- md->length = max(0, desc->bd_iov_count - mdidx * LNET_MAX_IOV);
- md->length = min_t(unsigned int, LNET_MAX_IOV, md->length);
+ /* just send a lnet header */
+ if (mdidx >= desc->bd_md_count) {
+ md->options |= LNET_MD_KIOV;
+ md->length = 0;
+ md->start = NULL;
+ return;
+ }
+
+ if (mdidx == (desc->bd_md_count - 1))
+ md->length = desc->bd_iov_count - start;
+ else
+ md->length = desc->bd_mds_off[mdidx + 1] - start;