From b98186aee22fa593bc8c6b2c5d839c2ee518bc8c Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 17 Nov 2022 18:40:14 +0000 Subject: [PATCH] io_uring: update res mask in io_poll_check_events When io_poll_check_events() collides with someone attempting to queue a task work, it'll spin for one more time. However, it'll continue to use the mask from the first iteration instead of updating it. For example, if the first wake up was a EPOLLIN and the second EPOLLOUT, the userspace will not get EPOLLOUT in time. Clear the mask for all subsequent iterations to force vfs_poll(). Cc: stable@vger.kernel.org Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/2dac97e8f691231049cb259c4ae57e79e40b537c.1668710222.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/poll.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/io_uring/poll.c b/io_uring/poll.c index f500506..90920ab 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -258,6 +258,9 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) return ret; } + /* force the next iteration to vfs_poll() */ + req->cqe.res = 0; + /* * Release all references, retry if someone tried to restart * task_work while we were executing it. -- 2.7.4