io_uring: check for need to re-wait in polled async handling

We added this for just the regular poll requests in commit a6ba632d2c24
("io_uring: retry poll if we got woken with non-matching mask"), we
should do the same for the poll handler used pollable async requests.
Move the re-wait check and arm into a helper, and call it from
io_async_task_func() as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0d1b5d5f12513b844b54c169bfc8a644c3ffb71d..7b41f6231955b4678c996339924504c88f0d737c 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4156,6 +4156,26 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
        return 1;
 }
 
+static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
+       __acquires(&req->ctx->completion_lock)
+{
+       struct io_ring_ctx *ctx = req->ctx;
+
+       if (!req->result && !READ_ONCE(poll->canceled)) {
+               struct poll_table_struct pt = { ._key = poll->events };
+
+               req->result = vfs_poll(req->file, &pt) & poll->events;
+       }
+
+       spin_lock_irq(&ctx->completion_lock);
+       if (!req->result && !READ_ONCE(poll->canceled)) {
+               add_wait_queue(poll->head, &poll->wait);
+               return true;
+       }
+
+       return false;
+}
+
 static void io_async_task_func(struct callback_head *cb)
 {
        struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
@@ -4164,14 +4184,16 @@ static void io_async_task_func(struct callback_head *cb)
 
        trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
 
-       WARN_ON_ONCE(!list_empty(&req->apoll->poll.wait.entry));
-
-       if (hash_hashed(&req->hash_node)) {
-               spin_lock_irq(&ctx->completion_lock);
-               hash_del(&req->hash_node);
+       if (io_poll_rewait(req, &apoll->poll)) {
                spin_unlock_irq(&ctx->completion_lock);
+               return;
        }
 
+       if (hash_hashed(&req->hash_node))
+               hash_del(&req->hash_node);
+
+       spin_unlock_irq(&ctx->completion_lock);
+
        /* restore ->work in case we need to retry again */
        memcpy(&req->work, &apoll->work, sizeof(req->work));
 
@@ -4436,18 +4458,11 @@ static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt)
        struct io_ring_ctx *ctx = req->ctx;
        struct io_poll_iocb *poll = &req->poll;
 
-       if (!req->result && !READ_ONCE(poll->canceled)) {
-               struct poll_table_struct pt = { ._key = poll->events };
-
-               req->result = vfs_poll(req->file, &pt) & poll->events;
-       }
-
-       spin_lock_irq(&ctx->completion_lock);
-       if (!req->result && !READ_ONCE(poll->canceled)) {
-               add_wait_queue(poll->head, &poll->wait);
+       if (io_poll_rewait(req, poll)) {
                spin_unlock_irq(&ctx->completion_lock);
                return;
        }
+
        hash_del(&req->hash_node);
        io_poll_complete(req, req->result, 0);
        req->flags |= REQ_F_COMP_LOCKED;