1 files changed, 43 insertions, 60 deletions

diff --git a/block/holder.c b/block/holder.c
index 5283bc804cc1..37d18c13d958 100644
--- a/block/holder.c
+++ b/block/holder.c
@@ -4,7 +4,7 @@
 
 struct bd_holder_disk {
 	struct list_head	list;
-	struct block_device	*bdev;
+	struct kobject		*holder_dir;
 	int			refcnt;
 };
 
@@ -14,7 +14,7 @@ static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
 	struct bd_holder_disk *holder;
 
 	list_for_each_entry(holder, &disk->slave_bdevs, list)
-		if (holder->bdev == bdev)
+		if (holder->holder_dir == bdev->bd_holder_dir)
 			return holder;
 	return NULL;
 }
@@ -29,19 +29,6 @@ static void del_symlink(struct kobject *from, struct kobject *to)
 	sysfs_remove_link(from, kobject_name(to));
 }
 
-static int __link_disk_holder(struct block_device *bdev, struct gendisk *disk)
-{
-	int ret;
-
-	ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
-	if (ret)
-		return ret;
-	ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
-	if (ret)
-		del_symlink(disk->slave_dir, bdev_kobj(bdev));
-	return ret;
-}
-
 /**
  * bd_link_disk_holder - create symlinks between holding disk and slave bdev
  * @bdev: the claimed slave bdev
@@ -75,12 +62,30 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
 	struct bd_holder_disk *holder;
 	int ret = 0;
 
-	mutex_lock(&disk->open_mutex);
+	if (WARN_ON_ONCE(!disk->slave_dir))
+		return -EINVAL;
+
+	if (bdev->bd_disk == disk)
+		return -EINVAL;
+
+	/*
+	 * del_gendisk drops the initial reference to bd_holder_dir, so we
+	 * need to keep our own here to allow for cleanup past that point.
+	 */
+	mutex_lock(&bdev->bd_disk->open_mutex);
+	if (!disk_live(bdev->bd_disk)) {
+		mutex_unlock(&bdev->bd_disk->open_mutex);
+		return -ENODEV;
+	}
+	kobject_get(bdev->bd_holder_dir);
+	mutex_unlock(&bdev->bd_disk->open_mutex);
 
+	mutex_lock(&disk->open_mutex);
 	WARN_ON_ONCE(!bdev->bd_holder);
 
 	holder = bd_find_holder_disk(bdev, disk);
 	if (holder) {
+		kobject_put(bdev->bd_holder_dir);
 		holder->refcnt++;
 		goto out_unlock;
 	}
@@ -92,36 +97,32 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
 	}
 
 	INIT_LIST_HEAD(&holder->list);
-	holder->bdev = bdev;
 	holder->refcnt = 1;
-	if (disk->slave_dir) {
-		ret = __link_disk_holder(bdev, disk);
-		if (ret) {
-			kfree(holder);
-			goto out_unlock;
-		}
-	}
+	holder->holder_dir = bdev->bd_holder_dir;
 
+	ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
+	if (ret)
+		goto out_free_holder;
+	ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
+	if (ret)
+		goto out_del_symlink;
 	list_add(&holder->list, &disk->slave_bdevs);
-	/*
-	 * del_gendisk drops the initial reference to bd_holder_dir, so we need
-	 * to keep our own here to allow for cleanup past that point.
-	 */
-	kobject_get(bdev->bd_holder_dir);
 
+	mutex_unlock(&disk->open_mutex);
+	return 0;
+
+out_del_symlink:
+	del_symlink(disk->slave_dir, bdev_kobj(bdev));
+out_free_holder:
+	kfree(holder);
 out_unlock:
 	mutex_unlock(&disk->open_mutex);
+	if (ret)
+		kobject_put(bdev->bd_holder_dir);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(bd_link_disk_holder);
 
-static void __unlink_disk_holder(struct block_device *bdev,
-		struct gendisk *disk)
-{
-	del_symlink(disk->slave_dir, bdev_kobj(bdev));
-	del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
-}
-
 /**
  * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
  * @bdev: the calimed slave bdev
@@ -136,36 +137,18 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
 {
 	struct bd_holder_disk *holder;
 
+	if (WARN_ON_ONCE(!disk->slave_dir))
+		return;
+
 	mutex_lock(&disk->open_mutex);
 	holder = bd_find_holder_disk(bdev, disk);
 	if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
-		if (disk->slave_dir)
-			__unlink_disk_holder(bdev, disk);
-		kobject_put(bdev->bd_holder_dir);
+		del_symlink(disk->slave_dir, bdev_kobj(bdev));
+		del_symlink(holder->holder_dir, &disk_to_dev(disk)->kobj);
+		kobject_put(holder->holder_dir);
 		list_del_init(&holder->list);
 		kfree(holder);
 	}
 	mutex_unlock(&disk->open_mutex);
 }
 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
-
-int bd_register_pending_holders(struct gendisk *disk)
-{
-	struct bd_holder_disk *holder;
-	int ret;
-
-	mutex_lock(&disk->open_mutex);
-	list_for_each_entry(holder, &disk->slave_bdevs, list) {
-		ret = __link_disk_holder(holder->bdev, disk);
-		if (ret)
-			goto out_undo;
-	}
-	mutex_unlock(&disk->open_mutex);
-	return 0;
-
-out_undo:
-	list_for_each_entry_continue_reverse(holder, &disk->slave_bdevs, list)
-		__unlink_disk_holder(holder->bdev, disk);
-	mutex_unlock(&disk->open_mutex);
-	return ret;
-}