[PATCH] block_dev.c mutex_lock_nested() fix

In the case below we are locking the whole disk not a partition.  This
change simply brings the code in line with the piece above where when we
are the 'first' opener, and we are a partition.
Signed-off-by: NJason Baron <jbaron@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/block_dev.c

@@ -1031,7 +1031,7 @@ do_open(struct block_device *bdev, struct file *file, unsigned int subclass)
 				rescan_partitions(bdev->bd_disk, bdev);
 		} else {
 			mutex_lock_nested(&bdev->bd_contains->bd_mutex,
-					  BD_MUTEX_PARTITION);
+					  BD_MUTEX_WHOLE);
 			bdev->bd_contains->bd_part_count++;
 			mutex_unlock(&bdev->bd_contains->bd_mutex);
 		}