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authorMing Lei <ming.lei@redhat.com>2023-09-28 20:43:25 +0800
committerJens Axboe <axboe@kernel.dk>2023-09-28 07:36:00 -0600
commit93b8cc60c37b9d17732b7a297e5dca29b50a990d (patch)
tree69dc83ff4f33883707fc33fc30ad70cc40638969 /io_uring
parent528ce6781726e022bc5dc84034360e6e8f1b89bd (diff)
io_uring: cancelable uring_cmd
uring_cmd may never complete, such as ublk, in which uring cmd isn't completed until one new block request is coming from ublk block device. Add cancelable uring_cmd to provide mechanism to driver for cancelling pending commands in its own way. Add API of io_uring_cmd_mark_cancelable() for driver to mark one command as cancelable, then io_uring will cancel this command in io_uring_cancel_generic(). ->uring_cmd() callback is reused for canceling command in driver's way, then driver gets notified with the cancelling from io_uring. Add API of io_uring_cmd_get_task() to help driver cancel handler deal with the canceling. Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
-rw-r--r--io_uring/io_uring.c33
-rw-r--r--io_uring/uring_cmd.c47
2 files changed, 80 insertions, 0 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index cb6bd9907045..08c9ea46bb95 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -352,6 +352,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
INIT_HLIST_HEAD(&ctx->waitid_list);
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);
return ctx;
err:
kfree(ctx->cancel_table.hbs);
@@ -3258,6 +3259,37 @@ static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)
return ret;
}
+static bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
+ struct task_struct *task, 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->task != task)
+ continue;
+
+ if (cmd->flags & IORING_URING_CMD_CANCELABLE) {
+ /* ->sqe isn't available if no async data */
+ if (!req_has_async_data(req))
+ cmd->sqe = NULL;
+ file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL);
+ ret = true;
+ }
+ }
+ io_submit_flush_completions(ctx);
+
+ return ret;
+}
+
static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
struct task_struct *task,
bool cancel_all)
@@ -3306,6 +3338,7 @@ static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
mutex_lock(&ctx->uring_lock);
ret |= io_poll_remove_all(ctx, task, cancel_all);
ret |= io_waitid_remove_all(ctx, task, cancel_all);
+ ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all);
mutex_unlock(&ctx->uring_lock);
ret |= io_kill_timeouts(ctx, task, cancel_all);
if (task)
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index a0b0ec5473bf..00a5e5621a28 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -13,6 +13,51 @@
#include "rsrc.h"
#include "uring_cmd.h"
+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);
+
+struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd)
+{
+ return cmd_to_io_kiocb(cmd)->task;
+}
+EXPORT_SYMBOL_GPL(io_uring_cmd_get_task);
+
static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
{
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
@@ -56,6 +101,8 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
{
struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
+ io_uring_cmd_del_cancelable(ioucmd, issue_flags);
+
if (ret < 0)
req_set_fail(req);