int write_ctree_super(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr);
+int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
+ char *result);
#endif