VNF_READONLY
vnd->sc_flags |= VNF_COMP | VNF_READONLY;
vnd->sc_flags |= VNF_READONLY;
if ((vnd->sc_flags & VNF_READONLY) == 0)
~(VNF_INITED | VNF_READONLY | VNF_KLABEL | VNF_VLABEL
if ((vnd->sc_flags & VNF_READONLY) && !(bp->b_flags & B_READ)) {