ISEQ
ip->i_flag |= (ICHG|ISEQ);
if (ip->i_flag & ISEQ) {
ip->i_flag &= ~ISEQ;
ip->i_flag |= ISEQ;
ip->i_flag &= ~ISEQ; /* no longer deferred */
ip->i_flag |= ISEQ;
ip->i_flag |= ISEQ;
ip->i_flag |= ISEQ;