[PATCH] dm: suspend: fix error path

If the device is already suspended, just return the error and skip the code
that would incorrectly wipe md->suspended_bdev.

(This isn't currently a problem because existing code avoids calling this
function if the device is already suspended.)
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <dm-devel@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/dm.c

@@ -1285,7 +1285,7 @@ int dm_suspend(struct mapped_device *md, int do_lockfs)
 	down(&md->suspend_lock);
 
 	if (dm_suspended(md))
-		goto out;
+		goto out_unlock;
 
 	map = dm_get_table(md);
 
@@ -1361,6 +1361,8 @@ out:
 	}
 
 	dm_table_put(map);
+
+out_unlock:
 	up(&md->suspend_lock);
 	return r;
 }