+int mdd_is_root(struct mdd_device *mdd, const struct lu_fid *fid);
+int mdd_lookup(const struct lu_env *env,
+ struct md_object *pobj, const struct lu_name *lname,
+ struct lu_fid* fid, struct md_op_spec *spec);
+struct lu_buf *mdd_links_get(const struct lu_env *env,
+ struct mdd_object *mdd_obj);
+void mdd_lee_unpack(const struct link_ea_entry *lee, int *reclen,
+ struct lu_name *lname, struct lu_fid *pfid);
+