mb_unmapped_to_ext
error = mb_unmapped_to_ext(m, &m1);
error = mb_unmapped_to_ext(m, &m1);
error = mb_unmapped_to_ext(m, &m1);
if (mb_unmapped_to_ext(m0, &md) != 0)
if (mb_unmapped_to_ext(*m0, &m) != 0) {
error = mb_unmapped_to_ext(m0, &md);
int mb_unmapped_to_ext(struct mbuf *m, struct mbuf **mres);