dm: hold suspend_lock while suspending device during device deletion

commit ab7c7bb6f4ab95dbca96fcfc4463cd69843e3e24 upstream.

__dm_destroy() must take the suspend_lock so that its presuspend and
postsuspend calls do not race with an internal suspend.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index d38d5248c23e09849006b871aa9c44e592468988..c00bcdcd36de1f1ce86a5788e6fb2add2e86431e 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2295,10 +2295,16 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
        set_bit(DMF_FREEING, &md->flags);
        spin_unlock(&_minor_lock);
 
+       /*
+        * Take suspend_lock so that presuspend and postsuspend methods
+        * do not race with internal suspend.
+        */
+       mutex_lock(&md->suspend_lock);
        if (!dm_suspended_md(md)) {
                dm_table_presuspend_targets(map);
                dm_table_postsuspend_targets(map);
        }
+       mutex_unlock(&md->suspend_lock);
 
        /*
         * Rare, but there may be I/O requests still going to complete,