[PATCH -next v2 3/3] md/dm-raid: protect md_stop() with 'reconfig_mutex'

[Yu Kuai]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

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

Fixes: 9d09e663d550 ("dm: raid456 basic support")
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/md/dm-raid.c | 4 +++-
 drivers/md/md.c      | 2 ++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 33742f5e7ee5..5f9991765f27 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3298,8 +3298,8 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	return 0;
 
 bad_unlock:
-	mddev_unlock(&rs->md);
 	md_stop(&rs->md);
+	mddev_unlock(&rs->md);
 bad:
 	raid_set_free(rs);
 
@@ -3310,7 +3310,9 @@ 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 a3d98273b295..ff40e362c927 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6290,6 +6290,8 @@ 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
 	 */
-- 
2.39.2