[lvc-project] [PATCH 5.15/6.1/6.6/6.12] md/raid10: wait barrier before returning discard request with REQ_NOWAIT

[Daniil Dulov]

From: Xiao Ni <xni at redhat.com>

commit 3db4404435397a345431b45f57876a3df133f3b4 upstream.

raid10_handle_discard should wait barrier before returning a discard bio
which has REQ_NOWAIT. And there is no need to print warning calltrace
if a discard bio has REQ_NOWAIT flag. Quality engineer usually checks
dmesg and reports error if dmesg has warning/error calltrace.

Fixes: c9aa889b035f ("md: raid10 add nowait support")
Signed-off-by: Xiao Ni <xni at redhat.com>
Acked-by: Coly Li <colyli at kernel.org>
Link: https://lore.kernel.org/linux-raid/20250306094938.48952-1-xni@redhat.com
Signed-off-by: Yu Kuai <yukuai3 at huawei.com>
Signed-off-by: Daniil Dulov <d.dulov at aladdin.ru>
---
Backport fix for CVE-2025-40325.

 drivers/md/raid10.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index cc194f6ec18d..a02c02684237 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1585,11 +1585,10 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
 		return -EAGAIN;
 
-	if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT)) {
+	if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
 		bio_wouldblock_error(bio);
 		return 0;
 	}
-	wait_barrier(conf, false);
 
 	/*
 	 * Check reshape again to avoid reshape happens after checking
-- 
2.34.1