This is a note to let you know that I've just added the patch titled
io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq
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-treat-eagain-for-req_f_nowait-as-final-for-io-wq.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 a9be202269580ca611c6cebac90eaf1795497800 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Thu, 20 Jul 2023 13:16:53 -0600
Subject: io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq
From: Jens Axboe <axboe@xxxxxxxxx>
commit a9be202269580ca611c6cebac90eaf1795497800 upstream.
io-wq assumes that an issue is blocking, but it may not be if the
request type has asked for a non-blocking attempt. If we get
-EAGAIN for that case, then we need to treat it as a final result
and not retry or arm poll for it.
Cc: stable@xxxxxxxxxxxxxxx # 5.10+
Link: https://github.com/axboe/liburing/issues/897
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/io_uring.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -7066,6 +7066,14 @@ static void io_wq_submit_work(struct io_
*/
if (ret != -EAGAIN || !(req->ctx->flags & IORING_SETUP_IOPOLL))
break;
+
+ /*
+ * If REQ_F_NOWAIT is set, then don't wait or retry with
+ * poll. -EAGAIN is final for that case.
+ */
+ if (req->flags & REQ_F_NOWAIT)
+ break;
+
cond_resched();
} while (1);
}
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-5.15/block-fix-a-source-code-comment-in-include-uapi-linu.patch
queue-5.15/io_uring-don-t-audit-the-capability-check-in-io_urin.patch
queue-5.15/s390-dasd-fix-hanging-device-after-quiesce-resume.patch
queue-5.15/io_uring-treat-eagain-for-req_f_nowait-as-final-for-io-wq.patch
