SKIPSYSTEM
KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
error = vflush(mp, 0, SKIPSYSTEM|flags, td);
if ((error = vflush(mp, 0, SKIPSYSTEM | flags, td)) != 0)