CDP_UNREF_DTR
if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
cdp->cdp_flags &= ~CDP_UNREF_DTR;
KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
cdp->cdp_flags |= CDP_UNREF_DTR;