LO_WITNESS
iflags |= LO_WITNESS;
flags |= LO_WITNESS;
liflags |= LO_WITNESS;
flags |= LO_WITNESS;
flags |= LO_WITNESS;
KASSERT((lock1->li_lock->lo_flags & LO_WITNESS) == 0,
KASSERT(lock->lo_flags & LO_WITNESS,
(lock->lo_flags & LO_WITNESS) == 0)
if ((lock->lo_flags & LO_WITNESS) == 0 || lock->lo_witness == NULL)