btrfs_free_reserved_bytes
void btrfs_free_reserved_bytes(struct btrfs_block_group *cache, u64 num_bytes,
btrfs_free_reserved_bytes(bg, buf->len, false);
btrfs_free_reserved_bytes(cache, len, is_delalloc);
btrfs_free_reserved_bytes(dest_bg, dest_length, 0);
btrfs_free_reserved_bytes(dest_bg, length, 0);