This is a note to let you know that I've just added the patch titled
io_uring: fix missing set of EPOLLONESHOT for CQ ring overflow
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-fix-missing-set-of-epolloneshot-for-cq-ring.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 094285a50f040bc69e8c074f30cf7459026bde1e
Author: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
Date: Wed Sep 22 18:12:37 2021 +0800
io_uring: fix missing set of EPOLLONESHOT for CQ ring overflow
[ Upstream commit a62682f92eedb41c1cd8290fa875a4b85624fb9a ]
We should set EPOLLONESHOT if cqring_fill_event() returns false since
io_poll_add() decides to put req or not by it.
Fixes: 5082620fb2ca ("io_uring: terminate multishot poll for CQ ring overflow")
Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210922101238.7177-3-haoxu@xxxxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 27a1c813f1e1..739e58ccc982 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4968,8 +4968,10 @@ static bool io_poll_complete(struct io_kiocb *req, __poll_t mask)
}
if (req->poll.events & EPOLLONESHOT)
flags = 0;
- if (!io_cqring_fill_event(ctx, req->user_data, error, flags))
+ if (!io_cqring_fill_event(ctx, req->user_data, error, flags)) {
+ req->poll.events |= EPOLLONESHOT;
flags = 0;
+ }
if (flags & IORING_CQE_F_MORE)
ctx->cq_extra++;
