This is a note to let you know that I've just added the patch titled
io_uring: ensure task_work gets run as part of cancelations
to the 5.15-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-ensure-task_work-gets-run-as-part-of-cancelations.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 78a780602075d8b00c98070fa26e389b3b3efa72 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Thu, 9 Dec 2021 08:54:29 -0700
Subject: io_uring: ensure task_work gets run as part of cancelations
From: Jens Axboe <axboe@xxxxxxxxx>
commit 78a780602075d8b00c98070fa26e389b3b3efa72 upstream.
If we successfully cancel a work item but that work item needs to be
processed through task_work, then we can be sleeping uninterruptibly
in io_uring_cancel_generic() and never process it. Hence we don't
make forward progress and we end up with an uninterruptible sleep
warning.
While in there, correct a comment that should be IFF, not IIF.
Reported-and-tested-by: syzbot+21e6887c0be14181206d@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9775,7 +9775,7 @@ static void io_uring_drop_tctx_refs(stru
/*
* Find any io_uring ctx that this task has registered or done IO on, and cancel
- * requests. @sqd should be not-null IIF it's an SQPOLL thread cancellation.
+ * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
*/
static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd)
{
@@ -9816,8 +9816,10 @@ static void io_uring_cancel_generic(bool
cancel_all);
}
- prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE);
+ io_run_task_work();
io_uring_drop_tctx_refs(current);
+
/*
* If we've seen completions, retry without waiting. This
* avoids a race where a completion comes in before we did
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-5.15/mm-bdi-initialize-bdi_min_ratio-when-bdi-is-unregistered.patch
queue-5.15/io_uring-ensure-task_work-gets-run-as-part-of-cancelations.patch
