dm raid: protect md_stop() with 'reconfig_mutex'

__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>

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 845b68c..becdb68 100644 (file)
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3298,8 +3298,8 @@ size_check:
        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 2e38ef4..78be781 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6247,6 +6247,8 @@ 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
         */