---
  block/genhd.c         | 10 +++++++
  block/holder.c        | 68 ++++++++++++++++++++++++++++++++-----------
  include/linux/genhd.h |  5 ++++
  3 files changed, 66 insertions(+), 17 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index cd4eab744667..db916f779077 100644
--- a/block/genhd.c
+++ b/block/genhd.c

@@ -447,6 +447,16 @@ static void register_disk(struct device *parent, struct gendisk *disk,
  		kobject_create_and_add("holders", &ddev->kobj);
  	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
  
+	/*
+	 * XXX: this is a mess, can't wait for real error handling in add_disk.
+	 * Make sure ->slave_dir is NULL if we failed some of the registration
+	 * so that the cleanup in bd_unlink_disk_holder works properly.
+	 */
+	if (bd_register_pending_holders(disk) < 0) {
+		kobject_put(disk->slave_dir);
+		disk->slave_dir = NULL;
+	}
+
  	if (disk->flags & GENHD_FL_HIDDEN)
  		return;
  

diff --git a/block/holder.c b/block/holder.c
index 11e65d99a9fb..4568cc4f6827 100644
--- a/block/holder.c
+++ b/block/holder.c

@@ -28,6 +28,19 @@ 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

@@ -66,7 +79,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
  	WARN_ON_ONCE(!bdev->bd_holder);
  
  	/* FIXME: remove the following once add_disk() handles errors */
-	if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir))
+	if (WARN_ON(!bdev->bd_holder_dir))
  		goto out_unlock;
  
  	holder = bd_find_holder_disk(bdev, disk);

@@ -84,28 +97,28 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
  	INIT_LIST_HEAD(&holder->list);
  	holder->bdev = bdev;
  	holder->refcnt = 1;
-
-	ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
-	if (ret)
-		goto out_free;
-
-	ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
-	if (ret)
-		goto out_del;
+	if (disk->slave_dir) {
+		ret = __link_disk_holder(bdev, disk);
+		if (ret) {
+			kfree(holder);
+			goto out_unlock;
+		}
+	}
  
  	list_add(&holder->list, &disk->slave_bdevs);
-	goto out_unlock;
-
-out_del:
-	del_symlink(disk->slave_dir, bdev_kobj(bdev));
-out_free:
-	kfree(holder);
  out_unlock:
  	mutex_unlock(&disk->open_mutex);
  	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

@@ -123,11 +136,32 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
  	mutex_lock(&disk->open_mutex);
  	holder = bd_find_holder_disk(bdev, disk);
  	if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
-		del_symlink(disk->slave_dir, bdev_kobj(bdev));
-		del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
+		if (disk->slave_dir)
+			__unlink_disk_holder(bdev, disk);
  		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;
+}

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 0721807d76ee..80952f038d79 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h

@@ -323,6 +323,7 @@ long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
  #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
  int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
  void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
+int bd_register_pending_holders(struct gendisk *disk);
  #else
  static inline int bd_link_disk_holder(struct block_device *bdev,
  				      struct gendisk *disk)

@@ -333,6 +334,10 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev,
  					 struct gendisk *disk)
  {
  }
+static inline int bd_register_pending_holders(struct gendisk *disk)
+{
+	return 0;
+}
  #endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
  
  dev_t part_devt(struct gendisk *disk, u8 partno);