[PATCH 3/3] sysfs representation of stacked devices (md)

[Jun'ichi Nomura]

This patch modifies md driver to create symlinks to/from
underlying devices.

-- 
Jun'ichi Nomura, NEC Solutions (America), Inc.
Exporting stacked device relationship to sysfs (md)

Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx>

--- linux-2.6.15.orig/include/linux/raid/md_k.h	2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/include/linux/raid/md_k.h	2006-02-16 15:36:22.000000000 -0500
@@ -155,6 +155,7 @@ struct mddev_s
 	struct gendisk			*gendisk;
 
 	struct kobject			kobj;
+	struct kobject			slave_dir;
 
 	/* Superblock information */
 	int				major_version,
md.c linux-2.6.15/drivers/md/md.c
--- linux-2.6.15.orig/drivers/md/md.c	2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/drivers/md/md.c	2006-02-16 17:44:49.000000000 -0500
@@ -182,6 +182,7 @@ static void mddev_put(mddev_t *mddev)
 		return;
 	if (!mddev->raid_disks && list_empty(&mddev->disks)) {
 		list_del(&mddev->all_mddevs);
+		stackdev_clear(&mddev->slave_dir);
 		blk_put_queue(mddev->queue);
 		kobject_unregister(&mddev->kobj);
 	}
@@ -1226,6 +1227,7 @@ static int bind_rdev_to_array(mdk_rdev_t
 	else
 		ko = &rdev->bdev->bd_disk->kobj;
 	sysfs_create_link(&rdev->kobj, ko, "block");
+	stackdev_link(rdev->bdev, &mddev->slave_dir, &mddev->gendisk->kobj);
 	return 0;
 }
 
@@ -1236,6 +1238,8 @@ static void unbind_rdev_from_array(mdk_r
 		MD_BUG();
 		return;
 	}
+	stackdev_unlink(rdev->bdev, &rdev->mddev->slave_dir,
+			&rdev->mddev->gendisk->kobj);
 	list_del_init(&rdev->same_set);
 	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
 	rdev->mddev = NULL;
@@ -1924,6 +1928,7 @@ static struct kobject *md_probe(dev_t de
 	snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
 	mddev->kobj.ktype = &md_ktype;
 	kobject_register(&mddev->kobj);
+	stackdev_init(&mddev->slave_dir, &mddev->gendisk->kobj);
 	return NULL;
 }