tmpnode_trunc
(void) tmpnode_trunc(tm, oldtp, 0);
(void) tmpnode_trunc(tm, tp, 0);
error = tmpnode_trunc((struct tmount *)VFSTOTM(vp->v_vfsp),
(void) tmpnode_trunc(tm, tp,
error = tmpnode_trunc(tm, tp, (ulong_t)vap->va_size);
extern int tmpnode_trunc(struct tmount *, struct tmpnode *, ulong_t);