NFLUSHWANT
np->n_flag |= NFLUSHWANT;
if (np->n_flag & NFLUSHWANT) {
np->n_flag &= ~NFLUSHWANT;
if (np->n_flag & NFLUSHWANT) {
np->n_flag &= ~NFLUSHWANT;
np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT);
if (flag & NFLUSHWANT)