int tgt_mdt_data_lock(struct ldlm_namespace *ns, struct ldlm_res_id *res_id,
struct lustre_handle *lh, int mode, __u64 *flags);
+void tgt_mdt_data_unlock(struct lustre_handle *lh, enum ldlm_mode mode);
int tgt_extent_lock(struct ldlm_namespace *ns, struct ldlm_res_id *res_id,
__u64 start, __u64 end, struct lustre_handle *lh,
int mode, __u64 *flags);