This is a note to let you know that I've just added the patch titled
io_uring: disable io-wq execution of multishot NOWAIT requests
to the 6.8-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-disable-io-wq-execution-of-multishot-nowait-requests.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5984bb9e2b72455e8e5a1925edde3079c9f949be Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Mon, 1 Apr 2024 11:30:06 -0600
Subject: io_uring: disable io-wq execution of multishot NOWAIT requests
From: Jens Axboe <axboe@xxxxxxxxx>
Commit bee1d5becdf5bf23d4ca0cd9c6b60bdf3c61d72b upstream.
Do the same check for direct io-wq execution for multishot requests that
commit 2a975d426c82 did for the inline execution, and disable multishot
mode (and revert to single shot) if the file type doesn't support NOWAIT,
and isn't opened in O_NONBLOCK mode. For multishot to work properly, it's
a requirement that nonblocking read attempts can be done.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/io_uring.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1964,10 +1964,15 @@ fail:
err = -EBADFD;
if (!file_can_poll(req->file))
goto fail;
- err = -ECANCELED;
- if (io_arm_poll_handler(req, issue_flags) != IO_APOLL_OK)
- goto fail;
- return;
+ if (req->file->f_flags & O_NONBLOCK ||
+ req->file->f_mode & FMODE_NOWAIT) {
+ err = -ECANCELED;
+ if (io_arm_poll_handler(req, issue_flags) != IO_APOLL_OK)
+ goto fail;
+ return;
+ } else {
+ req->flags &= ~REQ_F_APOLL_MULTISHOT;
+ }
}
if (req->flags & REQ_F_FORCE_ASYNC) {
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-6.8/io_uring-refactor-defer_taskrun-multishot-checks.patch
queue-6.8/block-fix-q-blkg_list-corruption-during-disk-rebind.patch
queue-6.8/io_uring-disable-io-wq-execution-of-multishot-nowait-requests.patch
