VIF_MARK_GOOD
vifp->v_marks = VIF_MARK_GOOD;
!(vifp->v_marks & VIF_MARK_GOOD)) {
vifp->v_marks &= ~VIF_MARK_GOOD;
if (vifp->v_marks & VIF_MARK_GOOD) {
vifp->v_marks &= ~VIF_MARK_GOOD;
if (!(vifp->v_marks & VIF_MARK_GOOD)) {
#define VIF_MARK_INUSE VIF_MARK_CONDEMNED | VIF_MARK_GOOD