Exporting stacked device relationship to sysfs (md)

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>

--- linux-2.6.15/drivers/md/md.c	2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/drivers/md/md.c	2006-02-21 19:11:16.000000000 -0500
@@ -1226,6 +1226,7 @@ static int bind_rdev_to_array(mdk_rdev_t
 	else
 		ko = &rdev->bdev->bd_disk->kobj;
 	sysfs_create_link(&rdev->kobj, ko, "block");
+	bd_claim_by_kobject(rdev->bdev, rdev, &mddev->gendisk->slave_dir);
 	return 0;
 }
 
@@ -1236,6 +1237,7 @@ static void unbind_rdev_from_array(mdk_r
 		MD_BUG();
 		return;
 	}
+	bd_release_from_kobject(rdev->bdev, &rdev->mddev->gendisk->slave_dir);
 	list_del_init(&rdev->same_set);
 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
 	rdev->mddev = NULL;