struct btrfs_block_group_cache *
btrfs_alloc_dummy_block_group(struct btrfs_fs_info *fs_info, unsigned long length);
void btrfs_free_dummy_block_group(struct btrfs_block_group_cache *cache);
struct btrfs_block_group_cache *
btrfs_alloc_dummy_block_group(struct btrfs_fs_info *fs_info, unsigned long length);
void btrfs_free_dummy_block_group(struct btrfs_block_group_cache *cache);