Commit 90b87490 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: maintain CQE order of a failed link 



Arguably we want CQEs of linked requests be in a strict order of
submission as it always was. Now if init of a request fails its CQE may
be posted before all prior linked requests including the head of the
link. Fix it by failing it last.

Fixes: de59bc10 ("io_uring: fail links more in io_submit_sqe()")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b7a96b05832e7ab23ad55f84092a2548c4a888b0.1616699075.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f5d2d23b

fs/io_uring.c

+2 −2
Original line number Diff line number Diff line
@@ -6480,8 +6480,6 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, 
	ret = io_init_req(ctx, req, sqe);

	if (unlikely(ret)) {

fail_req:

		io_put_req(req);

		io_req_complete(req, ret);

		if (link->head) {

			/* fail even hard links since we don't submit */

			link->head->flags |= REQ_F_FAIL_LINK;
@@ -6489,6 +6487,8 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, 
			io_req_complete(link->head, -ECANCELED);

			link->head = NULL;

		}

		io_put_req(req);

		io_req_complete(req, ret);

		return ret;

	}

	ret = io_req_prep(req, sqe);