-int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- u64 num_bytes, u64 parent,
- u64 root_objectid, u64 ref_generation,
- u64 owner, u64 empty_size, u64 hint_byte,
- u64 search_end, struct btrfs_key *ins, int data);