btrfs: dev delete should remove sysfs entry

when we delete the device from the mounted btrfs,
we would need its corresponding sysfs enty to
be removed as well.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/sysfs.c

@@ -605,6 +605,26 @@ static void init_feature_attrs(void)
 	}
 }
 
+int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *one_device)
+{
+	struct hd_struct *disk;
+	struct kobject *disk_kobj;
+
+	if (!fs_info->device_dir_kobj)
+		return -EINVAL;
+
+	if (one_device) {
+		disk = one_device->bdev->bd_part;
+		disk_kobj = &part_to_dev(disk)->kobj;
+
+		sysfs_remove_link(fs_info->device_dir_kobj,
+						disk_kobj->name);
+	}
+
+	return 0;
+}
+
 static int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info)
 {
 	int error = 0;