cache_nlookup
rncp = cache_nlookup(nch, &nlc);
rncp = cache_nlookup(nch, &nlc);
nch = cache_nlookup(&nd->nl_nch, &nlc);
nch = cache_nlookup(&nd->nl_nch, &nlc);
struct nchandle cache_nlookup(struct nchandle *nch,