Commit 74ce6ce4 authored by Jens Axboe's avatar Jens Axboe
Browse files

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



We added this for just the regular poll requests in commit a6ba632d
("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: default avatarJens Axboe <axboe@kernel.dk>
parent 88357580

fs/io_uring.c

+29 −14
Original line number Diff line number Diff line
@@ -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);
@@ -4164,13 +4184,15 @@ 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 (io_poll_rewait(req, &apoll->poll)) {

		spin_unlock_irq(&ctx->completion_lock);

		return;

	}



	if (hash_hashed(&req->hash_node)) {

		spin_lock_irq(&ctx->completion_lock);

	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;

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