- assert(iov[niov].iov_len > tail);
- orig_len = iov[niov].iov_len;
- iov[niov++].iov_len = tail;
- }
+ iov += niov;
+ iov_cnt -= niov;
+
+ if (offset) {
+ /* second, skip `offset' bytes from the (now) first element,
+ * undo it on exit */
+ iov[0].iov_base += offset;
+ iov[0].iov_len -= offset;
+ }
+ /* Find the end position skipping `bytes' bytes: */
+ /* first, skip all full-sized elements */
+ tail = bytes;
+ for (niov = 0; niov < iov_cnt && iov[niov].iov_len <= tail; ++niov) {
+ tail -= iov[niov].iov_len;
+ }
+ if (tail) {
+ /* second, fixup the last element, and remember the original
+ * length */
+ assert(niov < iov_cnt);
+ assert(iov[niov].iov_len > tail);
+ orig_len = iov[niov].iov_len;
+ iov[niov++].iov_len = tail;
+ }