FAILED: patch "[PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x a9be202269580ca611c6cebac90eaf1795497800
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023072352-cage-carnage-b38a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

a9be20226958 ("io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq")
ed29b0b4fd83 ("io_uring: move to separate directory")
d01905db14eb ("io_uring: clean iowq submit work cancellation")
255657d23704 ("io_uring: clean io_wq_submit_work()'s main loop")
90fa02883f06 ("io_uring: implement async hybrid mode for pollable requests")
3b44b3712c5b ("io_uring: split logic of force_nonblock")
9882131cd9de ("io_uring: kill io_wq_current_is_worker() in iopoll")
9983028e7660 ("io_uring: optimise req->ctx reloads")
5e49c973fc39 ("io_uring: clean up io_import_iovec")
51aac424aef9 ("io_uring: optimise io_import_iovec nonblock passing")
c88598a92a58 ("io_uring: optimise read/write iov state storing")
538941e2681c ("io_uring: encapsulate rw state")
d886e185a128 ("io_uring: control ->async_data with a REQ_F flag")
30d51dd4ad20 ("io_uring: clean up buffer select")
ef05d9ebcc92 ("io_uring: kill off ->inflight_entry field")
6f33b0bc4ea4 ("io_uring: use slist for completion batching")
c450178d9be9 ("io_uring: dedup CQE flushing non-empty checks")
4c928904ff77 ("block: move CONFIG_BLOCK guard to top Makefile")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a9be202269580ca611c6cebac90eaf1795497800 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 20 Jul 2023 13:16:53 -0600
Subject: [PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq

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@vger.kernel.org # 5.10+
Link: https://github.com/axboe/liburing/issues/897
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index a9923676d16d..5e97235a82d6 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1948,6 +1948,14 @@ void io_wq_submit_work(struct io_wq_work *work)
 		ret = io_issue_sqe(req, issue_flags);
 		if (ret != -EAGAIN)
 			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;
+
 		/*
 		 * We can get EAGAIN for iopolled IO even though we're
 		 * forcing a sync submission from here, since we can't

Re: FAILED: patch "[PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq" failed to apply to 5.15-stable tree

[Jens Axboe]

[-- Attachment #1: Type: text/plain, Size: 844 bytes --]

On 7/23/23 6:54 AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.15-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
> git checkout FETCH_HEAD
> git cherry-pick -x a9be202269580ca611c6cebac90eaf1795497800
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023072352-cage-carnage-b38a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Here's a tested backport for 5.10-stable and 5.15-stable. Thanks!

-- 
Jens Axboe


[-- Attachment #2: 0001-io_uring-treat-EAGAIN-for-REQ_F_NOWAIT-as-final-for-.patch --]
[-- Type: text/x-patch, Size: 1248 bytes --]

From 7e1a56ef1480fede35eaca84b9e5fcd2cfb99e5a Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Mon, 24 Jul 2023 12:27:37 -0600
Subject: [PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq

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@vger.kernel.org # 5.10+
Link: https://github.com/axboe/liburing/issues/897
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index eae7a3d89397..0d80dcd0ac32 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -7055,6 +7055,14 @@ static void io_wq_submit_work(struct io_wq_work *work)
 			 */
 			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);
 	}
-- 
2.40.1

Re: FAILED: patch "[PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq" failed to apply to 5.15-stable tree

[Greg KH]

On Mon, Jul 24, 2023 at 12:38:50PM -0600, Jens Axboe wrote:
> On 7/23/23 6:54 AM, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 5.15-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > To reproduce the conflict and resubmit, you may use the following commands:
> > 
> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x a9be202269580ca611c6cebac90eaf1795497800
> > # <resolve conflicts, build, test, etc.>
> > git commit -s
> > git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023072352-cage-carnage-b38a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
> 
> Here's a tested backport for 5.10-stable and 5.15-stable. Thanks!

Now queued up, sorry for the delay.

greg k-h