHOT; + + return 0; +} + +int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc); + struct socket *sock; + unsigned int len; + int ret; + + if (!(req->flags & REQ_F_POLLED) && + (zc->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + len = zc->len; + ret = io_zcrx_recv(req, zc->ifq, sock, 0, issue_flags, &zc->len); + if (len && zc->len == 0) { + io_req_set_res(req, 0, 0); + + return IOU_COMPLETE; + } + if (unlikely(ret <= 0) && ret != -EAGAIN) { + if (ret == -ERESTARTSYS) + ret = -EINTR; + if (ret == IOU_REQUEUE) + return IOU_REQUEUE; + + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; + } + return IOU_RETRY; +} + +void io_send_zc_cleanup(struct io_kiocb *req) +{ + struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *io = req->async_data; + + if (req_has_async_data(req)) + io_netmsg_iovec_free(io); + if (zc->notif) { + io_notif_flush(zc->notif); + zc->notif = NULL; + } +} + +#define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF) +#define IO_ZC_FLAGS_VALID (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE | \ + IORING_SEND_VECTORIZED) + +int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_ring_ctx *ctx = req->ctx; + struct io_async_msghdr *iomsg; + struct io_kiocb *notif; + int ret; + + zc->done_io = 0; + + if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3))) + return -EINVAL; + /* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */ + if (req->flags & REQ_F_CQE_SKIP) + return -EINVAL; + + notif = zc->notif = io_alloc_notif(ctx); + if (!notif) + return -ENOMEM; + notif->cqe.user_data = req->cqe.user_data; + notif->cqe.res = 0; + notif->cqe.flags = IORING_CQE_F_NOTIF; + req->flags |= REQ_F_NEED_CLEANUP | REQ_F_POLL_NO_LAZY; + + zc->flags = READ_ONCE(sqe->ioprio); + if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) { + if (zc->flags & ~IO_ZC_FLAGS_VALID) + return -EINVAL; + if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) { + struct io_notif_data *nd = io_notif_to_data(notif); + + nd->zc_report = true; + nd->zc_used = false; + nd->zc_copied = false; + } + } + + zc->len = READ_ONCE(sqe->len); + zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY; + req->buf_index = READ_ONCE(sqe->buf_index); + if (zc->msg_flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + + if (io_is_compat(req->ctx)) + zc->msg_flags |= MSG_CMSG_COMPAT; + + iomsg = io_msg_alloc_async(req); + if (unlikely(!iomsg)) + return -ENOMEM; + + if (req->opcode == IORING_OP_SEND_ZC) { + ret = io_send_setup(req, sqe); + } else { + if (unlikely(sqe->addr2 || sqe->file_index)) + return -EINVAL; + ret = io_sendmsg_setup(req, sqe); + } + if (unlikely(ret)) + return ret; + + if (!(zc->flags & IORING_RECVSEND_FIXED_BUF)) { + iomsg->msg.sg_from_iter = io_sg_from_iter_iovec; + return io_notif_account_mem(zc->notif, iomsg->msg.msg_iter.count); + } + iomsg->msg.sg_from_iter = io_sg_from_iter; + return 0; +} + +static int io_sg_from_iter_iovec(struct sk_buff *skb, + struct iov_iter *from, size_t length) +{ + skb_zcopy_downgrade_managed(skb); + return zerocopy_fill_skb_from_iter(skb, from, length); +} + +static int io_sg_from_iter(struct sk_buff *skb, + struct iov_iter *from, size_t length) +{ + struct skb_shared_info *shinfo = skb_shinfo(skb); + int frag = shinfo->nr_frags; + int ret = 0; + struct bvec_iter bi; + ssize_t copied = 0; + unsigned long truesize = 0; + + if (!frag) + shinfo->flags |= SKBFL_MANAGED_FRAG_REFS; + else if (unlikely(!skb_zcopy_managed(skb))) + return zerocopy_fill_skb_from_iter(skb, from, length); + + bi.bi_size = min(from->count, length); + bi.bi_bvec_done = from->iov_offset; + bi.bi_idx = 0; + + while (bi.bi_size && frag < MAX_SKB_FRAGS) { + struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi); + + copied += v.bv_len; + truesize += PAGE_ALIGN(v.bv_len + v.bv_offset); + __skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page, + v.bv_offset, v.bv_len); + bvec_iter_advance_single(from->bvec, &bi, v.bv_len); + } + if (bi.bi_size) + ret = -EMSGSIZE; + + shinfo->nr_frags = frag; + from->bvec += bi.bi_idx; + from->nr_segs -= bi.bi_idx; + from->count -= copied; + from->iov_offset = bi.bi_bvec_done; + + skb->data_len += copied; + skb->len += copied; + skb->truesize += truesize; + return ret; +} + +static int io_send_zc_import(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + + WARN_ON_ONCE(!(sr->flags & IORING_RECVSEND_FIXED_BUF)); + + sr->notif->buf_index = req->buf_index; + return io_import_reg_buf(sr->notif, &kmsg->msg.msg_iter, + (u64)(uintptr_t)sr->buf, sr->len, + ITER_SOURCE, issue_flags); +} + +int io_send_zc(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct socket *sock; + unsigned msg_flags; + int ret, min_ret = 0; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags)) + return -EOPNOTSUPP; + + if (!(req->flags & REQ_F_POLLED) && + (zc->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + if (req->flags & REQ_F_IMPORT_BUFFER) { + req->flags &= ~REQ_F_IMPORT_BUFFER; + ret = io_send_zc_import(req, issue_flags); + if (unlikely(ret)) + return ret; + } + + msg_flags = zc->msg_flags; + if (issue_flags & IO_URING_F_NONBLOCK) + msg_flags |= MSG_DONTWAIT; + if (msg_flags & MSG_WAITALL) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS; + + kmsg->msg.msg_flags = msg_flags; + kmsg->msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg; + ret = sock_sendmsg(sock, &kmsg->msg); + + if (unlikely(ret < min_ret)) { + if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK)) + return -EAGAIN; + + if (ret > 0 && io_net_retry(sock, kmsg->msg.msg_flags)) { + zc->len -= ret; + zc->buf += ret; + zc->done_io += ret; + return -EAGAIN; + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } + + if (ret >= 0) + ret += zc->done_io; + else if (zc->done_io) + ret = zc->done_io; + + /* + * If we're in io-wq we can't rely on tw ordering guarantees, defer + * flushing notif to io_send_zc_cleanup() + */ + if (!(issue_flags & IO_URING_F_UNLOCKED)) { + io_notif_flush(zc->notif); + zc->notif = NULL; + io_req_msg_cleanup(req, 0); + } + io_req_set_res(req, ret, IORING_CQE_F_MORE); + return IOU_COMPLETE; +} + +int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + struct io_async_msghdr *kmsg = req->async_data; + struct socket *sock; + unsigned flags; + int ret, min_ret = 0; + + if (req->flags & REQ_F_IMPORT_BUFFER) { + unsigned uvec_segs = kmsg->msg.msg_iter.nr_segs; + int ret; + + sr->notif->buf_index = req->buf_index; + ret = io_import_reg_vec(ITER_SOURCE, &kmsg->msg.msg_iter, + sr->notif, &kmsg->vec, uvec_segs, + issue_flags); + if (unlikely(ret)) + return ret; + req->flags &= ~REQ_F_IMPORT_BUFFER; + } + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags)) + return -EOPNOTSUPP; + + if (!(req->flags & REQ_F_POLLED) && + (sr->flags & IORING_RECVSEND_POLL_FIRST)) + return -EAGAIN; + + flags = sr->msg_flags; + if (issue_flags & IO_URING_F_NONBLOCK) + flags |= MSG_DONTWAIT; + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + + kmsg->msg.msg_control_user = sr->msg_control; + kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg; + ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); + + if (unlikely(ret < min_ret)) { + if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK)) + return -EAGAIN; + + if (ret > 0 && io_net_retry(sock, flags)) { + sr->done_io += ret; + return -EAGAIN; + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } + + if (ret >= 0) + ret += sr->done_io; + else if (sr->done_io) + ret = sr->done_io; + + /* + * If we're in io-wq we can't rely on tw ordering guarantees, defer + * flushing notif to io_send_zc_cleanup() + */ + if (!(issue_flags & IO_URING_F_UNLOCKED)) { + io_notif_flush(sr->notif); + sr->notif = NULL; + io_req_msg_cleanup(req, 0); + } + io_req_set_res(req, ret, IORING_CQE_F_MORE); + return IOU_COMPLETE; +} + +void io_sendrecv_fail(struct io_kiocb *req) +{ + struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); + + if (sr->done_io) + req->cqe.res = sr->done_io; + + if ((req->flags & REQ_F_NEED_CLEANUP) && + (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC)) + req->cqe.flags |= IORING_CQE_F_MORE; +} + +#define ACCEPT_FLAGS (IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \ + IORING_ACCEPT_POLL_FIRST) + +int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept); + + if (sqe->len || sqe->buf_index) + return -EINVAL; + + accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + accept->flags = READ_ONCE(sqe->accept_flags); + accept->nofile = rlimit(RLIMIT_NOFILE); + accept->iou_flags = READ_ONCE(sqe->ioprio); + if (accept->iou_flags & ~ACCEPT_FLAGS) + return -EINVAL; + + accept->file_slot = READ_ONCE(sqe->file_index); + if (accept->file_slot) { + if (accept->flags & SOCK_CLOEXEC) + return -EINVAL; + if (accept->iou_flags & IORING_ACCEPT_MULTISHOT && + accept->file_slot != IORING_FILE_INDEX_ALLOC) + return -EINVAL; + } + if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) + return -EINVAL; + if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK)) + accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK; + if (accept->iou_flags & IORING_ACCEPT_MULTISHOT) + req->flags |= REQ_F_APOLL_MULTISHOT; + if (accept->iou_flags & IORING_ACCEPT_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + return 0; +} + +int io_accept(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept); + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + bool fixed = !!accept->file_slot; + struct proto_accept_arg arg = { + .flags = force_nonblock ? O_NONBLOCK : 0, + }; + struct file *file; + unsigned cflags; + int ret, fd; + + if (!(req->flags & REQ_F_POLLED) && + accept->iou_flags & IORING_ACCEPT_POLL_FIRST) + return -EAGAIN; + +retry: + if (!fixed) { + fd = __get_unused_fd_flags(accept->flags, accept->nofile); + if (unlikely(fd < 0)) + return fd; + } + arg.err = 0; + arg.is_empty = -1; + file = do_accept(req->file, &arg, accept->addr, accept->addr_len, + accept->flags); + if (IS_ERR(file)) { + if (!fixed) + put_unused_fd(fd); + ret = PTR_ERR(file); + if (ret == -EAGAIN && force_nonblock && + !(accept->iou_flags & IORING_ACCEPT_DONTWAIT)) + return IOU_RETRY; + + if (ret == -ERESTARTSYS) + ret = -EINTR; + } else if (!fixed) { + fd_install(fd, file); + ret = fd; + } else { + ret = io_fixed_fd_install(req, issue_flags, file, + accept->file_slot); + } + + cflags = 0; + if (!arg.is_empty) + cflags |= IORING_CQE_F_SOCK_NONEMPTY; + + if (ret >= 0 && (req->flags & REQ_F_APOLL_MULTISHOT) && + io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) { + if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1) + goto retry; + return IOU_RETRY; + } + + io_req_set_res(req, ret, cflags); + if (ret < 0) + req_set_fail(req); + return IOU_COMPLETE; +} + +int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket); + + if (sqe->addr || sqe->rw_flags || sqe->buf_index) + return -EINVAL; + + sock->domain = READ_ONCE(sqe->fd); + sock->type = READ_ONCE(sqe->off); + sock->protocol = READ_ONCE(sqe->len); + sock->file_slot = READ_ONCE(sqe->file_index); + sock->nofile = rlimit(RLIMIT_NOFILE); + + sock->flags = sock->type & ~SOCK_TYPE_MASK; + if (sock->file_slot && (sock->flags & SOCK_CLOEXEC)) + return -EINVAL; + if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) + return -EINVAL; + return 0; +} + +int io_socket(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket); + bool fixed = !!sock->file_slot; + struct file *file; + int ret, fd; + + if (!fixed) { + fd = __get_unused_fd_flags(sock->flags, sock->nofile); + if (unlikely(fd < 0)) + return fd; + } + file = __sys_socket_file(sock->domain, sock->type, sock->protocol); + if (IS_ERR(file)) { + if (!fixed) + put_unused_fd(fd); + ret = PTR_ERR(file); + if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK)) + return -EAGAIN; + if (ret == -ERESTARTSYS) + ret = -EINTR; + req_set_fail(req); + } else if (!fixed) { + fd_install(fd, file); + ret = fd; + } else { + ret = io_fixed_fd_install(req, issue_flags, file, + sock->file_slot); + } + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect); + struct io_async_msghdr *io; + + if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in) + return -EINVAL; + + conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + conn->addr_len = READ_ONCE(sqe->addr2); + conn->in_progress = conn->seen_econnaborted = false; + + io = io_msg_alloc_async(req); + if (unlikely(!io)) + return -ENOMEM; + + return move_addr_to_kernel(conn->addr, conn->addr_len, &io->addr); +} + +int io_connect(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect); + struct io_async_msghdr *io = req->async_data; + unsigned file_flags; + int ret; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + + if (connect->in_progress) { + struct poll_table_struct pt = { ._key = EPOLLERR }; + + if (vfs_poll(req->file, &pt) & EPOLLERR) + goto get_sock_err; + } + + file_flags = force_nonblock ? O_NONBLOCK : 0; + + ret = __sys_connect_file(req->file, &io->addr, connect->addr_len, + file_flags); + if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED) + && force_nonblock) { + if (ret == -EINPROGRESS) { + connect->in_progress = true; + } else if (ret == -ECONNABORTED) { + if (connect->seen_econnaborted) + goto out; + connect->seen_econnaborted = true; + } + return -EAGAIN; + } + if (connect->in_progress) { + /* + * At least bluetooth will return -EBADFD on a re-connect + * attempt, and it's (supposedly) also valid to get -EISCONN + * which means the previous result is good. For both of these, + * grab the sock_error() and use that for the completion. + */ + if (ret == -EBADFD || ret == -EISCONN) { +get_sock_err: + ret = sock_error(sock_from_file(req->file)->sk); + } + } + if (ret == -ERESTARTSYS) + ret = -EINTR; +out: + if (ret < 0) + req_set_fail(req); + io_req_msg_cleanup(req, issue_flags); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind); + struct sockaddr __user *uaddr; + struct io_async_msghdr *io; + + if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in) + return -EINVAL; + + uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + bind->addr_len = READ_ONCE(sqe->addr2); + + io = io_msg_alloc_async(req); + if (unlikely(!io)) + return -ENOMEM; + return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr); +} + +int io_bind(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind); + struct io_async_msghdr *io = req->async_data; + struct socket *sock; + int ret; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + ret = __sys_bind_socket(sock, &io->addr, bind->addr_len); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return 0; +} + +int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen); + + if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2) + return -EINVAL; + + listen->backlog = READ_ONCE(sqe->len); + return 0; +} + +int io_listen(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen); + struct socket *sock; + int ret; + + sock = sock_from_file(req->file); + if (unlikely(!sock)) + return -ENOTSOCK; + + ret = __sys_listen_socket(sock, listen->backlog); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return 0; +} + +void io_netmsg_cache_free(const void *entry) +{ + struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry; + + io_vec_free(&kmsg->vec); + kfree(kmsg); +} diff --git a/io_uring/net.h b/io_uring/net.h new file mode 100644 index 000000000000..43e5ce5416b7 --- /dev/null +++ b/io_uring/net.h @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/net.h> +#include <linux/uio.h> +#include <linux/io_uring_types.h> + +struct io_async_msghdr { +#if defined(CONFIG_NET) + struct iou_vec vec; + + struct_group(clear, + int namelen; + struct iovec fast_iov; + __kernel_size_t controllen; + __kernel_size_t payloadlen; + struct sockaddr __user *uaddr; + struct msghdr msg; + struct sockaddr_storage addr; + ); +#else + struct_group(clear); +#endif +}; + +#if defined(CONFIG_NET) + +int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_shutdown(struct io_kiocb *req, unsigned int issue_flags); + +void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req); +int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags); + +int io_send(struct io_kiocb *req, unsigned int issue_flags); + +int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags); +int io_recv(struct io_kiocb *req, unsigned int issue_flags); + +void io_sendrecv_fail(struct io_kiocb *req); + +int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_accept(struct io_kiocb *req, unsigned int issue_flags); + +int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_socket(struct io_kiocb *req, unsigned int issue_flags); + +int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_connect(struct io_kiocb *req, unsigned int issue_flags); + +int io_send_zc(struct io_kiocb *req, unsigned int issue_flags); +int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags); +int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +void io_send_zc_cleanup(struct io_kiocb *req); + +int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_bind(struct io_kiocb *req, unsigned int issue_flags); + +int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_listen(struct io_kiocb *req, unsigned int issue_flags); + +void io_netmsg_cache_free(const void *entry); +#else +static inline void io_netmsg_cache_free(const void *entry) +{ +} +#endif diff --git a/io_uring/nop.c b/io_uring/nop.c new file mode 100644 index 000000000000..3caf07878f8a --- /dev/null +++ b/io_uring/nop.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "rsrc.h" +#include "nop.h" + +struct io_nop { + /* NOTE: kiocb has the file as the first member, so don't do it here */ + struct file *file; + int result; + int fd; + unsigned int flags; + __u64 extra1; + __u64 extra2; +}; + +#define NOP_FLAGS (IORING_NOP_INJECT_RESULT | IORING_NOP_FIXED_FILE | \ + IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE | \ + IORING_NOP_TW | IORING_NOP_CQE32) + +int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop); + + nop->flags = READ_ONCE(sqe->nop_flags); + if (nop->flags & ~NOP_FLAGS) + return -EINVAL; + + if (nop->flags & IORING_NOP_INJECT_RESULT) + nop->result = READ_ONCE(sqe->len); + else + nop->result = 0; + if (nop->flags & IORING_NOP_FILE) + nop->fd = READ_ONCE(sqe->fd); + else + nop->fd = -1; + if (nop->flags & IORING_NOP_FIXED_BUFFER) + req->buf_index = READ_ONCE(sqe->buf_index); + if (nop->flags & IORING_NOP_CQE32) { + struct io_ring_ctx *ctx = req->ctx; + + if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) + return -EINVAL; + nop->extra1 = READ_ONCE(sqe->off); + nop->extra2 = READ_ONCE(sqe->addr); + } + return 0; +} + +int io_nop(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop); + int ret = nop->result; + + if (nop->flags & IORING_NOP_FILE) { + if (nop->flags & IORING_NOP_FIXED_FILE) { + req->file = io_file_get_fixed(req, nop->fd, issue_flags); + req->flags |= REQ_F_FIXED_FILE; + } else { + req->file = io_file_get_normal(req, nop->fd); + } + if (!req->file) { + ret = -EBADF; + goto done; + } + } + if (nop->flags & IORING_NOP_FIXED_BUFFER) { + if (!io_find_buf_node(req, issue_flags)) + ret = -EFAULT; + } +done: + if (ret < 0) + req_set_fail(req); + if (nop->flags & IORING_NOP_CQE32) + io_req_set_res32(req, nop->result, 0, nop->extra1, nop->extra2); + else + io_req_set_res(req, nop->result, 0); + if (nop->flags & IORING_NOP_TW) { + req->io_task_work.func = io_req_task_complete; + io_req_task_work_add(req); + return IOU_ISSUE_SKIP_COMPLETE; + } + return IOU_COMPLETE; +} diff --git a/io_uring/nop.h b/io_uring/nop.h new file mode 100644 index 000000000000..97f1535c9dec --- /dev/null +++ b/io_uring/nop.h @@ -0,0 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_nop(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/notif.c b/io_uring/notif.c new file mode 100644 index 000000000000..f476775ba44b --- /dev/null +++ b/io_uring/notif.c @@ -0,0 +1,140 @@ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/net.h> +#include <linux/io_uring.h> + +#include "io_uring.h" +#include "notif.h" +#include "rsrc.h" + +static const struct ubuf_info_ops io_ubuf_ops; + +static void io_notif_tw_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *notif = tw_req.req; + struct io_notif_data *nd = io_notif_to_data(notif); + struct io_ring_ctx *ctx = notif->ctx; + + lockdep_assert_held(&ctx->uring_lock); + + do { + notif = cmd_to_io_kiocb(nd); + + if (WARN_ON_ONCE(ctx != notif->ctx)) + return; + lockdep_assert(refcount_read(&nd->uarg.refcnt) == 0); + + if (unlikely(nd->zc_report) && (nd->zc_copied || !nd->zc_used)) + notif->cqe.res |= IORING_NOTIF_USAGE_ZC_COPIED; + + if (nd->account_pages && notif->ctx->user) { + __io_unaccount_mem(notif->ctx->user, nd->account_pages); + nd->account_pages = 0; + } + + nd = nd->next; + io_req_task_complete((struct io_tw_req){notif}, tw); + } while (nd); +} + +void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg, + bool success) +{ + struct io_notif_data *nd = container_of(uarg, struct io_notif_data, uarg); + struct io_kiocb *notif = cmd_to_io_kiocb(nd); + unsigned tw_flags; + + if (nd->zc_report) { + if (success && !nd->zc_used && skb) + WRITE_ONCE(nd->zc_used, true); + else if (!success && !nd->zc_copied) + WRITE_ONCE(nd->zc_copied, true); + } + + if (!refcount_dec_and_test(&uarg->refcnt)) + return; + + if (nd->head != nd) { + io_tx_ubuf_complete(skb, &nd->head->uarg, success); + return; + } + + tw_flags = nd->next ? 0 : IOU_F_TWQ_LAZY_WAKE; + notif->io_task_work.func = io_notif_tw_complete; + __io_req_task_work_add(notif, tw_flags); +} + +static int io_link_skb(struct sk_buff *skb, struct ubuf_info *uarg) +{ + struct io_notif_data *nd, *prev_nd; + struct io_kiocb *prev_notif, *notif; + struct ubuf_info *prev_uarg = skb_zcopy(skb); + + nd = container_of(uarg, struct io_notif_data, uarg); + notif = cmd_to_io_kiocb(nd); + + if (!prev_uarg) { + net_zcopy_get(&nd->uarg); + skb_zcopy_init(skb, &nd->uarg); + return 0; + } + /* handle it separately as we can't link a notif to itself */ + if (unlikely(prev_uarg == &nd->uarg)) + return 0; + /* we can't join two links together, just request a fresh skb */ + if (unlikely(nd->head != nd || nd->next)) + return -EEXIST; + /* don't mix zc providers */ + if (unlikely(prev_uarg->ops != &io_ubuf_ops)) + return -EEXIST; + + prev_nd = container_of(prev_uarg, struct io_notif_data, uarg); + prev_notif = cmd_to_io_kiocb(prev_nd); + + /* make sure all notifications can be finished in the same task_work */ + if (unlikely(notif->ctx != prev_notif->ctx || + notif->tctx != prev_notif->tctx)) + return -EEXIST; + + nd->head = prev_nd->head; + nd->next = prev_nd->next; + prev_nd->next = nd; + net_zcopy_get(&nd->head->uarg); + return 0; +} + +static const struct ubuf_info_ops io_ubuf_ops = { + .complete = io_tx_ubuf_complete, + .link_skb = io_link_skb, +}; + +struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx) + __must_hold(&ctx->uring_lock) +{ + struct io_kiocb *notif; + struct io_notif_data *nd; + + if (unlikely(!io_alloc_req(ctx, ¬if))) + return NULL; + notif->ctx = ctx; + notif->opcode = IORING_OP_NOP; + notif->flags = 0; + notif->file = NULL; + notif->tctx = current->io_uring; + io_get_task_refs(1); + notif->file_node = NULL; + notif->buf_node = NULL; + + nd = io_notif_to_data(notif); + nd->zc_report = false; + nd->account_pages = 0; + nd->next = NULL; + nd->head = nd; + + nd->uarg.flags = IO_NOTIF_UBUF_FLAGS; + nd->uarg.ops = &io_ubuf_ops; + refcount_set(&nd->uarg.refcnt, 1); + return notif; +} diff --git a/io_uring/notif.h b/io_uring/notif.h new file mode 100644 index 000000000000..f3589cfef4a9 --- /dev/null +++ b/io_uring/notif.h @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/net.h> +#include <linux/uio.h> +#include <net/sock.h> +#include <linux/nospec.h> + +#include "rsrc.h" + +#define IO_NOTIF_UBUF_FLAGS (SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN) +#define IO_NOTIF_SPLICE_BATCH 32 + +struct io_notif_data { + struct file *file; + struct ubuf_info uarg; + + struct io_notif_data *next; + struct io_notif_data *head; + + unsigned account_pages; + bool zc_report; + bool zc_used; + bool zc_copied; +}; + +struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx); +void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg, + bool success); + +static inline struct io_notif_data *io_notif_to_data(struct io_kiocb *notif) +{ + return io_kiocb_to_cmd(notif, struct io_notif_data); +} + +static inline void io_notif_flush(struct io_kiocb *notif) + __must_hold(¬if->ctx->uring_lock) +{ + struct io_notif_data *nd = io_notif_to_data(notif); + + io_tx_ubuf_complete(NULL, &nd->uarg, true); +} + +static inline int io_notif_account_mem(struct io_kiocb *notif, unsigned len) +{ + struct io_ring_ctx *ctx = notif->ctx; + struct io_notif_data *nd = io_notif_to_data(notif); + unsigned nr_pages = (len >> PAGE_SHIFT) + 2; + int ret; + + if (ctx->user) { + ret = __io_account_mem(ctx->user, nr_pages); + if (ret) + return ret; + nd->account_pages += nr_pages; + } + return 0; +} diff --git a/io_uring/opdef.c b/io_uring/opdef.c new file mode 100644 index 000000000000..df52d760240e --- /dev/null +++ b/io_uring/opdef.c @@ -0,0 +1,884 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * io_uring opcode handling table + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/io_uring.h> +#include <linux/io_uring/cmd.h> + +#include "io_uring.h" +#include "opdef.h" +#include "refs.h" +#include "tctx.h" +#include "sqpoll.h" +#include "fdinfo.h" +#include "kbuf.h" +#include "rsrc.h" + +#include "xattr.h" +#include "nop.h" +#include "fs.h" +#include "splice.h" +#include "sync.h" +#include "advise.h" +#include "openclose.h" +#include "uring_cmd.h" +#include "epoll.h" +#include "statx.h" +#include "net.h" +#include "msg_ring.h" +#include "timeout.h" +#include "poll.h" +#include "cancel.h" +#include "rw.h" +#include "waitid.h" +#include "futex.h" +#include "truncate.h" +#include "zcrx.h" + +static int io_no_issue(struct io_kiocb *req, unsigned int issue_flags) +{ + WARN_ON_ONCE(1); + return -ECANCELED; +} + +static __maybe_unused int io_eopnotsupp_prep(struct io_kiocb *kiocb, + const struct io_uring_sqe *sqe) +{ + return -EOPNOTSUPP; +} + +const struct io_issue_def io_issue_defs[] = { + [IORING_OP_NOP] = { + .audit_skip = 1, + .iopoll = 1, + .prep = io_nop_prep, + .issue = io_nop, + }, + [IORING_OP_READV] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .buffer_select = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .vectored = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_readv, + .issue = io_read, + }, + [IORING_OP_WRITEV] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .vectored = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_writev, + .issue = io_write, + }, + [IORING_OP_FSYNC] = { + .needs_file = 1, + .audit_skip = 1, + .prep = io_fsync_prep, + .issue = io_fsync, + }, + [IORING_OP_READ_FIXED] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_read_fixed, + .issue = io_read_fixed, + }, + [IORING_OP_WRITE_FIXED] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_write_fixed, + .issue = io_write_fixed, + }, + [IORING_OP_POLL_ADD] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .audit_skip = 1, + .prep = io_poll_add_prep, + .issue = io_poll_add, + }, + [IORING_OP_POLL_REMOVE] = { + .audit_skip = 1, + .prep = io_poll_remove_prep, + .issue = io_poll_remove, + }, + [IORING_OP_SYNC_FILE_RANGE] = { + .needs_file = 1, + .audit_skip = 1, + .prep = io_sfr_prep, + .issue = io_sync_file_range, + }, + [IORING_OP_SENDMSG] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .ioprio = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_sendmsg_prep, + .issue = io_sendmsg, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_RECVMSG] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .buffer_select = 1, + .ioprio = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_recvmsg_prep, + .issue = io_recvmsg, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_TIMEOUT] = { + .audit_skip = 1, + .async_size = sizeof(struct io_timeout_data), + .prep = io_timeout_prep, + .issue = io_timeout, + }, + [IORING_OP_TIMEOUT_REMOVE] = { + /* used by timeout updates' prep() */ + .audit_skip = 1, + .prep = io_timeout_remove_prep, + .issue = io_timeout_remove, + }, + [IORING_OP_ACCEPT] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .poll_exclusive = 1, + .ioprio = 1, /* used for flags */ +#if defined(CONFIG_NET) + .prep = io_accept_prep, + .issue = io_accept, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_ASYNC_CANCEL] = { + .audit_skip = 1, + .prep = io_async_cancel_prep, + .issue = io_async_cancel, + }, + [IORING_OP_LINK_TIMEOUT] = { + .audit_skip = 1, + .async_size = sizeof(struct io_timeout_data), + .prep = io_link_timeout_prep, + .issue = io_no_issue, + }, + [IORING_OP_CONNECT] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_connect_prep, + .issue = io_connect, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FALLOCATE] = { + .needs_file = 1, + .hash_reg_file = 1, + .prep = io_fallocate_prep, + .issue = io_fallocate, + }, + [IORING_OP_OPENAT] = { + .prep = io_openat_prep, + .issue = io_openat, + }, + [IORING_OP_CLOSE] = { + .prep = io_close_prep, + .issue = io_close, + }, + [IORING_OP_FILES_UPDATE] = { + .audit_skip = 1, + .iopoll = 1, + .prep = io_files_update_prep, + .issue = io_files_update, + }, + [IORING_OP_STATX] = { + .audit_skip = 1, + .prep = io_statx_prep, + .issue = io_statx, + }, + [IORING_OP_READ] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .buffer_select = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_read, + .issue = io_read, + }, + [IORING_OP_WRITE] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_write, + .issue = io_write, + }, + [IORING_OP_FADVISE] = { + .needs_file = 1, + .audit_skip = 1, + .prep = io_fadvise_prep, + .issue = io_fadvise, + }, + [IORING_OP_MADVISE] = { + .audit_skip = 1, + .prep = io_madvise_prep, + .issue = io_madvise, + }, + [IORING_OP_SEND] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .audit_skip = 1, + .ioprio = 1, + .buffer_select = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_sendmsg_prep, + .issue = io_send, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_RECV] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .buffer_select = 1, + .audit_skip = 1, + .ioprio = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_recvmsg_prep, + .issue = io_recv, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_OPENAT2] = { + .prep = io_openat2_prep, + .issue = io_openat2, + }, + [IORING_OP_EPOLL_CTL] = { + .unbound_nonreg_file = 1, + .audit_skip = 1, +#if defined(CONFIG_EPOLL) + .prep = io_epoll_ctl_prep, + .issue = io_epoll_ctl, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_SPLICE] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + .audit_skip = 1, + .prep = io_splice_prep, + .issue = io_splice, + }, + [IORING_OP_PROVIDE_BUFFERS] = { + .audit_skip = 1, + .iopoll = 1, + .prep = io_provide_buffers_prep, + .issue = io_manage_buffers_legacy, + }, + [IORING_OP_REMOVE_BUFFERS] = { + .audit_skip = 1, + .iopoll = 1, + .prep = io_remove_buffers_prep, + .issue = io_manage_buffers_legacy, + }, + [IORING_OP_TEE] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + .audit_skip = 1, + .prep = io_tee_prep, + .issue = io_tee, + }, + [IORING_OP_SHUTDOWN] = { + .needs_file = 1, +#if defined(CONFIG_NET) + .prep = io_shutdown_prep, + .issue = io_shutdown, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_RENAMEAT] = { + .prep = io_renameat_prep, + .issue = io_renameat, + }, + [IORING_OP_UNLINKAT] = { + .prep = io_unlinkat_prep, + .issue = io_unlinkat, + }, + [IORING_OP_MKDIRAT] = { + .prep = io_mkdirat_prep, + .issue = io_mkdirat, + }, + [IORING_OP_SYMLINKAT] = { + .prep = io_symlinkat_prep, + .issue = io_symlinkat, + }, + [IORING_OP_LINKAT] = { + .prep = io_linkat_prep, + .issue = io_linkat, + }, + [IORING_OP_MSG_RING] = { + .needs_file = 1, + .iopoll = 1, + .prep = io_msg_ring_prep, + .issue = io_msg_ring, + }, + [IORING_OP_FSETXATTR] = { + .needs_file = 1, + .prep = io_fsetxattr_prep, + .issue = io_fsetxattr, + }, + [IORING_OP_SETXATTR] = { + .prep = io_setxattr_prep, + .issue = io_setxattr, + }, + [IORING_OP_FGETXATTR] = { + .needs_file = 1, + .prep = io_fgetxattr_prep, + .issue = io_fgetxattr, + }, + [IORING_OP_GETXATTR] = { + .prep = io_getxattr_prep, + .issue = io_getxattr, + }, + [IORING_OP_SOCKET] = { + .audit_skip = 1, +#if defined(CONFIG_NET) + .prep = io_socket_prep, + .issue = io_socket, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_URING_CMD] = { + .buffer_select = 1, + .needs_file = 1, + .plug = 1, + .iopoll = 1, + .iopoll_queue = 1, + .async_size = sizeof(struct io_async_cmd), + .prep = io_uring_cmd_prep, + .issue = io_uring_cmd, + }, + [IORING_OP_SEND_ZC] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .audit_skip = 1, + .ioprio = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_send_zc_prep, + .issue = io_send_zc, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_SENDMSG_ZC] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .ioprio = 1, +#if defined(CONFIG_NET) + .async_size = sizeof(struct io_async_msghdr), + .prep = io_send_zc_prep, + .issue = io_sendmsg_zc, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_READ_MULTISHOT] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .buffer_select = 1, + .audit_skip = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_read_mshot_prep, + .issue = io_read_mshot, + }, + [IORING_OP_WAITID] = { + .async_size = sizeof(struct io_waitid_async), + .prep = io_waitid_prep, + .issue = io_waitid, + }, + [IORING_OP_FUTEX_WAIT] = { +#if defined(CONFIG_FUTEX) + .prep = io_futex_prep, + .issue = io_futex_wait, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FUTEX_WAKE] = { +#if defined(CONFIG_FUTEX) + .prep = io_futex_prep, + .issue = io_futex_wake, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FUTEX_WAITV] = { +#if defined(CONFIG_FUTEX) + .prep = io_futexv_prep, + .issue = io_futexv_wait, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_FIXED_FD_INSTALL] = { + .needs_file = 1, + .prep = io_install_fixed_fd_prep, + .issue = io_install_fixed_fd, + }, + [IORING_OP_FTRUNCATE] = { + .needs_file = 1, + .hash_reg_file = 1, + .prep = io_ftruncate_prep, + .issue = io_ftruncate, + }, + [IORING_OP_BIND] = { +#if defined(CONFIG_NET) + .needs_file = 1, + .prep = io_bind_prep, + .issue = io_bind, + .async_size = sizeof(struct io_async_msghdr), +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_LISTEN] = { +#if defined(CONFIG_NET) + .needs_file = 1, + .prep = io_listen_prep, + .issue = io_listen, + .async_size = sizeof(struct io_async_msghdr), +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_RECV_ZC] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .ioprio = 1, +#if defined(CONFIG_NET) + .prep = io_recvzc_prep, + .issue = io_recvzc, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_EPOLL_WAIT] = { + .needs_file = 1, + .audit_skip = 1, + .pollin = 1, +#if defined(CONFIG_EPOLL) + .prep = io_epoll_wait_prep, + .issue = io_epoll_wait, +#else + .prep = io_eopnotsupp_prep, +#endif + }, + [IORING_OP_READV_FIXED] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + .pollin = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .vectored = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_readv_fixed, + .issue = io_read, + }, + [IORING_OP_WRITEV_FIXED] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + .pollout = 1, + .plug = 1, + .audit_skip = 1, + .ioprio = 1, + .iopoll = 1, + .iopoll_queue = 1, + .vectored = 1, + .async_size = sizeof(struct io_async_rw), + .prep = io_prep_writev_fixed, + .issue = io_write, + }, + [IORING_OP_PIPE] = { + .prep = io_pipe_prep, + .issue = io_pipe, + }, + [IORING_OP_NOP128] = { + .audit_skip = 1, + .iopoll = 1, + .is_128 = 1, + .prep = io_nop_prep, + .issue = io_nop, + }, + [IORING_OP_URING_CMD128] = { + .buffer_select = 1, + .needs_file = 1, + .plug = 1, + .iopoll = 1, + .iopoll_queue = 1, + .is_128 = 1, + .async_size = sizeof(struct io_async_cmd), + .prep = io_uring_cmd_prep, + .issue = io_uring_cmd, + }, +}; + +const struct io_cold_def io_cold_defs[] = { + [IORING_OP_NOP] = { + .name = "NOP", + }, + [IORING_OP_READV] = { + .name = "READV", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_WRITEV] = { + .name = "WRITEV", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_FSYNC] = { + .name = "FSYNC", + }, + [IORING_OP_READ_FIXED] = { + .name = "READ_FIXED", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_WRITE_FIXED] = { + .name = "WRITE_FIXED", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_POLL_ADD] = { + .name = "POLL_ADD", + }, + [IORING_OP_POLL_REMOVE] = { + .name = "POLL_REMOVE", + }, + [IORING_OP_SYNC_FILE_RANGE] = { + .name = "SYNC_FILE_RANGE", + }, + [IORING_OP_SENDMSG] = { + .name = "SENDMSG", +#if defined(CONFIG_NET) + .cleanup = io_sendmsg_recvmsg_cleanup, + .fail = io_sendrecv_fail, +#endif + }, + [IORING_OP_RECVMSG] = { + .name = "RECVMSG", +#if defined(CONFIG_NET) + .cleanup = io_sendmsg_recvmsg_cleanup, + .fail = io_sendrecv_fail, +#endif + }, + [IORING_OP_TIMEOUT] = { + .name = "TIMEOUT", + }, + [IORING_OP_TIMEOUT_REMOVE] = { + .name = "TIMEOUT_REMOVE", + }, + [IORING_OP_ACCEPT] = { + .name = "ACCEPT", + }, + [IORING_OP_ASYNC_CANCEL] = { + .name = "ASYNC_CANCEL", + }, + [IORING_OP_LINK_TIMEOUT] = { + .name = "LINK_TIMEOUT", + }, + [IORING_OP_CONNECT] = { + .name = "CONNECT", + }, + [IORING_OP_FALLOCATE] = { + .name = "FALLOCATE", + }, + [IORING_OP_OPENAT] = { + .name = "OPENAT", + .cleanup = io_open_cleanup, + }, + [IORING_OP_CLOSE] = { + .name = "CLOSE", + }, + [IORING_OP_FILES_UPDATE] = { + .name = "FILES_UPDATE", + }, + [IORING_OP_STATX] = { + .name = "STATX", + .cleanup = io_statx_cleanup, + }, + [IORING_OP_READ] = { + .name = "READ", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_WRITE] = { + .name = "WRITE", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_FADVISE] = { + .name = "FADVISE", + }, + [IORING_OP_MADVISE] = { + .name = "MADVISE", + }, + [IORING_OP_SEND] = { + .name = "SEND", +#if defined(CONFIG_NET) + .cleanup = io_sendmsg_recvmsg_cleanup, + .fail = io_sendrecv_fail, +#endif + }, + [IORING_OP_RECV] = { + .name = "RECV", +#if defined(CONFIG_NET) + .cleanup = io_sendmsg_recvmsg_cleanup, + .fail = io_sendrecv_fail, +#endif + }, + [IORING_OP_OPENAT2] = { + .name = "OPENAT2", + .cleanup = io_open_cleanup, + }, + [IORING_OP_EPOLL_CTL] = { + .name = "EPOLL", + }, + [IORING_OP_SPLICE] = { + .name = "SPLICE", + .cleanup = io_splice_cleanup, + }, + [IORING_OP_PROVIDE_BUFFERS] = { + .name = "PROVIDE_BUFFERS", + }, + [IORING_OP_REMOVE_BUFFERS] = { + .name = "REMOVE_BUFFERS", + }, + [IORING_OP_TEE] = { + .name = "TEE", + .cleanup = io_splice_cleanup, + }, + [IORING_OP_SHUTDOWN] = { + .name = "SHUTDOWN", + }, + [IORING_OP_RENAMEAT] = { + .name = "RENAMEAT", + .cleanup = io_renameat_cleanup, + }, + [IORING_OP_UNLINKAT] = { + .name = "UNLINKAT", + .cleanup = io_unlinkat_cleanup, + }, + [IORING_OP_MKDIRAT] = { + .name = "MKDIRAT", + .cleanup = io_mkdirat_cleanup, + }, + [IORING_OP_SYMLINKAT] = { + .name = "SYMLINKAT", + .cleanup = io_link_cleanup, + }, + [IORING_OP_LINKAT] = { + .name = "LINKAT", + .cleanup = io_link_cleanup, + }, + [IORING_OP_MSG_RING] = { + .name = "MSG_RING", + .cleanup = io_msg_ring_cleanup, + }, + [IORING_OP_FSETXATTR] = { + .name = "FSETXATTR", + .cleanup = io_xattr_cleanup, + }, + [IORING_OP_SETXATTR] = { + .name = "SETXATTR", + .cleanup = io_xattr_cleanup, + }, + [IORING_OP_FGETXATTR] = { + .name = "FGETXATTR", + .cleanup = io_xattr_cleanup, + }, + [IORING_OP_GETXATTR] = { + .name = "GETXATTR", + .cleanup = io_xattr_cleanup, + }, + [IORING_OP_SOCKET] = { + .name = "SOCKET", + }, + [IORING_OP_URING_CMD] = { + .name = "URING_CMD", + .sqe_copy = io_uring_cmd_sqe_copy, + .cleanup = io_uring_cmd_cleanup, + }, + [IORING_OP_SEND_ZC] = { + .name = "SEND_ZC", +#if defined(CONFIG_NET) + .cleanup = io_send_zc_cleanup, + .fail = io_sendrecv_fail, +#endif + }, + [IORING_OP_SENDMSG_ZC] = { + .name = "SENDMSG_ZC", +#if defined(CONFIG_NET) + .cleanup = io_send_zc_cleanup, + .fail = io_sendrecv_fail, +#endif + }, + [IORING_OP_READ_MULTISHOT] = { + .name = "READ_MULTISHOT", + .cleanup = io_readv_writev_cleanup, + }, + [IORING_OP_WAITID] = { + .name = "WAITID", + }, + [IORING_OP_FUTEX_WAIT] = { + .name = "FUTEX_WAIT", + }, + [IORING_OP_FUTEX_WAKE] = { + .name = "FUTEX_WAKE", + }, + [IORING_OP_FUTEX_WAITV] = { + .name = "FUTEX_WAITV", + }, + [IORING_OP_FIXED_FD_INSTALL] = { + .name = "FIXED_FD_INSTALL", + }, + [IORING_OP_FTRUNCATE] = { + .name = "FTRUNCATE", + }, + [IORING_OP_BIND] = { + .name = "BIND", + }, + [IORING_OP_LISTEN] = { + .name = "LISTEN", + }, + [IORING_OP_RECV_ZC] = { + .name = "RECV_ZC", + }, + [IORING_OP_EPOLL_WAIT] = { + .name = "EPOLL_WAIT", + }, + [IORING_OP_READV_FIXED] = { + .name = "READV_FIXED", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_WRITEV_FIXED] = { + .name = "WRITEV_FIXED", + .cleanup = io_readv_writev_cleanup, + .fail = io_rw_fail, + }, + [IORING_OP_PIPE] = { + .name = "PIPE", + }, + [IORING_OP_NOP128] = { + .name = "NOP128", + }, + [IORING_OP_URING_CMD128] = { + .name = "URING_CMD128", + .sqe_copy = io_uring_cmd_sqe_copy, + .cleanup = io_uring_cmd_cleanup, + }, +}; + +const char *io_uring_get_opcode(u8 opcode) +{ + if (opcode < IORING_OP_LAST) + return io_cold_defs[opcode].name; + return "INVALID"; +} + +bool io_uring_op_supported(u8 opcode) +{ + if (opcode < IORING_OP_LAST && + io_issue_defs[opcode].prep != io_eopnotsupp_prep) + return true; + return false; +} + +void __init io_uring_optable_init(void) +{ + int i; + + BUILD_BUG_ON(ARRAY_SIZE(io_cold_defs) != IORING_OP_LAST); + BUILD_BUG_ON(ARRAY_SIZE(io_issue_defs) != IORING_OP_LAST); + + for (i = 0; i < ARRAY_SIZE(io_issue_defs); i++) { + BUG_ON(!io_issue_defs[i].prep); + if (io_issue_defs[i].prep != io_eopnotsupp_prep) + BUG_ON(!io_issue_defs[i].issue); + WARN_ON_ONCE(!io_cold_defs[i].name); + } +} diff --git a/io_uring/opdef.h b/io_uring/opdef.h new file mode 100644 index 000000000000..aa37846880ff --- /dev/null +++ b/io_uring/opdef.h @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_OP_DEF_H +#define IOU_OP_DEF_H + +struct io_issue_def { + /* needs req->file assigned */ + unsigned needs_file : 1; + /* should block plug */ + unsigned plug : 1; + /* supports ioprio */ + unsigned ioprio : 1; + /* supports iopoll */ + unsigned iopoll : 1; + /* op supports buffer selection */ + unsigned buffer_select : 1; + /* hash wq insertion if file is a regular file */ + unsigned hash_reg_file : 1; + /* unbound wq insertion if file is a non-regular file */ + unsigned unbound_nonreg_file : 1; + /* set if opcode supports polled "wait" */ + unsigned pollin : 1; + unsigned pollout : 1; + unsigned poll_exclusive : 1; + /* skip auditing */ + unsigned audit_skip : 1; + /* have to be put into the iopoll list */ + unsigned iopoll_queue : 1; + /* vectored opcode, set if 1) vectored, and 2) handler needs to know */ + unsigned vectored : 1; + /* set to 1 if this opcode uses 128b sqes in a mixed sq */ + unsigned is_128 : 1; + + /* size of async data needed, if any */ + unsigned short async_size; + + int (*issue)(struct io_kiocb *, unsigned int); + int (*prep)(struct io_kiocb *, const struct io_uring_sqe *); +}; + +struct io_cold_def { + const char *name; + + void (*sqe_copy)(struct io_kiocb *); + void (*cleanup)(struct io_kiocb *); + void (*fail)(struct io_kiocb *); +}; + +extern const struct io_issue_def io_issue_defs[]; +extern const struct io_cold_def io_cold_defs[]; + +bool io_uring_op_supported(u8 opcode); + +void io_uring_optable_init(void); +#endif diff --git a/io_uring/openclose.c b/io_uring/openclose.c new file mode 100644 index 000000000000..bfeb91b31bba --- /dev/null +++ b/io_uring/openclose.c @@ -0,0 +1,436 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/fdtable.h> +#include <linux/fsnotify.h> +#include <linux/namei.h> +#include <linux/pipe_fs_i.h> +#include <linux/watch_queue.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "../fs/internal.h" + +#include "filetable.h" +#include "io_uring.h" +#include "rsrc.h" +#include "openclose.h" + +struct io_open { + struct file *file; + int dfd; + u32 file_slot; + struct filename *filename; + struct open_how how; + unsigned long nofile; +}; + +struct io_close { + struct file *file; + int fd; + u32 file_slot; +}; + +struct io_fixed_install { + struct file *file; + unsigned int o_flags; +}; + +static bool io_openat_force_async(struct io_open *open) +{ + /* + * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open, + * it'll always -EAGAIN. Note that we test for __O_TMPFILE because + * O_TMPFILE includes O_DIRECTORY, which isn't a flag we need to force + * async for. + */ + return open->how.flags & (O_TRUNC | O_CREAT | __O_TMPFILE); +} + +static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + const char __user *fname; + int ret; + + if (unlikely(sqe->buf_index)) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + /* open.how should be already initialised */ + if (!(open->how.flags & O_PATH) && force_o_largefile()) + open->how.flags |= O_LARGEFILE; + + open->dfd = READ_ONCE(sqe->fd); + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + open->filename = getname(fname); + if (IS_ERR(open->filename)) { + ret = PTR_ERR(open->filename); + open->filename = NULL; + return ret; + } + + open->file_slot = READ_ONCE(sqe->file_index); + if (open->file_slot && (open->how.flags & O_CLOEXEC)) + return -EINVAL; + + open->nofile = rlimit(RLIMIT_NOFILE); + req->flags |= REQ_F_NEED_CLEANUP; + if (io_openat_force_async(open)) + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + u64 mode = READ_ONCE(sqe->len); + u64 flags = READ_ONCE(sqe->open_flags); + + open->how = build_open_how(flags, mode); + return __io_openat_prep(req, sqe); +} + +int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + struct open_how __user *how; + size_t len; + int ret; + + how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + len = READ_ONCE(sqe->len); + if (len < OPEN_HOW_SIZE_VER0) + return -EINVAL; + + ret = copy_struct_from_user(&open->how, sizeof(open->how), how, len); + if (ret) + return ret; + + return __io_openat_prep(req, sqe); +} + +int io_openat2(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + struct open_flags op; + struct file *file; + bool resolve_nonblock, nonblock_set; + bool fixed = !!open->file_slot; + int ret; + + ret = build_open_flags(&open->how, &op); + if (ret) + goto err; + nonblock_set = op.open_flag & O_NONBLOCK; + resolve_nonblock = open->how.resolve & RESOLVE_CACHED; + if (issue_flags & IO_URING_F_NONBLOCK) { + WARN_ON_ONCE(io_openat_force_async(open)); + op.lookup_flags |= LOOKUP_CACHED; + op.open_flag |= O_NONBLOCK; + } + + if (!fixed) { + ret = __get_unused_fd_flags(open->how.flags, open->nofile); + if (ret < 0) + goto err; + } + + file = do_filp_open(open->dfd, open->filename, &op); + if (IS_ERR(file)) { + /* + * We could hang on to this 'fd' on retrying, but seems like + * marginal gain for something that is now known to be a slower + * path. So just put it, and we'll get a new one when we retry. + */ + if (!fixed) + put_unused_fd(ret); + + ret = PTR_ERR(file); + /* only retry if RESOLVE_CACHED wasn't already set by application */ + if (ret == -EAGAIN && + (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK))) + return -EAGAIN; + goto err; + } + + if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) + file->f_flags &= ~O_NONBLOCK; + + if (!fixed) + fd_install(ret, file); + else + ret = io_fixed_fd_install(req, issue_flags, file, + open->file_slot); +err: + putname(open->filename); + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_openat(struct io_kiocb *req, unsigned int issue_flags) +{ + return io_openat2(req, issue_flags); +} + +void io_open_cleanup(struct io_kiocb *req) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + + if (open->filename) + putname(open->filename); +} + +int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags, + unsigned int offset) +{ + int ret; + + io_ring_submit_lock(ctx, issue_flags); + ret = io_fixed_fd_remove(ctx, offset); + io_ring_submit_unlock(ctx, issue_flags); + + return ret; +} + +static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_close *close = io_kiocb_to_cmd(req, struct io_close); + + return __io_close_fixed(req->ctx, issue_flags, close->file_slot - 1); +} + +int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_close *close = io_kiocb_to_cmd(req, struct io_close); + + if (sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index) + return -EINVAL; + if (req->flags & REQ_F_FIXED_FILE) + return -EBADF; + + close->fd = READ_ONCE(sqe->fd); + close->file_slot = READ_ONCE(sqe->file_index); + if (close->file_slot && close->fd) + return -EINVAL; + + return 0; +} + +int io_close(struct io_kiocb *req, unsigned int issue_flags) +{ + struct files_struct *files = current->files; + struct io_close *close = io_kiocb_to_cmd(req, struct io_close); + struct file *file; + int ret = -EBADF; + + if (close->file_slot) { + ret = io_close_fixed(req, issue_flags); + goto err; + } + + spin_lock(&files->file_lock); + file = files_lookup_fd_locked(files, close->fd); + if (!file || io_is_uring_fops(file)) { + spin_unlock(&files->file_lock); + goto err; + } + + /* if the file has a flush method, be safe and punt to async */ + if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) { + spin_unlock(&files->file_lock); + return -EAGAIN; + } + + file = file_close_fd_locked(files, close->fd); + spin_unlock(&files->file_lock); + if (!file) + goto err; + + /* No ->flush() or already async, safely close from here */ + ret = filp_close(file, current->files); +err: + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_fixed_install *ifi; + unsigned int flags; + + if (sqe->off || sqe->addr || sqe->len || sqe->buf_index || + sqe->splice_fd_in || sqe->addr3) + return -EINVAL; + + /* must be a fixed file */ + if (!(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + flags = READ_ONCE(sqe->install_fd_flags); + if (flags & ~IORING_FIXED_FD_NO_CLOEXEC) + return -EINVAL; + + /* ensure the task's creds are used when installing/receiving fds */ + if (req->flags & REQ_F_CREDS) + return -EPERM; + + /* default to O_CLOEXEC, disable if IORING_FIXED_FD_NO_CLOEXEC is set */ + ifi = io_kiocb_to_cmd(req, struct io_fixed_install); + ifi->o_flags = O_CLOEXEC; + if (flags & IORING_FIXED_FD_NO_CLOEXEC) + ifi->o_flags = 0; + + return 0; +} + +int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_fixed_install *ifi; + int ret; + + ifi = io_kiocb_to_cmd(req, struct io_fixed_install); + ret = receive_fd(req->file, NULL, ifi->o_flags); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +struct io_pipe { + struct file *file; + int __user *fds; + int flags; + int file_slot; + unsigned long nofile; +}; + +int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + + if (sqe->fd || sqe->off || sqe->addr3) + return -EINVAL; + + p->fds = u64_to_user_ptr(READ_ONCE(sqe->addr)); + p->flags = READ_ONCE(sqe->pipe_flags); + if (p->flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT | O_NOTIFICATION_PIPE)) + return -EINVAL; + + p->file_slot = READ_ONCE(sqe->file_index); + p->nofile = rlimit(RLIMIT_NOFILE); + return 0; +} + +static int io_pipe_fixed(struct io_kiocb *req, struct file **files, + unsigned int issue_flags) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + struct io_ring_ctx *ctx = req->ctx; + int ret, fds[2] = { -1, -1 }; + int slot = p->file_slot; + + if (p->flags & O_CLOEXEC) + return -EINVAL; + + io_ring_submit_lock(ctx, issue_flags); + + ret = __io_fixed_fd_install(ctx, files[0], slot); + if (ret < 0) + goto err; + fds[0] = ret; + files[0] = NULL; + + /* + * If a specific slot is given, next one will be used for + * the write side. + */ + if (slot != IORING_FILE_INDEX_ALLOC) + slot++; + + ret = __io_fixed_fd_install(ctx, files[1], slot); + if (ret < 0) + goto err; + fds[1] = ret; + files[1] = NULL; + + io_ring_submit_unlock(ctx, issue_flags); + + if (!copy_to_user(p->fds, fds, sizeof(fds))) + return 0; + + ret = -EFAULT; + io_ring_submit_lock(ctx, issue_flags); +err: + if (fds[0] != -1) + io_fixed_fd_remove(ctx, fds[0]); + if (fds[1] != -1) + io_fixed_fd_remove(ctx, fds[1]); + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} + +static int io_pipe_fd(struct io_kiocb *req, struct file **files) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + int ret, fds[2] = { -1, -1 }; + + ret = __get_unused_fd_flags(p->flags, p->nofile); + if (ret < 0) + goto err; + fds[0] = ret; + + ret = __get_unused_fd_flags(p->flags, p->nofile); + if (ret < 0) + goto err; + fds[1] = ret; + + if (!copy_to_user(p->fds, fds, sizeof(fds))) { + fd_install(fds[0], files[0]); + fd_install(fds[1], files[1]); + return 0; + } + ret = -EFAULT; +err: + if (fds[0] != -1) + put_unused_fd(fds[0]); + if (fds[1] != -1) + put_unused_fd(fds[1]); + return ret; +} + +int io_pipe(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + struct file *files[2]; + int ret; + + ret = create_pipe_files(files, p->flags); + if (ret) + return ret; + + if (!!p->file_slot) + ret = io_pipe_fixed(req, files, issue_flags); + else + ret = io_pipe_fd(req, files); + + io_req_set_res(req, ret, 0); + if (!ret) + return IOU_COMPLETE; + + req_set_fail(req); + if (files[0]) + fput(files[0]); + if (files[1]) + fput(files[1]); + return ret; +} diff --git a/io_uring/openclose.h b/io_uring/openclose.h new file mode 100644 index 000000000000..4ca2a9935abc --- /dev/null +++ b/io_uring/openclose.h @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 + +int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags, + unsigned int offset); + +int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_openat(struct io_kiocb *req, unsigned int issue_flags); +void io_open_cleanup(struct io_kiocb *req); + +int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_openat2(struct io_kiocb *req, unsigned int issue_flags); + +int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_close(struct io_kiocb *req, unsigned int issue_flags); + +int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_pipe(struct io_kiocb *req, unsigned int issue_flags); + +int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/poll.c b/io_uring/poll.c new file mode 100644 index 000000000000..aac4b3b881fb --- /dev/null +++ b/io_uring/poll.c @@ -0,0 +1,963 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/poll.h> +#include <linux/hashtable.h> +#include <linux/io_uring.h> + +#include <trace/events/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "alloc_cache.h" +#include "refs.h" +#include "napi.h" +#include "opdef.h" +#include "kbuf.h" +#include "poll.h" +#include "cancel.h" + +struct io_poll_update { + struct file *file; + u64 old_user_data; + u64 new_user_data; + __poll_t events; + bool update_events; + bool update_user_data; +}; + +struct io_poll_table { + struct poll_table_struct pt; + struct io_kiocb *req; + int nr_entries; + int error; + bool owning; + /* output value, set only if arm poll returns >0 */ + __poll_t result_mask; +}; + +#define IO_POLL_CANCEL_FLAG BIT(31) +#define IO_POLL_RETRY_FLAG BIT(30) +#define IO_POLL_REF_MASK GENMASK(29, 0) + +/* + * We usually have 1-2 refs taken, 128 is more than enough and we want to + * maximise the margin between this amount and the moment when it overflows. + */ +#define IO_POLL_REF_BIAS 128 + +#define IO_WQE_F_DOUBLE 1 + +static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, + void *key); + +static inline struct io_kiocb *wqe_to_req(struct wait_queue_entry *wqe) +{ + unsigned long priv = (unsigned long)wqe->private; + + return (struct io_kiocb *)(priv & ~IO_WQE_F_DOUBLE); +} + +static inline bool wqe_is_double(struct wait_queue_entry *wqe) +{ + unsigned long priv = (unsigned long)wqe->private; + + return priv & IO_WQE_F_DOUBLE; +} + +static bool io_poll_get_ownership_slowpath(struct io_kiocb *req) +{ + int v; + + /* + * poll_refs are already elevated and we don't have much hope for + * grabbing the ownership. Instead of incrementing set a retry flag + * to notify the loop that there might have been some change. + */ + v = atomic_fetch_or(IO_POLL_RETRY_FLAG, &req->poll_refs); + if (v & IO_POLL_REF_MASK) + return false; + return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK); +} + +/* + * If refs part of ->poll_refs (see IO_POLL_REF_MASK) is 0, it's free. We can + * bump it and acquire ownership. It's disallowed to modify requests while not + * owning it, that prevents from races for enqueueing task_work's and b/w + * arming poll and wakeups. + */ +static inline bool io_poll_get_ownership(struct io_kiocb *req) +{ + if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) + return io_poll_get_ownership_slowpath(req); + return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK); +} + +static void io_poll_mark_cancelled(struct io_kiocb *req) +{ + atomic_or(IO_POLL_CANCEL_FLAG, &req->poll_refs); +} + +static struct io_poll *io_poll_get_double(struct io_kiocb *req) +{ + /* pure poll stashes this in ->async_data, poll driven retry elsewhere */ + if (req->opcode == IORING_OP_POLL_ADD) + return req->async_data; + return req->apoll->double_poll; +} + +static struct io_poll *io_poll_get_single(struct io_kiocb *req) +{ + if (req->opcode == IORING_OP_POLL_ADD) + return io_kiocb_to_cmd(req, struct io_poll); + return &req->apoll->poll; +} + +static void io_poll_req_insert(struct io_kiocb *req) +{ + struct io_hash_table *table = &req->ctx->cancel_table; + u32 index = hash_long(req->cqe.user_data, table->hash_bits); + + lockdep_assert_held(&req->ctx->uring_lock); + + hlist_add_head(&req->hash_node, &table->hbs[index].list); +} + +static void io_init_poll_iocb(struct io_poll *poll, __poll_t events) +{ + poll->head = NULL; +#define IO_POLL_UNMASK (EPOLLERR|EPOLLHUP|EPOLLNVAL|EPOLLRDHUP) + /* mask in events that we always want/need */ + poll->events = events | IO_POLL_UNMASK; + INIT_LIST_HEAD(&poll->wait.entry); + init_waitqueue_func_entry(&poll->wait, io_poll_wake); +} + +static void io_poll_remove_waitq(struct io_poll *poll) +{ + /* + * If the waitqueue is being freed early but someone is already holds + * ownership over it, we have to tear down the request as best we can. + * That means immediately removing the request from its waitqueue and + * preventing all further accesses to the waitqueue via the request. + */ + list_del_init(&poll->wait.entry); + + /* + * Careful: this *must* be the last step, since as soon as req->head is + * NULL'ed out, the request can be completed and freed, since + * io_poll_remove_entry() will no longer need to take the waitqueue + * lock. + */ + smp_store_release(&poll->head, NULL); +} + +static inline void io_poll_remove_entry(struct io_poll *poll) +{ + struct wait_queue_head *head = smp_load_acquire(&poll->head); + + if (head) { + spin_lock_irq(&head->lock); + io_poll_remove_waitq(poll); + spin_unlock_irq(&head->lock); + } +} + +static void io_poll_remove_entries(struct io_kiocb *req) +{ + /* + * Nothing to do if neither of those flags are set. Avoid dipping + * into the poll/apoll/double cachelines if we can. + */ + if (!(req->flags & (REQ_F_SINGLE_POLL | REQ_F_DOUBLE_POLL))) + return; + + /* + * While we hold the waitqueue lock and the waitqueue is nonempty, + * wake_up_pollfree() will wait for us. However, taking the waitqueue + * lock in the first place can race with the waitqueue being freed. + * + * We solve this as eventpoll does: by taking advantage of the fact that + * all users of wake_up_pollfree() will RCU-delay the actual free. If + * we enter rcu_read_lock() and see that the pointer to the queue is + * non-NULL, we can then lock it without the memory being freed out from + * under us. + * + * Keep holding rcu_read_lock() as long as we hold the queue lock, in + * case the caller deletes the entry from the queue, leaving it empty. + * In that case, only RCU prevents the queue memory from being freed. + */ + rcu_read_lock(); + if (req->flags & REQ_F_SINGLE_POLL) + io_poll_remove_entry(io_poll_get_single(req)); + if (req->flags & REQ_F_DOUBLE_POLL) + io_poll_remove_entry(io_poll_get_double(req)); + rcu_read_unlock(); +} + +enum { + IOU_POLL_DONE = 0, + IOU_POLL_NO_ACTION = 1, + IOU_POLL_REMOVE_POLL_USE_RES = 2, + IOU_POLL_REISSUE = 3, + IOU_POLL_REQUEUE = 4, +}; + +static void __io_poll_execute(struct io_kiocb *req, int mask) +{ + unsigned flags = 0; + + io_req_set_res(req, mask, 0); + req->io_task_work.func = io_poll_task_func; + + trace_io_uring_task_add(req, mask); + + if (!(req->flags & REQ_F_POLL_NO_LAZY)) + flags = IOU_F_TWQ_LAZY_WAKE; + __io_req_task_work_add(req, flags); +} + +static inline void io_poll_execute(struct io_kiocb *req, int res) +{ + if (io_poll_get_ownership(req)) + __io_poll_execute(req, res); +} + +/* + * All poll tw should go through this. Checks for poll events, manages + * references, does rewait, etc. + * + * Returns a negative error on failure. IOU_POLL_NO_ACTION when no action + * require, which is either spurious wakeup or multishot CQE is served. + * IOU_POLL_DONE when it's done with the request, then the mask is stored in + * req->cqe.res. IOU_POLL_REMOVE_POLL_USE_RES indicates to remove multishot + * poll and that the result is stored in req->cqe. + */ +static int io_poll_check_events(struct io_kiocb *req, io_tw_token_t tw) +{ + int v; + + if (unlikely(tw.cancel)) + return -ECANCELED; + + do { + v = atomic_read(&req->poll_refs); + + if (unlikely(v != 1)) { + /* tw should be the owner and so have some refs */ + if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK))) + return IOU_POLL_NO_ACTION; + if (v & IO_POLL_CANCEL_FLAG) + return -ECANCELED; + /* + * cqe.res contains only events of the first wake up + * and all others are to be lost. Redo vfs_poll() to get + * up to date state. + */ + if ((v & IO_POLL_REF_MASK) != 1) + req->cqe.res = 0; + + if (v & IO_POLL_RETRY_FLAG) { + req->cqe.res = 0; + /* + * We won't find new events that came in between + * vfs_poll and the ref put unless we clear the + * flag in advance. + */ + atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs); + v &= ~IO_POLL_RETRY_FLAG; + } + } + + /* the mask was stashed in __io_poll_execute */ + if (!req->cqe.res) { + struct poll_table_struct pt = { ._key = req->apoll_events }; + req->cqe.res = vfs_poll(req->file, &pt) & req->apoll_events; + /* + * We got woken with a mask, but someone else got to + * it first. The above vfs_poll() doesn't add us back + * to the waitqueue, so if we get nothing back, we + * should be safe and attempt a reissue. + */ + if (unlikely(!req->cqe.res)) { + /* Multishot armed need not reissue */ + if (!(req->apoll_events & EPOLLONESHOT)) + continue; + return IOU_POLL_REISSUE; + } + } + if (req->apoll_events & EPOLLONESHOT) + return IOU_POLL_DONE; + + /* multishot, just fill a CQE and proceed */ + if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { + __poll_t mask = mangle_poll(req->cqe.res & + req->apoll_events); + + if (!io_req_post_cqe(req, mask, IORING_CQE_F_MORE)) { + io_req_set_res(req, mask, 0); + return IOU_POLL_REMOVE_POLL_USE_RES; + } + } else { + int ret = io_poll_issue(req, tw); + + if (ret == IOU_COMPLETE) + return IOU_POLL_REMOVE_POLL_USE_RES; + else if (ret == IOU_REQUEUE) + return IOU_POLL_REQUEUE; + if (ret != IOU_RETRY && ret < 0) + return ret; + } + + /* force the next iteration to vfs_poll() */ + req->cqe.res = 0; + + /* + * Release all references, retry if someone tried to restart + * task_work while we were executing it. + */ + v &= IO_POLL_REF_MASK; + } while (atomic_sub_return(v, &req->poll_refs) & IO_POLL_REF_MASK); + + io_napi_add(req); + return IOU_POLL_NO_ACTION; +} + +void io_poll_task_func(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + int ret; + + ret = io_poll_check_events(req, tw); + if (ret == IOU_POLL_NO_ACTION) { + return; + } else if (ret == IOU_POLL_REQUEUE) { + __io_poll_execute(req, 0); + return; + } + io_poll_remove_entries(req); + /* task_work always has ->uring_lock held */ + hash_del(&req->hash_node); + + if (req->opcode == IORING_OP_POLL_ADD) { + if (ret == IOU_POLL_DONE) { + struct io_poll *poll; + + poll = io_kiocb_to_cmd(req, struct io_poll); + req->cqe.res = mangle_poll(req->cqe.res & poll->events); + } else if (ret == IOU_POLL_REISSUE) { + io_req_task_submit(tw_req, tw); + return; + } else if (ret != IOU_POLL_REMOVE_POLL_USE_RES) { + req->cqe.res = ret; + req_set_fail(req); + } + + io_req_set_res(req, req->cqe.res, 0); + io_req_task_complete(tw_req, tw); + } else { + io_tw_lock(req->ctx, tw); + + if (ret == IOU_POLL_REMOVE_POLL_USE_RES) + io_req_task_complete(tw_req, tw); + else if (ret == IOU_POLL_DONE || ret == IOU_POLL_REISSUE) + io_req_task_submit(tw_req, tw); + else + io_req_defer_failed(req, ret); + } +} + +static void io_poll_cancel_req(struct io_kiocb *req) +{ + io_poll_mark_cancelled(req); + /* kick tw, which should complete the request */ + io_poll_execute(req, 0); +} + +#define IO_ASYNC_POLL_COMMON (EPOLLONESHOT | EPOLLPRI) + +static __cold int io_pollfree_wake(struct io_kiocb *req, struct io_poll *poll) +{ + io_poll_mark_cancelled(req); + /* we have to kick tw in case it's not already */ + io_poll_execute(req, 0); + io_poll_remove_waitq(poll); + return 1; +} + +static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, + void *key) +{ + struct io_kiocb *req = wqe_to_req(wait); + struct io_poll *poll = container_of(wait, struct io_poll, wait); + __poll_t mask = key_to_poll(key); + + if (unlikely(mask & POLLFREE)) + return io_pollfree_wake(req, poll); + + /* for instances that support it check for an event match first */ + if (mask && !(mask & (poll->events & ~IO_ASYNC_POLL_COMMON))) + return 0; + + if (io_poll_get_ownership(req)) { + /* + * If we trigger a multishot poll off our own wakeup path, + * disable multishot as there is a circular dependency between + * CQ posting and triggering the event. + */ + if (mask & EPOLL_URING_WAKE) + poll->events |= EPOLLONESHOT; + + /* optional, saves extra locking for removal in tw handler */ + if (mask && poll->events & EPOLLONESHOT) { + io_poll_remove_waitq(poll); + if (wqe_is_double(wait)) + req->flags &= ~REQ_F_DOUBLE_POLL; + else + req->flags &= ~REQ_F_SINGLE_POLL; + } + __io_poll_execute(req, mask); + } + return 1; +} + +/* fails only when polling is already completing by the first entry */ +static bool io_poll_double_prepare(struct io_kiocb *req) +{ + struct wait_queue_head *head; + struct io_poll *poll = io_poll_get_single(req); + + /* head is RCU protected, see io_poll_remove_entries() comments */ + rcu_read_lock(); + head = smp_load_acquire(&poll->head); + /* + * poll arm might not hold ownership and so race for req->flags with + * io_poll_wake(). There is only one poll entry queued, serialise with + * it by taking its head lock. As we're still arming the tw hanlder + * is not going to be run, so there are no races with it. + */ + if (head) { + spin_lock_irq(&head->lock); + req->flags |= REQ_F_DOUBLE_POLL; + if (req->opcode == IORING_OP_POLL_ADD) + req->flags |= REQ_F_ASYNC_DATA; + spin_unlock_irq(&head->lock); + } + rcu_read_unlock(); + return !!head; +} + +static void __io_queue_proc(struct io_poll *poll, struct io_poll_table *pt, + struct wait_queue_head *head, + struct io_poll **poll_ptr) +{ + struct io_kiocb *req = pt->req; + unsigned long wqe_private = (unsigned long) req; + + /* + * The file being polled uses multiple waitqueues for poll handling + * (e.g. one for read, one for write). Setup a separate io_poll + * if this happens. + */ + if (unlikely(pt->nr_entries)) { + struct io_poll *first = poll; + + /* double add on the same waitqueue head, ignore */ + if (first->head == head) + return; + /* already have a 2nd entry, fail a third attempt */ + if (*poll_ptr) { + if ((*poll_ptr)->head == head) + return; + pt->error = -EINVAL; + return; + } + + poll = kmalloc(sizeof(*poll), GFP_ATOMIC); + if (!poll) { + pt->error = -ENOMEM; + return; + } + + /* mark as double wq entry */ + wqe_private |= IO_WQE_F_DOUBLE; + io_init_poll_iocb(poll, first->events); + if (!io_poll_double_prepare(req)) { + /* the request is completing, just back off */ + kfree(poll); + return; + } + *poll_ptr = poll; + } else { + /* fine to modify, there is no poll queued to race with us */ + req->flags |= REQ_F_SINGLE_POLL; + } + + pt->nr_entries++; + poll->head = head; + poll->wait.private = (void *) wqe_private; + + if (poll->events & EPOLLEXCLUSIVE) { + add_wait_queue_exclusive(head, &poll->wait); + } else { + add_wait_queue(head, &poll->wait); + } +} + +static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, + struct poll_table_struct *p) +{ + struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); + struct io_poll *poll = io_kiocb_to_cmd(pt->req, struct io_poll); + + __io_queue_proc(poll, pt, head, + (struct io_poll **) &pt->req->async_data); +} + +static bool io_poll_can_finish_inline(struct io_kiocb *req, + struct io_poll_table *pt) +{ + return pt->owning || io_poll_get_ownership(req); +} + +static void io_poll_add_hash(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + + io_ring_submit_lock(ctx, issue_flags); + io_poll_req_insert(req); + io_ring_submit_unlock(ctx, issue_flags); +} + +/* + * Returns 0 when it's handed over for polling. The caller owns the requests if + * it returns non-zero, but otherwise should not touch it. Negative values + * contain an error code. When the result is >0, the polling has completed + * inline and ipt.result_mask is set to the mask. + */ +static int __io_arm_poll_handler(struct io_kiocb *req, + struct io_poll *poll, + struct io_poll_table *ipt, __poll_t mask, + unsigned issue_flags) +{ + INIT_HLIST_NODE(&req->hash_node); + io_init_poll_iocb(poll, mask); + poll->file = req->file; + req->apoll_events = poll->events; + + ipt->pt._key = mask; + ipt->req = req; + ipt->error = 0; + ipt->nr_entries = 0; + /* + * Polling is either completed here or via task_work, so if we're in the + * task context we're naturally serialised with tw by merit of running + * the same task. When it's io-wq, take the ownership to prevent tw + * from running. However, when we're in the task context, skip taking + * it as an optimisation. + * + * Note: even though the request won't be completed/freed, without + * ownership we still can race with io_poll_wake(). + * io_poll_can_finish_inline() tries to deal with that. + */ + ipt->owning = issue_flags & IO_URING_F_UNLOCKED; + atomic_set(&req->poll_refs, (int)ipt->owning); + + /* + * Exclusive waits may only wake a limited amount of entries + * rather than all of them, this may interfere with lazy + * wake if someone does wait(events > 1). Ensure we don't do + * lazy wake for those, as we need to process each one as they + * come in. + */ + if (poll->events & EPOLLEXCLUSIVE) + req->flags |= REQ_F_POLL_NO_LAZY; + + mask = vfs_poll(req->file, &ipt->pt) & poll->events; + + if (unlikely(ipt->error || !ipt->nr_entries)) { + io_poll_remove_entries(req); + + if (!io_poll_can_finish_inline(req, ipt)) { + io_poll_mark_cancelled(req); + return 0; + } else if (mask && (poll->events & EPOLLET)) { + ipt->result_mask = mask; + return 1; + } + return ipt->error ?: -EINVAL; + } + + if (mask && + ((poll->events & (EPOLLET|EPOLLONESHOT)) == (EPOLLET|EPOLLONESHOT))) { + if (!io_poll_can_finish_inline(req, ipt)) { + io_poll_add_hash(req, issue_flags); + return 0; + } + io_poll_remove_entries(req); + ipt->result_mask = mask; + /* no one else has access to the req, forget about the ref */ + return 1; + } + + io_poll_add_hash(req, issue_flags); + + if (mask && (poll->events & EPOLLET) && + io_poll_can_finish_inline(req, ipt)) { + __io_poll_execute(req, mask); + return 0; + } + io_napi_add(req); + + if (ipt->owning) { + /* + * Try to release ownership. If we see a change of state, e.g. + * poll was waken up, queue up a tw, it'll deal with it. + */ + if (atomic_cmpxchg(&req->poll_refs, 1, 0) != 1) + __io_poll_execute(req, 0); + } + return 0; +} + +static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, + struct poll_table_struct *p) +{ + struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); + struct async_poll *apoll = pt->req->apoll; + + __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll); +} + +/* + * We can't reliably detect loops in repeated poll triggers and issue + * subsequently failing. But rather than fail these immediately, allow a + * certain amount of retries before we give up. Given that this condition + * should _rarely_ trigger even once, we should be fine with a larger value. + */ +#define APOLL_MAX_RETRY 128 + +static struct async_poll *io_req_alloc_apoll(struct io_kiocb *req, + unsigned issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + struct async_poll *apoll; + + if (req->flags & REQ_F_POLLED) { + apoll = req->apoll; + kfree(apoll->double_poll); + } else { + if (!(issue_flags & IO_URING_F_UNLOCKED)) + apoll = io_cache_alloc(&ctx->apoll_cache, GFP_ATOMIC); + else + apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); + if (!apoll) + return NULL; + apoll->poll.retries = APOLL_MAX_RETRY; + } + apoll->double_poll = NULL; + req->apoll = apoll; + if (unlikely(!--apoll->poll.retries)) + return NULL; + return apoll; +} + +int io_arm_apoll(struct io_kiocb *req, unsigned issue_flags, __poll_t mask) +{ + struct async_poll *apoll; + struct io_poll_table ipt; + int ret; + + mask |= EPOLLET; + if (!io_file_can_poll(req)) + return IO_APOLL_ABORTED; + if (!(req->flags & REQ_F_APOLL_MULTISHOT)) + mask |= EPOLLONESHOT; + + apoll = io_req_alloc_apoll(req, issue_flags); + if (!apoll) + return IO_APOLL_ABORTED; + req->flags &= ~(REQ_F_SINGLE_POLL | REQ_F_DOUBLE_POLL); + req->flags |= REQ_F_POLLED; + ipt.pt._qproc = io_async_queue_proc; + + ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, issue_flags); + if (ret) + return ret > 0 ? IO_APOLL_READY : IO_APOLL_ABORTED; + trace_io_uring_poll_arm(req, mask, apoll->poll.events); + return IO_APOLL_OK; +} + +int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags) +{ + const struct io_issue_def *def = &io_issue_defs[req->opcode]; + __poll_t mask = POLLPRI | POLLERR; + + if (!def->pollin && !def->pollout) + return IO_APOLL_ABORTED; + if (!io_file_can_poll(req)) + return IO_APOLL_ABORTED; + + if (def->pollin) { + mask |= EPOLLIN | EPOLLRDNORM; + + /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */ + if (req->flags & REQ_F_CLEAR_POLLIN) + mask &= ~EPOLLIN; + } else { + mask |= EPOLLOUT | EPOLLWRNORM; + } + if (def->poll_exclusive) + mask |= EPOLLEXCLUSIVE; + + return io_arm_apoll(req, issue_flags, mask); +} + +/* + * Returns true if we found and killed one or more poll requests + */ +__cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all) +{ + unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits; + struct hlist_node *tmp; + struct io_kiocb *req; + bool found = false; + int i; + + lockdep_assert_held(&ctx->uring_lock); + + for (i = 0; i < nr_buckets; i++) { + struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i]; + + hlist_for_each_entry_safe(req, tmp, &hb->list, hash_node) { + if (io_match_task_safe(req, tctx, cancel_all)) { + hlist_del_init(&req->hash_node); + io_poll_cancel_req(req); + found = true; + } + } + } + return found; +} + +static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only, + struct io_cancel_data *cd) +{ + struct io_kiocb *req; + u32 index = hash_long(cd->data, ctx->cancel_table.hash_bits); + struct io_hash_bucket *hb = &ctx->cancel_table.hbs[index]; + + hlist_for_each_entry(req, &hb->list, hash_node) { + if (cd->data != req->cqe.user_data) + continue; + if (poll_only && req->opcode != IORING_OP_POLL_ADD) + continue; + if (cd->flags & IORING_ASYNC_CANCEL_ALL) { + if (io_cancel_match_sequence(req, cd->seq)) + continue; + } + return req; + } + return NULL; +} + +static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx, + struct io_cancel_data *cd) +{ + unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits; + struct io_kiocb *req; + int i; + + for (i = 0; i < nr_buckets; i++) { + struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i]; + + hlist_for_each_entry(req, &hb->list, hash_node) { + if (io_cancel_req_match(req, cd)) + return req; + } + } + return NULL; +} + +static int io_poll_disarm(struct io_kiocb *req) +{ + if (!req) + return -ENOENT; + if (!io_poll_get_ownership(req)) + return -EALREADY; + io_poll_remove_entries(req); + hash_del(&req->hash_node); + return 0; +} + +static int __io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd) +{ + struct io_kiocb *req; + + if (cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP | + IORING_ASYNC_CANCEL_ANY)) + req = io_poll_file_find(ctx, cd); + else + req = io_poll_find(ctx, false, cd); + + if (req) { + io_poll_cancel_req(req); + return 0; + } + return -ENOENT; +} + +int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned issue_flags) +{ + int ret; + + io_ring_submit_lock(ctx, issue_flags); + ret = __io_poll_cancel(ctx, cd); + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} + +static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe, + unsigned int flags) +{ + u32 events; + + events = READ_ONCE(sqe->poll32_events); +#ifdef __BIG_ENDIAN + events = swahw32(events); +#endif + if (!(flags & IORING_POLL_ADD_MULTI)) + events |= EPOLLONESHOT; + if (!(flags & IORING_POLL_ADD_LEVEL)) + events |= EPOLLET; + return demangle_poll(events) | + (events & (EPOLLEXCLUSIVE|EPOLLONESHOT|EPOLLET)); +} + +int io_poll_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_poll_update *upd = io_kiocb_to_cmd(req, struct io_poll_update); + u32 flags; + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + flags = READ_ONCE(sqe->len); + if (flags & ~(IORING_POLL_UPDATE_EVENTS | IORING_POLL_UPDATE_USER_DATA | + IORING_POLL_ADD_MULTI)) + return -EINVAL; + /* meaningless without update */ + if (flags == IORING_POLL_ADD_MULTI) + return -EINVAL; + + upd->old_user_data = READ_ONCE(sqe->addr); + upd->update_events = flags & IORING_POLL_UPDATE_EVENTS; + upd->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA; + + upd->new_user_data = READ_ONCE(sqe->off); + if (!upd->update_user_data && upd->new_user_data) + return -EINVAL; + if (upd->update_events) + upd->events = io_poll_parse_events(sqe, flags); + else if (sqe->poll32_events) + return -EINVAL; + + return 0; +} + +int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_poll *poll = io_kiocb_to_cmd(req, struct io_poll); + u32 flags; + + if (sqe->buf_index || sqe->off || sqe->addr) + return -EINVAL; + flags = READ_ONCE(sqe->len); + if (flags & ~IORING_POLL_ADD_MULTI) + return -EINVAL; + if ((flags & IORING_POLL_ADD_MULTI) && (req->flags & REQ_F_CQE_SKIP)) + return -EINVAL; + + poll->events = io_poll_parse_events(sqe, flags); + return 0; +} + +int io_poll_add(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_poll *poll = io_kiocb_to_cmd(req, struct io_poll); + struct io_poll_table ipt; + int ret; + + ipt.pt._qproc = io_poll_queue_proc; + + ret = __io_arm_poll_handler(req, poll, &ipt, poll->events, issue_flags); + if (ret > 0) { + io_req_set_res(req, ipt.result_mask, 0); + return IOU_COMPLETE; + } + return ret ?: IOU_ISSUE_SKIP_COMPLETE; +} + +int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_poll_update *poll_update = io_kiocb_to_cmd(req, struct io_poll_update); + struct io_ring_ctx *ctx = req->ctx; + struct io_cancel_data cd = { .ctx = ctx, .data = poll_update->old_user_data, }; + struct io_kiocb *preq; + int ret2, ret = 0; + + io_ring_submit_lock(ctx, issue_flags); + preq = io_poll_find(ctx, true, &cd); + ret2 = io_poll_disarm(preq); + if (ret2) { + ret = ret2; + goto out; + } + if (WARN_ON_ONCE(preq->opcode != IORING_OP_POLL_ADD)) { + ret = -EFAULT; + goto out; + } + + if (poll_update->update_events || poll_update->update_user_data) { + /* only mask one event flags, keep behavior flags */ + if (poll_update->update_events) { + struct io_poll *poll = io_kiocb_to_cmd(preq, struct io_poll); + + poll->events &= ~0xffff; + poll->events |= poll_update->events & 0xffff; + poll->events |= IO_POLL_UNMASK; + } + if (poll_update->update_user_data) + preq->cqe.user_data = poll_update->new_user_data; + + ret2 = io_poll_add(preq, issue_flags & ~IO_URING_F_UNLOCKED); + /* successfully updated, don't complete poll request */ + if (ret2 == IOU_ISSUE_SKIP_COMPLETE) + goto out; + /* request completed as part of the update, complete it */ + else if (ret2 == IOU_COMPLETE) + goto complete; + } + + io_req_set_res(preq, -ECANCELED, 0); +complete: + if (preq->cqe.res < 0) + req_set_fail(preq); + preq->io_task_work.func = io_req_task_complete; + io_req_task_work_add(preq); +out: + io_ring_submit_unlock(ctx, issue_flags); + if (ret < 0) { + req_set_fail(req); + return ret; + } + /* complete update request, we're done with it */ + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/poll.h b/io_uring/poll.h new file mode 100644 index 000000000000..5647c5138932 --- /dev/null +++ b/io_uring/poll.h @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/io_uring_types.h> + +#define IO_POLL_ALLOC_CACHE_MAX 32 + +enum { + IO_APOLL_OK, + IO_APOLL_ABORTED, + IO_APOLL_READY +}; + +struct io_poll { + struct file *file; + struct wait_queue_head *head; + __poll_t events; + int retries; + struct wait_queue_entry wait; +}; + +struct async_poll { + struct io_poll poll; + struct io_poll *double_poll; +}; + +/* + * Must only be called inside issue_flags & IO_URING_F_MULTISHOT, or + * potentially other cases where we already "own" this poll request. + */ +static inline void io_poll_multishot_retry(struct io_kiocb *req) +{ + atomic_inc(&req->poll_refs); +} + +int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_poll_add(struct io_kiocb *req, unsigned int issue_flags); + +int io_poll_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags); + +struct io_cancel_data; +int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned issue_flags); +int io_arm_apoll(struct io_kiocb *req, unsigned issue_flags, __poll_t mask); +int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags); +bool io_poll_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all); + +void io_poll_task_func(struct io_tw_req tw_req, io_tw_token_t tw); diff --git a/io_uring/query.c b/io_uring/query.c new file mode 100644 index 000000000000..abdd6f3e1223 --- /dev/null +++ b/io_uring/query.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "linux/io_uring/query.h" + +#include "query.h" +#include "io_uring.h" +#include "zcrx.h" + +union io_query_data { + struct io_uring_query_opcode opcodes; + struct io_uring_query_zcrx zcrx; + struct io_uring_query_scq scq; +}; + +#define IO_MAX_QUERY_SIZE sizeof(union io_query_data) +#define IO_MAX_QUERY_ENTRIES 1000 + +static ssize_t io_query_ops(union io_query_data *data) +{ + struct io_uring_query_opcode *e = &data->opcodes; + + e->nr_request_opcodes = IORING_OP_LAST; + e->nr_register_opcodes = IORING_REGISTER_LAST; + e->feature_flags = IORING_FEAT_FLAGS; + e->ring_setup_flags = IORING_SETUP_FLAGS; + e->enter_flags = IORING_ENTER_FLAGS; + e->sqe_flags = SQE_VALID_FLAGS; + e->nr_query_opcodes = __IO_URING_QUERY_MAX; + e->__pad = 0; + return sizeof(*e); +} + +static ssize_t io_query_zcrx(union io_query_data *data) +{ + struct io_uring_query_zcrx *e = &data->zcrx; + + e->register_flags = ZCRX_REG_IMPORT; + e->area_flags = IORING_ZCRX_AREA_DMABUF; + e->nr_ctrl_opcodes = __ZCRX_CTRL_LAST; + e->rq_hdr_size = sizeof(struct io_uring); + e->rq_hdr_alignment = L1_CACHE_BYTES; + e->__resv1 = 0; + e->__resv2 = 0; + return sizeof(*e); +} + +static ssize_t io_query_scq(union io_query_data *data) +{ + struct io_uring_query_scq *e = &data->scq; + + e->hdr_size = sizeof(struct io_rings); + e->hdr_alignment = SMP_CACHE_BYTES; + return sizeof(*e); +} + +static int io_handle_query_entry(union io_query_data *data, void __user *uhdr, + u64 *next_entry) +{ + struct io_uring_query_hdr hdr; + size_t usize, res_size = 0; + ssize_t ret = -EINVAL; + void __user *udata; + + if (copy_from_user(&hdr, uhdr, sizeof(hdr))) + return -EFAULT; + usize = hdr.size; + hdr.size = min(hdr.size, IO_MAX_QUERY_SIZE); + udata = u64_to_user_ptr(hdr.query_data); + + if (hdr.query_op >= __IO_URING_QUERY_MAX) { + ret = -EOPNOTSUPP; + goto out; + } + if (!mem_is_zero(hdr.__resv, sizeof(hdr.__resv)) || hdr.result || !hdr.size) + goto out; + if (copy_from_user(data, udata, hdr.size)) + return -EFAULT; + + switch (hdr.query_op) { + case IO_URING_QUERY_OPCODES: + ret = io_query_ops(data); + break; + case IO_URING_QUERY_ZCRX: + ret = io_query_zcrx(data); + break; + case IO_URING_QUERY_SCQ: + ret = io_query_scq(data); + break; + } + + if (ret >= 0) { + if (WARN_ON_ONCE(ret > IO_MAX_QUERY_SIZE)) + return -EFAULT; + res_size = ret; + ret = 0; + } +out: + hdr.result = ret; + hdr.size = min_t(size_t, usize, res_size); + + if (copy_struct_to_user(udata, usize, data, hdr.size, NULL)) + return -EFAULT; + if (copy_to_user(uhdr, &hdr, sizeof(hdr))) + return -EFAULT; + *next_entry = hdr.next_entry; + return 0; +} + +int io_query(void __user *arg, unsigned nr_args) +{ + union io_query_data entry_buffer; + void __user *uhdr = arg; + int ret, nr = 0; + + memset(&entry_buffer, 0, sizeof(entry_buffer)); + + if (nr_args) + return -EINVAL; + + while (uhdr) { + u64 next_hdr; + + ret = io_handle_query_entry(&entry_buffer, uhdr, &next_hdr); + if (ret) + return ret; + uhdr = u64_to_user_ptr(next_hdr); + + /* Have some limit to avoid a potential cycle */ + if (++nr >= IO_MAX_QUERY_ENTRIES) + return -ERANGE; + if (fatal_signal_pending(current)) + return -EINTR; + cond_resched(); + } + return 0; +} diff --git a/io_uring/query.h b/io_uring/query.h new file mode 100644 index 000000000000..b35eb52f0ea8 --- /dev/null +++ b/io_uring/query.h @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IORING_QUERY_H +#define IORING_QUERY_H + +#include <linux/io_uring_types.h> + +int io_query(void __user *arg, unsigned nr_args); + +#endif diff --git a/io_uring/refs.h b/io_uring/refs.h new file mode 100644 index 000000000000..0d928d87c4ed --- /dev/null +++ b/io_uring/refs.h @@ -0,0 +1,62 @@ +#ifndef IOU_REQ_REF_H +#define IOU_REQ_REF_H + +#include <linux/atomic.h> +#include <linux/io_uring_types.h> + +/* + * Shamelessly stolen from the mm implementation of page reference checking, + * see commit f958d7b528b1 for details. + */ +#define req_ref_zero_or_close_to_overflow(req) \ + ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u) + +static inline bool req_ref_inc_not_zero(struct io_kiocb *req) +{ + WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); + return atomic_inc_not_zero(&req->refs); +} + +static inline bool req_ref_put_and_test_atomic(struct io_kiocb *req) +{ + WARN_ON_ONCE(!(data_race(req->flags) & REQ_F_REFCOUNT)); + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + return atomic_dec_and_test(&req->refs); +} + +static inline bool req_ref_put_and_test(struct io_kiocb *req) +{ + if (likely(!(req->flags & REQ_F_REFCOUNT))) + return true; + + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + return atomic_dec_and_test(&req->refs); +} + +static inline void req_ref_get(struct io_kiocb *req) +{ + WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + atomic_inc(&req->refs); +} + +static inline void req_ref_put(struct io_kiocb *req) +{ + WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + atomic_dec(&req->refs); +} + +static inline void __io_req_set_refcount(struct io_kiocb *req, int nr) +{ + if (!(req->flags & REQ_F_REFCOUNT)) { + req->flags |= REQ_F_REFCOUNT; + atomic_set(&req->refs, nr); + } +} + +static inline void io_req_set_refcount(struct io_kiocb *req) +{ + __io_req_set_refcount(req, 1); +} +#endif diff --git a/io_uring/register.c b/io_uring/register.c new file mode 100644 index 000000000000..62d39b3ff317 --- /dev/null +++ b/io_uring/register.c @@ -0,0 +1,927 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Code related to the io_uring_register() syscall + * + * Copyright (C) 2023 Jens Axboe + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/syscalls.h> +#include <linux/refcount.h> +#include <linux/bits.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/nospec.h> +#include <linux/compat.h> +#include <linux/io_uring.h> +#include <linux/io_uring_types.h> + +#include "filetable.h" +#include "io_uring.h" +#include "opdef.h" +#include "tctx.h" +#include "rsrc.h" +#include "sqpoll.h" +#include "register.h" +#include "cancel.h" +#include "kbuf.h" +#include "napi.h" +#include "eventfd.h" +#include "msg_ring.h" +#include "memmap.h" +#include "zcrx.h" +#include "query.h" + +#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ + IORING_REGISTER_LAST + IORING_OP_LAST) + +static __cold int io_probe(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + struct io_uring_probe *p; + size_t size; + int i, ret; + + if (nr_args > IORING_OP_LAST) + nr_args = IORING_OP_LAST; + + size = struct_size(p, ops, nr_args); + p = memdup_user(arg, size); + if (IS_ERR(p)) + return PTR_ERR(p); + ret = -EINVAL; + if (memchr_inv(p, 0, size)) + goto out; + + p->last_op = IORING_OP_LAST - 1; + + for (i = 0; i < nr_args; i++) { + p->ops[i].op = i; + if (io_uring_op_supported(i)) + p->ops[i].flags = IO_URING_OP_SUPPORTED; + } + p->ops_len = i; + + ret = 0; + if (copy_to_user(arg, p, size)) + ret = -EFAULT; +out: + kfree(p); + return ret; +} + +int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) +{ + const struct cred *creds; + + creds = xa_erase(&ctx->personalities, id); + if (creds) { + put_cred(creds); + return 0; + } + + return -EINVAL; +} + + +static int io_register_personality(struct io_ring_ctx *ctx) +{ + const struct cred *creds; + u32 id; + int ret; + + creds = get_current_cred(); + + ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds, + XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL); + if (ret < 0) { + put_cred(creds); + return ret; + } + return id; +} + +static __cold int io_parse_restrictions(void __user *arg, unsigned int nr_args, + struct io_restriction *restrictions) +{ + struct io_uring_restriction *res; + size_t size; + int i, ret; + + if (!arg || nr_args > IORING_MAX_RESTRICTIONS) + return -EINVAL; + + size = array_size(nr_args, sizeof(*res)); + if (size == SIZE_MAX) + return -EOVERFLOW; + + res = memdup_user(arg, size); + if (IS_ERR(res)) + return PTR_ERR(res); + + ret = -EINVAL; + + for (i = 0; i < nr_args; i++) { + switch (res[i].opcode) { + case IORING_RESTRICTION_REGISTER_OP: + if (res[i].register_op >= IORING_REGISTER_LAST) + goto err; + __set_bit(res[i].register_op, restrictions->register_op); + break; + case IORING_RESTRICTION_SQE_OP: + if (res[i].sqe_op >= IORING_OP_LAST) + goto err; + __set_bit(res[i].sqe_op, restrictions->sqe_op); + break; + case IORING_RESTRICTION_SQE_FLAGS_ALLOWED: + restrictions->sqe_flags_allowed = res[i].sqe_flags; + break; + case IORING_RESTRICTION_SQE_FLAGS_REQUIRED: + restrictions->sqe_flags_required = res[i].sqe_flags; + break; + default: + goto err; + } + } + + ret = 0; + +err: + kfree(res); + return ret; +} + +static __cold int io_register_restrictions(struct io_ring_ctx *ctx, + void __user *arg, unsigned int nr_args) +{ + int ret; + + /* Restrictions allowed only if rings started disabled */ + if (!(ctx->flags & IORING_SETUP_R_DISABLED)) + return -EBADFD; + + /* We allow only a single restrictions registration */ + if (ctx->restrictions.registered) + return -EBUSY; + + ret = io_parse_restrictions(arg, nr_args, &ctx->restrictions); + /* Reset all restrictions if an error happened */ + if (ret != 0) + memset(&ctx->restrictions, 0, sizeof(ctx->restrictions)); + else + ctx->restrictions.registered = true; + return ret; +} + +static int io_register_enable_rings(struct io_ring_ctx *ctx) +{ + if (!(ctx->flags & IORING_SETUP_R_DISABLED)) + return -EBADFD; + + if (ctx->flags & IORING_SETUP_SINGLE_ISSUER && !ctx->submitter_task) { + WRITE_ONCE(ctx->submitter_task, get_task_struct(current)); + /* + * Lazy activation attempts would fail if it was polled before + * submitter_task is set. + */ + if (wq_has_sleeper(&ctx->poll_wq)) + io_activate_pollwq(ctx); + } + + if (ctx->restrictions.registered) + ctx->restricted = 1; + + ctx->flags &= ~IORING_SETUP_R_DISABLED; + if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait)) + wake_up(&ctx->sq_data->wait); + return 0; +} + +static __cold int __io_register_iowq_aff(struct io_ring_ctx *ctx, + cpumask_var_t new_mask) +{ + int ret; + + if (!(ctx->flags & IORING_SETUP_SQPOLL)) { + ret = io_wq_cpu_affinity(current->io_uring, new_mask); + } else { + mutex_unlock(&ctx->uring_lock); + ret = io_sqpoll_wq_cpu_affinity(ctx, new_mask); + mutex_lock(&ctx->uring_lock); + } + + return ret; +} + +static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx, + void __user *arg, unsigned len) +{ + cpumask_var_t new_mask; + int ret; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_clear(new_mask); + if (len > cpumask_size()) + len = cpumask_size(); + +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_get_bitmap(cpumask_bits(new_mask), + (const compat_ulong_t __user *)arg, + len * 8 /* CHAR_BIT */); + else +#endif + ret = copy_from_user(new_mask, arg, len); + + if (ret) { + free_cpumask_var(new_mask); + return -EFAULT; + } + + ret = __io_register_iowq_aff(ctx, new_mask); + free_cpumask_var(new_mask); + return ret; +} + +static __cold int io_unregister_iowq_aff(struct io_ring_ctx *ctx) +{ + return __io_register_iowq_aff(ctx, NULL); +} + +static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx, + void __user *arg) + __must_hold(&ctx->uring_lock) +{ + struct io_tctx_node *node; + struct io_uring_task *tctx = NULL; + struct io_sq_data *sqd = NULL; + __u32 new_count[2]; + int i, ret; + + if (copy_from_user(new_count, arg, sizeof(new_count))) + return -EFAULT; + for (i = 0; i < ARRAY_SIZE(new_count); i++) + if (new_count[i] > INT_MAX) + return -EINVAL; + + if (ctx->flags & IORING_SETUP_SQPOLL) { + sqd = ctx->sq_data; + if (sqd) { + struct task_struct *tsk; + + /* + * Observe the correct sqd->lock -> ctx->uring_lock + * ordering. Fine to drop uring_lock here, we hold + * a ref to the ctx. + */ + refcount_inc(&sqd->refs); + mutex_unlock(&ctx->uring_lock); + mutex_lock(&sqd->lock); + mutex_lock(&ctx->uring_lock); + tsk = sqpoll_task_locked(sqd); + if (tsk) + tctx = tsk->io_uring; + } + } else { + tctx = current->io_uring; + } + + BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits)); + + for (i = 0; i < ARRAY_SIZE(new_count); i++) + if (new_count[i]) + ctx->iowq_limits[i] = new_count[i]; + ctx->iowq_limits_set = true; + + if (tctx && tctx->io_wq) { + ret = io_wq_max_workers(tctx->io_wq, new_count); + if (ret) + goto err; + } else { + memset(new_count, 0, sizeof(new_count)); + } + + if (sqd) { + mutex_unlock(&ctx->uring_lock); + mutex_unlock(&sqd->lock); + io_put_sq_data(sqd); + mutex_lock(&ctx->uring_lock); + } + + if (copy_to_user(arg, new_count, sizeof(new_count))) + return -EFAULT; + + /* that's it for SQPOLL, only the SQPOLL task creates requests */ + if (sqd) + return 0; + + /* now propagate the restriction to all registered users */ + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + tctx = node->task->io_uring; + if (WARN_ON_ONCE(!tctx->io_wq)) + continue; + + for (i = 0; i < ARRAY_SIZE(new_count); i++) + new_count[i] = ctx->iowq_limits[i]; + /* ignore errors, it always returns zero anyway */ + (void)io_wq_max_workers(tctx->io_wq, new_count); + } + return 0; +err: + if (sqd) { + mutex_unlock(&ctx->uring_lock); + mutex_unlock(&sqd->lock); + io_put_sq_data(sqd); + mutex_lock(&ctx->uring_lock); + } + return ret; +} + +static int io_register_clock(struct io_ring_ctx *ctx, + struct io_uring_clock_register __user *arg) +{ + struct io_uring_clock_register reg; + + if (copy_from_user(®, arg, sizeof(reg))) + return -EFAULT; + if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) + return -EINVAL; + + switch (reg.clockid) { + case CLOCK_MONOTONIC: + ctx->clock_offset = 0; + break; + case CLOCK_BOOTTIME: + ctx->clock_offset = TK_OFFS_BOOT; + break; + default: + return -EINVAL; + } + + ctx->clockid = reg.clockid; + return 0; +} + +/* + * State to maintain until we can swap. Both new and old state, used for + * either mapping or freeing. + */ +struct io_ring_ctx_rings { + struct io_rings *rings; + struct io_uring_sqe *sq_sqes; + + struct io_mapped_region sq_region; + struct io_mapped_region ring_region; +}; + +static void io_register_free_rings(struct io_ring_ctx *ctx, + struct io_ring_ctx_rings *r) +{ + io_free_region(ctx->user, &r->sq_region); + io_free_region(ctx->user, &r->ring_region); +} + +#define swap_old(ctx, o, n, field) \ + do { \ + (o).field = (ctx)->field; \ + (ctx)->field = (n).field; \ + } while (0) + +#define RESIZE_FLAGS (IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP) +#define COPY_FLAGS (IORING_SETUP_NO_SQARRAY | IORING_SETUP_SQE128 | \ + IORING_SETUP_CQE32 | IORING_SETUP_NO_MMAP | \ + IORING_SETUP_CQE_MIXED | IORING_SETUP_SQE_MIXED) + +static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) +{ + struct io_ctx_config config; + struct io_uring_region_desc rd; + struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; + unsigned i, tail, old_head; + struct io_uring_params *p = &config.p; + struct io_rings_layout *rl = &config.layout; + int ret; + + memset(&config, 0, sizeof(config)); + + /* limited to DEFER_TASKRUN for now */ + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + return -EINVAL; + if (copy_from_user(p, arg, sizeof(*p))) + return -EFAULT; + if (p->flags & ~RESIZE_FLAGS) + return -EINVAL; + + /* properties that are always inherited */ + p->flags |= (ctx->flags & COPY_FLAGS); + + ret = io_prepare_config(&config); + if (unlikely(ret)) + return ret; + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(rl->rings_size); + if (p->flags & IORING_SETUP_NO_MMAP) { + rd.user_addr = p->cq_off.user_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &n.ring_region, &rd, IORING_OFF_CQ_RING); + if (ret) + return ret; + + n.rings = io_region_get_ptr(&n.ring_region); + + /* + * At this point n.rings is shared with userspace, just like o.rings + * is as well. While we don't expect userspace to modify it while + * a resize is in progress, and it's most likely that userspace will + * shoot itself in the foot if it does, we can't always assume good + * intent... Use read/write once helpers from here on to indicate the + * shared nature of it. + */ + WRITE_ONCE(n.rings->sq_ring_mask, p->sq_entries - 1); + WRITE_ONCE(n.rings->cq_ring_mask, p->cq_entries - 1); + WRITE_ONCE(n.rings->sq_ring_entries, p->sq_entries); + WRITE_ONCE(n.rings->cq_ring_entries, p->cq_entries); + + if (copy_to_user(arg, p, sizeof(*p))) { + io_register_free_rings(ctx, &n); + return -EFAULT; + } + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(rl->sq_size); + if (p->flags & IORING_SETUP_NO_MMAP) { + rd.user_addr = p->sq_off.user_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &n.sq_region, &rd, IORING_OFF_SQES); + if (ret) { + io_register_free_rings(ctx, &n); + return ret; + } + n.sq_sqes = io_region_get_ptr(&n.sq_region); + + /* + * If using SQPOLL, park the thread + */ + if (ctx->sq_data) { + mutex_unlock(&ctx->uring_lock); + io_sq_thread_park(ctx->sq_data); + mutex_lock(&ctx->uring_lock); + } + + /* + * We'll do the swap. Grab the ctx->mmap_lock, which will exclude + * any new mmap's on the ring fd. Clear out existing mappings to prevent + * mmap from seeing them, as we'll unmap them. Any attempt to mmap + * existing rings beyond this point will fail. Not that it could proceed + * at this point anyway, as the io_uring mmap side needs go grab the + * ctx->mmap_lock as well. Likewise, hold the completion lock over the + * duration of the actual swap. + */ + mutex_lock(&ctx->mmap_lock); + spin_lock(&ctx->completion_lock); + o.rings = ctx->rings; + ctx->rings = NULL; + o.sq_sqes = ctx->sq_sqes; + ctx->sq_sqes = NULL; + + /* + * Now copy SQ and CQ entries, if any. If either of the destination + * rings can't hold what is already there, then fail the operation. + */ + tail = READ_ONCE(o.rings->sq.tail); + old_head = READ_ONCE(o.rings->sq.head); + if (tail - old_head > p->sq_entries) + goto overflow; + for (i = old_head; i < tail; i++) { + unsigned src_head = i & (ctx->sq_entries - 1); + unsigned dst_head = i & (p->sq_entries - 1); + + n.sq_sqes[dst_head] = o.sq_sqes[src_head]; + } + WRITE_ONCE(n.rings->sq.head, old_head); + WRITE_ONCE(n.rings->sq.tail, tail); + + tail = READ_ONCE(o.rings->cq.tail); + old_head = READ_ONCE(o.rings->cq.head); + if (tail - old_head > p->cq_entries) { +overflow: + /* restore old rings, and return -EOVERFLOW via cleanup path */ + ctx->rings = o.rings; + ctx->sq_sqes = o.sq_sqes; + to_free = &n; + ret = -EOVERFLOW; + goto out; + } + for (i = old_head; i < tail; i++) { + unsigned src_head = i & (ctx->cq_entries - 1); + unsigned dst_head = i & (p->cq_entries - 1); + + n.rings->cqes[dst_head] = o.rings->cqes[src_head]; + } + WRITE_ONCE(n.rings->cq.head, old_head); + WRITE_ONCE(n.rings->cq.tail, tail); + /* invalidate cached cqe refill */ + ctx->cqe_cached = ctx->cqe_sentinel = NULL; + + WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings->sq_dropped)); + atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); + WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); + WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings->cq_overflow)); + + /* all done, store old pointers and assign new ones */ + if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) + ctx->sq_array = (u32 *)((char *)n.rings + rl->sq_array_offset); + + ctx->sq_entries = p->sq_entries; + ctx->cq_entries = p->cq_entries; + + ctx->rings = n.rings; + ctx->sq_sqes = n.sq_sqes; + swap_old(ctx, o, n, ring_region); + swap_old(ctx, o, n, sq_region); + to_free = &o; + ret = 0; +out: + spin_unlock(&ctx->completion_lock); + mutex_unlock(&ctx->mmap_lock); + io_register_free_rings(ctx, to_free); + + if (ctx->sq_data) + io_sq_thread_unpark(ctx->sq_data); + + return ret; +} + +static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg) +{ + struct io_uring_mem_region_reg __user *reg_uptr = uarg; + struct io_uring_mem_region_reg reg; + struct io_uring_region_desc __user *rd_uptr; + struct io_uring_region_desc rd; + struct io_mapped_region region = {}; + int ret; + + if (io_region_is_set(&ctx->param_region)) + return -EBUSY; + if (copy_from_user(®, reg_uptr, sizeof(reg))) + return -EFAULT; + rd_uptr = u64_to_user_ptr(reg.region_uptr); + if (copy_from_user(&rd, rd_uptr, sizeof(rd))) + return -EFAULT; + if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) + return -EINVAL; + if (reg.flags & ~IORING_MEM_REGION_REG_WAIT_ARG) + return -EINVAL; + + /* + * This ensures there are no waiters. Waiters are unlocked and it's + * hard to synchronise with them, especially if we need to initialise + * the region. + */ + if ((reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) && + !(ctx->flags & IORING_SETUP_R_DISABLED)) + return -EINVAL; + + ret = io_create_region(ctx, ®ion, &rd, IORING_MAP_OFF_PARAM_REGION); + if (ret) + return ret; + if (copy_to_user(rd_uptr, &rd, sizeof(rd))) { + io_free_region(ctx->user, ®ion); + return -EFAULT; + } + + if (reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) { + ctx->cq_wait_arg = io_region_get_ptr(®ion); + ctx->cq_wait_size = rd.size; + } + + io_region_publish(ctx, ®ion, &ctx->param_region); + return 0; +} + +static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, + void __user *arg, unsigned nr_args) + __releases(ctx->uring_lock) + __acquires(ctx->uring_lock) +{ + int ret; + + /* + * We don't quiesce the refs for register anymore and so it can't be + * dying as we're holding a file ref here. + */ + if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) + return -ENXIO; + + if (ctx->submitter_task && ctx->submitter_task != current) + return -EEXIST; + + if (ctx->restricted) { + opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); + if (!test_bit(opcode, ctx->restrictions.register_op)) + return -EACCES; + } + + switch (opcode) { + case IORING_REGISTER_BUFFERS: + ret = -EFAULT; + if (!arg) + break; + ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); + break; + case IORING_UNREGISTER_BUFFERS: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_buffers_unregister(ctx); + break; + case IORING_REGISTER_FILES: + ret = -EFAULT; + if (!arg) + break; + ret = io_sqe_files_register(ctx, arg, nr_args, NULL); + break; + case IORING_UNREGISTER_FILES: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_files_unregister(ctx); + break; + case IORING_REGISTER_FILES_UPDATE: + ret = io_register_files_update(ctx, arg, nr_args); + break; + case IORING_REGISTER_EVENTFD: + ret = -EINVAL; + if (nr_args != 1) + break; + ret = io_eventfd_register(ctx, arg, 0); + break; + case IORING_REGISTER_EVENTFD_ASYNC: + ret = -EINVAL; + if (nr_args != 1) + break; + ret = io_eventfd_register(ctx, arg, 1); + break; + case IORING_UNREGISTER_EVENTFD: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_eventfd_unregister(ctx); + break; + case IORING_REGISTER_PROBE: + ret = -EINVAL; + if (!arg || nr_args > 256) + break; + ret = io_probe(ctx, arg, nr_args); + break; + case IORING_REGISTER_PERSONALITY: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_register_personality(ctx); + break; + case IORING_UNREGISTER_PERSONALITY: + ret = -EINVAL; + if (arg) + break; + ret = io_unregister_personality(ctx, nr_args); + break; + case IORING_REGISTER_ENABLE_RINGS: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_register_enable_rings(ctx); + break; + case IORING_REGISTER_RESTRICTIONS: + ret = io_register_restrictions(ctx, arg, nr_args); + break; + case IORING_REGISTER_FILES2: + ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); + break; + case IORING_REGISTER_FILES_UPDATE2: + ret = io_register_rsrc_update(ctx, arg, nr_args, + IORING_RSRC_FILE); + break; + case IORING_REGISTER_BUFFERS2: + ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); + break; + case IORING_REGISTER_BUFFERS_UPDATE: + ret = io_register_rsrc_update(ctx, arg, nr_args, + IORING_RSRC_BUFFER); + break; + case IORING_REGISTER_IOWQ_AFF: + ret = -EINVAL; + if (!arg || !nr_args) + break; + ret = io_register_iowq_aff(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_IOWQ_AFF: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_unregister_iowq_aff(ctx); + break; + case IORING_REGISTER_IOWQ_MAX_WORKERS: + ret = -EINVAL; + if (!arg || nr_args != 2) + break; + ret = io_register_iowq_max_workers(ctx, arg); + break; + case IORING_REGISTER_RING_FDS: + ret = io_ringfd_register(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_RING_FDS: + ret = io_ringfd_unregister(ctx, arg, nr_args); + break; + case IORING_REGISTER_PBUF_RING: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_pbuf_ring(ctx, arg); + break; + case IORING_UNREGISTER_PBUF_RING: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_unregister_pbuf_ring(ctx, arg); + break; + case IORING_REGISTER_SYNC_CANCEL: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_sync_cancel(ctx, arg); + break; + case IORING_REGISTER_FILE_ALLOC_RANGE: + ret = -EINVAL; + if (!arg || nr_args) + break; + ret = io_register_file_alloc_range(ctx, arg); + break; + case IORING_REGISTER_PBUF_STATUS: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_pbuf_status(ctx, arg); + break; + case IORING_REGISTER_NAPI: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_napi(ctx, arg); + break; + case IORING_UNREGISTER_NAPI: + ret = -EINVAL; + if (nr_args != 1) + break; + ret = io_unregister_napi(ctx, arg); + break; + case IORING_REGISTER_CLOCK: + ret = -EINVAL; + if (!arg || nr_args) + break; + ret = io_register_clock(ctx, arg); + break; + case IORING_REGISTER_CLONE_BUFFERS: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_clone_buffers(ctx, arg); + break; + case IORING_REGISTER_ZCRX_IFQ: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_zcrx_ifq(ctx, arg); + break; + case IORING_REGISTER_RESIZE_RINGS: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_resize_rings(ctx, arg); + break; + case IORING_REGISTER_MEM_REGION: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_mem_region(ctx, arg); + break; + case IORING_REGISTER_QUERY: + ret = io_query(arg, nr_args); + break; + case IORING_REGISTER_ZCRX_CTRL: + ret = io_zcrx_ctrl(ctx, arg, nr_args); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +/* + * Given an 'fd' value, return the ctx associated with if. If 'registered' is + * true, then the registered index is used. Otherwise, the normal fd table. + * Caller must call fput() on the returned file, unless it's an ERR_PTR. + */ +struct file *io_uring_register_get_file(unsigned int fd, bool registered) +{ + struct file *file; + + if (registered) { + /* + * Ring fd has been registered via IORING_REGISTER_RING_FDS, we + * need only dereference our task private array to find it. + */ + struct io_uring_task *tctx = current->io_uring; + + if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) + return ERR_PTR(-EINVAL); + fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); + file = tctx->registered_rings[fd]; + if (file) + get_file(file); + } else { + file = fget(fd); + } + + if (unlikely(!file)) + return ERR_PTR(-EBADF); + if (io_is_uring_fops(file)) + return file; + fput(file); + return ERR_PTR(-EOPNOTSUPP); +} + +static int io_uring_register_send_msg_ring(void __user *arg, unsigned int nr_args) +{ + struct io_uring_sqe sqe; + + if (!arg || nr_args != 1) + return -EINVAL; + if (copy_from_user(&sqe, arg, sizeof(sqe))) + return -EFAULT; + /* no flags supported */ + if (sqe.flags) + return -EINVAL; + if (sqe.opcode != IORING_OP_MSG_RING) + return -EINVAL; + + return io_uring_sync_msg_ring(&sqe); +} + +/* + * "blind" registration opcodes are ones where there's no ring given, and + * hence the source fd must be -1. + */ +static int io_uring_register_blind(unsigned int opcode, void __user *arg, + unsigned int nr_args) +{ + switch (opcode) { + case IORING_REGISTER_SEND_MSG_RING: + return io_uring_register_send_msg_ring(arg, nr_args); + case IORING_REGISTER_QUERY: + return io_query(arg, nr_args); + } + return -EINVAL; +} + +SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, + void __user *, arg, unsigned int, nr_args) +{ + struct io_ring_ctx *ctx; + long ret = -EBADF; + struct file *file; + bool use_registered_ring; + + use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); + opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; + + if (opcode >= IORING_REGISTER_LAST) + return -EINVAL; + + if (fd == -1) + return io_uring_register_blind(opcode, arg, nr_args); + + file = io_uring_register_get_file(fd, use_registered_ring); + if (IS_ERR(file)) + return PTR_ERR(file); + ctx = file->private_data; + + mutex_lock(&ctx->uring_lock); + ret = __io_uring_register(ctx, opcode, arg, nr_args); + + trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr, + ctx->buf_table.nr, ret); + mutex_unlock(&ctx->uring_lock); + + fput(file); + return ret; +} diff --git a/io_uring/register.h b/io_uring/register.h new file mode 100644 index 000000000000..a5f39d5ef9e0 --- /dev/null +++ b/io_uring/register.h @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IORING_REGISTER_H +#define IORING_REGISTER_H + +int io_eventfd_unregister(struct io_ring_ctx *ctx); +int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id); +struct file *io_uring_register_get_file(unsigned int fd, bool registered); + +#endif diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c new file mode 100644 index 000000000000..a63474b331bf --- /dev/null +++ b/io_uring/rsrc.c @@ -0,0 +1,1577 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/nospec.h> +#include <linux/hugetlb.h> +#include <linux/compat.h> +#include <linux/io_uring.h> +#include <linux/io_uring/cmd.h> + +#include <uapi/linux/io_uring.h> + +#include "filetable.h" +#include "io_uring.h" +#include "openclose.h" +#include "rsrc.h" +#include "memmap.h" +#include "register.h" + +struct io_rsrc_update { + struct file *file; + u64 arg; + u32 nr_args; + u32 offset; +}; + +static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx, + struct iovec *iov, struct page **last_hpage); + +/* only define max */ +#define IORING_MAX_FIXED_FILES (1U << 20) +#define IORING_MAX_REG_BUFFERS (1U << 14) + +#define IO_CACHED_BVECS_SEGS 32 + +int __io_account_mem(struct user_struct *user, unsigned long nr_pages) +{ + unsigned long page_limit, cur_pages, new_pages; + + if (!nr_pages) + return 0; + + /* Don't allow more pages than we can safely lock */ + page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + + cur_pages = atomic_long_read(&user->locked_vm); + do { + new_pages = cur_pages + nr_pages; + if (new_pages > page_limit) + return -ENOMEM; + } while (!atomic_long_try_cmpxchg(&user->locked_vm, + &cur_pages, new_pages)); + return 0; +} + +void io_unaccount_mem(struct user_struct *user, struct mm_struct *mm_account, + unsigned long nr_pages) +{ + if (user) + __io_unaccount_mem(user, nr_pages); + + if (mm_account) + atomic64_sub(nr_pages, &mm_account->pinned_vm); +} + +int io_account_mem(struct user_struct *user, struct mm_struct *mm_account, + unsigned long nr_pages) +{ + int ret; + + if (user) { + ret = __io_account_mem(user, nr_pages); + if (ret) + return ret; + } + + if (mm_account) + atomic64_add(nr_pages, &mm_account->pinned_vm); + + return 0; +} + +int io_validate_user_buf_range(u64 uaddr, u64 ulen) +{ + unsigned long tmp, base = (unsigned long)uaddr; + unsigned long acct_len = (unsigned long)PAGE_ALIGN(ulen); + + /* arbitrary limit, but we need something */ + if (ulen > SZ_1G || !ulen) + return -EFAULT; + if (check_add_overflow(base, acct_len, &tmp)) + return -EOVERFLOW; + return 0; +} + +static int io_buffer_validate(struct iovec *iov) +{ + /* + * Don't impose further limits on the size and buffer + * constraints here, we'll -EINVAL later when IO is + * submitted if they are wrong. + */ + if (!iov->iov_base) + return iov->iov_len ? -EFAULT : 0; + + return io_validate_user_buf_range((unsigned long)iov->iov_base, + iov->iov_len); +} + +static void io_release_ubuf(void *priv) +{ + struct io_mapped_ubuf *imu = priv; + unsigned int i; + + for (i = 0; i < imu->nr_bvecs; i++) { + struct folio *folio = page_folio(imu->bvec[i].bv_page); + + unpin_user_folio(folio, 1); + } +} + +static struct io_mapped_ubuf *io_alloc_imu(struct io_ring_ctx *ctx, + int nr_bvecs) +{ + if (nr_bvecs <= IO_CACHED_BVECS_SEGS) + return io_cache_alloc(&ctx->imu_cache, GFP_KERNEL); + return kvmalloc(struct_size_t(struct io_mapped_ubuf, bvec, nr_bvecs), + GFP_KERNEL); +} + +static void io_free_imu(struct io_ring_ctx *ctx, struct io_mapped_ubuf *imu) +{ + if (imu->nr_bvecs <= IO_CACHED_BVECS_SEGS) + io_cache_free(&ctx->imu_cache, imu); + else + kvfree(imu); +} + +static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf *imu) +{ + if (unlikely(refcount_read(&imu->refs) > 1)) { + if (!refcount_dec_and_test(&imu->refs)) + return; + } + + if (imu->acct_pages) + io_unaccount_mem(ctx->user, ctx->mm_account, imu->acct_pages); + imu->release(imu->priv); + io_free_imu(ctx, imu); +} + +struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx, int type) +{ + struct io_rsrc_node *node; + + node = io_cache_alloc(&ctx->node_cache, GFP_KERNEL); + if (node) { + node->type = type; + node->refs = 1; + node->tag = 0; + node->file_ptr = 0; + } + return node; +} + +bool io_rsrc_cache_init(struct io_ring_ctx *ctx) +{ + const int imu_cache_size = struct_size_t(struct io_mapped_ubuf, bvec, + IO_CACHED_BVECS_SEGS); + const int node_size = sizeof(struct io_rsrc_node); + bool ret; + + ret = io_alloc_cache_init(&ctx->node_cache, IO_ALLOC_CACHE_MAX, + node_size, 0); + ret |= io_alloc_cache_init(&ctx->imu_cache, IO_ALLOC_CACHE_MAX, + imu_cache_size, 0); + return ret; +} + +void io_rsrc_cache_free(struct io_ring_ctx *ctx) +{ + io_alloc_cache_free(&ctx->node_cache, kfree); + io_alloc_cache_free(&ctx->imu_cache, kfree); +} + +static void io_clear_table_tags(struct io_rsrc_data *data) +{ + int i; + + for (i = 0; i < data->nr; i++) { + struct io_rsrc_node *node = data->nodes[i]; + + if (node) + node->tag = 0; + } +} + +__cold void io_rsrc_data_free(struct io_ring_ctx *ctx, + struct io_rsrc_data *data) +{ + if (!data->nr) + return; + while (data->nr--) { + if (data->nodes[data->nr]) + io_put_rsrc_node(ctx, data->nodes[data->nr]); + } + kvfree(data->nodes); + data->nodes = NULL; + data->nr = 0; +} + +__cold int io_rsrc_data_alloc(struct io_rsrc_data *data, unsigned nr) +{ + data->nodes = kvmalloc_array(nr, sizeof(struct io_rsrc_node *), + GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (data->nodes) { + data->nr = nr; + return 0; + } + return -ENOMEM; +} + +static int __io_sqe_files_update(struct io_ring_ctx *ctx, + struct io_uring_rsrc_update2 *up, + unsigned nr_args) +{ + u64 __user *tags = u64_to_user_ptr(up->tags); + __s32 __user *fds = u64_to_user_ptr(up->data); + int fd, i, err = 0; + unsigned int done; + + if (!ctx->file_table.data.nr) + return -ENXIO; + if (up->offset + nr_args > ctx->file_table.data.nr) + return -EINVAL; + + for (done = 0; done < nr_args; done++) { + u64 tag = 0; + + if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) || + copy_from_user(&fd, &fds[done], sizeof(fd))) { + err = -EFAULT; + break; + } + if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) { + err = -EINVAL; + break; + } + if (fd == IORING_REGISTER_FILES_SKIP) + continue; + + i = up->offset + done; + if (io_reset_rsrc_node(ctx, &ctx->file_table.data, i)) + io_file_bitmap_clear(&ctx->file_table, i); + + if (fd != -1) { + struct file *file = fget(fd); + struct io_rsrc_node *node; + + if (!file) { + err = -EBADF; + break; + } + /* + * Don't allow io_uring instances to be registered. + */ + if (io_is_uring_fops(file)) { + fput(file); + err = -EBADF; + break; + } + node = io_rsrc_node_alloc(ctx, IORING_RSRC_FILE); + if (!node) { + err = -ENOMEM; + fput(file); + break; + } + ctx->file_table.data.nodes[i] = node; + if (tag) + node->tag = tag; + io_fixed_file_set(node, file); + io_file_bitmap_set(&ctx->file_table, i); + } + } + return done ? done : err; +} + +static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, + struct io_uring_rsrc_update2 *up, + unsigned int nr_args) +{ + u64 __user *tags = u64_to_user_ptr(up->tags); + struct iovec fast_iov, *iov; + struct page *last_hpage = NULL; + struct iovec __user *uvec; + u64 user_data = up->data; + __u32 done; + int i, err; + + if (!ctx->buf_table.nr) + return -ENXIO; + if (up->offset + nr_args > ctx->buf_table.nr) + return -EINVAL; + + for (done = 0; done < nr_args; done++) { + struct io_rsrc_node *node; + u64 tag = 0; + + uvec = u64_to_user_ptr(user_data); + iov = iovec_from_user(uvec, 1, 1, &fast_iov, ctx->compat); + if (IS_ERR(iov)) { + err = PTR_ERR(iov); + break; + } + if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) { + err = -EFAULT; + break; + } + err = io_buffer_validate(iov); + if (err) + break; + node = io_sqe_buffer_register(ctx, iov, &last_hpage); + if (IS_ERR(node)) { + err = PTR_ERR(node); + break; + } + if (tag) { + if (!node) { + err = -EINVAL; + break; + } + node->tag = tag; + } + i = array_index_nospec(up->offset + done, ctx->buf_table.nr); + io_reset_rsrc_node(ctx, &ctx->buf_table, i); + ctx->buf_table.nodes[i] = node; + if (ctx->compat) + user_data += sizeof(struct compat_iovec); + else + user_data += sizeof(struct iovec); + } + return done ? done : err; +} + +static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, + struct io_uring_rsrc_update2 *up, + unsigned nr_args) +{ + __u32 tmp; + + lockdep_assert_held(&ctx->uring_lock); + + if (check_add_overflow(up->offset, nr_args, &tmp)) + return -EOVERFLOW; + + switch (type) { + case IORING_RSRC_FILE: + return __io_sqe_files_update(ctx, up, nr_args); + case IORING_RSRC_BUFFER: + return __io_sqe_buffers_update(ctx, up, nr_args); + } + return -EINVAL; +} + +int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + struct io_uring_rsrc_update2 up; + + if (!nr_args) + return -EINVAL; + memset(&up, 0, sizeof(up)); + if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update))) + return -EFAULT; + if (up.resv || up.resv2) + return -EINVAL; + return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args); +} + +int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned size, unsigned type) +{ + struct io_uring_rsrc_update2 up; + + if (size != sizeof(up)) + return -EINVAL; + if (copy_from_user(&up, arg, sizeof(up))) + return -EFAULT; + if (!up.nr || up.resv || up.resv2) + return -EINVAL; + return __io_register_rsrc_update(ctx, type, &up, up.nr); +} + +__cold int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, + unsigned int size, unsigned int type) +{ + struct io_uring_rsrc_register rr; + + /* keep it extendible */ + if (size != sizeof(rr)) + return -EINVAL; + + memset(&rr, 0, sizeof(rr)); + if (copy_from_user(&rr, arg, size)) + return -EFAULT; + if (!rr.nr || rr.resv2) + return -EINVAL; + if (rr.flags & ~IORING_RSRC_REGISTER_SPARSE) + return -EINVAL; + + switch (type) { + case IORING_RSRC_FILE: + if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data) + break; + return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data), + rr.nr, u64_to_user_ptr(rr.tags)); + case IORING_RSRC_BUFFER: + if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data) + break; + return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data), + rr.nr, u64_to_user_ptr(rr.tags)); + } + return -EINVAL; +} + +int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update); + + if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) + return -EINVAL; + if (sqe->rw_flags || sqe->splice_fd_in) + return -EINVAL; + + up->offset = READ_ONCE(sqe->off); + up->nr_args = READ_ONCE(sqe->len); + if (!up->nr_args) + return -EINVAL; + up->arg = READ_ONCE(sqe->addr); + return 0; +} + +static int io_files_update_with_index_alloc(struct io_kiocb *req, + unsigned int issue_flags) +{ + struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update); + __s32 __user *fds = u64_to_user_ptr(up->arg); + unsigned int done; + struct file *file; + int ret, fd; + + if (!req->ctx->file_table.data.nr) + return -ENXIO; + + for (done = 0; done < up->nr_args; done++) { + if (get_user(fd, &fds[done])) { + ret = -EFAULT; + break; + } + + file = fget(fd); + if (!file) { + ret = -EBADF; + break; + } + ret = io_fixed_fd_install(req, issue_flags, file, + IORING_FILE_INDEX_ALLOC); + if (ret < 0) + break; + if (put_user(ret, &fds[done])) { + __io_close_fixed(req->ctx, issue_flags, ret); + ret = -EFAULT; + break; + } + } + + if (done) + return done; + return ret; +} + +int io_files_update(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update); + struct io_ring_ctx *ctx = req->ctx; + struct io_uring_rsrc_update2 up2; + int ret; + + up2.offset = up->offset; + up2.data = up->arg; + up2.nr = 0; + up2.tags = 0; + up2.resv = 0; + up2.resv2 = 0; + + if (up->offset == IORING_FILE_INDEX_ALLOC) { + ret = io_files_update_with_index_alloc(req, issue_flags); + } else { + io_ring_submit_lock(ctx, issue_flags); + ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE, + &up2, up->nr_args); + io_ring_submit_unlock(ctx, issue_flags); + } + + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +void io_free_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node) +{ + if (node->tag) + io_post_aux_cqe(ctx, node->tag, 0, 0); + + switch (node->type) { + case IORING_RSRC_FILE: + fput(io_slot_file(node)); + break; + case IORING_RSRC_BUFFER: + io_buffer_unmap(ctx, node->buf); + break; + default: + WARN_ON_ONCE(1); + break; + } + + io_cache_free(&ctx->node_cache, node); +} + +int io_sqe_files_unregister(struct io_ring_ctx *ctx) +{ + if (!ctx->file_table.data.nr) + return -ENXIO; + + io_free_file_tables(ctx, &ctx->file_table); + io_file_table_set_alloc_range(ctx, 0, 0); + return 0; +} + +int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args, u64 __user *tags) +{ + __s32 __user *fds = (__s32 __user *) arg; + struct file *file; + int fd, ret; + unsigned i; + + if (ctx->file_table.data.nr) + return -EBUSY; + if (!nr_args) + return -EINVAL; + if (nr_args > IORING_MAX_FIXED_FILES) + return -EMFILE; + if (nr_args > rlimit(RLIMIT_NOFILE)) + return -EMFILE; + if (!io_alloc_file_tables(ctx, &ctx->file_table, nr_args)) + return -ENOMEM; + + for (i = 0; i < nr_args; i++) { + struct io_rsrc_node *node; + u64 tag = 0; + + ret = -EFAULT; + if (tags && copy_from_user(&tag, &tags[i], sizeof(tag))) + goto fail; + if (fds && copy_from_user(&fd, &fds[i], sizeof(fd))) + goto fail; + /* allow sparse sets */ + if (!fds || fd == -1) { + ret = -EINVAL; + if (tag) + goto fail; + continue; + } + + file = fget(fd); + ret = -EBADF; + if (unlikely(!file)) + goto fail; + + /* + * Don't allow io_uring instances to be registered. + */ + if (io_is_uring_fops(file)) { + fput(file); + goto fail; + } + ret = -ENOMEM; + node = io_rsrc_node_alloc(ctx, IORING_RSRC_FILE); + if (!node) { + fput(file); + goto fail; + } + if (tag) + node->tag = tag; + ctx->file_table.data.nodes[i] = node; + io_fixed_file_set(node, file); + io_file_bitmap_set(&ctx->file_table, i); + } + + /* default it to the whole table */ + io_file_table_set_alloc_range(ctx, 0, ctx->file_table.data.nr); + return 0; +fail: + io_clear_table_tags(&ctx->file_table.data); + io_sqe_files_unregister(ctx); + return ret; +} + +int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +{ + if (!ctx->buf_table.nr) + return -ENXIO; + io_rsrc_data_free(ctx, &ctx->buf_table); + return 0; +} + +/* + * Not super efficient, but this is just a registration time. And we do cache + * the last compound head, so generally we'll only do a full search if we don't + * match that one. + * + * We check if the given compound head page has already been accounted, to + * avoid double accounting it. This allows us to account the full size of the + * page, not just the constituent pages of a huge page. + */ +static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages, + int nr_pages, struct page *hpage) +{ + int i, j; + + /* check current page array */ + for (i = 0; i < nr_pages; i++) { + if (!PageCompound(pages[i])) + continue; + if (compound_head(pages[i]) == hpage) + return true; + } + + /* check previously registered pages */ + for (i = 0; i < ctx->buf_table.nr; i++) { + struct io_rsrc_node *node = ctx->buf_table.nodes[i]; + struct io_mapped_ubuf *imu; + + if (!node) + continue; + imu = node->buf; + for (j = 0; j < imu->nr_bvecs; j++) { + if (!PageCompound(imu->bvec[j].bv_page)) + continue; + if (compound_head(imu->bvec[j].bv_page) == hpage) + return true; + } + } + + return false; +} + +static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages, + int nr_pages, struct io_mapped_ubuf *imu, + struct page **last_hpage) +{ + int i, ret; + + imu->acct_pages = 0; + for (i = 0; i < nr_pages; i++) { + if (!PageCompound(pages[i])) { + imu->acct_pages++; + } else { + struct page *hpage; + + hpage = compound_head(pages[i]); + if (hpage == *last_hpage) + continue; + *last_hpage = hpage; + if (headpage_already_acct(ctx, pages, i, hpage)) + continue; + imu->acct_pages += page_size(hpage) >> PAGE_SHIFT; + } + } + + if (!imu->acct_pages) + return 0; + + ret = io_account_mem(ctx->user, ctx->mm_account, imu->acct_pages); + if (ret) + imu->acct_pages = 0; + return ret; +} + +static bool io_coalesce_buffer(struct page ***pages, int *nr_pages, + struct io_imu_folio_data *data) +{ + struct page **page_array = *pages, **new_array = NULL; + unsigned nr_pages_left = *nr_pages; + unsigned nr_folios = data->nr_folios; + unsigned i, j; + + /* Store head pages only*/ + new_array = kvmalloc_array(nr_folios, sizeof(struct page *), GFP_KERNEL); + if (!new_array) + return false; + + for (i = 0, j = 0; i < nr_folios; i++) { + struct page *p = compound_head(page_array[j]); + struct folio *folio = page_folio(p); + unsigned int nr; + + WARN_ON_ONCE(i > 0 && p != page_array[j]); + + nr = i ? data->nr_pages_mid : data->nr_pages_head; + nr = min(nr, nr_pages_left); + /* Drop all but one ref, the entire folio will remain pinned. */ + if (nr > 1) + unpin_user_folio(folio, nr - 1); + j += nr; + nr_pages_left -= nr; + new_array[i] = p; + } + + WARN_ON_ONCE(j != *nr_pages); + + kvfree(page_array); + *pages = new_array; + *nr_pages = nr_folios; + return true; +} + +bool io_check_coalesce_buffer(struct page **page_array, int nr_pages, + struct io_imu_folio_data *data) +{ + struct folio *folio = page_folio(page_array[0]); + unsigned int count = 1, nr_folios = 1; + int i; + + data->nr_pages_mid = folio_nr_pages(folio); + data->folio_shift = folio_shift(folio); + data->first_folio_page_idx = folio_page_idx(folio, page_array[0]); + + /* + * Check if pages are contiguous inside a folio, and all folios have + * the same page count except for the head and tail. + */ + for (i = 1; i < nr_pages; i++) { + if (page_folio(page_array[i]) == folio && + page_array[i] == page_array[i-1] + 1) { + count++; + continue; + } + + if (nr_folios == 1) { + if (folio_page_idx(folio, page_array[i-1]) != + data->nr_pages_mid - 1) + return false; + + data->nr_pages_head = count; + } else if (count != data->nr_pages_mid) { + return false; + } + + folio = page_folio(page_array[i]); + if (folio_size(folio) != (1UL << data->folio_shift) || + folio_page_idx(folio, page_array[i]) != 0) + return false; + + count = 1; + nr_folios++; + } + if (nr_folios == 1) + data->nr_pages_head = count; + + data->nr_folios = nr_folios; + return true; +} + +static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx, + struct iovec *iov, + struct page **last_hpage) +{ + struct io_mapped_ubuf *imu = NULL; + struct page **pages = NULL; + struct io_rsrc_node *node; + unsigned long off; + size_t size; + int ret, nr_pages, i; + struct io_imu_folio_data data; + bool coalesced = false; + + if (!iov->iov_base) + return NULL; + + node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER); + if (!node) + return ERR_PTR(-ENOMEM); + + ret = -ENOMEM; + pages = io_pin_pages((unsigned long) iov->iov_base, iov->iov_len, + &nr_pages); + if (IS_ERR(pages)) { + ret = PTR_ERR(pages); + pages = NULL; + goto done; + } + + /* If it's huge page(s), try to coalesce them into fewer bvec entries */ + if (nr_pages > 1 && io_check_coalesce_buffer(pages, nr_pages, &data)) { + if (data.nr_pages_mid != 1) + coalesced = io_coalesce_buffer(&pages, &nr_pages, &data); + } + + imu = io_alloc_imu(ctx, nr_pages); + if (!imu) + goto done; + + imu->nr_bvecs = nr_pages; + ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage); + if (ret) + goto done; + + size = iov->iov_len; + /* store original address for later verification */ + imu->ubuf = (unsigned long) iov->iov_base; + imu->len = iov->iov_len; + imu->folio_shift = PAGE_SHIFT; + imu->release = io_release_ubuf; + imu->priv = imu; + imu->is_kbuf = false; + imu->dir = IO_IMU_DEST | IO_IMU_SOURCE; + if (coalesced) + imu->folio_shift = data.folio_shift; + refcount_set(&imu->refs, 1); + + off = (unsigned long)iov->iov_base & ~PAGE_MASK; + if (coalesced) + off += data.first_folio_page_idx << PAGE_SHIFT; + + node->buf = imu; + ret = 0; + + for (i = 0; i < nr_pages; i++) { + size_t vec_len; + + vec_len = min_t(size_t, size, (1UL << imu->folio_shift) - off); + bvec_set_page(&imu->bvec[i], pages[i], vec_len, off); + off = 0; + size -= vec_len; + } +done: + if (ret) { + if (imu) + io_free_imu(ctx, imu); + if (pages) { + for (i = 0; i < nr_pages; i++) + unpin_user_folio(page_folio(pages[i]), 1); + } + io_cache_free(&ctx->node_cache, node); + node = ERR_PTR(ret); + } + kvfree(pages); + return node; +} + +int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned int nr_args, u64 __user *tags) +{ + struct page *last_hpage = NULL; + struct io_rsrc_data data; + struct iovec fast_iov, *iov = &fast_iov; + const struct iovec __user *uvec; + int i, ret; + + BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16)); + + if (ctx->buf_table.nr) + return -EBUSY; + if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS) + return -EINVAL; + ret = io_rsrc_data_alloc(&data, nr_args); + if (ret) + return ret; + + if (!arg) + memset(iov, 0, sizeof(*iov)); + + for (i = 0; i < nr_args; i++) { + struct io_rsrc_node *node; + u64 tag = 0; + + if (arg) { + uvec = (struct iovec __user *) arg; + iov = iovec_from_user(uvec, 1, 1, &fast_iov, ctx->compat); + if (IS_ERR(iov)) { + ret = PTR_ERR(iov); + break; + } + ret = io_buffer_validate(iov); + if (ret) + break; + if (ctx->compat) + arg += sizeof(struct compat_iovec); + else + arg += sizeof(struct iovec); + } + + if (tags) { + if (copy_from_user(&tag, &tags[i], sizeof(tag))) { + ret = -EFAULT; + break; + } + } + + node = io_sqe_buffer_register(ctx, iov, &last_hpage); + if (IS_ERR(node)) { + ret = PTR_ERR(node); + break; + } + if (tag) { + if (!node) { + ret = -EINVAL; + break; + } + node->tag = tag; + } + data.nodes[i] = node; + } + + ctx->buf_table = data; + if (ret) { + io_clear_table_tags(&ctx->buf_table); + io_sqe_buffers_unregister(ctx); + } + return ret; +} + +int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq, + void (*release)(void *), unsigned int index, + unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx; + struct io_rsrc_data *data = &ctx->buf_table; + struct req_iterator rq_iter; + struct io_mapped_ubuf *imu; + struct io_rsrc_node *node; + struct bio_vec bv; + unsigned int nr_bvecs = 0; + int ret = 0; + + io_ring_submit_lock(ctx, issue_flags); + if (index >= data->nr) { + ret = -EINVAL; + goto unlock; + } + index = array_index_nospec(index, data->nr); + + if (data->nodes[index]) { + ret = -EBUSY; + goto unlock; + } + + node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER); + if (!node) { + ret = -ENOMEM; + goto unlock; + } + + /* + * blk_rq_nr_phys_segments() may overestimate the number of bvecs + * but avoids needing to iterate over the bvecs + */ + imu = io_alloc_imu(ctx, blk_rq_nr_phys_segments(rq)); + if (!imu) { + kfree(node); + ret = -ENOMEM; + goto unlock; + } + + imu->ubuf = 0; + imu->len = blk_rq_bytes(rq); + imu->acct_pages = 0; + imu->folio_shift = PAGE_SHIFT; + refcount_set(&imu->refs, 1); + imu->release = release; + imu->priv = rq; + imu->is_kbuf = true; + imu->dir = 1 << rq_data_dir(rq); + + rq_for_each_bvec(bv, rq, rq_iter) + imu->bvec[nr_bvecs++] = bv; + imu->nr_bvecs = nr_bvecs; + + node->buf = imu; + data->nodes[index] = node; +unlock: + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} +EXPORT_SYMBOL_GPL(io_buffer_register_bvec); + +int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index, + unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx; + struct io_rsrc_data *data = &ctx->buf_table; + struct io_rsrc_node *node; + int ret = 0; + + io_ring_submit_lock(ctx, issue_flags); + if (index >= data->nr) { + ret = -EINVAL; + goto unlock; + } + index = array_index_nospec(index, data->nr); + + node = data->nodes[index]; + if (!node) { + ret = -EINVAL; + goto unlock; + } + if (!node->buf->is_kbuf) { + ret = -EBUSY; + goto unlock; + } + + io_put_rsrc_node(ctx, node); + data->nodes[index] = NULL; +unlock: + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} +EXPORT_SYMBOL_GPL(io_buffer_unregister_bvec); + +static int validate_fixed_range(u64 buf_addr, size_t len, + const struct io_mapped_ubuf *imu) +{ + u64 buf_end; + + if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end))) + return -EFAULT; + /* not inside the mapped region */ + if (unlikely(buf_addr < imu->ubuf || buf_end > (imu->ubuf + imu->len))) + return -EFAULT; + if (unlikely(len > MAX_RW_COUNT)) + return -EFAULT; + return 0; +} + +static int io_import_kbuf(int ddir, struct iov_iter *iter, + struct io_mapped_ubuf *imu, size_t len, size_t offset) +{ + size_t count = len + offset; + + iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, count); + iov_iter_advance(iter, offset); + + if (count < imu->len) { + const struct bio_vec *bvec = iter->bvec; + + while (len > bvec->bv_len) { + len -= bvec->bv_len; + bvec++; + } + iter->nr_segs = 1 + bvec - iter->bvec; + } + return 0; +} + +static int io_import_fixed(int ddir, struct iov_iter *iter, + struct io_mapped_ubuf *imu, + u64 buf_addr, size_t len) +{ + const struct bio_vec *bvec; + size_t folio_mask; + unsigned nr_segs; + size_t offset; + int ret; + + ret = validate_fixed_range(buf_addr, len, imu); + if (unlikely(ret)) + return ret; + if (!(imu->dir & (1 << ddir))) + return -EFAULT; + + offset = buf_addr - imu->ubuf; + + if (imu->is_kbuf) + return io_import_kbuf(ddir, iter, imu, len, offset); + + /* + * Don't use iov_iter_advance() here, as it's really slow for + * using the latter parts of a big fixed buffer - it iterates + * over each segment manually. We can cheat a bit here for user + * registered nodes, because we know that: + * + * 1) it's a BVEC iter, we set it up + * 2) all bvecs are the same in size, except potentially the + * first and last bvec + */ + folio_mask = (1UL << imu->folio_shift) - 1; + bvec = imu->bvec; + if (offset >= bvec->bv_len) { + unsigned long seg_skip; + + /* skip first vec */ + offset -= bvec->bv_len; + seg_skip = 1 + (offset >> imu->folio_shift); + bvec += seg_skip; + offset &= folio_mask; + } + nr_segs = (offset + len + bvec->bv_offset + folio_mask) >> imu->folio_shift; + iov_iter_bvec(iter, ddir, bvec, nr_segs, len); + iter->iov_offset = offset; + return 0; +} + +inline struct io_rsrc_node *io_find_buf_node(struct io_kiocb *req, + unsigned issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_rsrc_node *node; + + if (req->flags & REQ_F_BUF_NODE) + return req->buf_node; + req->flags |= REQ_F_BUF_NODE; + + io_ring_submit_lock(ctx, issue_flags); + node = io_rsrc_node_lookup(&ctx->buf_table, req->buf_index); + if (node) { + node->refs++; + req->buf_node = node; + io_ring_submit_unlock(ctx, issue_flags); + return node; + } + req->flags &= ~REQ_F_BUF_NODE; + io_ring_submit_unlock(ctx, issue_flags); + return NULL; +} + +int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter, + u64 buf_addr, size_t len, int ddir, + unsigned issue_flags) +{ + struct io_rsrc_node *node; + + node = io_find_buf_node(req, issue_flags); + if (!node) + return -EFAULT; + return io_import_fixed(ddir, iter, node->buf, buf_addr, len); +} + +/* Lock two rings at once. The rings must be different! */ +static void lock_two_rings(struct io_ring_ctx *ctx1, struct io_ring_ctx *ctx2) +{ + if (ctx1 > ctx2) + swap(ctx1, ctx2); + mutex_lock(&ctx1->uring_lock); + mutex_lock_nested(&ctx2->uring_lock, SINGLE_DEPTH_NESTING); +} + +/* Both rings are locked by the caller. */ +static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx, + struct io_uring_clone_buffers *arg) +{ + struct io_rsrc_data data; + int i, ret, off, nr; + unsigned int nbufs; + + lockdep_assert_held(&ctx->uring_lock); + lockdep_assert_held(&src_ctx->uring_lock); + + /* + * Accounting state is shared between the two rings; that only works if + * both rings are accounted towards the same counters. + */ + if (ctx->user != src_ctx->user || ctx->mm_account != src_ctx->mm_account) + return -EINVAL; + + /* if offsets are given, must have nr specified too */ + if (!arg->nr && (arg->dst_off || arg->src_off)) + return -EINVAL; + /* not allowed unless REPLACE is set */ + if (ctx->buf_table.nr && !(arg->flags & IORING_REGISTER_DST_REPLACE)) + return -EBUSY; + + nbufs = src_ctx->buf_table.nr; + if (!nbufs) + return -ENXIO; + if (!arg->nr) + arg->nr = nbufs; + else if (arg->nr > nbufs) + return -EINVAL; + else if (arg->nr > IORING_MAX_REG_BUFFERS) + return -EINVAL; + if (check_add_overflow(arg->nr, arg->src_off, &off) || off > nbufs) + return -EOVERFLOW; + if (check_add_overflow(arg->nr, arg->dst_off, &nbufs)) + return -EOVERFLOW; + if (nbufs > IORING_MAX_REG_BUFFERS) + return -EINVAL; + + ret = io_rsrc_data_alloc(&data, max(nbufs, ctx->buf_table.nr)); + if (ret) + return ret; + + /* Copy original dst nodes from before the cloned range */ + for (i = 0; i < min(arg->dst_off, ctx->buf_table.nr); i++) { + struct io_rsrc_node *node = ctx->buf_table.nodes[i]; + + if (node) { + data.nodes[i] = node; + node->refs++; + } + } + + off = arg->dst_off; + i = arg->src_off; + nr = arg->nr; + while (nr--) { + struct io_rsrc_node *dst_node, *src_node; + + src_node = io_rsrc_node_lookup(&src_ctx->buf_table, i); + if (!src_node) { + dst_node = NULL; + } else { + dst_node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER); + if (!dst_node) { + io_rsrc_data_free(ctx, &data); + return -ENOMEM; + } + + refcount_inc(&src_node->buf->refs); + dst_node->buf = src_node->buf; + } + data.nodes[off++] = dst_node; + i++; + } + + /* Copy original dst nodes from after the cloned range */ + for (i = nbufs; i < ctx->buf_table.nr; i++) { + struct io_rsrc_node *node = ctx->buf_table.nodes[i]; + + if (node) { + data.nodes[i] = node; + node->refs++; + } + } + + /* + * If asked for replace, put the old table. data->nodes[] holds both + * old and new nodes at this point. + */ + if (arg->flags & IORING_REGISTER_DST_REPLACE) + io_rsrc_data_free(ctx, &ctx->buf_table); + + /* + * ctx->buf_table must be empty now - either the contents are being + * replaced and we just freed the table, or the contents are being + * copied to a ring that does not have buffers yet (checked at function + * entry). + */ + WARN_ON_ONCE(ctx->buf_table.nr); + ctx->buf_table = data; + return 0; +} + +/* + * Copy the registered buffers from the source ring whose file descriptor + * is given in the src_fd to the current ring. This is identical to registering + * the buffers with ctx, except faster as mappings already exist. + * + * Since the memory is already accounted once, don't account it again. + */ +int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg) +{ + struct io_uring_clone_buffers buf; + struct io_ring_ctx *src_ctx; + bool registered_src; + struct file *file; + int ret; + + if (copy_from_user(&buf, arg, sizeof(buf))) + return -EFAULT; + if (buf.flags & ~(IORING_REGISTER_SRC_REGISTERED|IORING_REGISTER_DST_REPLACE)) + return -EINVAL; + if (!(buf.flags & IORING_REGISTER_DST_REPLACE) && ctx->buf_table.nr) + return -EBUSY; + if (memchr_inv(buf.pad, 0, sizeof(buf.pad))) + return -EINVAL; + + registered_src = (buf.flags & IORING_REGISTER_SRC_REGISTERED) != 0; + file = io_uring_register_get_file(buf.src_fd, registered_src); + if (IS_ERR(file)) + return PTR_ERR(file); + + src_ctx = file->private_data; + if (src_ctx != ctx) { + mutex_unlock(&ctx->uring_lock); + lock_two_rings(ctx, src_ctx); + + if (src_ctx->submitter_task && + src_ctx->submitter_task != current) { + ret = -EEXIST; + goto out; + } + } + + ret = io_clone_buffers(ctx, src_ctx, &buf); + +out: + if (src_ctx != ctx) + mutex_unlock(&src_ctx->uring_lock); + + fput(file); + return ret; +} + +void io_vec_free(struct iou_vec *iv) +{ + if (!iv->iovec) + return; + kfree(iv->iovec); + iv->iovec = NULL; + iv->nr = 0; +} + +int io_vec_realloc(struct iou_vec *iv, unsigned nr_entries) +{ + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; + struct iovec *iov; + + iov = kmalloc_array(nr_entries, sizeof(iov[0]), gfp); + if (!iov) + return -ENOMEM; + + io_vec_free(iv); + iv->iovec = iov; + iv->nr = nr_entries; + return 0; +} + +static int io_vec_fill_bvec(int ddir, struct iov_iter *iter, + struct io_mapped_ubuf *imu, + struct iovec *iovec, unsigned nr_iovs, + struct iou_vec *vec) +{ + unsigned long folio_size = 1 << imu->folio_shift; + unsigned long folio_mask = folio_size - 1; + struct bio_vec *res_bvec = vec->bvec; + size_t total_len = 0; + unsigned bvec_idx = 0; + unsigned iov_idx; + + for (iov_idx = 0; iov_idx < nr_iovs; iov_idx++) { + size_t iov_len = iovec[iov_idx].iov_len; + u64 buf_addr = (u64)(uintptr_t)iovec[iov_idx].iov_base; + struct bio_vec *src_bvec; + size_t offset; + int ret; + + ret = validate_fixed_range(buf_addr, iov_len, imu); + if (unlikely(ret)) + return ret; + + if (unlikely(!iov_len)) + return -EFAULT; + if (unlikely(check_add_overflow(total_len, iov_len, &total_len))) + return -EOVERFLOW; + + offset = buf_addr - imu->ubuf; + /* + * Only the first bvec can have non zero bv_offset, account it + * here and work with full folios below. + */ + offset += imu->bvec[0].bv_offset; + + src_bvec = imu->bvec + (offset >> imu->folio_shift); + offset &= folio_mask; + + for (; iov_len; offset = 0, bvec_idx++, src_bvec++) { + size_t seg_size = min_t(size_t, iov_len, + folio_size - offset); + + bvec_set_page(&res_bvec[bvec_idx], + src_bvec->bv_page, seg_size, offset); + iov_len -= seg_size; + } + } + if (total_len > MAX_RW_COUNT) + return -EINVAL; + + iov_iter_bvec(iter, ddir, res_bvec, bvec_idx, total_len); + return 0; +} + +static int io_estimate_bvec_size(struct iovec *iov, unsigned nr_iovs, + struct io_mapped_ubuf *imu) +{ + unsigned shift = imu->folio_shift; + size_t max_segs = 0; + unsigned i; + + for (i = 0; i < nr_iovs; i++) { + max_segs += (iov[i].iov_len >> shift) + 2; + if (max_segs > INT_MAX) + return -EOVERFLOW; + } + return max_segs; +} + +static int io_vec_fill_kern_bvec(int ddir, struct iov_iter *iter, + struct io_mapped_ubuf *imu, + struct iovec *iovec, unsigned nr_iovs, + struct iou_vec *vec) +{ + const struct bio_vec *src_bvec = imu->bvec; + struct bio_vec *res_bvec = vec->bvec; + unsigned res_idx = 0; + size_t total_len = 0; + unsigned iov_idx; + + for (iov_idx = 0; iov_idx < nr_iovs; iov_idx++) { + size_t offset = (size_t)(uintptr_t)iovec[iov_idx].iov_base; + size_t iov_len = iovec[iov_idx].iov_len; + struct bvec_iter bi = { + .bi_size = offset + iov_len, + }; + struct bio_vec bv; + + bvec_iter_advance(src_bvec, &bi, offset); + for_each_mp_bvec(bv, src_bvec, bi, bi) + res_bvec[res_idx++] = bv; + total_len += iov_len; + } + iov_iter_bvec(iter, ddir, res_bvec, res_idx, total_len); + return 0; +} + +static int iov_kern_bvec_size(const struct iovec *iov, + const struct io_mapped_ubuf *imu, + unsigned int *nr_seg) +{ + size_t offset = (size_t)(uintptr_t)iov->iov_base; + const struct bio_vec *bvec = imu->bvec; + int start = 0, i = 0; + size_t off = 0; + int ret; + + ret = validate_fixed_range(offset, iov->iov_len, imu); + if (unlikely(ret)) + return ret; + + for (i = 0; off < offset + iov->iov_len && i < imu->nr_bvecs; + off += bvec[i].bv_len, i++) { + if (offset >= off && offset < off + bvec[i].bv_len) + start = i; + } + *nr_seg = i - start; + return 0; +} + +static int io_kern_bvec_size(struct iovec *iov, unsigned nr_iovs, + struct io_mapped_ubuf *imu, unsigned *nr_segs) +{ + unsigned max_segs = 0; + size_t total_len = 0; + unsigned i; + int ret; + + *nr_segs = 0; + for (i = 0; i < nr_iovs; i++) { + if (unlikely(!iov[i].iov_len)) + return -EFAULT; + if (unlikely(check_add_overflow(total_len, iov[i].iov_len, + &total_len))) + return -EOVERFLOW; + ret = iov_kern_bvec_size(&iov[i], imu, &max_segs); + if (unlikely(ret)) + return ret; + *nr_segs += max_segs; + } + if (total_len > MAX_RW_COUNT) + return -EINVAL; + return 0; +} + +int io_import_reg_vec(int ddir, struct iov_iter *iter, + struct io_kiocb *req, struct iou_vec *vec, + unsigned nr_iovs, unsigned issue_flags) +{ + struct io_rsrc_node *node; + struct io_mapped_ubuf *imu; + unsigned iovec_off; + struct iovec *iov; + unsigned nr_segs; + + node = io_find_buf_node(req, issue_flags); + if (!node) + return -EFAULT; + imu = node->buf; + if (!(imu->dir & (1 << ddir))) + return -EFAULT; + + iovec_off = vec->nr - nr_iovs; + iov = vec->iovec + iovec_off; + + if (imu->is_kbuf) { + int ret = io_kern_bvec_size(iov, nr_iovs, imu, &nr_segs); + + if (unlikely(ret)) + return ret; + } else { + int ret = io_estimate_bvec_size(iov, nr_iovs, imu); + + if (ret < 0) + return ret; + nr_segs = ret; + } + + if (sizeof(struct bio_vec) > sizeof(struct iovec)) { + size_t bvec_bytes; + + bvec_bytes = nr_segs * sizeof(struct bio_vec); + nr_segs = (bvec_bytes + sizeof(*iov) - 1) / sizeof(*iov); + nr_segs += nr_iovs; + } + + if (nr_segs > vec->nr) { + struct iou_vec tmp_vec = {}; + int ret; + + ret = io_vec_realloc(&tmp_vec, nr_segs); + if (ret) + return ret; + + iovec_off = tmp_vec.nr - nr_iovs; + memcpy(tmp_vec.iovec + iovec_off, iov, sizeof(*iov) * nr_iovs); + io_vec_free(vec); + + *vec = tmp_vec; + iov = vec->iovec + iovec_off; + req->flags |= REQ_F_NEED_CLEANUP; + } + + if (imu->is_kbuf) + return io_vec_fill_kern_bvec(ddir, iter, imu, iov, nr_iovs, vec); + + return io_vec_fill_bvec(ddir, iter, imu, iov, nr_iovs, vec); +} + +int io_prep_reg_iovec(struct io_kiocb *req, struct iou_vec *iv, + const struct iovec __user *uvec, size_t uvec_segs) +{ + struct iovec *iov; + int iovec_off, ret; + void *res; + + if (uvec_segs > iv->nr) { + ret = io_vec_realloc(iv, uvec_segs); + if (ret) + return ret; + req->flags |= REQ_F_NEED_CLEANUP; + } + + /* pad iovec to the right */ + iovec_off = iv->nr - uvec_segs; + iov = iv->iovec + iovec_off; + res = iovec_from_user(uvec, uvec_segs, uvec_segs, iov, + io_is_compat(req->ctx)); + if (IS_ERR(res)) + return PTR_ERR(res); + + req->flags |= REQ_F_IMPORT_BUFFER; + return 0; +} diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h new file mode 100644 index 000000000000..d603f6a47f5e --- /dev/null +++ b/io_uring/rsrc.h @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_RSRC_H +#define IOU_RSRC_H + +#include <linux/io_uring_types.h> +#include <linux/lockdep.h> + +#define IO_VEC_CACHE_SOFT_CAP 256 + +enum { + IORING_RSRC_FILE = 0, + IORING_RSRC_BUFFER = 1, +}; + +struct io_rsrc_node { + unsigned char type; + int refs; + + u64 tag; + union { + unsigned long file_ptr; + struct io_mapped_ubuf *buf; + }; +}; + +enum { + IO_IMU_DEST = 1 << ITER_DEST, + IO_IMU_SOURCE = 1 << ITER_SOURCE, +}; + +struct io_mapped_ubuf { + u64 ubuf; + unsigned int len; + unsigned int nr_bvecs; + unsigned int folio_shift; + refcount_t refs; + unsigned long acct_pages; + void (*release)(void *); + void *priv; + bool is_kbuf; + u8 dir; + struct bio_vec bvec[] __counted_by(nr_bvecs); +}; + +struct io_imu_folio_data { + /* Head folio can be partially included in the fixed buf */ + unsigned int nr_pages_head; + /* For non-head/tail folios, has to be fully included */ + unsigned int nr_pages_mid; + unsigned int folio_shift; + unsigned int nr_folios; + unsigned long first_folio_page_idx; +}; + +bool io_rsrc_cache_init(struct io_ring_ctx *ctx); +void io_rsrc_cache_free(struct io_ring_ctx *ctx); +struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx, int type); +void io_free_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node); +void io_rsrc_data_free(struct io_ring_ctx *ctx, struct io_rsrc_data *data); +int io_rsrc_data_alloc(struct io_rsrc_data *data, unsigned nr); + +struct io_rsrc_node *io_find_buf_node(struct io_kiocb *req, + unsigned issue_flags); +int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter, + u64 buf_addr, size_t len, int ddir, + unsigned issue_flags); +int io_import_reg_vec(int ddir, struct iov_iter *iter, + struct io_kiocb *req, struct iou_vec *vec, + unsigned nr_iovs, unsigned issue_flags); +int io_prep_reg_iovec(struct io_kiocb *req, struct iou_vec *iv, + const struct iovec __user *uvec, size_t uvec_segs); + +int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg); +int io_sqe_buffers_unregister(struct io_ring_ctx *ctx); +int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned int nr_args, u64 __user *tags); +int io_sqe_files_unregister(struct io_ring_ctx *ctx); +int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args, u64 __user *tags); + +int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args); +int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned size, unsigned type); +int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, + unsigned int size, unsigned int type); +int io_validate_user_buf_range(u64 uaddr, u64 ulen); + +bool io_check_coalesce_buffer(struct page **page_array, int nr_pages, + struct io_imu_folio_data *data); + +static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data, + int index) +{ + if (index < data->nr) + return data->nodes[array_index_nospec(index, data->nr)]; + return NULL; +} + +static inline void io_put_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node) +{ + lockdep_assert_held(&ctx->uring_lock); + if (!--node->refs) + io_free_rsrc_node(ctx, node); +} + +static inline bool io_reset_rsrc_node(struct io_ring_ctx *ctx, + struct io_rsrc_data *data, int index) +{ + struct io_rsrc_node *node = data->nodes[index]; + + if (!node) + return false; + io_put_rsrc_node(ctx, node); + data->nodes[index] = NULL; + return true; +} + +int io_files_update(struct io_kiocb *req, unsigned int issue_flags); +int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); + +int __io_account_mem(struct user_struct *user, unsigned long nr_pages); +int io_account_mem(struct user_struct *user, struct mm_struct *mm_account, + unsigned long nr_pages); +void io_unaccount_mem(struct user_struct *user, struct mm_struct *mm_account, + unsigned long nr_pages); + +static inline void __io_unaccount_mem(struct user_struct *user, + unsigned long nr_pages) +{ + atomic_long_sub(nr_pages, &user->locked_vm); +} + +void io_vec_free(struct iou_vec *iv); +int io_vec_realloc(struct iou_vec *iv, unsigned nr_entries); + +static inline void io_vec_reset_iovec(struct iou_vec *iv, + struct iovec *iovec, unsigned nr) +{ + io_vec_free(iv); + iv->iovec = iovec; + iv->nr = nr; +} + +static inline void io_alloc_cache_vec_kasan(struct iou_vec *iv) +{ + if (IS_ENABLED(CONFIG_KASAN)) + io_vec_free(iv); +} + +#endif diff --git a/io_uring/rw.c b/io_uring/rw.c new file mode 100644 index 000000000000..70ca88cc1f54 --- /dev/null +++ b/io_uring/rw.c @@ -0,0 +1,1394 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/blk-mq.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/fsnotify.h> +#include <linux/poll.h> +#include <linux/nospec.h> +#include <linux/compat.h> +#include <linux/io_uring/cmd.h> +#include <linux/indirect_call_wrapper.h> + +#include <uapi/linux/io_uring.h> + +#include "filetable.h" +#include "io_uring.h" +#include "opdef.h" +#include "kbuf.h" +#include "alloc_cache.h" +#include "rsrc.h" +#include "poll.h" +#include "rw.h" + +static void io_complete_rw(struct kiocb *kiocb, long res); +static void io_complete_rw_iopoll(struct kiocb *kiocb, long res); + +struct io_rw { + /* NOTE: kiocb has the file as the first member, so don't do it here */ + struct kiocb kiocb; + u64 addr; + u32 len; + rwf_t flags; +}; + +static bool io_file_supports_nowait(struct io_kiocb *req, __poll_t mask) +{ + /* If FMODE_NOWAIT is set for a file, we're golden */ + if (req->flags & REQ_F_SUPPORT_NOWAIT) + return true; + /* No FMODE_NOWAIT, if we can poll, check the status */ + if (io_file_can_poll(req)) { + struct poll_table_struct pt = { ._key = mask }; + + return vfs_poll(req->file, &pt) & mask; + } + /* No FMODE_NOWAIT support, and file isn't pollable. Tough luck. */ + return false; +} + +static int io_iov_compat_buffer_select_prep(struct io_rw *rw) +{ + struct compat_iovec __user *uiov = u64_to_user_ptr(rw->addr); + struct compat_iovec iov; + + if (copy_from_user(&iov, uiov, sizeof(iov))) + return -EFAULT; + rw->len = iov.iov_len; + return 0; +} + +static int io_iov_buffer_select_prep(struct io_kiocb *req) +{ + struct iovec __user *uiov; + struct iovec iov; + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + + if (rw->len != 1) + return -EINVAL; + + if (io_is_compat(req->ctx)) + return io_iov_compat_buffer_select_prep(rw); + + uiov = u64_to_user_ptr(rw->addr); + if (copy_from_user(&iov, uiov, sizeof(*uiov))) + return -EFAULT; + rw->len = iov.iov_len; + return 0; +} + +static int io_import_vec(int ddir, struct io_kiocb *req, + struct io_async_rw *io, + const struct iovec __user *uvec, + size_t uvec_segs) +{ + int ret, nr_segs; + struct iovec *iov; + + if (io->vec.iovec) { + nr_segs = io->vec.nr; + iov = io->vec.iovec; + } else { + nr_segs = 1; + iov = &io->fast_iov; + } + + ret = __import_iovec(ddir, uvec, uvec_segs, nr_segs, &iov, &io->iter, + io_is_compat(req->ctx)); + if (unlikely(ret < 0)) + return ret; + if (iov) { + req->flags |= REQ_F_NEED_CLEANUP; + io_vec_reset_iovec(&io->vec, iov, io->iter.nr_segs); + } + return 0; +} + +static int __io_import_rw_buffer(int ddir, struct io_kiocb *req, + struct io_async_rw *io, struct io_br_sel *sel, + unsigned int issue_flags) +{ + const struct io_issue_def *def = &io_issue_defs[req->opcode]; + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + size_t sqe_len = rw->len; + + sel->addr = u64_to_user_ptr(rw->addr); + if (def->vectored && !(req->flags & REQ_F_BUFFER_SELECT)) + return io_import_vec(ddir, req, io, sel->addr, sqe_len); + + if (io_do_buffer_select(req)) { + *sel = io_buffer_select(req, &sqe_len, io->buf_group, issue_flags); + if (!sel->addr) + return -ENOBUFS; + rw->addr = (unsigned long) sel->addr; + rw->len = sqe_len; + } + return import_ubuf(ddir, sel->addr, sqe_len, &io->iter); +} + +static inline int io_import_rw_buffer(int rw, struct io_kiocb *req, + struct io_async_rw *io, + struct io_br_sel *sel, + unsigned int issue_flags) +{ + int ret; + + ret = __io_import_rw_buffer(rw, req, io, sel, issue_flags); + if (unlikely(ret < 0)) + return ret; + + iov_iter_save_state(&io->iter, &io->iter_state); + return 0; +} + +static void io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_async_rw *rw = req->async_data; + + if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) + return; + + io_alloc_cache_vec_kasan(&rw->vec); + if (rw->vec.nr > IO_VEC_CACHE_SOFT_CAP) + io_vec_free(&rw->vec); + + if (io_alloc_cache_put(&req->ctx->rw_cache, rw)) + io_req_async_data_clear(req, 0); +} + +static void io_req_rw_cleanup(struct io_kiocb *req, unsigned int issue_flags) +{ + /* + * Disable quick recycling for anything that's gone through io-wq. + * In theory, this should be fine to cleanup. However, some read or + * write iter handling touches the iovec AFTER having called into the + * handler, eg to reexpand or revert. This means we can have: + * + * task io-wq + * issue + * punt to io-wq + * issue + * blkdev_write_iter() + * ->ki_complete() + * io_complete_rw() + * queue tw complete + * run tw + * req_rw_cleanup + * iov_iter_count() <- look at iov_iter again + * + * which can lead to a UAF. This is only possible for io-wq offload + * as the cleanup can run in parallel. As io-wq is not the fast path, + * just leave cleanup to the end. + * + * This is really a bug in the core code that does this, any issue + * path should assume that a successful (or -EIOCBQUEUED) return can + * mean that the underlying data can be gone at any time. But that + * should be fixed separately, and then this check could be killed. + */ + if (!(req->flags & (REQ_F_REISSUE | REQ_F_REFCOUNT))) { + req->flags &= ~REQ_F_NEED_CLEANUP; + io_rw_recycle(req, issue_flags); + } +} + +static int io_rw_alloc_async(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_async_rw *rw; + + rw = io_uring_alloc_async_data(&ctx->rw_cache, req); + if (!rw) + return -ENOMEM; + if (rw->vec.iovec) + req->flags |= REQ_F_NEED_CLEANUP; + rw->bytes_done = 0; + return 0; +} + +static inline void io_meta_save_state(struct io_async_rw *io) +{ + io->meta_state.seed = io->meta.seed; + iov_iter_save_state(&io->meta.iter, &io->meta_state.iter_meta); +} + +static inline void io_meta_restore(struct io_async_rw *io, struct kiocb *kiocb) +{ + if (kiocb->ki_flags & IOCB_HAS_METADATA) { + io->meta.seed = io->meta_state.seed; + iov_iter_restore(&io->meta.iter, &io->meta_state.iter_meta); + } +} + +static int io_prep_rw_pi(struct io_kiocb *req, struct io_rw *rw, int ddir, + u64 attr_ptr, u64 attr_type_mask) +{ + struct io_uring_attr_pi pi_attr; + struct io_async_rw *io; + int ret; + + if (copy_from_user(&pi_attr, u64_to_user_ptr(attr_ptr), + sizeof(pi_attr))) + return -EFAULT; + + if (pi_attr.rsvd) + return -EINVAL; + + io = req->async_data; + io->meta.flags = pi_attr.flags; + io->meta.app_tag = pi_attr.app_tag; + io->meta.seed = pi_attr.seed; + ret = import_ubuf(ddir, u64_to_user_ptr(pi_attr.addr), + pi_attr.len, &io->meta.iter); + if (unlikely(ret < 0)) + return ret; + req->flags |= REQ_F_HAS_METADATA; + io_meta_save_state(io); + return ret; +} + +static int __io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, + int ddir) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct io_async_rw *io; + unsigned ioprio; + u64 attr_type_mask; + int ret; + + if (io_rw_alloc_async(req)) + return -ENOMEM; + io = req->async_data; + + rw->kiocb.ki_pos = READ_ONCE(sqe->off); + /* used for fixed read/write too - just read unconditionally */ + req->buf_index = READ_ONCE(sqe->buf_index); + io->buf_group = req->buf_index; + + ioprio = READ_ONCE(sqe->ioprio); + if (ioprio) { + ret = ioprio_check_cap(ioprio); + if (ret) + return ret; + + rw->kiocb.ki_ioprio = ioprio; + } else { + rw->kiocb.ki_ioprio = get_current_ioprio(); + } + rw->kiocb.ki_flags = 0; + rw->kiocb.ki_write_stream = READ_ONCE(sqe->write_stream); + + if (req->ctx->flags & IORING_SETUP_IOPOLL) + rw->kiocb.ki_complete = io_complete_rw_iopoll; + else + rw->kiocb.ki_complete = io_complete_rw; + + rw->addr = READ_ONCE(sqe->addr); + rw->len = READ_ONCE(sqe->len); + rw->flags = (__force rwf_t) READ_ONCE(sqe->rw_flags); + + attr_type_mask = READ_ONCE(sqe->attr_type_mask); + if (attr_type_mask) { + u64 attr_ptr; + + /* only PI attribute is supported currently */ + if (attr_type_mask != IORING_RW_ATTR_FLAG_PI) + return -EINVAL; + + attr_ptr = READ_ONCE(sqe->attr_ptr); + return io_prep_rw_pi(req, rw, ddir, attr_ptr, attr_type_mask); + } + return 0; +} + +static int io_rw_do_import(struct io_kiocb *req, int ddir) +{ + struct io_br_sel sel = { }; + + if (io_do_buffer_select(req)) + return 0; + + return io_import_rw_buffer(ddir, req, req->async_data, &sel, 0); +} + +static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, + int ddir) +{ + int ret; + + ret = __io_prep_rw(req, sqe, ddir); + if (unlikely(ret)) + return ret; + + return io_rw_do_import(req, ddir); +} + +int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return io_prep_rw(req, sqe, ITER_DEST); +} + +int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return io_prep_rw(req, sqe, ITER_SOURCE); +} + +static int io_prep_rwv(struct io_kiocb *req, const struct io_uring_sqe *sqe, + int ddir) +{ + int ret; + + ret = io_prep_rw(req, sqe, ddir); + if (unlikely(ret)) + return ret; + if (!(req->flags & REQ_F_BUFFER_SELECT)) + return 0; + + /* + * Have to do this validation here, as this is in io_read() rw->len + * might have changed due to buffer selection + */ + return io_iov_buffer_select_prep(req); +} + +int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return io_prep_rwv(req, sqe, ITER_DEST); +} + +int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return io_prep_rwv(req, sqe, ITER_SOURCE); +} + +static int io_init_rw_fixed(struct io_kiocb *req, unsigned int issue_flags, + int ddir) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct io_async_rw *io = req->async_data; + int ret; + + if (io->bytes_done) + return 0; + + ret = io_import_reg_buf(req, &io->iter, rw->addr, rw->len, ddir, + issue_flags); + iov_iter_save_state(&io->iter, &io->iter_state); + return ret; +} + +int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_prep_rw(req, sqe, ITER_DEST); +} + +int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_prep_rw(req, sqe, ITER_SOURCE); +} + +static int io_rw_import_reg_vec(struct io_kiocb *req, + struct io_async_rw *io, + int ddir, unsigned int issue_flags) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + unsigned uvec_segs = rw->len; + int ret; + + ret = io_import_reg_vec(ddir, &io->iter, req, &io->vec, + uvec_segs, issue_flags); + if (unlikely(ret)) + return ret; + iov_iter_save_state(&io->iter, &io->iter_state); + req->flags &= ~REQ_F_IMPORT_BUFFER; + return 0; +} + +static int io_rw_prep_reg_vec(struct io_kiocb *req) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct io_async_rw *io = req->async_data; + const struct iovec __user *uvec; + + uvec = u64_to_user_ptr(rw->addr); + return io_prep_reg_iovec(req, &io->vec, uvec, rw->len); +} + +int io_prep_readv_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + int ret; + + ret = __io_prep_rw(req, sqe, ITER_DEST); + if (unlikely(ret)) + return ret; + return io_rw_prep_reg_vec(req); +} + +int io_prep_writev_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + int ret; + + ret = __io_prep_rw(req, sqe, ITER_SOURCE); + if (unlikely(ret)) + return ret; + return io_rw_prep_reg_vec(req); +} + +/* + * Multishot read is prepared just like a normal read/write request, only + * difference is that we set the MULTISHOT flag. + */ +int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + int ret; + + /* must be used with provided buffers */ + if (!(req->flags & REQ_F_BUFFER_SELECT)) + return -EINVAL; + + ret = __io_prep_rw(req, sqe, ITER_DEST); + if (unlikely(ret)) + return ret; + + if (rw->addr || rw->len) + return -EINVAL; + + req->flags |= REQ_F_APOLL_MULTISHOT; + return 0; +} + +void io_readv_writev_cleanup(struct io_kiocb *req) +{ + struct io_async_rw *rw = req->async_data; + + lockdep_assert_held(&req->ctx->uring_lock); + io_vec_free(&rw->vec); + io_rw_recycle(req, 0); +} + +static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + + if (rw->kiocb.ki_pos != -1) + return &rw->kiocb.ki_pos; + + if (!(req->file->f_mode & FMODE_STREAM)) { + req->flags |= REQ_F_CUR_POS; + rw->kiocb.ki_pos = req->file->f_pos; + return &rw->kiocb.ki_pos; + } + + rw->kiocb.ki_pos = 0; + return NULL; +} + +static bool io_rw_should_reissue(struct io_kiocb *req) +{ +#ifdef CONFIG_BLOCK + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + umode_t mode = file_inode(req->file)->i_mode; + struct io_async_rw *io = req->async_data; + struct io_ring_ctx *ctx = req->ctx; + + if (!S_ISBLK(mode) && !S_ISREG(mode)) + return false; + if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() && + !(ctx->flags & IORING_SETUP_IOPOLL))) + return false; + /* + * If ref is dying, we might be running poll reap from the exit work. + * Don't attempt to reissue from that path, just let it fail with + * -EAGAIN. + */ + if (percpu_ref_is_dying(&ctx->refs)) + return false; + + io_meta_restore(io, &rw->kiocb); + iov_iter_restore(&io->iter, &io->iter_state); + return true; +#else + return false; +#endif +} + +static void io_req_end_write(struct io_kiocb *req) +{ + if (req->flags & REQ_F_ISREG) { + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + + kiocb_end_write(&rw->kiocb); + } +} + +/* + * Trigger the notifications after having done some IO, and finish the write + * accounting, if any. + */ +static void io_req_io_end(struct io_kiocb *req) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + + if (rw->kiocb.ki_flags & IOCB_WRITE) { + io_req_end_write(req); + fsnotify_modify(req->file); + } else { + fsnotify_access(req->file); + } +} + +static void __io_complete_rw_common(struct io_kiocb *req, long res) +{ + if (res == req->cqe.res) + return; + if ((res == -EOPNOTSUPP || res == -EAGAIN) && io_rw_should_reissue(req)) { + req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE; + } else { + req_set_fail(req); + req->cqe.res = res; + } +} + +static inline int io_fixup_rw_res(struct io_kiocb *req, long res) +{ + struct io_async_rw *io = req->async_data; + + /* add previously done IO, if any */ + if (req_has_async_data(req) && io->bytes_done > 0) { + if (res < 0) + res = io->bytes_done; + else + res += io->bytes_done; + } + return res; +} + +void io_req_rw_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + + io_req_io_end(req); + + if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) + req->cqe.flags |= io_put_kbuf(req, req->cqe.res, NULL); + + io_req_rw_cleanup(req, 0); + io_req_task_complete(tw_req, tw); +} + +static void io_complete_rw(struct kiocb *kiocb, long res) +{ + struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); + struct io_kiocb *req = cmd_to_io_kiocb(rw); + + __io_complete_rw_common(req, res); + io_req_set_res(req, io_fixup_rw_res(req, res), 0); + req->io_task_work.func = io_req_rw_complete; + __io_req_task_work_add(req, IOU_F_TWQ_LAZY_WAKE); +} + +static void io_complete_rw_iopoll(struct kiocb *kiocb, long res) +{ + struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); + struct io_kiocb *req = cmd_to_io_kiocb(rw); + + if (kiocb->ki_flags & IOCB_WRITE) + io_req_end_write(req); + if (unlikely(res != req->cqe.res)) { + if (res == -EAGAIN && io_rw_should_reissue(req)) + req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE; + else + req->cqe.res = res; + } + + /* order with io_iopoll_complete() checking ->iopoll_completed */ + smp_store_release(&req->iopoll_completed, 1); +} + +static inline void io_rw_done(struct io_kiocb *req, ssize_t ret) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + + /* IO was queued async, completion will happen later */ + if (ret == -EIOCBQUEUED) + return; + + /* transform internal restart error codes */ + if (unlikely(ret < 0)) { + switch (ret) { + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* + * We can't just restart the syscall, since previously + * submitted sqes may already be in progress. Just fail + * this IO with EINTR. + */ + ret = -EINTR; + break; + } + } + + if (req->ctx->flags & IORING_SETUP_IOPOLL) + io_complete_rw_iopoll(&rw->kiocb, ret); + else + io_complete_rw(&rw->kiocb, ret); +} + +static int kiocb_done(struct io_kiocb *req, ssize_t ret, + struct io_br_sel *sel, unsigned int issue_flags) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + unsigned final_ret = io_fixup_rw_res(req, ret); + + if (ret >= 0 && req->flags & REQ_F_CUR_POS) + req->file->f_pos = rw->kiocb.ki_pos; + if (ret >= 0 && !(req->ctx->flags & IORING_SETUP_IOPOLL)) { + u32 cflags = 0; + + __io_complete_rw_common(req, ret); + /* + * Safe to call io_end from here as we're inline + * from the submission path. + */ + io_req_io_end(req); + if (sel) + cflags = io_put_kbuf(req, ret, sel->buf_list); + io_req_set_res(req, final_ret, cflags); + io_req_rw_cleanup(req, issue_flags); + return IOU_COMPLETE; + } else { + io_rw_done(req, ret); + } + + return IOU_ISSUE_SKIP_COMPLETE; +} + +static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) +{ + return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos; +} + +/* + * For files that don't have ->read_iter() and ->write_iter(), handle them + * by looping over ->read() or ->write() manually. + */ +static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter) +{ + struct io_kiocb *req = cmd_to_io_kiocb(rw); + struct kiocb *kiocb = &rw->kiocb; + struct file *file = kiocb->ki_filp; + ssize_t ret = 0; + loff_t *ppos; + + /* + * Don't support polled IO through this interface, and we can't + * support non-blocking either. For the latter, this just causes + * the kiocb to be handled from an async context. + */ + if (kiocb->ki_flags & IOCB_HIPRI) + return -EOPNOTSUPP; + if ((kiocb->ki_flags & IOCB_NOWAIT) && + !(kiocb->ki_filp->f_flags & O_NONBLOCK)) + return -EAGAIN; + if ((req->flags & REQ_F_BUF_NODE) && req->buf_node->buf->is_kbuf) + return -EFAULT; + + ppos = io_kiocb_ppos(kiocb); + + while (iov_iter_count(iter)) { + void __user *addr; + size_t len; + ssize_t nr; + + if (iter_is_ubuf(iter)) { + addr = iter->ubuf + iter->iov_offset; + len = iov_iter_count(iter); + } else if (!iov_iter_is_bvec(iter)) { + addr = iter_iov_addr(iter); + len = iter_iov_len(iter); + } else { + addr = u64_to_user_ptr(rw->addr); + len = rw->len; + } + + if (ddir == READ) + nr = file->f_op->read(file, addr, len, ppos); + else + nr = file->f_op->write(file, addr, len, ppos); + + if (nr < 0) { + if (!ret) + ret = nr; + break; + } + ret += nr; + if (!iov_iter_is_bvec(iter)) { + iov_iter_advance(iter, nr); + } else { + rw->addr += nr; + rw->len -= nr; + if (!rw->len) + break; + } + if (nr != len) + break; + } + + return ret; +} + +/* + * This is our waitqueue callback handler, registered through __folio_lock_async() + * when we initially tried to do the IO with the iocb armed our waitqueue. + * This gets called when the page is unlocked, and we generally expect that to + * happen when the page IO is completed and the page is now uptodate. This will + * queue a task_work based retry of the operation, attempting to copy the data + * again. If the latter fails because the page was NOT uptodate, then we will + * do a thread based blocking retry of the operation. That's the unexpected + * slow path. + */ +static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, + int sync, void *arg) +{ + struct wait_page_queue *wpq; + struct io_kiocb *req = wait->private; + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct wait_page_key *key = arg; + + wpq = container_of(wait, struct wait_page_queue, wait); + + if (!wake_page_match(wpq, key)) + return 0; + + rw->kiocb.ki_flags &= ~IOCB_WAITQ; + list_del_init(&wait->entry); + io_req_task_queue(req); + return 1; +} + +/* + * This controls whether a given IO request should be armed for async page + * based retry. If we return false here, the request is handed to the async + * worker threads for retry. If we're doing buffered reads on a regular file, + * we prepare a private wait_page_queue entry and retry the operation. This + * will either succeed because the page is now uptodate and unlocked, or it + * will register a callback when the page is unlocked at IO completion. Through + * that callback, io_uring uses task_work to setup a retry of the operation. + * That retry will attempt the buffered read again. The retry will generally + * succeed, or in rare cases where it fails, we then fall back to using the + * async worker threads for a blocking retry. + */ +static bool io_rw_should_retry(struct io_kiocb *req) +{ + struct io_async_rw *io = req->async_data; + struct wait_page_queue *wait = &io->wpq; + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct kiocb *kiocb = &rw->kiocb; + + /* + * Never retry for NOWAIT or a request with metadata, we just complete + * with -EAGAIN. + */ + if (req->flags & (REQ_F_NOWAIT | REQ_F_HAS_METADATA)) + return false; + + /* Only for buffered IO */ + if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI)) + return false; + + /* + * just use poll if we can, and don't attempt if the fs doesn't + * support callback based unlocks + */ + if (io_file_can_poll(req) || + !(req->file->f_op->fop_flags & FOP_BUFFER_RASYNC)) + return false; + + wait->wait.func = io_async_buf_func; + wait->wait.private = req; + wait->wait.flags = 0; + INIT_LIST_HEAD(&wait->wait.entry); + kiocb->ki_flags |= IOCB_WAITQ; + kiocb->ki_flags &= ~IOCB_NOWAIT; + kiocb->ki_waitq = wait; + return true; +} + +static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter) +{ + struct file *file = rw->kiocb.ki_filp; + + if (likely(file->f_op->read_iter)) + return file->f_op->read_iter(&rw->kiocb, iter); + else if (file->f_op->read) + return loop_rw_iter(READ, rw, iter); + else + return -EINVAL; +} + +static bool need_complete_io(struct io_kiocb *req) +{ + return req->flags & REQ_F_ISREG || + S_ISBLK(file_inode(req->file)->i_mode); +} + +static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct kiocb *kiocb = &rw->kiocb; + struct io_ring_ctx *ctx = req->ctx; + struct file *file = req->file; + int ret; + + if (unlikely(!(file->f_mode & mode))) + return -EBADF; + + if (!(req->flags & REQ_F_FIXED_FILE)) + req->flags |= io_file_get_flags(file); + + kiocb->ki_flags = file->f_iocb_flags; + ret = kiocb_set_rw_flags(kiocb, rw->flags, rw_type); + if (unlikely(ret)) + return ret; + + /* + * If the file is marked O_NONBLOCK, still allow retry for it if it + * supports async. Otherwise it's impossible to use O_NONBLOCK files + * reliably. If not, or it IOCB_NOWAIT is set, don't retry. + */ + if (kiocb->ki_flags & IOCB_NOWAIT || + ((file->f_flags & O_NONBLOCK && !(req->flags & REQ_F_SUPPORT_NOWAIT)))) + req->flags |= REQ_F_NOWAIT; + + if (ctx->flags & IORING_SETUP_IOPOLL) { + if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll) + return -EOPNOTSUPP; + kiocb->private = NULL; + kiocb->ki_flags |= IOCB_HIPRI; + req->iopoll_completed = 0; + if (ctx->flags & IORING_SETUP_HYBRID_IOPOLL) { + /* make sure every req only blocks once*/ + req->flags &= ~REQ_F_IOPOLL_STATE; + req->iopoll_start = ktime_get_ns(); + } + } else { + if (kiocb->ki_flags & IOCB_HIPRI) + return -EINVAL; + } + + if (req->flags & REQ_F_HAS_METADATA) { + struct io_async_rw *io = req->async_data; + + if (!(file->f_mode & FMODE_HAS_METADATA)) + return -EINVAL; + + /* + * We have a union of meta fields with wpq used for buffered-io + * in io_async_rw, so fail it here. + */ + if (!(req->file->f_flags & O_DIRECT)) + return -EOPNOTSUPP; + kiocb->ki_flags |= IOCB_HAS_METADATA; + kiocb->private = &io->meta; + } + + return 0; +} + +static int __io_read(struct io_kiocb *req, struct io_br_sel *sel, + unsigned int issue_flags) +{ + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct io_async_rw *io = req->async_data; + struct kiocb *kiocb = &rw->kiocb; + ssize_t ret; + loff_t *ppos; + + if (req->flags & REQ_F_IMPORT_BUFFER) { + ret = io_rw_import_reg_vec(req, io, ITER_DEST, issue_flags); + if (unlikely(ret)) + return ret; + } else if (io_do_buffer_select(req)) { + ret = io_import_rw_buffer(ITER_DEST, req, io, sel, issue_flags); + if (unlikely(ret < 0)) + return ret; + } + ret = io_rw_init_file(req, FMODE_READ, READ); + if (unlikely(ret)) + return ret; + req->cqe.res = iov_iter_count(&io->iter); + + if (force_nonblock) { + /* If the file doesn't support async, just async punt */ + if (unlikely(!io_file_supports_nowait(req, EPOLLIN))) + return -EAGAIN; + kiocb->ki_flags |= IOCB_NOWAIT; + } else { + /* Ensure we clear previously set non-block flag */ + kiocb->ki_flags &= ~IOCB_NOWAIT; + } + + ppos = io_kiocb_update_pos(req); + + ret = rw_verify_area(READ, req->file, ppos, req->cqe.res); + if (unlikely(ret)) + return ret; + + ret = io_iter_do_read(rw, &io->iter); + + /* + * Some file systems like to return -EOPNOTSUPP for an IOCB_NOWAIT + * issue, even though they should be returning -EAGAIN. To be safe, + * retry from blocking context for either. + */ + if (ret == -EOPNOTSUPP && force_nonblock) + ret = -EAGAIN; + + if (ret == -EAGAIN) { + /* If we can poll, just do that. */ + if (io_file_can_poll(req)) + return -EAGAIN; + /* IOPOLL retry should happen for io-wq threads */ + if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) + goto done; + /* no retry on NONBLOCK nor RWF_NOWAIT */ + if (req->flags & REQ_F_NOWAIT) + goto done; + ret = 0; + } else if (ret == -EIOCBQUEUED) { + return IOU_ISSUE_SKIP_COMPLETE; + } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock || + (req->flags & REQ_F_NOWAIT) || !need_complete_io(req) || + (issue_flags & IO_URING_F_MULTISHOT)) { + /* read all, failed, already did sync or don't want to retry */ + goto done; + } + + /* + * Don't depend on the iter state matching what was consumed, or being + * untouched in case of error. Restore it and we'll advance it + * manually if we need to. + */ + iov_iter_restore(&io->iter, &io->iter_state); + io_meta_restore(io, kiocb); + + do { + /* + * We end up here because of a partial read, either from + * above or inside this loop. Advance the iter by the bytes + * that were consumed. + */ + iov_iter_advance(&io->iter, ret); + if (!iov_iter_count(&io->iter)) + break; + io->bytes_done += ret; + iov_iter_save_state(&io->iter, &io->iter_state); + + /* if we can retry, do so with the callbacks armed */ + if (!io_rw_should_retry(req)) { + kiocb->ki_flags &= ~IOCB_WAITQ; + return -EAGAIN; + } + + req->cqe.res = iov_iter_count(&io->iter); + /* + * Now retry read with the IOCB_WAITQ parts set in the iocb. If + * we get -EIOCBQUEUED, then we'll get a notification when the + * desired page gets unlocked. We can also get a partial read + * here, and if we do, then just retry at the new offset. + */ + ret = io_iter_do_read(rw, &io->iter); + if (ret == -EIOCBQUEUED) + return IOU_ISSUE_SKIP_COMPLETE; + /* we got some bytes, but not all. retry. */ + kiocb->ki_flags &= ~IOCB_WAITQ; + iov_iter_restore(&io->iter, &io->iter_state); + } while (ret > 0); +done: + /* it's faster to check here than delegate to kfree */ + return ret; +} + +int io_read(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_br_sel sel = { }; + int ret; + + ret = __io_read(req, &sel, issue_flags); + if (ret >= 0) + return kiocb_done(req, ret, &sel, issue_flags); + + if (req->flags & REQ_F_BUFFERS_COMMIT) + io_kbuf_recycle(req, sel.buf_list, issue_flags); + return ret; +} + +int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct io_br_sel sel = { }; + unsigned int cflags = 0; + int ret; + + /* + * Multishot MUST be used on a pollable file + */ + if (!io_file_can_poll(req)) + return -EBADFD; + + /* make it sync, multishot doesn't support async execution */ + rw->kiocb.ki_complete = NULL; + ret = __io_read(req, &sel, issue_flags); + + /* + * If we get -EAGAIN, recycle our buffer and just let normal poll + * handling arm it. + */ + if (ret == -EAGAIN) { + /* + * Reset rw->len to 0 again to avoid clamping future mshot + * reads, in case the buffer size varies. + */ + if (io_kbuf_recycle(req, sel.buf_list, issue_flags)) + rw->len = 0; + return IOU_RETRY; + } else if (ret <= 0) { + io_kbuf_recycle(req, sel.buf_list, issue_flags); + if (ret < 0) + req_set_fail(req); + } else if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { + cflags = io_put_kbuf(req, ret, sel.buf_list); + } else { + /* + * Any successful return value will keep the multishot read + * armed, if it's still set. Put our buffer and post a CQE. If + * we fail to post a CQE, or multishot is no longer set, then + * jump to the termination path. This request is then done. + */ + cflags = io_put_kbuf(req, ret, sel.buf_list); + rw->len = 0; /* similarly to above, reset len to 0 */ + + if (io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) { + if (issue_flags & IO_URING_F_MULTISHOT) + /* + * Force retry, as we might have more data to + * be read and otherwise it won't get retried + * until (if ever) another poll is triggered. + */ + io_poll_multishot_retry(req); + + return IOU_RETRY; + } + } + + /* + * Either an error, or we've hit overflow posting the CQE. For any + * multishot request, hitting overflow will terminate it. + */ + io_req_set_res(req, ret, cflags); + io_req_rw_cleanup(req, issue_flags); + return IOU_COMPLETE; +} + +static bool io_kiocb_start_write(struct io_kiocb *req, struct kiocb *kiocb) +{ + struct inode *inode; + bool ret; + + if (!(req->flags & REQ_F_ISREG)) + return true; + if (!(kiocb->ki_flags & IOCB_NOWAIT)) { + kiocb_start_write(kiocb); + return true; + } + + inode = file_inode(kiocb->ki_filp); + ret = sb_start_write_trylock(inode->i_sb); + if (ret) + __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE); + return ret; +} + +int io_write(struct io_kiocb *req, unsigned int issue_flags) +{ + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + struct io_async_rw *io = req->async_data; + struct kiocb *kiocb = &rw->kiocb; + ssize_t ret, ret2; + loff_t *ppos; + + if (req->flags & REQ_F_IMPORT_BUFFER) { + ret = io_rw_import_reg_vec(req, io, ITER_SOURCE, issue_flags); + if (unlikely(ret)) + return ret; + } + + ret = io_rw_init_file(req, FMODE_WRITE, WRITE); + if (unlikely(ret)) + return ret; + req->cqe.res = iov_iter_count(&io->iter); + + if (force_nonblock) { + /* If the file doesn't support async, just async punt */ + if (unlikely(!io_file_supports_nowait(req, EPOLLOUT))) + goto ret_eagain; + + /* Check if we can support NOWAIT. */ + if (!(kiocb->ki_flags & IOCB_DIRECT) && + !(req->file->f_op->fop_flags & FOP_BUFFER_WASYNC) && + (req->flags & REQ_F_ISREG)) + goto ret_eagain; + + kiocb->ki_flags |= IOCB_NOWAIT; + } else { + /* Ensure we clear previously set non-block flag */ + kiocb->ki_flags &= ~IOCB_NOWAIT; + } + + ppos = io_kiocb_update_pos(req); + + ret = rw_verify_area(WRITE, req->file, ppos, req->cqe.res); + if (unlikely(ret)) + return ret; + + if (unlikely(!io_kiocb_start_write(req, kiocb))) + return -EAGAIN; + kiocb->ki_flags |= IOCB_WRITE; + + if (likely(req->file->f_op->write_iter)) + ret2 = req->file->f_op->write_iter(kiocb, &io->iter); + else if (req->file->f_op->write) + ret2 = loop_rw_iter(WRITE, rw, &io->iter); + else + ret2 = -EINVAL; + + /* + * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just + * retry them without IOCB_NOWAIT. + */ + if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) + ret2 = -EAGAIN; + /* no retry on NONBLOCK nor RWF_NOWAIT */ + if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) + goto done; + if (!force_nonblock || ret2 != -EAGAIN) { + /* IOPOLL retry should happen for io-wq threads */ + if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL)) + goto ret_eagain; + + if (ret2 != req->cqe.res && ret2 >= 0 && need_complete_io(req)) { + trace_io_uring_short_write(req->ctx, kiocb->ki_pos - ret2, + req->cqe.res, ret2); + + /* This is a partial write. The file pos has already been + * updated, setup the async struct to complete the request + * in the worker. Also update bytes_done to account for + * the bytes already written. + */ + iov_iter_save_state(&io->iter, &io->iter_state); + io->bytes_done += ret2; + + if (kiocb->ki_flags & IOCB_WRITE) + io_req_end_write(req); + return -EAGAIN; + } +done: + return kiocb_done(req, ret2, NULL, issue_flags); + } else { +ret_eagain: + iov_iter_restore(&io->iter, &io->iter_state); + io_meta_restore(io, kiocb); + if (kiocb->ki_flags & IOCB_WRITE) + io_req_end_write(req); + return -EAGAIN; + } +} + +int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags) +{ + int ret; + + ret = io_init_rw_fixed(req, issue_flags, ITER_DEST); + if (unlikely(ret)) + return ret; + + return io_read(req, issue_flags); +} + +int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags) +{ + int ret; + + ret = io_init_rw_fixed(req, issue_flags, ITER_SOURCE); + if (unlikely(ret)) + return ret; + + return io_write(req, issue_flags); +} + +void io_rw_fail(struct io_kiocb *req) +{ + int res; + + res = io_fixup_rw_res(req, req->cqe.res); + io_req_set_res(req, res, req->cqe.flags); +} + +static int io_uring_classic_poll(struct io_kiocb *req, struct io_comp_batch *iob, + unsigned int poll_flags) +{ + struct file *file = req->file; + + if (req->opcode == IORING_OP_URING_CMD) { + struct io_uring_cmd *ioucmd; + + ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + return file->f_op->uring_cmd_iopoll(ioucmd, iob, poll_flags); + } else { + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); + + return file->f_op->iopoll(&rw->kiocb, iob, poll_flags); + } +} + +static u64 io_hybrid_iopoll_delay(struct io_ring_ctx *ctx, struct io_kiocb *req) +{ + struct hrtimer_sleeper timer; + enum hrtimer_mode mode; + ktime_t kt; + u64 sleep_time; + + if (req->flags & REQ_F_IOPOLL_STATE) + return 0; + + if (ctx->hybrid_poll_time == LLONG_MAX) + return 0; + + /* Using half the running time to do schedule */ + sleep_time = ctx->hybrid_poll_time / 2; + + kt = ktime_set(0, sleep_time); + req->flags |= REQ_F_IOPOLL_STATE; + + mode = HRTIMER_MODE_REL; + hrtimer_setup_sleeper_on_stack(&timer, CLOCK_MONOTONIC, mode); + hrtimer_set_expires(&timer.timer, kt); + set_current_state(TASK_INTERRUPTIBLE); + hrtimer_sleeper_start_expires(&timer, mode); + + if (timer.task) + io_schedule(); + + hrtimer_cancel(&timer.timer); + __set_current_state(TASK_RUNNING); + destroy_hrtimer_on_stack(&timer.timer); + return sleep_time; +} + +static int io_uring_hybrid_poll(struct io_kiocb *req, + struct io_comp_batch *iob, unsigned int poll_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + u64 runtime, sleep_time; + int ret; + + sleep_time = io_hybrid_iopoll_delay(ctx, req); + ret = io_uring_classic_poll(req, iob, poll_flags); + runtime = ktime_get_ns() - req->iopoll_start - sleep_time; + + /* + * Use minimum sleep time if we're polling devices with different + * latencies. We could get more completions from the faster ones. + */ + if (ctx->hybrid_poll_time > runtime) + ctx->hybrid_poll_time = runtime; + + return ret; +} + +int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) +{ + struct io_wq_work_node *pos, *start, *prev; + unsigned int poll_flags = 0; + DEFINE_IO_COMP_BATCH(iob); + int nr_events = 0; + + /* + * Only spin for completions if we don't have multiple devices hanging + * off our complete list. + */ + if (ctx->poll_multi_queue || force_nonspin) + poll_flags |= BLK_POLL_ONESHOT; + + wq_list_for_each(pos, start, &ctx->iopoll_list) { + struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); + int ret; + + /* + * Move completed and retryable entries to our local lists. + * If we find a request that requires polling, break out + * and complete those lists first, if we have entries there. + */ + if (READ_ONCE(req->iopoll_completed)) + break; + + if (ctx->flags & IORING_SETUP_HYBRID_IOPOLL) + ret = io_uring_hybrid_poll(req, &iob, poll_flags); + else + ret = io_uring_classic_poll(req, &iob, poll_flags); + + if (unlikely(ret < 0)) + return ret; + else if (ret) + poll_flags |= BLK_POLL_ONESHOT; + + /* iopoll may have completed current req */ + if (!rq_list_empty(&iob.req_list) || + READ_ONCE(req->iopoll_completed)) + break; + } + + if (!rq_list_empty(&iob.req_list)) + iob.complete(&iob); + else if (!pos) + return 0; + + prev = start; + wq_list_for_each_resume(pos, prev) { + struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); + + /* order with io_complete_rw_iopoll(), e.g. ->result updates */ + if (!smp_load_acquire(&req->iopoll_completed)) + break; + nr_events++; + req->cqe.flags = io_put_kbuf(req, req->cqe.res, NULL); + if (req->opcode != IORING_OP_URING_CMD) + io_req_rw_cleanup(req, 0); + } + if (unlikely(!nr_events)) + return 0; + + pos = start ? start->next : ctx->iopoll_list.first; + wq_list_cut(&ctx->iopoll_list, prev, start); + + if (WARN_ON_ONCE(!wq_list_empty(&ctx->submit_state.compl_reqs))) + return 0; + ctx->submit_state.compl_reqs.first = pos; + __io_submit_flush_completions(ctx); + return nr_events; +} + +void io_rw_cache_free(const void *entry) +{ + struct io_async_rw *rw = (struct io_async_rw *) entry; + + io_vec_free(&rw->vec); + kfree(rw); +} diff --git a/io_uring/rw.h b/io_uring/rw.h new file mode 100644 index 000000000000..9bd7fbf70ea9 --- /dev/null +++ b/io_uring/rw.h @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/io_uring_types.h> +#include <linux/pagemap.h> + +struct io_meta_state { + u32 seed; + struct iov_iter_state iter_meta; +}; + +struct io_async_rw { + struct iou_vec vec; + size_t bytes_done; + + struct_group(clear, + struct iov_iter iter; + struct iov_iter_state iter_state; + struct iovec fast_iov; + unsigned buf_group; + + /* + * wpq is for buffered io, while meta fields are used with + * direct io + */ + union { + struct wait_page_queue wpq; + struct { + struct uio_meta meta; + struct io_meta_state meta_state; + }; + }; + ); +}; + +int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_readv_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_writev_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_read(struct io_kiocb *req, unsigned int issue_flags); +int io_write(struct io_kiocb *req, unsigned int issue_flags); +int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags); +int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags); +void io_readv_writev_cleanup(struct io_kiocb *req); +void io_rw_fail(struct io_kiocb *req); +void io_req_rw_complete(struct io_tw_req tw_req, io_tw_token_t tw); +int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags); +void io_rw_cache_free(const void *entry); diff --git a/io_uring/slist.h b/io_uring/slist.h new file mode 100644 index 000000000000..7ef747442754 --- /dev/null +++ b/io_uring/slist.h @@ -0,0 +1,101 @@ +#ifndef INTERNAL_IO_SLIST_H +#define INTERNAL_IO_SLIST_H + +#include <linux/io_uring_types.h> + +#define __wq_list_for_each(pos, head) \ + for (pos = (head)->first; pos; pos = (pos)->next) + +#define wq_list_for_each(pos, prv, head) \ + for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next) + +#define wq_list_for_each_resume(pos, prv) \ + for (; pos; prv = pos, pos = (pos)->next) + +#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL) + +#define INIT_WQ_LIST(list) do { \ + (list)->first = NULL; \ +} while (0) + +static inline void wq_list_add_after(struct io_wq_work_node *node, + struct io_wq_work_node *pos, + struct io_wq_work_list *list) +{ + struct io_wq_work_node *next = pos->next; + + pos->next = node; + node->next = next; + if (!next) + list->last = node; +} + +static inline void wq_list_add_tail(struct io_wq_work_node *node, + struct io_wq_work_list *list) +{ + node->next = NULL; + if (!list->first) { + list->last = node; + WRITE_ONCE(list->first, node); + } else { + list->last->next = node; + list->last = node; + } +} + +static inline void wq_list_add_head(struct io_wq_work_node *node, + struct io_wq_work_list *list) +{ + node->next = list->first; + if (!node->next) + list->last = node; + WRITE_ONCE(list->first, node); +} + +static inline void wq_list_cut(struct io_wq_work_list *list, + struct io_wq_work_node *last, + struct io_wq_work_node *prev) +{ + /* first in the list, if prev==NULL */ + if (!prev) + WRITE_ONCE(list->first, last->next); + else + prev->next = last->next; + + if (last == list->last) + list->last = prev; + last->next = NULL; +} + +static inline void wq_stack_add_head(struct io_wq_work_node *node, + struct io_wq_work_node *stack) +{ + node->next = stack->next; + stack->next = node; +} + +static inline void wq_list_del(struct io_wq_work_list *list, + struct io_wq_work_node *node, + struct io_wq_work_node *prev) +{ + wq_list_cut(list, node, prev); +} + +static inline +struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack) +{ + struct io_wq_work_node *node = stack->next; + + stack->next = node->next; + return node; +} + +static inline struct io_wq_work *wq_next_work(struct io_wq_work *work) +{ + if (!work->list.next) + return NULL; + + return container_of(work->list.next, struct io_wq_work, list); +} + +#endif // INTERNAL_IO_SLIST_H diff --git a/io_uring/splice.c b/io_uring/splice.c new file mode 100644 index 000000000000..e81ebbb91925 --- /dev/null +++ b/io_uring/splice.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/io_uring.h> +#include <linux/splice.h> + +#include <uapi/linux/io_uring.h> + +#include "filetable.h" +#include "io_uring.h" +#include "splice.h" + +struct io_splice { + struct file *file_out; + loff_t off_out; + loff_t off_in; + u64 len; + int splice_fd_in; + unsigned int flags; + struct io_rsrc_node *rsrc_node; +}; + +static int __io_splice_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice); + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL; + + sp->len = READ_ONCE(sqe->len); + sp->flags = READ_ONCE(sqe->splice_flags); + if (unlikely(sp->flags & ~valid_flags)) + return -EINVAL; + sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in); + sp->rsrc_node = NULL; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off)) + return -EINVAL; + return __io_splice_prep(req, sqe); +} + +void io_splice_cleanup(struct io_kiocb *req) +{ + struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice); + + if (sp->rsrc_node) + io_put_rsrc_node(req->ctx, sp->rsrc_node); +} + +static struct file *io_splice_get_file(struct io_kiocb *req, + unsigned int issue_flags) +{ + struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice); + struct io_ring_ctx *ctx = req->ctx; + struct io_rsrc_node *node; + struct file *file = NULL; + + if (!(sp->flags & SPLICE_F_FD_IN_FIXED)) + return io_file_get_normal(req, sp->splice_fd_in); + + io_ring_submit_lock(ctx, issue_flags); + node = io_rsrc_node_lookup(&ctx->file_table.data, sp->splice_fd_in); + if (node) { + node->refs++; + sp->rsrc_node = node; + file = io_slot_file(node); + req->flags |= REQ_F_NEED_CLEANUP; + } + io_ring_submit_unlock(ctx, issue_flags); + return file; +} + +int io_tee(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice); + struct file *out = sp->file_out; + unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; + struct file *in; + ssize_t ret = 0; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + in = io_splice_get_file(req, issue_flags); + if (!in) { + ret = -EBADF; + goto done; + } + + if (sp->len) + ret = do_tee(in, out, sp->len, flags); + + if (!(sp->flags & SPLICE_F_FD_IN_FIXED)) + fput(in); +done: + if (ret != sp->len) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice); + + sp->off_in = READ_ONCE(sqe->splice_off_in); + sp->off_out = READ_ONCE(sqe->off); + return __io_splice_prep(req, sqe); +} + +int io_splice(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice); + struct file *out = sp->file_out; + unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; + loff_t *poff_in, *poff_out; + struct file *in; + ssize_t ret = 0; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + in = io_splice_get_file(req, issue_flags); + if (!in) { + ret = -EBADF; + goto done; + } + + poff_in = (sp->off_in == -1) ? NULL : &sp->off_in; + poff_out = (sp->off_out == -1) ? NULL : &sp->off_out; + + if (sp->len) + ret = do_splice(in, poff_in, out, poff_out, sp->len, flags); + + if (!(sp->flags & SPLICE_F_FD_IN_FIXED)) + fput(in); +done: + if (ret != sp->len) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/splice.h b/io_uring/splice.h new file mode 100644 index 000000000000..b9b2848327fb --- /dev/null +++ b/io_uring/splice.h @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_tee(struct io_kiocb *req, unsigned int issue_flags); + +void io_splice_cleanup(struct io_kiocb *req); +int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_splice(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c new file mode 100644 index 000000000000..74c1a130cd87 --- /dev/null +++ b/io_uring/sqpoll.c @@ -0,0 +1,563 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Contains the core associated with submission side polling of the SQ + * ring, offloading submissions from the application to a kernel thread. + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/audit.h> +#include <linux/security.h> +#include <linux/cpuset.h> +#include <linux/sched/cputime.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "tctx.h" +#include "napi.h" +#include "cancel.h" +#include "sqpoll.h" + +#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8 +#define IORING_TW_CAP_ENTRIES_VALUE 32 + +enum { + IO_SQ_THREAD_SHOULD_STOP = 0, + IO_SQ_THREAD_SHOULD_PARK, +}; + +void io_sq_thread_unpark(struct io_sq_data *sqd) + __releases(&sqd->lock) +{ + WARN_ON_ONCE(sqpoll_task_locked(sqd) == current); + + /* + * Do the dance but not conditional clear_bit() because it'd race with + * other threads incrementing park_pending and setting the bit. + */ + clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + if (atomic_dec_return(&sqd->park_pending)) + set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + mutex_unlock(&sqd->lock); + wake_up(&sqd->wait); +} + +void io_sq_thread_park(struct io_sq_data *sqd) + __acquires(&sqd->lock) +{ + struct task_struct *tsk; + + atomic_inc(&sqd->park_pending); + set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + mutex_lock(&sqd->lock); + + tsk = sqpoll_task_locked(sqd); + if (tsk) { + WARN_ON_ONCE(tsk == current); + wake_up_process(tsk); + } +} + +void io_sq_thread_stop(struct io_sq_data *sqd) +{ + struct task_struct *tsk; + + WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state)); + + set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); + mutex_lock(&sqd->lock); + tsk = sqpoll_task_locked(sqd); + if (tsk) { + WARN_ON_ONCE(tsk == current); + wake_up_process(tsk); + } + mutex_unlock(&sqd->lock); + wait_for_completion(&sqd->exited); +} + +void io_put_sq_data(struct io_sq_data *sqd) +{ + if (refcount_dec_and_test(&sqd->refs)) { + WARN_ON_ONCE(atomic_read(&sqd->park_pending)); + + io_sq_thread_stop(sqd); + kfree(sqd); + } +} + +static __cold void io_sqd_update_thread_idle(struct io_sq_data *sqd) +{ + struct io_ring_ctx *ctx; + unsigned sq_thread_idle = 0; + + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + sq_thread_idle = max(sq_thread_idle, ctx->sq_thread_idle); + sqd->sq_thread_idle = sq_thread_idle; +} + +void io_sq_thread_finish(struct io_ring_ctx *ctx) +{ + struct io_sq_data *sqd = ctx->sq_data; + + if (sqd) { + io_sq_thread_park(sqd); + list_del_init(&ctx->sqd_list); + io_sqd_update_thread_idle(sqd); + io_sq_thread_unpark(sqd); + + io_put_sq_data(sqd); + ctx->sq_data = NULL; + } +} + +static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p) +{ + struct io_ring_ctx *ctx_attach; + struct io_sq_data *sqd; + CLASS(fd, f)(p->wq_fd); + + if (fd_empty(f)) + return ERR_PTR(-ENXIO); + if (!io_is_uring_fops(fd_file(f))) + return ERR_PTR(-EINVAL); + + ctx_attach = fd_file(f)->private_data; + sqd = ctx_attach->sq_data; + if (!sqd) + return ERR_PTR(-EINVAL); + if (sqd->task_tgid != current->tgid) + return ERR_PTR(-EPERM); + + refcount_inc(&sqd->refs); + return sqd; +} + +static struct io_sq_data *io_get_sq_data(struct io_uring_params *p, + bool *attached) +{ + struct io_sq_data *sqd; + + *attached = false; + if (p->flags & IORING_SETUP_ATTACH_WQ) { + sqd = io_attach_sq_data(p); + if (!IS_ERR(sqd)) { + *attached = true; + return sqd; + } + /* fall through for EPERM case, setup new sqd/task */ + if (PTR_ERR(sqd) != -EPERM) + return sqd; + } + + sqd = kzalloc(sizeof(*sqd), GFP_KERNEL); + if (!sqd) + return ERR_PTR(-ENOMEM); + + atomic_set(&sqd->park_pending, 0); + refcount_set(&sqd->refs, 1); + INIT_LIST_HEAD(&sqd->ctx_list); + mutex_init(&sqd->lock); + init_waitqueue_head(&sqd->wait); + init_completion(&sqd->exited); + return sqd; +} + +static inline bool io_sqd_events_pending(struct io_sq_data *sqd) +{ + return READ_ONCE(sqd->state); +} + +struct io_sq_time { + bool started; + u64 usec; +}; + +u64 io_sq_cpu_usec(struct task_struct *tsk) +{ + u64 utime, stime; + + task_cputime_adjusted(tsk, &utime, &stime); + do_div(stime, 1000); + return stime; +} + +static void io_sq_update_worktime(struct io_sq_data *sqd, struct io_sq_time *ist) +{ + if (!ist->started) + return; + ist->started = false; + sqd->work_time += io_sq_cpu_usec(current) - ist->usec; +} + +static void io_sq_start_worktime(struct io_sq_time *ist) +{ + if (ist->started) + return; + ist->started = true; + ist->usec = io_sq_cpu_usec(current); +} + +static int __io_sq_thread(struct io_ring_ctx *ctx, struct io_sq_data *sqd, + bool cap_entries, struct io_sq_time *ist) +{ + unsigned int to_submit; + int ret = 0; + + to_submit = io_sqring_entries(ctx); + /* if we're handling multiple rings, cap submit size for fairness */ + if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE) + to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE; + + if (to_submit || !wq_list_empty(&ctx->iopoll_list)) { + const struct cred *creds = NULL; + + io_sq_start_worktime(ist); + + if (ctx->sq_creds != current_cred()) + creds = override_creds(ctx->sq_creds); + + mutex_lock(&ctx->uring_lock); + if (!wq_list_empty(&ctx->iopoll_list)) + io_do_iopoll(ctx, true); + + /* + * Don't submit if refs are dying, good for io_uring_register(), + * but also it is relied upon by io_ring_exit_work() + */ + if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) && + !(ctx->flags & IORING_SETUP_R_DISABLED)) + ret = io_submit_sqes(ctx, to_submit); + mutex_unlock(&ctx->uring_lock); + + if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait)) + wake_up(&ctx->sqo_sq_wait); + if (creds) + revert_creds(creds); + } + + return ret; +} + +static bool io_sqd_handle_event(struct io_sq_data *sqd) +{ + bool did_sig = false; + struct ksignal ksig; + + if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) || + signal_pending(current)) { + mutex_unlock(&sqd->lock); + if (signal_pending(current)) + did_sig = get_signal(&ksig); + wait_event(sqd->wait, !atomic_read(&sqd->park_pending)); + mutex_lock(&sqd->lock); + sqd->sq_cpu = raw_smp_processor_id(); + } + return did_sig || test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); +} + +/* + * Run task_work, processing the retry_list first. The retry_list holds + * entries that we passed on in the previous run, if we had more task_work + * than we were asked to process. Newly queued task_work isn't run until the + * retry list has been fully processed. + */ +static unsigned int io_sq_tw(struct llist_node **retry_list, int max_entries) +{ + struct io_uring_task *tctx = current->io_uring; + unsigned int count = 0; + + if (*retry_list) { + *retry_list = io_handle_tw_list(*retry_list, &count, max_entries); + if (count >= max_entries) + goto out; + max_entries -= count; + } + *retry_list = tctx_task_work_run(tctx, max_entries, &count); +out: + if (task_work_pending(current)) + task_work_run(); + return count; +} + +static bool io_sq_tw_pending(struct llist_node *retry_list) +{ + struct io_uring_task *tctx = current->io_uring; + + return retry_list || !llist_empty(&tctx->task_list); +} + +static int io_sq_thread(void *data) +{ + struct llist_node *retry_list = NULL; + struct io_sq_data *sqd = data; + struct io_ring_ctx *ctx; + unsigned long timeout = 0; + char buf[TASK_COMM_LEN] = {}; + DEFINE_WAIT(wait); + + /* offload context creation failed, just exit */ + if (!current->io_uring) { + mutex_lock(&sqd->lock); + rcu_assign_pointer(sqd->thread, NULL); + put_task_struct(current); + mutex_unlock(&sqd->lock); + goto err_out; + } + + snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid); + set_task_comm(current, buf); + + /* reset to our pid after we've set task_comm, for fdinfo */ + sqd->task_pid = current->pid; + + if (sqd->sq_cpu != -1) { + set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu)); + } else { + set_cpus_allowed_ptr(current, cpu_online_mask); + sqd->sq_cpu = raw_smp_processor_id(); + } + + /* + * Force audit context to get setup, in case we do prep side async + * operations that would trigger an audit call before any issue side + * audit has been done. + */ + audit_uring_entry(IORING_OP_NOP); + audit_uring_exit(true, 0); + + mutex_lock(&sqd->lock); + while (1) { + bool cap_entries, sqt_spin = false; + struct io_sq_time ist = { }; + + if (io_sqd_events_pending(sqd) || signal_pending(current)) { + if (io_sqd_handle_event(sqd)) + break; + timeout = jiffies + sqd->sq_thread_idle; + } + + cap_entries = !list_is_singular(&sqd->ctx_list); + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { + int ret = __io_sq_thread(ctx, sqd, cap_entries, &ist); + + if (!sqt_spin && (ret > 0 || !wq_list_empty(&ctx->iopoll_list))) + sqt_spin = true; + } + if (io_sq_tw(&retry_list, IORING_TW_CAP_ENTRIES_VALUE)) + sqt_spin = true; + + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { + if (io_napi(ctx)) { + io_sq_start_worktime(&ist); + io_napi_sqpoll_busy_poll(ctx); + } + } + + io_sq_update_worktime(sqd, &ist); + + if (sqt_spin || !time_after(jiffies, timeout)) { + if (sqt_spin) + timeout = jiffies + sqd->sq_thread_idle; + if (unlikely(need_resched())) { + mutex_unlock(&sqd->lock); + cond_resched(); + mutex_lock(&sqd->lock); + sqd->sq_cpu = raw_smp_processor_id(); + } + continue; + } + + prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE); + if (!io_sqd_events_pending(sqd) && !io_sq_tw_pending(retry_list)) { + bool needs_sched = true; + + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { + atomic_or(IORING_SQ_NEED_WAKEUP, + &ctx->rings->sq_flags); + if ((ctx->flags & IORING_SETUP_IOPOLL) && + !wq_list_empty(&ctx->iopoll_list)) { + needs_sched = false; + break; + } + + /* + * Ensure the store of the wakeup flag is not + * reordered with the load of the SQ tail + */ + smp_mb__after_atomic(); + + if (io_sqring_entries(ctx)) { + needs_sched = false; + break; + } + } + + if (needs_sched) { + mutex_unlock(&sqd->lock); + schedule(); + mutex_lock(&sqd->lock); + sqd->sq_cpu = raw_smp_processor_id(); + } + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + atomic_andnot(IORING_SQ_NEED_WAKEUP, + &ctx->rings->sq_flags); + } + + finish_wait(&sqd->wait, &wait); + timeout = jiffies + sqd->sq_thread_idle; + } + + if (retry_list) + io_sq_tw(&retry_list, UINT_MAX); + + io_uring_cancel_generic(true, sqd); + rcu_assign_pointer(sqd->thread, NULL); + put_task_struct(current); + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + atomic_or(IORING_SQ_NEED_WAKEUP, &ctx->rings->sq_flags); + io_run_task_work(); + mutex_unlock(&sqd->lock); +err_out: + complete(&sqd->exited); + do_exit(0); +} + +void io_sqpoll_wait_sq(struct io_ring_ctx *ctx) +{ + DEFINE_WAIT(wait); + + do { + if (!io_sqring_full(ctx)) + break; + prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE); + + if (!io_sqring_full(ctx)) + break; + schedule(); + } while (!signal_pending(current)); + + finish_wait(&ctx->sqo_sq_wait, &wait); +} + +__cold int io_sq_offload_create(struct io_ring_ctx *ctx, + struct io_uring_params *p) +{ + int ret; + + /* Retain compatibility with failing for an invalid attach attempt */ + if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) == + IORING_SETUP_ATTACH_WQ) { + CLASS(fd, f)(p->wq_fd); + if (fd_empty(f)) + return -ENXIO; + if (!io_is_uring_fops(fd_file(f))) + return -EINVAL; + } + if (ctx->flags & IORING_SETUP_SQPOLL) { + struct task_struct *tsk; + struct io_sq_data *sqd; + bool attached; + + ret = security_uring_sqpoll(); + if (ret) + return ret; + + sqd = io_get_sq_data(p, &attached); + if (IS_ERR(sqd)) { + ret = PTR_ERR(sqd); + goto err; + } + + ctx->sq_creds = get_current_cred(); + ctx->sq_data = sqd; + ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); + if (!ctx->sq_thread_idle) + ctx->sq_thread_idle = HZ; + + io_sq_thread_park(sqd); + list_add(&ctx->sqd_list, &sqd->ctx_list); + io_sqd_update_thread_idle(sqd); + /* don't attach to a dying SQPOLL thread, would be racy */ + ret = (attached && !sqd->thread) ? -ENXIO : 0; + io_sq_thread_unpark(sqd); + + if (ret < 0) + goto err; + if (attached) + return 0; + + if (p->flags & IORING_SETUP_SQ_AFF) { + cpumask_var_t allowed_mask; + int cpu = p->sq_thread_cpu; + + ret = -EINVAL; + if (cpu >= nr_cpu_ids || !cpu_online(cpu)) + goto err_sqpoll; + ret = -ENOMEM; + if (!alloc_cpumask_var(&allowed_mask, GFP_KERNEL)) + goto err_sqpoll; + ret = -EINVAL; + cpuset_cpus_allowed(current, allowed_mask); + if (!cpumask_test_cpu(cpu, allowed_mask)) { + free_cpumask_var(allowed_mask); + goto err_sqpoll; + } + free_cpumask_var(allowed_mask); + sqd->sq_cpu = cpu; + } else { + sqd->sq_cpu = -1; + } + + sqd->task_pid = current->pid; + sqd->task_tgid = current->tgid; + tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE); + if (IS_ERR(tsk)) { + ret = PTR_ERR(tsk); + goto err_sqpoll; + } + + mutex_lock(&sqd->lock); + rcu_assign_pointer(sqd->thread, tsk); + mutex_unlock(&sqd->lock); + + get_task_struct(tsk); + ret = io_uring_alloc_task_context(tsk, ctx); + wake_up_new_task(tsk); + if (ret) + goto err; + } else if (p->flags & IORING_SETUP_SQ_AFF) { + /* Can't have SQ_AFF without SQPOLL */ + ret = -EINVAL; + goto err; + } + return 0; +err_sqpoll: + complete(&ctx->sq_data->exited); +err: + io_sq_thread_finish(ctx); + return ret; +} + +__cold int io_sqpoll_wq_cpu_affinity(struct io_ring_ctx *ctx, + cpumask_var_t mask) +{ + struct io_sq_data *sqd = ctx->sq_data; + int ret = -EINVAL; + + if (sqd) { + struct task_struct *tsk; + + io_sq_thread_park(sqd); + /* Don't set affinity for a dying thread */ + tsk = sqpoll_task_locked(sqd); + if (tsk) + ret = io_wq_cpu_affinity(tsk->io_uring, mask); + io_sq_thread_unpark(sqd); + } + + return ret; +} diff --git a/io_uring/sqpoll.h b/io_uring/sqpoll.h new file mode 100644 index 000000000000..fd2f6f29b516 --- /dev/null +++ b/io_uring/sqpoll.h @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0 + +struct io_sq_data { + refcount_t refs; + atomic_t park_pending; + struct mutex lock; + + /* ctx's that are using this sqd */ + struct list_head ctx_list; + + struct task_struct __rcu *thread; + struct wait_queue_head wait; + + unsigned sq_thread_idle; + int sq_cpu; + pid_t task_pid; + pid_t task_tgid; + + u64 work_time; + unsigned long state; + struct completion exited; +}; + +int io_sq_offload_create(struct io_ring_ctx *ctx, struct io_uring_params *p); +void io_sq_thread_finish(struct io_ring_ctx *ctx); +void io_sq_thread_stop(struct io_sq_data *sqd); +void io_sq_thread_park(struct io_sq_data *sqd); +void io_sq_thread_unpark(struct io_sq_data *sqd); +void io_put_sq_data(struct io_sq_data *sqd); +void io_sqpoll_wait_sq(struct io_ring_ctx *ctx); +int io_sqpoll_wq_cpu_affinity(struct io_ring_ctx *ctx, cpumask_var_t mask); +u64 io_sq_cpu_usec(struct task_struct *tsk); + +static inline struct task_struct *sqpoll_task_locked(struct io_sq_data *sqd) +{ + return rcu_dereference_protected(sqd->thread, + lockdep_is_held(&sqd->lock)); +} diff --git a/io_uring/statx.c b/io_uring/statx.c new file mode 100644 index 000000000000..5111e9befbfe --- /dev/null +++ b/io_uring/statx.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "../fs/internal.h" + +#include "io_uring.h" +#include "statx.h" + +struct io_statx { + struct file *file; + int dfd; + unsigned int mask; + unsigned int flags; + struct filename *filename; + struct statx __user *buffer; +}; + +int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_statx *sx = io_kiocb_to_cmd(req, struct io_statx); + const char __user *path; + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (req->flags & REQ_F_FIXED_FILE) + return -EBADF; + + sx->dfd = READ_ONCE(sqe->fd); + sx->mask = READ_ONCE(sqe->len); + path = u64_to_user_ptr(READ_ONCE(sqe->addr)); + sx->buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + sx->flags = READ_ONCE(sqe->statx_flags); + + sx->filename = getname_uflags(path, sx->flags); + + if (IS_ERR(sx->filename)) { + int ret = PTR_ERR(sx->filename); + + sx->filename = NULL; + return ret; + } + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_statx(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_statx *sx = io_kiocb_to_cmd(req, struct io_statx); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_statx(sx->dfd, sx->filename, sx->flags, sx->mask, sx->buffer); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +void io_statx_cleanup(struct io_kiocb *req) +{ + struct io_statx *sx = io_kiocb_to_cmd(req, struct io_statx); + + if (sx->filename) + putname(sx->filename); +} diff --git a/io_uring/statx.h b/io_uring/statx.h new file mode 100644 index 000000000000..9a17f4d45a7d --- /dev/null +++ b/io_uring/statx.h @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_statx(struct io_kiocb *req, unsigned int issue_flags); +void io_statx_cleanup(struct io_kiocb *req); diff --git a/io_uring/sync.c b/io_uring/sync.c new file mode 100644 index 000000000000..cea2d381ffd2 --- /dev/null +++ b/io_uring/sync.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/io_uring.h> +#include <linux/fsnotify.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "sync.h" + +struct io_sync { + struct file *file; + loff_t len; + loff_t off; + int flags; + int mode; +}; + +int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync); + + if (unlikely(sqe->addr || sqe->buf_index || sqe->splice_fd_in)) + return -EINVAL; + + sync->off = READ_ONCE(sqe->off); + sync->len = READ_ONCE(sqe->len); + sync->flags = READ_ONCE(sqe->sync_range_flags); + req->flags |= REQ_F_FORCE_ASYNC; + + return 0; +} + +int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync); + int ret; + + /* sync_file_range always requires a blocking context */ + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = sync_file_range(req->file, sync->off, sync->len, sync->flags); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync); + + if (unlikely(sqe->addr || sqe->buf_index || sqe->splice_fd_in)) + return -EINVAL; + + sync->flags = READ_ONCE(sqe->fsync_flags); + if (unlikely(sync->flags & ~IORING_FSYNC_DATASYNC)) + return -EINVAL; + + sync->off = READ_ONCE(sqe->off); + sync->len = READ_ONCE(sqe->len); + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_fsync(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync); + loff_t end = sync->off + sync->len; + int ret; + + /* fsync always requires a blocking context */ + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = vfs_fsync_range(req->file, sync->off, end > 0 ? end : LLONG_MAX, + sync->flags & IORING_FSYNC_DATASYNC); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_fallocate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync); + + if (sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in) + return -EINVAL; + + sync->off = READ_ONCE(sqe->off); + sync->len = READ_ONCE(sqe->addr); + sync->mode = READ_ONCE(sqe->len); + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_fallocate(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync); + int ret; + + /* fallocate always requiring blocking context */ + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = vfs_fallocate(req->file, sync->mode, sync->off, sync->len); + if (ret >= 0) + fsnotify_modify(req->file); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/sync.h b/io_uring/sync.h new file mode 100644 index 000000000000..e873c888da79 --- /dev/null +++ b/io_uring/sync.h @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags); + +int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_fsync(struct io_kiocb *req, unsigned int issue_flags); + +int io_fallocate(struct io_kiocb *req, unsigned int issue_flags); +int io_fallocate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); diff --git a/io_uring/tctx.c b/io_uring/tctx.c new file mode 100644 index 000000000000..5b66755579c0 --- /dev/null +++ b/io_uring/tctx.c @@ -0,0 +1,353 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/nospec.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "tctx.h" + +static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx, + struct task_struct *task) +{ + struct io_wq_hash *hash; + struct io_wq_data data; + unsigned int concurrency; + + mutex_lock(&ctx->uring_lock); + hash = ctx->hash_map; + if (!hash) { + hash = kzalloc(sizeof(*hash), GFP_KERNEL); + if (!hash) { + mutex_unlock(&ctx->uring_lock); + return ERR_PTR(-ENOMEM); + } + refcount_set(&hash->refs, 1); + init_waitqueue_head(&hash->wait); + ctx->hash_map = hash; + } + mutex_unlock(&ctx->uring_lock); + + data.hash = hash; + data.task = task; + + /* Do QD, or 4 * CPUS, whatever is smallest */ + concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); + + return io_wq_create(concurrency, &data); +} + +void __io_uring_free(struct task_struct *tsk) +{ + struct io_uring_task *tctx = tsk->io_uring; + struct io_tctx_node *node; + unsigned long index; + + /* + * Fault injection forcing allocation errors in the xa_store() path + * can lead to xa_empty() returning false, even though no actual + * node is stored in the xarray. Until that gets sorted out, attempt + * an iteration here and warn if any entries are found. + */ + xa_for_each(&tctx->xa, index, node) { + WARN_ON_ONCE(1); + break; + } + WARN_ON_ONCE(tctx->io_wq); + WARN_ON_ONCE(tctx->cached_refs); + + percpu_counter_destroy(&tctx->inflight); + kfree(tctx); + tsk->io_uring = NULL; +} + +__cold int io_uring_alloc_task_context(struct task_struct *task, + struct io_ring_ctx *ctx) +{ + struct io_uring_task *tctx; + int ret; + + tctx = kzalloc(sizeof(*tctx), GFP_KERNEL); + if (unlikely(!tctx)) + return -ENOMEM; + + ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL); + if (unlikely(ret)) { + kfree(tctx); + return ret; + } + + tctx->io_wq = io_init_wq_offload(ctx, task); + if (IS_ERR(tctx->io_wq)) { + ret = PTR_ERR(tctx->io_wq); + percpu_counter_destroy(&tctx->inflight); + kfree(tctx); + return ret; + } + + tctx->task = task; + xa_init(&tctx->xa); + init_waitqueue_head(&tctx->wait); + atomic_set(&tctx->in_cancel, 0); + atomic_set(&tctx->inflight_tracked, 0); + task->io_uring = tctx; + init_llist_head(&tctx->task_list); + init_task_work(&tctx->task_work, tctx_task_work); + return 0; +} + +int __io_uring_add_tctx_node(struct io_ring_ctx *ctx) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_node *node; + int ret; + + if (unlikely(!tctx)) { + ret = io_uring_alloc_task_context(current, ctx); + if (unlikely(ret)) + return ret; + + tctx = current->io_uring; + if (ctx->iowq_limits_set) { + unsigned int limits[2] = { ctx->iowq_limits[0], + ctx->iowq_limits[1], }; + + ret = io_wq_max_workers(tctx->io_wq, limits); + if (ret) + return ret; + } + } + if (!xa_load(&tctx->xa, (unsigned long)ctx)) { + node = kmalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return -ENOMEM; + node->ctx = ctx; + node->task = current; + + ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx, + node, GFP_KERNEL)); + if (ret) { + kfree(node); + return ret; + } + + mutex_lock(&ctx->uring_lock); + list_add(&node->ctx_node, &ctx->tctx_list); + mutex_unlock(&ctx->uring_lock); + } + return 0; +} + +int __io_uring_add_tctx_node_from_submit(struct io_ring_ctx *ctx) +{ + int ret; + + if (ctx->flags & IORING_SETUP_SINGLE_ISSUER + && ctx->submitter_task != current) + return -EEXIST; + + ret = __io_uring_add_tctx_node(ctx); + if (ret) + return ret; + + current->io_uring->last = ctx; + return 0; +} + +/* + * Remove this io_uring_file -> task mapping. + */ +__cold void io_uring_del_tctx_node(unsigned long index) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_node *node; + + if (!tctx) + return; + node = xa_erase(&tctx->xa, index); + if (!node) + return; + + WARN_ON_ONCE(current != node->task); + WARN_ON_ONCE(list_empty(&node->ctx_node)); + + mutex_lock(&node->ctx->uring_lock); + list_del(&node->ctx_node); + mutex_unlock(&node->ctx->uring_lock); + + if (tctx->last == node->ctx) + tctx->last = NULL; + kfree(node); +} + +__cold void io_uring_clean_tctx(struct io_uring_task *tctx) +{ + struct io_wq *wq = tctx->io_wq; + struct io_tctx_node *node; + unsigned long index; + + xa_for_each(&tctx->xa, index, node) { + io_uring_del_tctx_node(index); + cond_resched(); + } + if (wq) { + /* + * Must be after io_uring_del_tctx_node() (removes nodes under + * uring_lock) to avoid race with io_uring_try_cancel_iowq(). + */ + io_wq_put_and_exit(wq); + tctx->io_wq = NULL; + } +} + +void io_uring_unreg_ringfd(void) +{ + struct io_uring_task *tctx = current->io_uring; + int i; + + for (i = 0; i < IO_RINGFD_REG_MAX; i++) { + if (tctx->registered_rings[i]) { + fput(tctx->registered_rings[i]); + tctx->registered_rings[i] = NULL; + } + } +} + +int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file, + int start, int end) +{ + int offset; + for (offset = start; offset < end; offset++) { + offset = array_index_nospec(offset, IO_RINGFD_REG_MAX); + if (tctx->registered_rings[offset]) + continue; + + tctx->registered_rings[offset] = file; + return offset; + } + return -EBUSY; +} + +static int io_ring_add_registered_fd(struct io_uring_task *tctx, int fd, + int start, int end) +{ + struct file *file; + int offset; + + file = fget(fd); + if (!file) { + return -EBADF; + } else if (!io_is_uring_fops(file)) { + fput(file); + return -EOPNOTSUPP; + } + offset = io_ring_add_registered_file(tctx, file, start, end); + if (offset < 0) + fput(file); + return offset; +} + +/* + * Register a ring fd to avoid fdget/fdput for each io_uring_enter() + * invocation. User passes in an array of struct io_uring_rsrc_update + * with ->data set to the ring_fd, and ->offset given for the desired + * index. If no index is desired, application may set ->offset == -1U + * and we'll find an available index. Returns number of entries + * successfully processed, or < 0 on error if none were processed. + */ +int io_ringfd_register(struct io_ring_ctx *ctx, void __user *__arg, + unsigned nr_args) +{ + struct io_uring_rsrc_update __user *arg = __arg; + struct io_uring_rsrc_update reg; + struct io_uring_task *tctx; + int ret, i; + + if (!nr_args || nr_args > IO_RINGFD_REG_MAX) + return -EINVAL; + + mutex_unlock(&ctx->uring_lock); + ret = __io_uring_add_tctx_node(ctx); + mutex_lock(&ctx->uring_lock); + if (ret) + return ret; + + tctx = current->io_uring; + for (i = 0; i < nr_args; i++) { + int start, end; + + if (copy_from_user(®, &arg[i], sizeof(reg))) { + ret = -EFAULT; + break; + } + + if (reg.resv) { + ret = -EINVAL; + break; + } + + if (reg.offset == -1U) { + start = 0; + end = IO_RINGFD_REG_MAX; + } else { + if (reg.offset >= IO_RINGFD_REG_MAX) { + ret = -EINVAL; + break; + } + start = reg.offset; + end = start + 1; + } + + ret = io_ring_add_registered_fd(tctx, reg.data, start, end); + if (ret < 0) + break; + + reg.offset = ret; + if (copy_to_user(&arg[i], ®, sizeof(reg))) { + fput(tctx->registered_rings[reg.offset]); + tctx->registered_rings[reg.offset] = NULL; + ret = -EFAULT; + break; + } + } + + return i ? i : ret; +} + +int io_ringfd_unregister(struct io_ring_ctx *ctx, void __user *__arg, + unsigned nr_args) +{ + struct io_uring_rsrc_update __user *arg = __arg; + struct io_uring_task *tctx = current->io_uring; + struct io_uring_rsrc_update reg; + int ret = 0, i; + + if (!nr_args || nr_args > IO_RINGFD_REG_MAX) + return -EINVAL; + if (!tctx) + return 0; + + for (i = 0; i < nr_args; i++) { + if (copy_from_user(®, &arg[i], sizeof(reg))) { + ret = -EFAULT; + break; + } + if (reg.resv || reg.data || reg.offset >= IO_RINGFD_REG_MAX) { + ret = -EINVAL; + break; + } + + reg.offset = array_index_nospec(reg.offset, IO_RINGFD_REG_MAX); + if (tctx->registered_rings[reg.offset]) { + fput(tctx->registered_rings[reg.offset]); + tctx->registered_rings[reg.offset] = NULL; + } + } + + return i ? i : ret; +} diff --git a/io_uring/tctx.h b/io_uring/tctx.h new file mode 100644 index 000000000000..608e96de70a2 --- /dev/null +++ b/io_uring/tctx.h @@ -0,0 +1,33 @@ +// SPDX-License-Identifier: GPL-2.0 + +struct io_tctx_node { + struct list_head ctx_node; + struct task_struct *task; + struct io_ring_ctx *ctx; +}; + +int io_uring_alloc_task_context(struct task_struct *task, + struct io_ring_ctx *ctx); +void io_uring_del_tctx_node(unsigned long index); +int __io_uring_add_tctx_node(struct io_ring_ctx *ctx); +int __io_uring_add_tctx_node_from_submit(struct io_ring_ctx *ctx); +void io_uring_clean_tctx(struct io_uring_task *tctx); + +void io_uring_unreg_ringfd(void); +int io_ringfd_register(struct io_ring_ctx *ctx, void __user *__arg, + unsigned nr_args); +int io_ringfd_unregister(struct io_ring_ctx *ctx, void __user *__arg, + unsigned nr_args); + +/* + * Note that this task has used io_uring. We use it for cancelation purposes. + */ +static inline int io_uring_add_tctx_node(struct io_ring_ctx *ctx) +{ + struct io_uring_task *tctx = current->io_uring; + + if (likely(tctx && tctx->last == ctx)) + return 0; + + return __io_uring_add_tctx_node_from_submit(ctx); +} diff --git a/io_uring/timeout.c b/io_uring/timeout.c new file mode 100644 index 000000000000..d8fbbaf31cf3 --- /dev/null +++ b/io_uring/timeout.c @@ -0,0 +1,708 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/io_uring.h> + +#include <trace/events/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "refs.h" +#include "cancel.h" +#include "timeout.h" + +struct io_timeout { + struct file *file; + u32 off; + u32 target_seq; + u32 repeats; + struct list_head list; + /* head of the link, used by linked timeouts only */ + struct io_kiocb *head; + /* for linked completions */ + struct io_kiocb *prev; +}; + +struct io_timeout_rem { + struct file *file; + u64 addr; + + /* timeout update */ + struct timespec64 ts; + u32 flags; + bool ltimeout; +}; + +static struct io_kiocb *__io_disarm_linked_timeout(struct io_kiocb *req, + struct io_kiocb *link); + +static inline bool io_is_timeout_noseq(struct io_kiocb *req) +{ + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_timeout_data *data = req->async_data; + + return !timeout->off || data->flags & IORING_TIMEOUT_MULTISHOT; +} + +static inline void io_put_req(struct io_kiocb *req) +{ + if (req_ref_put_and_test(req)) { + io_queue_next(req); + io_free_req(req); + } +} + +static inline bool io_timeout_finish(struct io_timeout *timeout, + struct io_timeout_data *data) +{ + if (!(data->flags & IORING_TIMEOUT_MULTISHOT)) + return true; + + if (!timeout->off || (timeout->repeats && --timeout->repeats)) + return false; + + return true; +} + +static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer); + +static void io_timeout_complete(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_timeout_data *data = req->async_data; + struct io_ring_ctx *ctx = req->ctx; + + if (!io_timeout_finish(timeout, data)) { + if (io_req_post_cqe(req, -ETIME, IORING_CQE_F_MORE)) { + /* re-arm timer */ + raw_spin_lock_irq(&ctx->timeout_lock); + list_add(&timeout->list, ctx->timeout_list.prev); + hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); + raw_spin_unlock_irq(&ctx->timeout_lock); + return; + } + } + + io_req_task_complete(tw_req, tw); +} + +static __cold bool io_flush_killed_timeouts(struct list_head *list, int err) +{ + if (list_empty(list)) + return false; + + while (!list_empty(list)) { + struct io_timeout *timeout; + struct io_kiocb *req; + + timeout = list_first_entry(list, struct io_timeout, list); + list_del_init(&timeout->list); + req = cmd_to_io_kiocb(timeout); + if (err) + req_set_fail(req); + io_req_queue_tw_complete(req, err); + } + + return true; +} + +static void io_kill_timeout(struct io_kiocb *req, struct list_head *list) + __must_hold(&req->ctx->timeout_lock) +{ + struct io_timeout_data *io = req->async_data; + + if (hrtimer_try_to_cancel(&io->timer) != -1) { + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + + atomic_set(&req->ctx->cq_timeouts, + atomic_read(&req->ctx->cq_timeouts) + 1); + list_move_tail(&timeout->list, list); + } +} + +__cold void io_flush_timeouts(struct io_ring_ctx *ctx) +{ + struct io_timeout *timeout, *tmp; + LIST_HEAD(list); + u32 seq; + + raw_spin_lock_irq(&ctx->timeout_lock); + seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); + + list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) { + struct io_kiocb *req = cmd_to_io_kiocb(timeout); + u32 events_needed, events_got; + + if (io_is_timeout_noseq(req)) + break; + + /* + * Since seq can easily wrap around over time, subtract + * the last seq at which timeouts were flushed before comparing. + * Assuming not more than 2^31-1 events have happened since, + * these subtractions won't have wrapped, so we can check if + * target is in [last_seq, current_seq] by comparing the two. + */ + events_needed = timeout->target_seq - ctx->cq_last_tm_flush; + events_got = seq - ctx->cq_last_tm_flush; + if (events_got < events_needed) + break; + + io_kill_timeout(req, &list); + } + ctx->cq_last_tm_flush = seq; + raw_spin_unlock_irq(&ctx->timeout_lock); + io_flush_killed_timeouts(&list, 0); +} + +static void io_req_tw_fail_links(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *link = tw_req.req; + + io_tw_lock(link->ctx, tw); + while (link) { + struct io_kiocb *nxt = link->link; + long res = -ECANCELED; + + if (link->flags & REQ_F_FAIL) + res = link->cqe.res; + link->link = NULL; + io_req_set_res(link, res, 0); + io_req_task_complete((struct io_tw_req){link}, tw); + link = nxt; + } +} + +static void io_fail_links(struct io_kiocb *req) + __must_hold(&req->ctx->completion_lock) +{ + struct io_kiocb *link = req->link; + bool ignore_cqes = req->flags & REQ_F_SKIP_LINK_CQES; + + if (!link) + return; + + while (link) { + if (ignore_cqes) + link->flags |= REQ_F_CQE_SKIP; + else + link->flags &= ~REQ_F_CQE_SKIP; + trace_io_uring_fail_link(req, link); + link = link->link; + } + + link = req->link; + link->io_task_work.func = io_req_tw_fail_links; + io_req_task_work_add(link); + req->link = NULL; +} + +static inline void io_remove_next_linked(struct io_kiocb *req) +{ + struct io_kiocb *nxt = req->link; + + req->link = nxt->link; + nxt->link = NULL; +} + +void io_disarm_next(struct io_kiocb *req) + __must_hold(&req->ctx->completion_lock) +{ + struct io_kiocb *link = NULL; + + if (req->flags & REQ_F_ARM_LTIMEOUT) { + link = req->link; + req->flags &= ~REQ_F_ARM_LTIMEOUT; + if (link && link->opcode == IORING_OP_LINK_TIMEOUT) { + io_remove_next_linked(req); + io_req_queue_tw_complete(link, -ECANCELED); + } + } else if (req->flags & REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = req->ctx; + + raw_spin_lock_irq(&ctx->timeout_lock); + if (req->link && req->link->opcode == IORING_OP_LINK_TIMEOUT) + link = __io_disarm_linked_timeout(req, req->link); + + raw_spin_unlock_irq(&ctx->timeout_lock); + if (link) + io_req_queue_tw_complete(link, -ECANCELED); + } + if (unlikely((req->flags & REQ_F_FAIL) && + !(req->flags & REQ_F_HARDLINK))) + io_fail_links(req); +} + +static struct io_kiocb *__io_disarm_linked_timeout(struct io_kiocb *req, + struct io_kiocb *link) + __must_hold(&req->ctx->completion_lock) + __must_hold(&req->ctx->timeout_lock) +{ + struct io_timeout_data *io = link->async_data; + struct io_timeout *timeout = io_kiocb_to_cmd(link, struct io_timeout); + + io_remove_next_linked(req); + timeout->head = NULL; + if (hrtimer_try_to_cancel(&io->timer) != -1) { + list_del(&timeout->list); + return link; + } + + return NULL; +} + +static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) +{ + struct io_timeout_data *data = container_of(timer, + struct io_timeout_data, timer); + struct io_kiocb *req = data->req; + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_ring_ctx *ctx = req->ctx; + unsigned long flags; + + raw_spin_lock_irqsave(&ctx->timeout_lock, flags); + list_del_init(&timeout->list); + atomic_set(&req->ctx->cq_timeouts, + atomic_read(&req->ctx->cq_timeouts) + 1); + raw_spin_unlock_irqrestore(&ctx->timeout_lock, flags); + + if (!(data->flags & IORING_TIMEOUT_ETIME_SUCCESS)) + req_set_fail(req); + + io_req_set_res(req, -ETIME, 0); + req->io_task_work.func = io_timeout_complete; + io_req_task_work_add(req); + return HRTIMER_NORESTART; +} + +static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx, + struct io_cancel_data *cd) + __must_hold(&ctx->timeout_lock) +{ + struct io_timeout *timeout; + struct io_timeout_data *io; + struct io_kiocb *req = NULL; + + list_for_each_entry(timeout, &ctx->timeout_list, list) { + struct io_kiocb *tmp = cmd_to_io_kiocb(timeout); + + if (io_cancel_req_match(tmp, cd)) { + req = tmp; + break; + } + } + if (!req) + return ERR_PTR(-ENOENT); + + io = req->async_data; + if (hrtimer_try_to_cancel(&io->timer) == -1) + return ERR_PTR(-EALREADY); + timeout = io_kiocb_to_cmd(req, struct io_timeout); + list_del_init(&timeout->list); + return req; +} + +int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd) + __must_hold(&ctx->completion_lock) +{ + struct io_kiocb *req; + + raw_spin_lock_irq(&ctx->timeout_lock); + req = io_timeout_extract(ctx, cd); + raw_spin_unlock_irq(&ctx->timeout_lock); + + if (IS_ERR(req)) + return PTR_ERR(req); + io_req_task_queue_fail(req, -ECANCELED); + return 0; +} + +static void io_req_task_link_timeout(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_kiocb *prev = timeout->prev; + int ret; + + if (prev) { + if (!tw.cancel) { + struct io_cancel_data cd = { + .ctx = req->ctx, + .data = prev->cqe.user_data, + }; + + ret = io_try_cancel(req->tctx, &cd, 0); + } else { + ret = -ECANCELED; + } + io_req_set_res(req, ret ?: -ETIME, 0); + io_req_task_complete(tw_req, tw); + io_put_req(prev); + } else { + io_req_set_res(req, -ETIME, 0); + io_req_task_complete(tw_req, tw); + } +} + +static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) +{ + struct io_timeout_data *data = container_of(timer, + struct io_timeout_data, timer); + struct io_kiocb *prev, *req = data->req; + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_ring_ctx *ctx = req->ctx; + unsigned long flags; + + raw_spin_lock_irqsave(&ctx->timeout_lock, flags); + prev = timeout->head; + timeout->head = NULL; + + /* + * We don't expect the list to be empty, that will only happen if we + * race with the completion of the linked work. + */ + if (prev) { + io_remove_next_linked(prev); + if (!req_ref_inc_not_zero(prev)) + prev = NULL; + } + list_del(&timeout->list); + timeout->prev = prev; + raw_spin_unlock_irqrestore(&ctx->timeout_lock, flags); + + req->io_task_work.func = io_req_task_link_timeout; + io_req_task_work_add(req); + return HRTIMER_NORESTART; +} + +static clockid_t io_timeout_get_clock(struct io_timeout_data *data) +{ + switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) { + case IORING_TIMEOUT_BOOTTIME: + return CLOCK_BOOTTIME; + case IORING_TIMEOUT_REALTIME: + return CLOCK_REALTIME; + default: + /* can't happen, vetted at prep time */ + WARN_ON_ONCE(1); + fallthrough; + case 0: + return CLOCK_MONOTONIC; + } +} + +static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data, + struct timespec64 *ts, enum hrtimer_mode mode) + __must_hold(&ctx->timeout_lock) +{ + struct io_timeout_data *io; + struct io_timeout *timeout; + struct io_kiocb *req = NULL; + + list_for_each_entry(timeout, &ctx->ltimeout_list, list) { + struct io_kiocb *tmp = cmd_to_io_kiocb(timeout); + + if (user_data == tmp->cqe.user_data) { + req = tmp; + break; + } + } + if (!req) + return -ENOENT; + + io = req->async_data; + if (hrtimer_try_to_cancel(&io->timer) == -1) + return -EALREADY; + hrtimer_setup(&io->timer, io_link_timeout_fn, io_timeout_get_clock(io), mode); + hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode); + return 0; +} + +static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data, + struct timespec64 *ts, enum hrtimer_mode mode) + __must_hold(&ctx->timeout_lock) +{ + struct io_cancel_data cd = { .ctx = ctx, .data = user_data, }; + struct io_kiocb *req = io_timeout_extract(ctx, &cd); + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_timeout_data *data; + + if (IS_ERR(req)) + return PTR_ERR(req); + + timeout->off = 0; /* noseq */ + data = req->async_data; + data->ts = *ts; + + list_add_tail(&timeout->list, &ctx->timeout_list); + hrtimer_setup(&data->timer, io_timeout_fn, io_timeout_get_clock(data), mode); + hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), mode); + return 0; +} + +int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem); + + if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) + return -EINVAL; + if (sqe->buf_index || sqe->len || sqe->splice_fd_in) + return -EINVAL; + + tr->ltimeout = false; + tr->addr = READ_ONCE(sqe->addr); + tr->flags = READ_ONCE(sqe->timeout_flags); + if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) { + if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1) + return -EINVAL; + if (tr->flags & IORING_LINK_TIMEOUT_UPDATE) + tr->ltimeout = true; + if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS)) + return -EINVAL; + if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2))) + return -EFAULT; + if (tr->ts.tv_sec < 0 || tr->ts.tv_nsec < 0) + return -EINVAL; + } else if (tr->flags) { + /* timeout removal doesn't support flags */ + return -EINVAL; + } + + return 0; +} + +static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags) +{ + return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS + : HRTIMER_MODE_REL; +} + +/* + * Remove or update an existing timeout command + */ +int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem); + struct io_ring_ctx *ctx = req->ctx; + int ret; + + if (!(tr->flags & IORING_TIMEOUT_UPDATE)) { + struct io_cancel_data cd = { .ctx = ctx, .data = tr->addr, }; + + spin_lock(&ctx->completion_lock); + ret = io_timeout_cancel(ctx, &cd); + spin_unlock(&ctx->completion_lock); + } else { + enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags); + + raw_spin_lock_irq(&ctx->timeout_lock); + if (tr->ltimeout) + ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode); + else + ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode); + raw_spin_unlock_irq(&ctx->timeout_lock); + } + + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +static int __io_timeout_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe, + bool is_timeout_link) +{ + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_timeout_data *data; + unsigned flags; + u32 off = READ_ONCE(sqe->off); + + if (sqe->buf_index || sqe->len != 1 || sqe->splice_fd_in) + return -EINVAL; + if (off && is_timeout_link) + return -EINVAL; + flags = READ_ONCE(sqe->timeout_flags); + if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK | + IORING_TIMEOUT_ETIME_SUCCESS | + IORING_TIMEOUT_MULTISHOT)) + return -EINVAL; + /* more than one clock specified is invalid, obviously */ + if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1) + return -EINVAL; + /* multishot requests only make sense with rel values */ + if (!(~flags & (IORING_TIMEOUT_MULTISHOT | IORING_TIMEOUT_ABS))) + return -EINVAL; + + INIT_LIST_HEAD(&timeout->list); + timeout->off = off; + if (unlikely(off && !req->ctx->off_timeout_used)) + req->ctx->off_timeout_used = true; + /* + * for multishot reqs w/ fixed nr of repeats, repeats tracks the + * remaining nr + */ + timeout->repeats = 0; + if ((flags & IORING_TIMEOUT_MULTISHOT) && off > 0) + timeout->repeats = off; + + if (WARN_ON_ONCE(req_has_async_data(req))) + return -EFAULT; + data = io_uring_alloc_async_data(NULL, req); + if (!data) + return -ENOMEM; + data->req = req; + data->flags = flags; + + if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) + return -EFAULT; + + if (data->ts.tv_sec < 0 || data->ts.tv_nsec < 0) + return -EINVAL; + + data->mode = io_translate_timeout_mode(flags); + + if (is_timeout_link) { + struct io_submit_link *link = &req->ctx->submit_state.link; + + if (!link->head) + return -EINVAL; + if (link->last->opcode == IORING_OP_LINK_TIMEOUT) + return -EINVAL; + timeout->head = link->last; + link->last->flags |= REQ_F_ARM_LTIMEOUT; + hrtimer_setup(&data->timer, io_link_timeout_fn, io_timeout_get_clock(data), + data->mode); + } else { + hrtimer_setup(&data->timer, io_timeout_fn, io_timeout_get_clock(data), data->mode); + } + return 0; +} + +int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_timeout_prep(req, sqe, false); +} + +int io_link_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_timeout_prep(req, sqe, true); +} + +int io_timeout(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_ring_ctx *ctx = req->ctx; + struct io_timeout_data *data = req->async_data; + struct list_head *entry; + u32 tail, off = timeout->off; + + raw_spin_lock_irq(&ctx->timeout_lock); + + /* + * sqe->off holds how many events that need to occur for this + * timeout event to be satisfied. If it isn't set, then this is + * a pure timeout request, sequence isn't used. + */ + if (io_is_timeout_noseq(req)) { + entry = ctx->timeout_list.prev; + goto add; + } + + tail = data_race(ctx->cached_cq_tail) - atomic_read(&ctx->cq_timeouts); + timeout->target_seq = tail + off; + + /* Update the last seq here in case io_flush_timeouts() hasn't. + * This is safe because ->completion_lock is held, and submissions + * and completions are never mixed in the same ->completion_lock section. + */ + ctx->cq_last_tm_flush = tail; + + /* + * Insertion sort, ensuring the first entry in the list is always + * the one we need first. + */ + list_for_each_prev(entry, &ctx->timeout_list) { + struct io_timeout *nextt = list_entry(entry, struct io_timeout, list); + struct io_kiocb *nxt = cmd_to_io_kiocb(nextt); + + if (io_is_timeout_noseq(nxt)) + continue; + /* nxt.seq is behind @tail, otherwise would've been completed */ + if (off >= nextt->target_seq - tail) + break; + } +add: + list_add(&timeout->list, entry); + hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); + raw_spin_unlock_irq(&ctx->timeout_lock); + return IOU_ISSUE_SKIP_COMPLETE; +} + +void io_queue_linked_timeout(struct io_kiocb *req) +{ + struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); + struct io_ring_ctx *ctx = req->ctx; + + raw_spin_lock_irq(&ctx->timeout_lock); + /* + * If the back reference is NULL, then our linked request finished + * before we got a chance to setup the timer + */ + if (timeout->head) { + struct io_timeout_data *data = req->async_data; + + hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), + data->mode); + list_add_tail(&timeout->list, &ctx->ltimeout_list); + } + raw_spin_unlock_irq(&ctx->timeout_lock); + /* drop submission reference */ + io_put_req(req); +} + +static bool io_match_task(struct io_kiocb *head, struct io_uring_task *tctx, + bool cancel_all) + __must_hold(&head->ctx->timeout_lock) +{ + struct io_kiocb *req; + + if (tctx && head->tctx != tctx) + return false; + if (cancel_all) + return true; + + io_for_each_link(req, head) { + if (req->flags & REQ_F_INFLIGHT) + return true; + } + return false; +} + +/* Returns true if we found and killed one or more timeouts */ +__cold bool io_kill_timeouts(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all) +{ + struct io_timeout *timeout, *tmp; + LIST_HEAD(list); + + /* + * completion_lock is needed for io_match_task(). Take it before + * timeout_lockfirst to keep locking ordering. + */ + spin_lock(&ctx->completion_lock); + raw_spin_lock_irq(&ctx->timeout_lock); + list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) { + struct io_kiocb *req = cmd_to_io_kiocb(timeout); + + if (io_match_task(req, tctx, cancel_all)) + io_kill_timeout(req, &list); + } + raw_spin_unlock_irq(&ctx->timeout_lock); + spin_unlock(&ctx->completion_lock); + + return io_flush_killed_timeouts(&list, -ECANCELED); +} diff --git a/io_uring/timeout.h b/io_uring/timeout.h new file mode 100644 index 000000000000..2b7c9ad72992 --- /dev/null +++ b/io_uring/timeout.h @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 + +struct io_timeout_data { + struct io_kiocb *req; + struct hrtimer timer; + struct timespec64 ts; + enum hrtimer_mode mode; + u32 flags; +}; + +__cold void io_flush_timeouts(struct io_ring_ctx *ctx); +struct io_cancel_data; +int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd); +__cold bool io_kill_timeouts(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all); +void io_queue_linked_timeout(struct io_kiocb *req); +void io_disarm_next(struct io_kiocb *req); + +int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_link_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_timeout(struct io_kiocb *req, unsigned int issue_flags); +int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/truncate.c b/io_uring/truncate.c new file mode 100644 index 000000000000..487baf23b44e --- /dev/null +++ b/io_uring/truncate.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/syscalls.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "../fs/internal.h" + +#include "io_uring.h" +#include "truncate.h" + +struct io_ftrunc { + struct file *file; + loff_t len; +}; + +int io_ftruncate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_ftrunc *ft = io_kiocb_to_cmd(req, struct io_ftrunc); + + if (sqe->rw_flags || sqe->addr || sqe->len || sqe->buf_index || + sqe->splice_fd_in || sqe->addr3) + return -EINVAL; + + ft->len = READ_ONCE(sqe->off); + + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_ftruncate(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ftrunc *ft = io_kiocb_to_cmd(req, struct io_ftrunc); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_ftruncate(req->file, ft->len, 1); + + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/truncate.h b/io_uring/truncate.h new file mode 100644 index 000000000000..ec088293a478 --- /dev/null +++ b/io_uring/truncate.h @@ -0,0 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 + +int io_ftruncate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_ftruncate(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c new file mode 100644 index 000000000000..197474911f04 --- /dev/null +++ b/io_uring/uring_cmd.c @@ -0,0 +1,400 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/io_uring/cmd.h> +#include <linux/security.h> +#include <linux/nospec.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "alloc_cache.h" +#include "rsrc.h" +#include "kbuf.h" +#include "uring_cmd.h" +#include "poll.h" + +void io_cmd_cache_free(const void *entry) +{ + struct io_async_cmd *ac = (struct io_async_cmd *)entry; + + io_vec_free(&ac->vec); + kfree(ac); +} + +static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + struct io_async_cmd *ac = req->async_data; + + if (issue_flags & IO_URING_F_UNLOCKED) + return; + + io_alloc_cache_vec_kasan(&ac->vec); + if (ac->vec.nr > IO_VEC_CACHE_SOFT_CAP) + io_vec_free(&ac->vec); + + if (io_alloc_cache_put(&req->ctx->cmd_cache, ac)) { + ioucmd->sqe = NULL; + io_req_async_data_clear(req, REQ_F_NEED_CLEANUP); + } +} + +void io_uring_cmd_cleanup(struct io_kiocb *req) +{ + io_req_uring_cleanup(req, 0); +} + +bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, bool cancel_all) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + bool ret = false; + + lockdep_assert_held(&ctx->uring_lock); + + hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd, + hash_node) { + struct io_uring_cmd *cmd = io_kiocb_to_cmd(req, + struct io_uring_cmd); + struct file *file = req->file; + + if (!cancel_all && req->tctx != tctx) + continue; + + if (cmd->flags & IORING_URING_CMD_CANCELABLE) { + file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL | + IO_URING_F_COMPLETE_DEFER); + ret = true; + } + } + io_submit_flush_completions(ctx); + return ret; +} + +static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_ring_ctx *ctx = req->ctx; + + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) + return; + + cmd->flags &= ~IORING_URING_CMD_CANCELABLE; + io_ring_submit_lock(ctx, issue_flags); + hlist_del(&req->hash_node); + io_ring_submit_unlock(ctx, issue_flags); +} + +/* + * Mark this command as concelable, then io_uring_try_cancel_uring_cmd() + * will try to cancel this issued command by sending ->uring_cmd() with + * issue_flags of IO_URING_F_CANCEL. + * + * The command is guaranteed to not be done when calling ->uring_cmd() + * with IO_URING_F_CANCEL, but it is driver's responsibility to deal + * with race between io_uring canceling and normal completion. + */ +void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_ring_ctx *ctx = req->ctx; + + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) { + cmd->flags |= IORING_URING_CMD_CANCELABLE; + io_ring_submit_lock(ctx, issue_flags); + hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd); + io_ring_submit_unlock(ctx, issue_flags); + } +} +EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); + +void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, + io_req_tw_func_t task_work_cb, + unsigned flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + + if (WARN_ON_ONCE(req->flags & REQ_F_APOLL_MULTISHOT)) + return; + + req->io_task_work.func = task_work_cb; + __io_req_task_work_add(req, flags); +} +EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task); + +static inline void io_req_set_cqe32_extra(struct io_kiocb *req, + u64 extra1, u64 extra2) +{ + req->big_cqe.extra1 = extra1; + req->big_cqe.extra2 = extra2; +} + +/* + * Called by consumers of io_uring_cmd, if they originally returned + * -EIOCBQUEUED upon receiving the command. + */ +void __io_uring_cmd_done(struct io_uring_cmd *ioucmd, s32 ret, u64 res2, + unsigned issue_flags, bool is_cqe32) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + + if (WARN_ON_ONCE(req->flags & REQ_F_APOLL_MULTISHOT)) + return; + + io_uring_cmd_del_cancelable(ioucmd, issue_flags); + + if (ret < 0) + req_set_fail(req); + + io_req_set_res(req, ret, 0); + if (is_cqe32) { + if (req->ctx->flags & IORING_SETUP_CQE_MIXED) + req->cqe.flags |= IORING_CQE_F_32; + io_req_set_cqe32_extra(req, res2, 0); + } + io_req_uring_cleanup(req, issue_flags); + if (req->ctx->flags & IORING_SETUP_IOPOLL) { + /* order with io_iopoll_req_issued() checking ->iopoll_complete */ + smp_store_release(&req->iopoll_completed, 1); + } else if (issue_flags & IO_URING_F_COMPLETE_DEFER) { + if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED)) + return; + io_req_complete_defer(req); + } else { + req->io_task_work.func = io_req_task_complete; + io_req_task_work_add(req); + } +} +EXPORT_SYMBOL_GPL(__io_uring_cmd_done); + +int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + struct io_async_cmd *ac; + + if (sqe->__pad1) + return -EINVAL; + + ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags); + if (ioucmd->flags & ~IORING_URING_CMD_MASK) + return -EINVAL; + + if (ioucmd->flags & IORING_URING_CMD_FIXED) { + if (ioucmd->flags & IORING_URING_CMD_MULTISHOT) + return -EINVAL; + req->buf_index = READ_ONCE(sqe->buf_index); + } + + if (!!(ioucmd->flags & IORING_URING_CMD_MULTISHOT) != + !!(req->flags & REQ_F_BUFFER_SELECT)) + return -EINVAL; + + ioucmd->cmd_op = READ_ONCE(sqe->cmd_op); + + ac = io_uring_alloc_async_data(&req->ctx->cmd_cache, req); + if (!ac) + return -ENOMEM; + ioucmd->sqe = sqe; + return 0; +} + +/* + * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each + * slot. + */ +static inline size_t uring_sqe_size(struct io_kiocb *req) +{ + if (req->ctx->flags & IORING_SETUP_SQE128 || + req->opcode == IORING_OP_URING_CMD128) + return 2 * sizeof(struct io_uring_sqe); + return sizeof(struct io_uring_sqe); +} + +void io_uring_cmd_sqe_copy(struct io_kiocb *req) +{ + struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + struct io_async_cmd *ac = req->async_data; + + /* Should not happen, as REQ_F_SQE_COPIED covers this */ + if (WARN_ON_ONCE(ioucmd->sqe == ac->sqes)) + return; + memcpy(ac->sqes, ioucmd->sqe, uring_sqe_size(req)); + ioucmd->sqe = ac->sqes; +} + +int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + struct io_ring_ctx *ctx = req->ctx; + struct file *file = req->file; + int ret; + + if (!file->f_op->uring_cmd) + return -EOPNOTSUPP; + + ret = security_uring_cmd(ioucmd); + if (ret) + return ret; + + if (ctx->flags & IORING_SETUP_SQE128 || + req->opcode == IORING_OP_URING_CMD128) + issue_flags |= IO_URING_F_SQE128; + if (ctx->flags & (IORING_SETUP_CQE32 | IORING_SETUP_CQE_MIXED)) + issue_flags |= IO_URING_F_CQE32; + if (io_is_compat(ctx)) + issue_flags |= IO_URING_F_COMPAT; + if (ctx->flags & IORING_SETUP_IOPOLL) { + if (!file->f_op->uring_cmd_iopoll) + return -EOPNOTSUPP; + issue_flags |= IO_URING_F_IOPOLL; + req->iopoll_completed = 0; + if (ctx->flags & IORING_SETUP_HYBRID_IOPOLL) { + /* make sure every req only blocks once */ + req->flags &= ~REQ_F_IOPOLL_STATE; + req->iopoll_start = ktime_get_ns(); + } + } + + ret = file->f_op->uring_cmd(ioucmd, issue_flags); + if (ioucmd->flags & IORING_URING_CMD_MULTISHOT) { + if (ret >= 0) + return IOU_ISSUE_SKIP_COMPLETE; + } + if (ret == -EAGAIN) { + ioucmd->flags |= IORING_URING_CMD_REISSUE; + return ret; + } + if (ret == -EIOCBQUEUED) + return ret; + if (ret < 0) + req_set_fail(req); + io_req_uring_cleanup(req, issue_flags); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, + struct iov_iter *iter, + struct io_uring_cmd *ioucmd, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + + if (WARN_ON_ONCE(!(ioucmd->flags & IORING_URING_CMD_FIXED))) + return -EINVAL; + + return io_import_reg_buf(req, iter, ubuf, len, rw, issue_flags); +} +EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed); + +int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd, + const struct iovec __user *uvec, + size_t uvec_segs, + int ddir, struct iov_iter *iter, + unsigned issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + struct io_async_cmd *ac = req->async_data; + int ret; + + if (WARN_ON_ONCE(!(ioucmd->flags & IORING_URING_CMD_FIXED))) + return -EINVAL; + + ret = io_prep_reg_iovec(req, &ac->vec, uvec, uvec_segs); + if (ret) + return ret; + + return io_import_reg_vec(ddir, iter, req, &ac->vec, uvec_segs, + issue_flags); +} +EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed_vec); + +void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + + io_req_queue_iowq(req); +} + +int io_cmd_poll_multishot(struct io_uring_cmd *cmd, + unsigned int issue_flags, __poll_t mask) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + int ret; + + if (likely(req->flags & REQ_F_APOLL_MULTISHOT)) + return 0; + + req->flags |= REQ_F_APOLL_MULTISHOT; + mask &= ~EPOLLONESHOT; + + ret = io_arm_apoll(req, issue_flags, mask); + return ret == IO_APOLL_OK ? -EIOCBQUEUED : -ECANCELED; +} + +bool io_uring_cmd_post_mshot_cqe32(struct io_uring_cmd *cmd, + unsigned int issue_flags, + struct io_uring_cqe cqe[2]) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + + if (WARN_ON_ONCE(!(issue_flags & IO_URING_F_MULTISHOT))) + return false; + return io_req_post_cqe32(req, cqe); +} + +/* + * Work with io_uring_mshot_cmd_post_cqe() together for committing the + * provided buffer upfront + */ +struct io_br_sel io_uring_cmd_buffer_select(struct io_uring_cmd *ioucmd, + unsigned buf_group, size_t *len, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + + if (!(ioucmd->flags & IORING_URING_CMD_MULTISHOT)) + return (struct io_br_sel) { .val = -EINVAL }; + + if (WARN_ON_ONCE(!io_do_buffer_select(req))) + return (struct io_br_sel) { .val = -EINVAL }; + + return io_buffer_select(req, len, buf_group, issue_flags); +} +EXPORT_SYMBOL_GPL(io_uring_cmd_buffer_select); + +/* + * Return true if this multishot uring_cmd needs to be completed, otherwise + * the event CQE is posted successfully. + * + * This function must use `struct io_br_sel` returned from + * io_uring_cmd_buffer_select() for committing the buffer in the same + * uring_cmd submission context. + */ +bool io_uring_mshot_cmd_post_cqe(struct io_uring_cmd *ioucmd, + struct io_br_sel *sel, unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + unsigned int cflags = 0; + + if (!(ioucmd->flags & IORING_URING_CMD_MULTISHOT)) + return true; + + if (sel->val > 0) { + cflags = io_put_kbuf(req, sel->val, sel->buf_list); + if (io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) + return false; + } + + io_kbuf_recycle(req, sel->buf_list, issue_flags); + if (sel->val < 0) + req_set_fail(req); + io_req_set_res(req, sel->val, cflags); + return true; +} +EXPORT_SYMBOL_GPL(io_uring_mshot_cmd_post_cqe); diff --git a/io_uring/uring_cmd.h b/io_uring/uring_cmd.h new file mode 100644 index 000000000000..041aef8a8aa3 --- /dev/null +++ b/io_uring/uring_cmd.h @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/io_uring/cmd.h> +#include <linux/io_uring_types.h> + +struct io_async_cmd { + struct iou_vec vec; + struct io_uring_sqe sqes[2]; +}; + +int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags); +int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +void io_uring_cmd_sqe_copy(struct io_kiocb *req); +void io_uring_cmd_cleanup(struct io_kiocb *req); + +bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, bool cancel_all); + +bool io_uring_cmd_post_mshot_cqe32(struct io_uring_cmd *cmd, + unsigned int issue_flags, + struct io_uring_cqe cqe[2]); + +void io_cmd_cache_free(const void *entry); + +int io_cmd_poll_multishot(struct io_uring_cmd *cmd, + unsigned int issue_flags, __poll_t mask); diff --git a/io_uring/waitid.c b/io_uring/waitid.c new file mode 100644 index 000000000000..2d4cbd47c67c --- /dev/null +++ b/io_uring/waitid.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Support for async notification of waitid + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/compat.h> +#include <linux/io_uring.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "cancel.h" +#include "waitid.h" +#include "../kernel/exit.h" + +static void io_waitid_cb(struct io_tw_req tw_req, io_tw_token_t tw); + +#define IO_WAITID_CANCEL_FLAG BIT(31) +#define IO_WAITID_REF_MASK GENMASK(30, 0) + +struct io_waitid { + struct file *file; + int which; + pid_t upid; + int options; + atomic_t refs; + struct wait_queue_head *head; + struct siginfo __user *infop; + struct waitid_info info; +}; + +static void io_waitid_free(struct io_kiocb *req) +{ + struct io_waitid_async *iwa = req->async_data; + + put_pid(iwa->wo.wo_pid); + io_req_async_data_free(req); +} + +static bool io_waitid_compat_copy_si(struct io_waitid *iw, int signo) +{ + struct compat_siginfo __user *infop; + bool ret; + + infop = (struct compat_siginfo __user *) iw->infop; + + if (!user_write_access_begin(infop, sizeof(*infop))) + return false; + + unsafe_put_user(signo, &infop->si_signo, Efault); + unsafe_put_user(0, &infop->si_errno, Efault); + unsafe_put_user(iw->info.cause, &infop->si_code, Efault); + unsafe_put_user(iw->info.pid, &infop->si_pid, Efault); + unsafe_put_user(iw->info.uid, &infop->si_uid, Efault); + unsafe_put_user(iw->info.status, &infop->si_status, Efault); + ret = true; +done: + user_write_access_end(); + return ret; +Efault: + ret = false; + goto done; +} + +static bool io_waitid_copy_si(struct io_kiocb *req, int signo) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + bool ret; + + if (!iw->infop) + return true; + + if (io_is_compat(req->ctx)) + return io_waitid_compat_copy_si(iw, signo); + + if (!user_write_access_begin(iw->infop, sizeof(*iw->infop))) + return false; + + unsafe_put_user(signo, &iw->infop->si_signo, Efault); + unsafe_put_user(0, &iw->infop->si_errno, Efault); + unsafe_put_user(iw->info.cause, &iw->infop->si_code, Efault); + unsafe_put_user(iw->info.pid, &iw->infop->si_pid, Efault); + unsafe_put_user(iw->info.uid, &iw->infop->si_uid, Efault); + unsafe_put_user(iw->info.status, &iw->infop->si_status, Efault); + ret = true; +done: + user_write_access_end(); + return ret; +Efault: + ret = false; + goto done; +} + +static int io_waitid_finish(struct io_kiocb *req, int ret) +{ + int signo = 0; + + if (ret > 0) { + signo = SIGCHLD; + ret = 0; + } + + if (!io_waitid_copy_si(req, signo)) + ret = -EFAULT; + io_waitid_free(req); + return ret; +} + +static void io_waitid_remove_wq(struct io_kiocb *req) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + struct wait_queue_head *head; + + head = READ_ONCE(iw->head); + if (head) { + struct io_waitid_async *iwa = req->async_data; + + iw->head = NULL; + spin_lock_irq(&head->lock); + list_del_init(&iwa->wo.child_wait.entry); + spin_unlock_irq(&head->lock); + } +} + +static void io_waitid_complete(struct io_kiocb *req, int ret) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + + /* anyone completing better be holding a reference */ + WARN_ON_ONCE(!(atomic_read(&iw->refs) & IO_WAITID_REF_MASK)); + + lockdep_assert_held(&req->ctx->uring_lock); + + hlist_del_init(&req->hash_node); + io_waitid_remove_wq(req); + + ret = io_waitid_finish(req, ret); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); +} + +static bool __io_waitid_cancel(struct io_kiocb *req) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + + lockdep_assert_held(&req->ctx->uring_lock); + + /* + * Mark us canceled regardless of ownership. This will prevent a + * potential retry from a spurious wakeup. + */ + atomic_or(IO_WAITID_CANCEL_FLAG, &iw->refs); + + /* claim ownership */ + if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK) + return false; + + io_waitid_complete(req, -ECANCELED); + io_req_queue_tw_complete(req, -ECANCELED); + return true; +} + +int io_waitid_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags) +{ + return io_cancel_remove(ctx, cd, issue_flags, &ctx->waitid_list, __io_waitid_cancel); +} + +bool io_waitid_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all) +{ + return io_cancel_remove_all(ctx, tctx, &ctx->waitid_list, cancel_all, __io_waitid_cancel); +} + +static inline bool io_waitid_drop_issue_ref(struct io_kiocb *req) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + + if (!atomic_sub_return(1, &iw->refs)) + return false; + + io_waitid_remove_wq(req); + + /* + * Wakeup triggered, racing with us. It was prevented from + * completing because of that, queue up the tw to do that. + */ + req->io_task_work.func = io_waitid_cb; + io_req_task_work_add(req); + return true; +} + +static void io_waitid_cb(struct io_tw_req tw_req, io_tw_token_t tw) +{ + struct io_kiocb *req = tw_req.req; + struct io_waitid_async *iwa = req->async_data; + struct io_ring_ctx *ctx = req->ctx; + int ret; + + io_tw_lock(ctx, tw); + + ret = __do_wait(&iwa->wo); + + /* + * If we get -ERESTARTSYS here, we need to re-arm and check again + * to ensure we get another callback. If the retry works, then we can + * just remove ourselves from the waitqueue again and finish the + * request. + */ + if (unlikely(ret == -ERESTARTSYS)) { + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + + /* Don't retry if cancel found it meanwhile */ + ret = -ECANCELED; + if (!(atomic_read(&iw->refs) & IO_WAITID_CANCEL_FLAG)) { + iw->head = ¤t->signal->wait_chldexit; + add_wait_queue(iw->head, &iwa->wo.child_wait); + ret = __do_wait(&iwa->wo); + if (ret == -ERESTARTSYS) { + /* retry armed, drop our ref */ + io_waitid_drop_issue_ref(req); + return; + } + /* fall through to complete, will kill waitqueue */ + } + } + + io_waitid_complete(req, ret); + io_req_task_complete(tw_req, tw); +} + +static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode, + int sync, void *key) +{ + struct wait_opts *wo = container_of(wait, struct wait_opts, child_wait); + struct io_waitid_async *iwa = container_of(wo, struct io_waitid_async, wo); + struct io_kiocb *req = iwa->req; + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + struct task_struct *p = key; + + if (!pid_child_should_wake(wo, p)) + return 0; + + list_del_init(&wait->entry); + iw->head = NULL; + + /* cancel is in progress */ + if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK) + return 1; + + req->io_task_work.func = io_waitid_cb; + io_req_task_work_add(req); + return 1; +} + +int io_waitid_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + struct io_waitid_async *iwa; + + if (sqe->addr || sqe->buf_index || sqe->addr3 || sqe->waitid_flags) + return -EINVAL; + + iwa = io_uring_alloc_async_data(NULL, req); + if (unlikely(!iwa)) + return -ENOMEM; + iwa->req = req; + + iw->which = READ_ONCE(sqe->len); + iw->upid = READ_ONCE(sqe->fd); + iw->options = READ_ONCE(sqe->file_index); + iw->head = NULL; + iw->infop = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + return 0; +} + +int io_waitid(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + struct io_waitid_async *iwa = req->async_data; + struct io_ring_ctx *ctx = req->ctx; + int ret; + + ret = kernel_waitid_prepare(&iwa->wo, iw->which, iw->upid, &iw->info, + iw->options, NULL); + if (ret) + goto done; + + /* + * Mark the request as busy upfront, in case we're racing with the + * wakeup. If we are, then we'll notice when we drop this initial + * reference again after arming. + */ + atomic_set(&iw->refs, 1); + + /* + * Cancel must hold the ctx lock, so there's no risk of cancelation + * finding us until a) we remain on the list, and b) the lock is + * dropped. We only need to worry about racing with the wakeup + * callback. + */ + io_ring_submit_lock(ctx, issue_flags); + + /* + * iw->head is valid under the ring lock, and as long as the request + * is on the waitid_list where cancelations may find it. + */ + iw->head = ¤t->signal->wait_chldexit; + hlist_add_head(&req->hash_node, &ctx->waitid_list); + + init_waitqueue_func_entry(&iwa->wo.child_wait, io_waitid_wait); + iwa->wo.child_wait.private = req->tctx->task; + add_wait_queue(iw->head, &iwa->wo.child_wait); + + ret = __do_wait(&iwa->wo); + if (ret == -ERESTARTSYS) { + /* + * Nobody else grabbed a reference, it'll complete when we get + * a waitqueue callback, or if someone cancels it. + */ + if (!io_waitid_drop_issue_ref(req)) { + io_ring_submit_unlock(ctx, issue_flags); + return IOU_ISSUE_SKIP_COMPLETE; + } + + /* + * Wakeup triggered, racing with us. It was prevented from + * completing because of that, queue up the tw to do that. + */ + io_ring_submit_unlock(ctx, issue_flags); + return IOU_ISSUE_SKIP_COMPLETE; + } + + hlist_del_init(&req->hash_node); + io_waitid_remove_wq(req); + ret = io_waitid_finish(req, ret); + + io_ring_submit_unlock(ctx, issue_flags); +done: + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} diff --git a/io_uring/waitid.h b/io_uring/waitid.h new file mode 100644 index 000000000000..d5544aaf302a --- /dev/null +++ b/io_uring/waitid.h @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "../kernel/exit.h" + +struct io_waitid_async { + struct io_kiocb *req; + struct wait_opts wo; +}; + +int io_waitid_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_waitid(struct io_kiocb *req, unsigned int issue_flags); +int io_waitid_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, + unsigned int issue_flags); +bool io_waitid_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, + bool cancel_all); diff --git a/io_uring/xattr.c b/io_uring/xattr.c new file mode 100644 index 000000000000..322b94ff9e4b --- /dev/null +++ b/io_uring/xattr.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/io_uring.h> +#include <linux/xattr.h> + +#include <uapi/linux/io_uring.h> + +#include "../fs/internal.h" + +#include "io_uring.h" +#include "xattr.h" + +struct io_xattr { + struct file *file; + struct kernel_xattr_ctx ctx; + struct filename *filename; +}; + +void io_xattr_cleanup(struct io_kiocb *req) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + + if (ix->filename) + putname(ix->filename); + + kfree(ix->ctx.kname); + kvfree(ix->ctx.kvalue); +} + +static void io_xattr_finish(struct io_kiocb *req, int ret) +{ + req->flags &= ~REQ_F_NEED_CLEANUP; + + io_xattr_cleanup(req); + io_req_set_res(req, ret, 0); +} + +static int __io_getxattr_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + const char __user *name; + int ret; + + ix->filename = NULL; + ix->ctx.kvalue = NULL; + name = u64_to_user_ptr(READ_ONCE(sqe->addr)); + ix->ctx.value = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + ix->ctx.size = READ_ONCE(sqe->len); + ix->ctx.flags = READ_ONCE(sqe->xattr_flags); + + if (ix->ctx.flags) + return -EINVAL; + + ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL); + if (!ix->ctx.kname) + return -ENOMEM; + + ret = import_xattr_name(ix->ctx.kname, name); + if (ret) { + kfree(ix->ctx.kname); + return ret; + } + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_fgetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_getxattr_prep(req, sqe); +} + +int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + const char __user *path; + int ret; + + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + ret = __io_getxattr_prep(req, sqe); + if (ret) + return ret; + + path = u64_to_user_ptr(READ_ONCE(sqe->addr3)); + + ix->filename = getname(path); + if (IS_ERR(ix->filename)) + return PTR_ERR(ix->filename); + + return 0; +} + +int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = file_getxattr(req->file, &ix->ctx); + io_xattr_finish(req, ret); + return IOU_COMPLETE; +} + +int io_getxattr(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = filename_getxattr(AT_FDCWD, ix->filename, LOOKUP_FOLLOW, &ix->ctx); + ix->filename = NULL; + io_xattr_finish(req, ret); + return IOU_COMPLETE; +} + +static int __io_setxattr_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + const char __user *name; + int ret; + + ix->filename = NULL; + name = u64_to_user_ptr(READ_ONCE(sqe->addr)); + ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + ix->ctx.kvalue = NULL; + ix->ctx.size = READ_ONCE(sqe->len); + ix->ctx.flags = READ_ONCE(sqe->xattr_flags); + + ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL); + if (!ix->ctx.kname) + return -ENOMEM; + + ret = setxattr_copy(name, &ix->ctx); + if (ret) { + kfree(ix->ctx.kname); + return ret; + } + + req->flags |= REQ_F_NEED_CLEANUP; + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + const char __user *path; + int ret; + + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + ret = __io_setxattr_prep(req, sqe); + if (ret) + return ret; + + path = u64_to_user_ptr(READ_ONCE(sqe->addr3)); + + ix->filename = getname(path); + if (IS_ERR(ix->filename)) + return PTR_ERR(ix->filename); + + return 0; +} + +int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + return __io_setxattr_prep(req, sqe); +} + +int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = file_setxattr(req->file, &ix->ctx); + io_xattr_finish(req, ret); + return IOU_COMPLETE; +} + +int io_setxattr(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = filename_setxattr(AT_FDCWD, ix->filename, LOOKUP_FOLLOW, &ix->ctx); + ix->filename = NULL; + io_xattr_finish(req, ret); + return IOU_COMPLETE; +} diff --git a/io_uring/xattr.h b/io_uring/xattr.h new file mode 100644 index 000000000000..9b459d2ae90c --- /dev/null +++ b/io_uring/xattr.h @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 + +void io_xattr_cleanup(struct io_kiocb *req); + +int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags); + +int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_setxattr(struct io_kiocb *req, unsigned int issue_flags); + +int io_fgetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags); + +int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_getxattr(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c new file mode 100644 index 000000000000..b99cf2c6670a --- /dev/null +++ b/io_uring/zcrx.c @@ -0,0 +1,1485 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/dma-map-ops.h> +#include <linux/mm.h> +#include <linux/nospec.h> +#include <linux/io_uring.h> +#include <linux/netdevice.h> +#include <linux/rtnetlink.h> +#include <linux/skbuff_ref.h> +#include <linux/anon_inodes.h> + +#include <net/page_pool/helpers.h> +#include <net/page_pool/memory_provider.h> +#include <net/netlink.h> +#include <net/netdev_queues.h> +#include <net/netdev_rx_queue.h> +#include <net/tcp.h> +#include <net/rps.h> + +#include <trace/events/page_pool.h> + +#include <uapi/linux/io_uring.h> + +#include "io_uring.h" +#include "kbuf.h" +#include "memmap.h" +#include "zcrx.h" +#include "rsrc.h" + +#define IO_ZCRX_AREA_SUPPORTED_FLAGS (IORING_ZCRX_AREA_DMABUF) + +#define IO_DMA_ATTR (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING) + +static inline struct io_zcrx_ifq *io_pp_to_ifq(struct page_pool *pp) +{ + return pp->mp_priv; +} + +static inline struct io_zcrx_area *io_zcrx_iov_to_area(const struct net_iov *niov) +{ + struct net_iov_area *owner = net_iov_owner(niov); + + return container_of(owner, struct io_zcrx_area, nia); +} + +static inline struct page *io_zcrx_iov_page(const struct net_iov *niov) +{ + struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); + unsigned niov_pages_shift; + + lockdep_assert(!area->mem.is_dmabuf); + + niov_pages_shift = area->ifq->niov_shift - PAGE_SHIFT; + return area->mem.pages[net_iov_idx(niov) << niov_pages_shift]; +} + +static int io_populate_area_dma(struct io_zcrx_ifq *ifq, + struct io_zcrx_area *area) +{ + unsigned niov_size = 1U << ifq->niov_shift; + struct sg_table *sgt = area->mem.sgt; + struct scatterlist *sg; + unsigned i, niov_idx = 0; + + for_each_sgtable_dma_sg(sgt, sg, i) { + dma_addr_t dma = sg_dma_address(sg); + unsigned long sg_len = sg_dma_len(sg); + + if (WARN_ON_ONCE(sg_len % niov_size)) + return -EINVAL; + + while (sg_len && niov_idx < area->nia.num_niovs) { + struct net_iov *niov = &area->nia.niovs[niov_idx]; + + if (net_mp_niov_set_dma_addr(niov, dma)) + return -EFAULT; + sg_len -= niov_size; + dma += niov_size; + niov_idx++; + } + } + + if (WARN_ON_ONCE(niov_idx != area->nia.num_niovs)) + return -EFAULT; + return 0; +} + +static void io_release_dmabuf(struct io_zcrx_mem *mem) +{ + if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) + return; + + if (mem->sgt) + dma_buf_unmap_attachment_unlocked(mem->attach, mem->sgt, + DMA_FROM_DEVICE); + if (mem->attach) + dma_buf_detach(mem->dmabuf, mem->attach); + if (mem->dmabuf) + dma_buf_put(mem->dmabuf); + + mem->sgt = NULL; + mem->attach = NULL; + mem->dmabuf = NULL; +} + +static int io_import_dmabuf(struct io_zcrx_ifq *ifq, + struct io_zcrx_mem *mem, + struct io_uring_zcrx_area_reg *area_reg) +{ + unsigned long off = (unsigned long)area_reg->addr; + unsigned long len = (unsigned long)area_reg->len; + unsigned long total_size = 0; + struct scatterlist *sg; + int dmabuf_fd = area_reg->dmabuf_fd; + int i, ret; + + if (off) + return -EINVAL; + if (WARN_ON_ONCE(!ifq->dev)) + return -EFAULT; + if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) + return -EINVAL; + + mem->is_dmabuf = true; + mem->dmabuf = dma_buf_get(dmabuf_fd); + if (IS_ERR(mem->dmabuf)) { + ret = PTR_ERR(mem->dmabuf); + mem->dmabuf = NULL; + goto err; + } + + mem->attach = dma_buf_attach(mem->dmabuf, ifq->dev); + if (IS_ERR(mem->attach)) { + ret = PTR_ERR(mem->attach); + mem->attach = NULL; + goto err; + } + + mem->sgt = dma_buf_map_attachment_unlocked(mem->attach, DMA_FROM_DEVICE); + if (IS_ERR(mem->sgt)) { + ret = PTR_ERR(mem->sgt); + mem->sgt = NULL; + goto err; + } + + for_each_sgtable_dma_sg(mem->sgt, sg, i) + total_size += sg_dma_len(sg); + + if (total_size != len) { + ret = -EINVAL; + goto err; + } + + mem->size = len; + return 0; +err: + io_release_dmabuf(mem); + return ret; +} + +static unsigned long io_count_account_pages(struct page **pages, unsigned nr_pages) +{ + struct folio *last_folio = NULL; + unsigned long res = 0; + int i; + + for (i = 0; i < nr_pages; i++) { + struct folio *folio = page_folio(pages[i]); + + if (folio == last_folio) + continue; + last_folio = folio; + res += folio_nr_pages(folio); + } + return res; +} + +static int io_import_umem(struct io_zcrx_ifq *ifq, + struct io_zcrx_mem *mem, + struct io_uring_zcrx_area_reg *area_reg) +{ + struct page **pages; + int nr_pages, ret; + + if (area_reg->dmabuf_fd) + return -EINVAL; + if (!area_reg->addr) + return -EFAULT; + pages = io_pin_pages((unsigned long)area_reg->addr, area_reg->len, + &nr_pages); + if (IS_ERR(pages)) + return PTR_ERR(pages); + + ret = sg_alloc_table_from_pages(&mem->page_sg_table, pages, nr_pages, + 0, nr_pages << PAGE_SHIFT, + GFP_KERNEL_ACCOUNT); + if (ret) { + unpin_user_pages(pages, nr_pages); + return ret; + } + + mem->account_pages = io_count_account_pages(pages, nr_pages); + ret = io_account_mem(ifq->user, ifq->mm_account, mem->account_pages); + if (ret < 0) + mem->account_pages = 0; + + mem->sgt = &mem->page_sg_table; + mem->pages = pages; + mem->nr_folios = nr_pages; + mem->size = area_reg->len; + return ret; +} + +static void io_release_area_mem(struct io_zcrx_mem *mem) +{ + if (mem->is_dmabuf) { + io_release_dmabuf(mem); + return; + } + if (mem->pages) { + unpin_user_pages(mem->pages, mem->nr_folios); + sg_free_table(mem->sgt); + mem->sgt = NULL; + kvfree(mem->pages); + } +} + +static int io_import_area(struct io_zcrx_ifq *ifq, + struct io_zcrx_mem *mem, + struct io_uring_zcrx_area_reg *area_reg) +{ + int ret; + + if (area_reg->flags & ~IO_ZCRX_AREA_SUPPORTED_FLAGS) + return -EINVAL; + if (area_reg->rq_area_token) + return -EINVAL; + if (area_reg->__resv2[0] || area_reg->__resv2[1]) + return -EINVAL; + + ret = io_validate_user_buf_range(area_reg->addr, area_reg->len); + if (ret) + return ret; + if (area_reg->addr & ~PAGE_MASK || area_reg->len & ~PAGE_MASK) + return -EINVAL; + + if (area_reg->flags & IORING_ZCRX_AREA_DMABUF) + return io_import_dmabuf(ifq, mem, area_reg); + return io_import_umem(ifq, mem, area_reg); +} + +static void io_zcrx_unmap_area(struct io_zcrx_ifq *ifq, + struct io_zcrx_area *area) +{ + int i; + + guard(mutex)(&ifq->pp_lock); + if (!area->is_mapped) + return; + area->is_mapped = false; + + for (i = 0; i < area->nia.num_niovs; i++) + net_mp_niov_set_dma_addr(&area->nia.niovs[i], 0); + + if (area->mem.is_dmabuf) { + io_release_dmabuf(&area->mem); + } else { + dma_unmap_sgtable(ifq->dev, &area->mem.page_sg_table, + DMA_FROM_DEVICE, IO_DMA_ATTR); + } +} + +static int io_zcrx_map_area(struct io_zcrx_ifq *ifq, struct io_zcrx_area *area) +{ + int ret; + + guard(mutex)(&ifq->pp_lock); + if (area->is_mapped) + return 0; + + if (!area->mem.is_dmabuf) { + ret = dma_map_sgtable(ifq->dev, &area->mem.page_sg_table, + DMA_FROM_DEVICE, IO_DMA_ATTR); + if (ret < 0) + return ret; + } + + ret = io_populate_area_dma(ifq, area); + if (ret == 0) + area->is_mapped = true; + return ret; +} + +static void io_zcrx_sync_for_device(struct page_pool *pool, + struct net_iov *niov) +{ +#if defined(CONFIG_HAS_DMA) && defined(CONFIG_DMA_NEED_SYNC) + dma_addr_t dma_addr; + + unsigned niov_size; + + if (!dma_dev_need_sync(pool->p.dev)) + return; + + niov_size = 1U << io_pp_to_ifq(pool)->niov_shift; + dma_addr = page_pool_get_dma_addr_netmem(net_iov_to_netmem(niov)); + __dma_sync_single_for_device(pool->p.dev, dma_addr + pool->p.offset, + niov_size, pool->p.dma_dir); +#endif +} + +#define IO_RQ_MAX_ENTRIES 32768 + +#define IO_SKBS_PER_CALL_LIMIT 20 + +struct io_zcrx_args { + struct io_kiocb *req; + struct io_zcrx_ifq *ifq; + struct socket *sock; + unsigned nr_skbs; +}; + +static const struct memory_provider_ops io_uring_pp_zc_ops; + +static inline atomic_t *io_get_user_counter(struct net_iov *niov) +{ + struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); + + return &area->user_refs[net_iov_idx(niov)]; +} + +static bool io_zcrx_put_niov_uref(struct net_iov *niov) +{ + atomic_t *uref = io_get_user_counter(niov); + + if (unlikely(!atomic_read(uref))) + return false; + atomic_dec(uref); + return true; +} + +static void io_zcrx_get_niov_uref(struct net_iov *niov) +{ + atomic_inc(io_get_user_counter(niov)); +} + +static void io_fill_zcrx_offsets(struct io_uring_zcrx_offsets *offsets) +{ + offsets->head = offsetof(struct io_uring, head); + offsets->tail = offsetof(struct io_uring, tail); + offsets->rqes = ALIGN(sizeof(struct io_uring), L1_CACHE_BYTES); +} + +static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx, + struct io_zcrx_ifq *ifq, + struct io_uring_zcrx_ifq_reg *reg, + struct io_uring_region_desc *rd, + u32 id) +{ + u64 mmap_offset; + size_t off, size; + void *ptr; + int ret; + + io_fill_zcrx_offsets(®->offsets); + off = reg->offsets.rqes; + size = off + sizeof(struct io_uring_zcrx_rqe) * reg->rq_entries; + if (size > rd->size) + return -EINVAL; + + mmap_offset = IORING_MAP_OFF_ZCRX_REGION; + mmap_offset += id << IORING_OFF_PBUF_SHIFT; + + ret = io_create_region(ctx, &ifq->region, rd, mmap_offset); + if (ret < 0) + return ret; + + ptr = io_region_get_ptr(&ifq->region); + ifq->rq_ring = (struct io_uring *)ptr; + ifq->rqes = (struct io_uring_zcrx_rqe *)(ptr + off); + + return 0; +} + +static void io_free_rbuf_ring(struct io_zcrx_ifq *ifq) +{ + io_free_region(ifq->user, &ifq->region); + ifq->rq_ring = NULL; + ifq->rqes = NULL; +} + +static void io_zcrx_free_area(struct io_zcrx_ifq *ifq, + struct io_zcrx_area *area) +{ + io_zcrx_unmap_area(ifq, area); + io_release_area_mem(&area->mem); + + if (area->mem.account_pages) + io_unaccount_mem(ifq->user, ifq->mm_account, + area->mem.account_pages); + + kvfree(area->freelist); + kvfree(area->nia.niovs); + kvfree(area->user_refs); + kfree(area); +} + +static int io_zcrx_append_area(struct io_zcrx_ifq *ifq, + struct io_zcrx_area *area) +{ + if (ifq->area) + return -EINVAL; + ifq->area = area; + return 0; +} + +static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, + struct io_uring_zcrx_area_reg *area_reg) +{ + struct io_zcrx_area *area; + unsigned nr_iovs; + int i, ret; + + ret = -ENOMEM; + area = kzalloc(sizeof(*area), GFP_KERNEL); + if (!area) + goto err; + area->ifq = ifq; + + ret = io_import_area(ifq, &area->mem, area_reg); + if (ret) + goto err; + + ifq->niov_shift = PAGE_SHIFT; + nr_iovs = area->mem.size >> ifq->niov_shift; + area->nia.num_niovs = nr_iovs; + + ret = -ENOMEM; + area->nia.niovs = kvmalloc_array(nr_iovs, sizeof(area->nia.niovs[0]), + GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (!area->nia.niovs) + goto err; + + area->freelist = kvmalloc_array(nr_iovs, sizeof(area->freelist[0]), + GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (!area->freelist) + goto err; + + area->user_refs = kvmalloc_array(nr_iovs, sizeof(area->user_refs[0]), + GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (!area->user_refs) + goto err; + + for (i = 0; i < nr_iovs; i++) { + struct net_iov *niov = &area->nia.niovs[i]; + + niov->owner = &area->nia; + area->freelist[i] = i; + atomic_set(&area->user_refs[i], 0); + niov->type = NET_IOV_IOURING; + } + + area->free_count = nr_iovs; + /* we're only supporting one area per ifq for now */ + area->area_id = 0; + area_reg->rq_area_token = (u64)area->area_id << IORING_ZCRX_AREA_SHIFT; + spin_lock_init(&area->freelist_lock); + + ret = io_zcrx_append_area(ifq, area); + if (!ret) + return 0; +err: + if (area) + io_zcrx_free_area(ifq, area); + return ret; +} + +static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx) +{ + struct io_zcrx_ifq *ifq; + + ifq = kzalloc(sizeof(*ifq), GFP_KERNEL); + if (!ifq) + return NULL; + + ifq->if_rxq = -1; + spin_lock_init(&ifq->rq_lock); + mutex_init(&ifq->pp_lock); + refcount_set(&ifq->refs, 1); + refcount_set(&ifq->user_refs, 1); + return ifq; +} + +static void io_zcrx_drop_netdev(struct io_zcrx_ifq *ifq) +{ + guard(mutex)(&ifq->pp_lock); + + if (!ifq->netdev) + return; + netdev_put(ifq->netdev, &ifq->netdev_tracker); + ifq->netdev = NULL; +} + +static void io_close_queue(struct io_zcrx_ifq *ifq) +{ + struct net_device *netdev; + netdevice_tracker netdev_tracker; + struct pp_memory_provider_params p = { + .mp_ops = &io_uring_pp_zc_ops, + .mp_priv = ifq, + }; + + if (ifq->if_rxq == -1) + return; + + scoped_guard(mutex, &ifq->pp_lock) { + netdev = ifq->netdev; + netdev_tracker = ifq->netdev_tracker; + ifq->netdev = NULL; + } + + if (netdev) { + net_mp_close_rxq(netdev, ifq->if_rxq, &p); + netdev_put(netdev, &netdev_tracker); + } + ifq->if_rxq = -1; +} + +static void io_zcrx_ifq_free(struct io_zcrx_ifq *ifq) +{ + io_close_queue(ifq); + + if (ifq->area) + io_zcrx_free_area(ifq, ifq->area); + free_uid(ifq->user); + if (ifq->mm_account) + mmdrop(ifq->mm_account); + if (ifq->dev) + put_device(ifq->dev); + + io_free_rbuf_ring(ifq); + mutex_destroy(&ifq->pp_lock); + kfree(ifq); +} + +static void io_put_zcrx_ifq(struct io_zcrx_ifq *ifq) +{ + if (refcount_dec_and_test(&ifq->refs)) + io_zcrx_ifq_free(ifq); +} + +static void io_zcrx_return_niov_freelist(struct net_iov *niov) +{ + struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); + + spin_lock_bh(&area->freelist_lock); + area->freelist[area->free_count++] = net_iov_idx(niov); + spin_unlock_bh(&area->freelist_lock); +} + +static void io_zcrx_return_niov(struct net_iov *niov) +{ + netmem_ref netmem = net_iov_to_netmem(niov); + + if (!niov->desc.pp) { + /* copy fallback allocated niovs */ + io_zcrx_return_niov_freelist(niov); + return; + } + page_pool_put_unrefed_netmem(niov->desc.pp, netmem, -1, false); +} + +static void io_zcrx_scrub(struct io_zcrx_ifq *ifq) +{ + struct io_zcrx_area *area = ifq->area; + int i; + + if (!area) + return; + + /* Reclaim back all buffers given to the user space. */ + for (i = 0; i < area->nia.num_niovs; i++) { + struct net_iov *niov = &area->nia.niovs[i]; + int nr; + + if (!atomic_read(io_get_user_counter(niov))) + continue; + nr = atomic_xchg(io_get_user_counter(niov), 0); + if (nr && !page_pool_unref_netmem(net_iov_to_netmem(niov), nr)) + io_zcrx_return_niov(niov); + } +} + +static void zcrx_unregister(struct io_zcrx_ifq *ifq) +{ + if (refcount_dec_and_test(&ifq->user_refs)) { + io_close_queue(ifq); + io_zcrx_scrub(ifq); + } + io_put_zcrx_ifq(ifq); +} + +struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx, + unsigned int id) +{ + struct io_zcrx_ifq *ifq = xa_load(&ctx->zcrx_ctxs, id); + + lockdep_assert_held(&ctx->mmap_lock); + + return ifq ? &ifq->region : NULL; +} + +static int zcrx_box_release(struct inode *inode, struct file *file) +{ + struct io_zcrx_ifq *ifq = file->private_data; + + if (WARN_ON_ONCE(!ifq)) + return -EFAULT; + zcrx_unregister(ifq); + return 0; +} + +static const struct file_operations zcrx_box_fops = { + .owner = THIS_MODULE, + .release = zcrx_box_release, +}; + +static int zcrx_export(struct io_ring_ctx *ctx, struct io_zcrx_ifq *ifq, + struct zcrx_ctrl *ctrl, void __user *arg) +{ + struct zcrx_ctrl_export *ce = &ctrl->zc_export; + struct file *file; + int fd = -1; + + if (!mem_is_zero(ce, sizeof(*ce))) + return -EINVAL; + fd = get_unused_fd_flags(O_CLOEXEC); + if (fd < 0) + return fd; + + ce->zcrx_fd = fd; + if (copy_to_user(arg, ctrl, sizeof(*ctrl))) { + put_unused_fd(fd); + return -EFAULT; + } + + refcount_inc(&ifq->refs); + refcount_inc(&ifq->user_refs); + + file = anon_inode_create_getfile("[zcrx]", &zcrx_box_fops, + ifq, O_CLOEXEC, NULL); + if (IS_ERR(file)) { + put_unused_fd(fd); + zcrx_unregister(ifq); + return PTR_ERR(file); + } + + fd_install(fd, file); + return 0; +} + +static int import_zcrx(struct io_ring_ctx *ctx, + struct io_uring_zcrx_ifq_reg __user *arg, + struct io_uring_zcrx_ifq_reg *reg) +{ + struct io_zcrx_ifq *ifq; + struct file *file; + int fd, ret; + u32 id; + + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + return -EINVAL; + if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) + return -EINVAL; + if (reg->if_rxq || reg->rq_entries || reg->area_ptr || reg->region_ptr) + return -EINVAL; + + fd = reg->if_idx; + CLASS(fd, f)(fd); + if (fd_empty(f)) + return -EBADF; + + file = fd_file(f); + if (file->f_op != &zcrx_box_fops || !file->private_data) + return -EBADF; + + ifq = file->private_data; + refcount_inc(&ifq->refs); + refcount_inc(&ifq->user_refs); + + scoped_guard(mutex, &ctx->mmap_lock) { + ret = xa_alloc(&ctx->zcrx_ctxs, &id, NULL, xa_limit_31b, GFP_KERNEL); + if (ret) + goto err; + } + + reg->zcrx_id = id; + io_fill_zcrx_offsets(®->offsets); + if (copy_to_user(arg, reg, sizeof(*reg))) { + ret = -EFAULT; + goto err_xa_erase; + } + + scoped_guard(mutex, &ctx->mmap_lock) { + ret = -ENOMEM; + if (xa_store(&ctx->zcrx_ctxs, id, ifq, GFP_KERNEL)) + goto err_xa_erase; + } + + return 0; +err_xa_erase: + scoped_guard(mutex, &ctx->mmap_lock) + xa_erase(&ctx->zcrx_ctxs, id); +err: + zcrx_unregister(ifq); + return ret; +} + +int io_register_zcrx_ifq(struct io_ring_ctx *ctx, + struct io_uring_zcrx_ifq_reg __user *arg) +{ + struct pp_memory_provider_params mp_param = {}; + struct io_uring_zcrx_area_reg area; + struct io_uring_zcrx_ifq_reg reg; + struct io_uring_region_desc rd; + struct io_zcrx_ifq *ifq; + int ret; + u32 id; + + /* + * 1. Interface queue allocation. + * 2. It can observe data destined for sockets of other tasks. + */ + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + /* mandatory io_uring features for zc rx */ + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + return -EINVAL; + if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) + return -EINVAL; + if (copy_from_user(®, arg, sizeof(reg))) + return -EFAULT; + if (!mem_is_zero(®.__resv, sizeof(reg.__resv)) || + reg.__resv2 || reg.zcrx_id) + return -EINVAL; + if (reg.flags & ZCRX_REG_IMPORT) + return import_zcrx(ctx, arg, ®); + if (copy_from_user(&rd, u64_to_user_ptr(reg.region_ptr), sizeof(rd))) + return -EFAULT; + if (reg.if_rxq == -1 || !reg.rq_entries || reg.flags) + return -EINVAL; + if (reg.rq_entries > IO_RQ_MAX_ENTRIES) { + if (!(ctx->flags & IORING_SETUP_CLAMP)) + return -EINVAL; + reg.rq_entries = IO_RQ_MAX_ENTRIES; + } + reg.rq_entries = roundup_pow_of_two(reg.rq_entries); + + if (copy_from_user(&area, u64_to_user_ptr(reg.area_ptr), sizeof(area))) + return -EFAULT; + + ifq = io_zcrx_ifq_alloc(ctx); + if (!ifq) + return -ENOMEM; + + if (ctx->user) { + get_uid(ctx->user); + ifq->user = ctx->user; + } + if (ctx->mm_account) { + mmgrab(ctx->mm_account); + ifq->mm_account = ctx->mm_account; + } + ifq->rq_entries = reg.rq_entries; + + scoped_guard(mutex, &ctx->mmap_lock) { + /* preallocate id */ + ret = xa_alloc(&ctx->zcrx_ctxs, &id, NULL, xa_limit_31b, GFP_KERNEL); + if (ret) + goto ifq_free; + } + + ret = io_allocate_rbuf_ring(ctx, ifq, ®, &rd, id); + if (ret) + goto err; + + ifq->netdev = netdev_get_by_index_lock(current->nsproxy->net_ns, reg.if_idx); + if (!ifq->netdev) { + ret = -ENODEV; + goto err; + } + netdev_hold(ifq->netdev, &ifq->netdev_tracker, GFP_KERNEL); + + ifq->dev = netdev_queue_get_dma_dev(ifq->netdev, reg.if_rxq); + if (!ifq->dev) { + ret = -EOPNOTSUPP; + goto netdev_put_unlock; + } + get_device(ifq->dev); + + ret = io_zcrx_create_area(ifq, &area); + if (ret) + goto netdev_put_unlock; + + mp_param.mp_ops = &io_uring_pp_zc_ops; + mp_param.mp_priv = ifq; + ret = __net_mp_open_rxq(ifq->netdev, reg.if_rxq, &mp_param, NULL); + if (ret) + goto netdev_put_unlock; + netdev_unlock(ifq->netdev); + ifq->if_rxq = reg.if_rxq; + + reg.zcrx_id = id; + + scoped_guard(mutex, &ctx->mmap_lock) { + /* publish ifq */ + ret = -ENOMEM; + if (xa_store(&ctx->zcrx_ctxs, id, ifq, GFP_KERNEL)) + goto err; + } + + if (copy_to_user(arg, ®, sizeof(reg)) || + copy_to_user(u64_to_user_ptr(reg.region_ptr), &rd, sizeof(rd)) || + copy_to_user(u64_to_user_ptr(reg.area_ptr), &area, sizeof(area))) { + ret = -EFAULT; + goto err; + } + return 0; +netdev_put_unlock: + netdev_put(ifq->netdev, &ifq->netdev_tracker); + netdev_unlock(ifq->netdev); +err: + scoped_guard(mutex, &ctx->mmap_lock) + xa_erase(&ctx->zcrx_ctxs, id); +ifq_free: + io_zcrx_ifq_free(ifq); + return ret; +} + +static struct net_iov *__io_zcrx_get_free_niov(struct io_zcrx_area *area) +{ + unsigned niov_idx; + + lockdep_assert_held(&area->freelist_lock); + + niov_idx = area->freelist[--area->free_count]; + return &area->nia.niovs[niov_idx]; +} + +void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx) +{ + struct io_zcrx_ifq *ifq; + + lockdep_assert_held(&ctx->uring_lock); + + while (1) { + scoped_guard(mutex, &ctx->mmap_lock) { + unsigned long id = 0; + + ifq = xa_find(&ctx->zcrx_ctxs, &id, ULONG_MAX, XA_PRESENT); + if (ifq) + xa_erase(&ctx->zcrx_ctxs, id); + } + if (!ifq) + break; + zcrx_unregister(ifq); + } + + xa_destroy(&ctx->zcrx_ctxs); +} + +static inline u32 io_zcrx_rqring_entries(struct io_zcrx_ifq *ifq) +{ + u32 entries; + + entries = smp_load_acquire(&ifq->rq_ring->tail) - ifq->cached_rq_head; + return min(entries, ifq->rq_entries); +} + +static struct io_uring_zcrx_rqe *io_zcrx_get_rqe(struct io_zcrx_ifq *ifq, + unsigned mask) +{ + unsigned int idx = ifq->cached_rq_head++ & mask; + + return &ifq->rqes[idx]; +} + +static inline bool io_parse_rqe(struct io_uring_zcrx_rqe *rqe, + struct io_zcrx_ifq *ifq, + struct net_iov **ret_niov) +{ + unsigned niov_idx, area_idx; + struct io_zcrx_area *area; + + area_idx = rqe->off >> IORING_ZCRX_AREA_SHIFT; + niov_idx = (rqe->off & ~IORING_ZCRX_AREA_MASK) >> ifq->niov_shift; + + if (unlikely(rqe->__pad || area_idx)) + return false; + area = ifq->area; + + if (unlikely(niov_idx >= area->nia.num_niovs)) + return false; + niov_idx = array_index_nospec(niov_idx, area->nia.num_niovs); + + *ret_niov = &area->nia.niovs[niov_idx]; + return true; +} + +static void io_zcrx_ring_refill(struct page_pool *pp, + struct io_zcrx_ifq *ifq) +{ + unsigned int mask = ifq->rq_entries - 1; + unsigned int entries; + + guard(spinlock_bh)(&ifq->rq_lock); + + entries = io_zcrx_rqring_entries(ifq); + entries = min_t(unsigned, entries, PP_ALLOC_CACHE_REFILL); + if (unlikely(!entries)) + return; + + do { + struct io_uring_zcrx_rqe *rqe = io_zcrx_get_rqe(ifq, mask); + struct net_iov *niov; + netmem_ref netmem; + + if (!io_parse_rqe(rqe, ifq, &niov)) + continue; + if (!io_zcrx_put_niov_uref(niov)) + continue; + + netmem = net_iov_to_netmem(niov); + if (!page_pool_unref_and_test(netmem)) + continue; + + if (unlikely(niov->desc.pp != pp)) { + io_zcrx_return_niov(niov); + continue; + } + + io_zcrx_sync_for_device(pp, niov); + net_mp_netmem_place_in_cache(pp, netmem); + } while (--entries); + + smp_store_release(&ifq->rq_ring->head, ifq->cached_rq_head); +} + +static void io_zcrx_refill_slow(struct page_pool *pp, struct io_zcrx_ifq *ifq) +{ + struct io_zcrx_area *area = ifq->area; + + spin_lock_bh(&area->freelist_lock); + while (area->free_count && pp->alloc.count < PP_ALLOC_CACHE_REFILL) { + struct net_iov *niov = __io_zcrx_get_free_niov(area); + netmem_ref netmem = net_iov_to_netmem(niov); + + net_mp_niov_set_page_pool(pp, niov); + io_zcrx_sync_for_device(pp, niov); + net_mp_netmem_place_in_cache(pp, netmem); + } + spin_unlock_bh(&area->freelist_lock); +} + +static netmem_ref io_pp_zc_alloc_netmems(struct page_pool *pp, gfp_t gfp) +{ + struct io_zcrx_ifq *ifq = io_pp_to_ifq(pp); + + /* pp should already be ensuring that */ + if (unlikely(pp->alloc.count)) + goto out_return; + + io_zcrx_ring_refill(pp, ifq); + if (likely(pp->alloc.count)) + goto out_return; + + io_zcrx_refill_slow(pp, ifq); + if (!pp->alloc.count) + return 0; +out_return: + return pp->alloc.cache[--pp->alloc.count]; +} + +static bool io_pp_zc_release_netmem(struct page_pool *pp, netmem_ref netmem) +{ + struct net_iov *niov; + + if (WARN_ON_ONCE(!netmem_is_net_iov(netmem))) + return false; + + niov = netmem_to_net_iov(netmem); + net_mp_niov_clear_page_pool(niov); + io_zcrx_return_niov_freelist(niov); + return false; +} + +static int io_pp_zc_init(struct page_pool *pp) +{ + struct io_zcrx_ifq *ifq = io_pp_to_ifq(pp); + int ret; + + if (WARN_ON_ONCE(!ifq)) + return -EINVAL; + if (WARN_ON_ONCE(ifq->dev != pp->p.dev)) + return -EINVAL; + if (WARN_ON_ONCE(!pp->dma_map)) + return -EOPNOTSUPP; + if (pp->p.order + PAGE_SHIFT != ifq->niov_shift) + return -EINVAL; + if (pp->p.dma_dir != DMA_FROM_DEVICE) + return -EOPNOTSUPP; + + ret = io_zcrx_map_area(ifq, ifq->area); + if (ret) + return ret; + + refcount_inc(&ifq->refs); + return 0; +} + +static void io_pp_zc_destroy(struct page_pool *pp) +{ + io_put_zcrx_ifq(io_pp_to_ifq(pp)); +} + +static int io_pp_nl_fill(void *mp_priv, struct sk_buff *rsp, + struct netdev_rx_queue *rxq) +{ + struct nlattr *nest; + int type; + + type = rxq ? NETDEV_A_QUEUE_IO_URING : NETDEV_A_PAGE_POOL_IO_URING; + nest = nla_nest_start(rsp, type); + if (!nest) + return -EMSGSIZE; + nla_nest_end(rsp, nest); + + return 0; +} + +static void io_pp_uninstall(void *mp_priv, struct netdev_rx_queue *rxq) +{ + struct pp_memory_provider_params *p = &rxq->mp_params; + struct io_zcrx_ifq *ifq = mp_priv; + + io_zcrx_drop_netdev(ifq); + if (ifq->area) + io_zcrx_unmap_area(ifq, ifq->area); + + p->mp_ops = NULL; + p->mp_priv = NULL; +} + +static const struct memory_provider_ops io_uring_pp_zc_ops = { + .alloc_netmems = io_pp_zc_alloc_netmems, + .release_netmem = io_pp_zc_release_netmem, + .init = io_pp_zc_init, + .destroy = io_pp_zc_destroy, + .nl_fill = io_pp_nl_fill, + .uninstall = io_pp_uninstall, +}; + +static unsigned zcrx_parse_rq(netmem_ref *netmem_array, unsigned nr, + struct io_zcrx_ifq *zcrx) +{ + unsigned int mask = zcrx->rq_entries - 1; + unsigned int i; + + guard(spinlock_bh)(&zcrx->rq_lock); + + nr = min(nr, io_zcrx_rqring_entries(zcrx)); + for (i = 0; i < nr; i++) { + struct io_uring_zcrx_rqe *rqe = io_zcrx_get_rqe(zcrx, mask); + struct net_iov *niov; + + if (!io_parse_rqe(rqe, zcrx, &niov)) + break; + netmem_array[i] = net_iov_to_netmem(niov); + } + + smp_store_release(&zcrx->rq_ring->head, zcrx->cached_rq_head); + return i; +} + +#define ZCRX_FLUSH_BATCH 32 + +static void zcrx_return_buffers(netmem_ref *netmems, unsigned nr) +{ + unsigned i; + + for (i = 0; i < nr; i++) { + netmem_ref netmem = netmems[i]; + struct net_iov *niov = netmem_to_net_iov(netmem); + + if (!io_zcrx_put_niov_uref(niov)) + continue; + if (!page_pool_unref_and_test(netmem)) + continue; + io_zcrx_return_niov(niov); + } +} + +static int zcrx_flush_rq(struct io_ring_ctx *ctx, struct io_zcrx_ifq *zcrx, + struct zcrx_ctrl *ctrl) +{ + struct zcrx_ctrl_flush_rq *frq = &ctrl->zc_flush; + netmem_ref netmems[ZCRX_FLUSH_BATCH]; + unsigned total = 0; + unsigned nr; + + if (!mem_is_zero(&frq->__resv, sizeof(frq->__resv))) + return -EINVAL; + + do { + nr = zcrx_parse_rq(netmems, ZCRX_FLUSH_BATCH, zcrx); + + zcrx_return_buffers(netmems, nr); + total += nr; + + if (fatal_signal_pending(current)) + break; + cond_resched(); + } while (nr == ZCRX_FLUSH_BATCH && total < zcrx->rq_entries); + + return 0; +} + +int io_zcrx_ctrl(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) +{ + struct zcrx_ctrl ctrl; + struct io_zcrx_ifq *zcrx; + + if (nr_args) + return -EINVAL; + if (copy_from_user(&ctrl, arg, sizeof(ctrl))) + return -EFAULT; + if (!mem_is_zero(&ctrl.__resv, sizeof(ctrl.__resv))) + return -EFAULT; + + zcrx = xa_load(&ctx->zcrx_ctxs, ctrl.zcrx_id); + if (!zcrx) + return -ENXIO; + + switch (ctrl.op) { + case ZCRX_CTRL_FLUSH_RQ: + return zcrx_flush_rq(ctx, zcrx, &ctrl); + case ZCRX_CTRL_EXPORT: + return zcrx_export(ctx, zcrx, &ctrl, arg); + } + + return -EOPNOTSUPP; +} + +static bool io_zcrx_queue_cqe(struct io_kiocb *req, struct net_iov *niov, + struct io_zcrx_ifq *ifq, int off, int len) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_uring_zcrx_cqe *rcqe; + struct io_zcrx_area *area; + struct io_uring_cqe *cqe; + u64 offset; + + if (!io_defer_get_uncommited_cqe(ctx, &cqe)) + return false; + + cqe->user_data = req->cqe.user_data; + cqe->res = len; + cqe->flags = IORING_CQE_F_MORE; + if (ctx->flags & IORING_SETUP_CQE_MIXED) + cqe->flags |= IORING_CQE_F_32; + + area = io_zcrx_iov_to_area(niov); + offset = off + (net_iov_idx(niov) << ifq->niov_shift); + rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1); + rcqe->off = offset + ((u64)area->area_id << IORING_ZCRX_AREA_SHIFT); + rcqe->__pad = 0; + return true; +} + +static struct net_iov *io_alloc_fallback_niov(struct io_zcrx_ifq *ifq) +{ + struct io_zcrx_area *area = ifq->area; + struct net_iov *niov = NULL; + + if (area->mem.is_dmabuf) + return NULL; + + spin_lock_bh(&area->freelist_lock); + if (area->free_count) + niov = __io_zcrx_get_free_niov(area); + spin_unlock_bh(&area->freelist_lock); + + if (niov) + page_pool_fragment_netmem(net_iov_to_netmem(niov), 1); + return niov; +} + +struct io_copy_cache { + struct page *page; + unsigned long offset; + size_t size; +}; + +static ssize_t io_copy_page(struct io_copy_cache *cc, struct page *src_page, + unsigned int src_offset, size_t len) +{ + size_t copied = 0; + + len = min(len, cc->size); + + while (len) { + void *src_addr, *dst_addr; + struct page *dst_page = cc->page; + unsigned dst_offset = cc->offset; + size_t n = len; + + if (folio_test_partial_kmap(page_folio(dst_page)) || + folio_test_partial_kmap(page_folio(src_page))) { + dst_page += dst_offset / PAGE_SIZE; + dst_offset = offset_in_page(dst_offset); + src_page += src_offset / PAGE_SIZE; + src_offset = offset_in_page(src_offset); + n = min(PAGE_SIZE - src_offset, PAGE_SIZE - dst_offset); + n = min(n, len); + } + + dst_addr = kmap_local_page(dst_page) + dst_offset; + src_addr = kmap_local_page(src_page) + src_offset; + + memcpy(dst_addr, src_addr, n); + + kunmap_local(src_addr); + kunmap_local(dst_addr); + + cc->size -= n; + cc->offset += n; + src_offset += n; + len -= n; + copied += n; + } + return copied; +} + +static ssize_t io_zcrx_copy_chunk(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + struct page *src_page, unsigned int src_offset, + size_t len) +{ + size_t copied = 0; + int ret = 0; + + while (len) { + struct io_copy_cache cc; + struct net_iov *niov; + size_t n; + + niov = io_alloc_fallback_niov(ifq); + if (!niov) { + ret = -ENOMEM; + break; + } + + cc.page = io_zcrx_iov_page(niov); + cc.offset = 0; + cc.size = PAGE_SIZE; + + n = io_copy_page(&cc, src_page, src_offset, len); + + if (!io_zcrx_queue_cqe(req, niov, ifq, 0, n)) { + io_zcrx_return_niov(niov); + ret = -ENOSPC; + break; + } + + io_zcrx_get_niov_uref(niov); + src_offset += n; + len -= n; + copied += n; + } + + return copied ? copied : ret; +} + +static int io_zcrx_copy_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + const skb_frag_t *frag, int off, int len) +{ + struct page *page = skb_frag_page(frag); + + return io_zcrx_copy_chunk(req, ifq, page, off + skb_frag_off(frag), len); +} + +static int io_zcrx_recv_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + const skb_frag_t *frag, int off, int len) +{ + struct net_iov *niov; + struct page_pool *pp; + + if (unlikely(!skb_frag_is_net_iov(frag))) + return io_zcrx_copy_frag(req, ifq, frag, off, len); + + niov = netmem_to_net_iov(frag->netmem); + pp = niov->desc.pp; + + if (!pp || pp->mp_ops != &io_uring_pp_zc_ops || io_pp_to_ifq(pp) != ifq) + return -EFAULT; + + if (!io_zcrx_queue_cqe(req, niov, ifq, off + skb_frag_off(frag), len)) + return -ENOSPC; + + /* + * Prevent it from being recycled while user is accessing it. + * It has to be done before grabbing a user reference. + */ + page_pool_ref_netmem(net_iov_to_netmem(niov)); + io_zcrx_get_niov_uref(niov); + return len; +} + +static int +io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, + unsigned int offset, size_t len) +{ + struct io_zcrx_args *args = desc->arg.data; + struct io_zcrx_ifq *ifq = args->ifq; + struct io_kiocb *req = args->req; + struct sk_buff *frag_iter; + unsigned start, start_off = offset; + int i, copy, end, off; + int ret = 0; + + len = min_t(size_t, len, desc->count); + /* + * __tcp_read_sock() always calls io_zcrx_recv_skb one last time, even + * if desc->count is already 0. This is caused by the if (offset + 1 != + * skb->len) check. Return early in this case to break out of + * __tcp_read_sock(). + */ + if (!len) + return 0; + if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT)) + return -EAGAIN; + + if (unlikely(offset < skb_headlen(skb))) { + ssize_t copied; + size_t to_copy; + + to_copy = min_t(size_t, skb_headlen(skb) - offset, len); + copied = io_zcrx_copy_chunk(req, ifq, virt_to_page(skb->data), + offset_in_page(skb->data) + offset, + to_copy); + if (copied < 0) { + ret = copied; + goto out; + } + offset += copied; + len -= copied; + if (!len) + goto out; + if (offset != skb_headlen(skb)) + goto out; + } + + start = skb_headlen(skb); + + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + const skb_frag_t *frag; + + if (WARN_ON(start > offset + len)) + return -EFAULT; + + frag = &skb_shinfo(skb)->frags[i]; + end = start + skb_frag_size(frag); + + if (offset < end) { + copy = end - offset; + if (copy > len) + copy = len; + + off = offset - start; + ret = io_zcrx_recv_frag(req, ifq, frag, off, copy); + if (ret < 0) + goto out; + + offset += ret; + len -= ret; + if (len == 0 || ret != copy) + goto out; + } + start = end; + } + + skb_walk_frags(skb, frag_iter) { + if (WARN_ON(start > offset + len)) + return -EFAULT; + + end = start + frag_iter->len; + if (offset < end) { + size_t count; + + copy = end - offset; + if (copy > len) + copy = len; + + off = offset - start; + count = desc->count; + ret = io_zcrx_recv_skb(desc, frag_iter, off, copy); + desc->count = count; + if (ret < 0) + goto out; + + offset += ret; + len -= ret; + if (len == 0 || ret != copy) + goto out; + } + start = end; + } + +out: + if (offset == start_off) + return ret; + desc->count -= (offset - start_off); + return offset - start_off; +} + +static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + struct sock *sk, int flags, + unsigned issue_flags, unsigned int *outlen) +{ + unsigned int len = *outlen; + struct io_zcrx_args args = { + .req = req, + .ifq = ifq, + .sock = sk->sk_socket, + }; + read_descriptor_t rd_desc = { + .count = len ? len : UINT_MAX, + .arg.data = &args, + }; + int ret; + + lock_sock(sk); + ret = tcp_read_sock(sk, &rd_desc, io_zcrx_recv_skb); + if (len && ret > 0) + *outlen = len - ret; + if (ret <= 0) { + if (ret < 0 || sock_flag(sk, SOCK_DONE)) + goto out; + if (sk->sk_err) + ret = sock_error(sk); + else if (sk->sk_shutdown & RCV_SHUTDOWN) + goto out; + else if (sk->sk_state == TCP_CLOSE) + ret = -ENOTCONN; + else + ret = -EAGAIN; + } else if (unlikely(args.nr_skbs > IO_SKBS_PER_CALL_LIMIT) && + (issue_flags & IO_URING_F_MULTISHOT)) { + ret = IOU_REQUEUE; + } else if (sock_flag(sk, SOCK_DONE)) { + /* Make it to retry until it finally gets 0. */ + if (issue_flags & IO_URING_F_MULTISHOT) + ret = IOU_REQUEUE; + else + ret = -EAGAIN; + } +out: + release_sock(sk); + return ret; +} + +int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + struct socket *sock, unsigned int flags, + unsigned issue_flags, unsigned int *len) +{ + struct sock *sk = sock->sk; + const struct proto *prot = READ_ONCE(sk->sk_prot); + + if (prot->recvmsg != tcp_recvmsg) + return -EPROTONOSUPPORT; + + sock_rps_record_flow(sk); + return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags, len); +} diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h new file mode 100644 index 000000000000..32ab95b2cb81 --- /dev/null +++ b/io_uring/zcrx.h @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_ZC_RX_H +#define IOU_ZC_RX_H + +#include <linux/io_uring_types.h> +#include <linux/dma-buf.h> +#include <linux/socket.h> +#include <net/page_pool/types.h> +#include <net/net_trackers.h> + +struct io_zcrx_mem { + unsigned long size; + bool is_dmabuf; + + struct page **pages; + unsigned long nr_folios; + struct sg_table page_sg_table; + unsigned long account_pages; + struct sg_table *sgt; + + struct dma_buf_attachment *attach; + struct dma_buf *dmabuf; +}; + +struct io_zcrx_area { + struct net_iov_area nia; + struct io_zcrx_ifq *ifq; + atomic_t *user_refs; + + bool is_mapped; + u16 area_id; + + /* freelist */ + spinlock_t freelist_lock ____cacheline_aligned_in_smp; + u32 free_count; + u32 *freelist; + + struct io_zcrx_mem mem; +}; + +struct io_zcrx_ifq { + struct io_zcrx_area *area; + unsigned niov_shift; + struct user_struct *user; + struct mm_struct *mm_account; + + spinlock_t rq_lock ____cacheline_aligned_in_smp; + struct io_uring *rq_ring; + struct io_uring_zcrx_rqe *rqes; + u32 cached_rq_head; + u32 rq_entries; + + u32 if_rxq; + struct device *dev; + struct net_device *netdev; + netdevice_tracker netdev_tracker; + refcount_t refs; + /* counts userspace facing users like io_uring */ + refcount_t user_refs; + + /* + * Page pool and net configuration lock, can be taken deeper in the + * net stack. + */ + struct mutex pp_lock; + struct io_mapped_region region; +}; + +#if defined(CONFIG_IO_URING_ZCRX) +int io_zcrx_ctrl(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_arg); +int io_register_zcrx_ifq(struct io_ring_ctx *ctx, + struct io_uring_zcrx_ifq_reg __user *arg); +void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx); +int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + struct socket *sock, unsigned int flags, + unsigned issue_flags, unsigned int *len); +struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx, + unsigned int id); +#else +static inline int io_register_zcrx_ifq(struct io_ring_ctx *ctx, + struct io_uring_zcrx_ifq_reg __user *arg) +{ + return -EOPNOTSUPP; +} +static inline void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx) +{ +} +static inline int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, + struct socket *sock, unsigned int flags, + unsigned issue_flags, unsigned int *len) +{ + return -EOPNOTSUPP; +} +static inline struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx, + unsigned int id) +{ + return NULL; +} +static inline int io_zcrx_ctrl(struct io_ring_ctx *ctx, + void __user *arg, unsigned nr_arg) +{ + return -EOPNOTSUPP; +} +#endif + +int io_recvzc(struct io_kiocb *req, unsigned int issue_flags); +int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); + +#endif |