DN_ID_NEW_EXIST
if (flags & DN_ID_NEW_EXIST) {
if (dn->dn_id_flags & DN_ID_NEW_EXIST) {
dn->dn_id_flags &= ~(DN_ID_NEW_EXIST);
dn->dn_id_flags |= DN_ID_NEW_EXIST;
ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);