dm: hold suspend_lock while suspending device during device deletion

__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>
Cc: stable@vger.kernel.org

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 73f2880..e79d5cc 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2638,10 +2638,16 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
        if (dm_request_based(md))
                flush_kthread_worker(&md->kworker);
 
+       /*
+        * 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);
 
        /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
        dm_put_live_table(md, srcu_idx);