[PATCH] md: make sure /block link in /sys/.../md/ goes to correct devices

If a block_device is a partition, then it's kobject is
  bdev->bd_part->kobj
otherwise (if it is a full device), the kobject is
  bdev->bd_disk->kobj

As md wants back-links to the correct object (whether partition or not), we
need to respect this difference...  (Thus current code shows a link to the
whole device, whether we are using a partition or not, which is wrong).
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/md.c

@@ -1182,6 +1182,7 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 {
 	mdk_rdev_t *same_pdev;
 	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
+	struct kobject *ko;
 
 	if (rdev->mddev) {
 		MD_BUG();
@@ -1221,7 +1222,11 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 	rdev->kobj.parent = &mddev->kobj;
 	kobject_add(&rdev->kobj);
 
-	sysfs_create_link(&rdev->kobj, &rdev->bdev->bd_disk->kobj, "block");
+	if (rdev->bdev->bd_part)
+		ko = &rdev->bdev->bd_part->kobj;
+	else
+		ko = &rdev->bdev->bd_disk->kobj;
+	sysfs_create_link(&rdev->kobj, ko, "block");
 	return 0;
 }