sf_ffiles
sfp->sf_ffiles.nfsuquad[0] = 0;
sfp->sf_ffiles.nfsuquad[1] = txdr_unsigned(sf->f_ffree);
sfp->sf_ffiles.nfsuquad[1]) & 0x7fffffff);
sbp->f_ffree = fxdr_hyper(&sfp->sf_ffiles);