sf_tbytes
sbp->f_blocks = sfp->sf_tbytes / NFS_FABLKSIZE;
sbp->sf_tbytes = fxdr_hyper(tl); tl += 2;
sfp->sf_tbytes != fxdr_hyper(tl))
sfp->sf_tbytes = fxdr_hyper(tl);
txdr_hyper(tval, &sfp->sf_tbytes);
tquad = fxdr_hyper(&sfp->sf_tbytes);