rfs4_tsize
if (args->count > rfs4_tsize(req))
args->count = rfs4_tsize(req);
na->maxread = rfs4_tsize(sarg->cs->req);
if (na->maxread != rfs4_tsize(sarg->cs->req))
na->maxwrite = rfs4_tsize(sarg->cs->req);
if (na->maxwrite != rfs4_tsize(sarg->cs->req))
maxread = maxwrite = rfs4_tsize(req);
tsize = rfs4_tsize(req);
extern uint_t rfs4_tsize(struct svc_req *);