diff options
Diffstat (limited to 'io_uring/io_uring.h')
| -rw-r--r-- | io_uring/io_uring.h | 616 |
1 files changed, 616 insertions, 0 deletions
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 |