From: Yu Kuai <yukuai3@huawei.com>
Date: Sat, 8 Jul 2023 09:21:53 +0000 (+0800)
Subject: dm raid: protect md_stop() with 'reconfig_mutex'
X-Git-Tag: v5.15.124~61
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e1c1d742970d65f1551a455a780c17a61ce4251;p=thirdparty%2Fkernel%2Fstable.git

dm raid: protect md_stop() with 'reconfig_mutex'

[ Upstream commit 7d5fff8982a2199d49ec067818af7d84d4f95ca0 ]

__md_stop_writes() and __md_stop() will modify many fields that are
protected by 'reconfig_mutex', and all the callers will grab
'reconfig_mutex' except for md_stop().

Also, update md_stop() to make certain 'reconfig_mutex' is held using
lockdep_assert_held().

Fixes: 9d09e663d550 ("dm: raid456 basic support")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 6d4e287350a33..8d489933d5792 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3305,8 +3305,8 @@ size_check:
 	return 0;
 
 bad_unlock:
-	mddev_unlock(&rs->md);
 	md_stop(&rs->md);
+	mddev_unlock(&rs->md);
 bad:
 	raid_set_free(rs);
 
@@ -3317,7 +3317,9 @@ static void raid_dtr(struct dm_target *ti)
 {
 	struct raid_set *rs = ti->private;
 
+	mddev_lock_nointr(&rs->md);
 	md_stop(&rs->md);
+	mddev_unlock(&rs->md);
 	raid_set_free(rs);
 }
 
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5a21aeedc1ba7..89a270d293698 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6281,6 +6281,8 @@ static void __md_stop(struct mddev *mddev)
 
 void md_stop(struct mddev *mddev)
 {
+	lockdep_assert_held(&mddev->reconfig_mutex);
+
 	/* stop the array and free an attached data structures.
 	 * This is called from dm-raid
 	 */