current/SOURCES/io_uring-fix-issue-with-io_write-not-always-undoing-.patch

From e6ab6c526bab6020869d6d97eb46bec06b4fd287 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 25 Aug 2022 10:17:25 -0600
Subject: [PATCH] io_uring: fix issue with io_write() not always undoing
 sb_start_write()

commit e053aaf4da56cbf0afb33a0fda4a62188e2c0637 upstream.

This is actually an older issue, but we never used to hit the -EAGAIN
path before having done sb_start_write(). Make sure that we always call
kiocb_end_write() if we need to retry the write, so that we keep the
calls to sb_start_write() etc balanced.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 6a67dbf5195f..cd155b7e1346 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -4331,7 +4331,12 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
 copy_iov:
                iov_iter_restore(&s->iter, &s->iter_state);
                ret = io_setup_async_rw(req, iovec, s, false);
-               return ret ?: -EAGAIN;
+               if (!ret) {
+                       if (kiocb->ki_flags & IOCB_WRITE)
+                               kiocb_end_write(req);
+                       return -EAGAIN;
+               }
+               return ret;
        }
 out_free:
        /* it's reportedly faster than delegating the null check to kfree() */
-- 
2.35.1

1	From e6ab6c526bab6020869d6d97eb46bec06b4fd287 Mon Sep 17 00:00:00 2001
2	From: Jens Axboe <axboe@kernel.dk>
3	Date: Thu, 25 Aug 2022 10:17:25 -0600
4	Subject: [PATCH] io_uring: fix issue with io_write() not always undoing
5	sb_start_write()
6
7	commit e053aaf4da56cbf0afb33a0fda4a62188e2c0637 upstream.
8
9	This is actually an older issue, but we never used to hit the -EAGAIN
10	path before having done sb_start_write(). Make sure that we always call
11	kiocb_end_write() if we need to retry the write, so that we keep the
12	calls to sb_start_write() etc balanced.
13
14	Signed-off-by: Jens Axboe <axboe@kernel.dk>
15	---
16	io_uring/io_uring.c \| 7 ++++++-
17	1 file changed, 6 insertions(+), 1 deletion(-)
18
19	diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
20	index 6a67dbf5195f..cd155b7e1346 100644
21	--- a/io_uring/io_uring.c
22	+++ b/io_uring/io_uring.c
23	@@ -4331,7 +4331,12 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
24	copy_iov:
25	iov_iter_restore(&s->iter, &s->iter_state);
26	ret = io_setup_async_rw(req, iovec, s, false);
27	- return ret ?: -EAGAIN;
28	+ if (!ret) {
29	+ if (kiocb->ki_flags & IOCB_WRITE)
30	+ kiocb_end_write(req);
31	+ return -EAGAIN;
32	+ }
33	+ return ret;
34	}
35	out_free:
36	/* it's reportedly faster than delegating the null check to kfree() */
37	--
38	2.35.1
39