[PATCH] lockdep: annotate the BLKPG_DEL_PARTITION ioctl

The delete partition IOCTL takes the bd_mutex for both the disk and the
partition; these have an obvious hierarchical relationship and this patch
annotates this relationship for lockdep.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

block/ioctl.c

@@ -72,7 +72,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
 			bdevp = bdget_disk(disk, part);
 			if (!bdevp)
 				return -ENOMEM;
-			mutex_lock(&bdevp->bd_mutex);
+			mutex_lock_nested(&bdevp->bd_mutex, BD_MUTEX_PARTITION);
 			if (bdevp->bd_openers) {
 				mutex_unlock(&bdevp->bd_mutex);
 				bdput(bdevp);
@@ -82,7 +82,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
 			fsync_bdev(bdevp);
 			invalidate_bdev(bdevp, 0);
 
-			mutex_lock(&bdev->bd_mutex);
+			mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_WHOLE);
 			delete_partition(disk, part);
 			mutex_unlock(&bdev->bd_mutex);
 			mutex_unlock(&bdevp->bd_mutex);