VPO_SWAPINPROG
m->oflags |= VPO_SWAPINPROG;
while ((m->oflags & VPO_SWAPINPROG) != 0) {
mreq->oflags |= VPO_SWAPINPROG;
m->oflags &= ~VPO_SWAPINPROG;
if (m != NULL && (m->oflags & VPO_SWAPINPROG) != 0) {
KASSERT((m->oflags & (VPO_SWAPINPROG |