sf_bsize
sbp->f_bsize = (int32_t)sfp->sf_bsize;
sbp->sf_bsize = fxdr_unsigned(u_int32_t, *tl++);
sfp->sf_bsize = txdr_unsigned(NFS_V2CLAMP16(sf->f_frsize));
sbp->f_frsize = fxdr_unsigned(int32_t, sfp->sf_bsize);