is_raidz_mirror
if (is_raidz_mirror(&lastrep, &rep, &raidz, &mirror) ||
is_raidz_mirror(&rep, &lastrep, &raidz, &mirror)) {
if (is_raidz_mirror(current, new, &raidz, &mirror) ||
is_raidz_mirror(new, current, &raidz, &mirror)) {