FLUSH_DI_ACTIVE
if ((ump->um_softdep->sd_flags & FLUSH_DI_ACTIVE) == 0) {
ump->um_softdep->sd_flags |= FLUSH_DI_ACTIVE;
ump->um_softdep->sd_flags &= ~FLUSH_DI_ACTIVE;
FLUSH_DI_ACTIVE) != 0) {