u64_to_xdr
x->group = u64_to_xdr(0);
x->mtime_client = u64_to_xdr(mtime);
x->owner = u64_to_xdr(owner);
x->group = u64_to_xdr(group);
*x = u64_to_xdr(n);
x->volume = u64_to_xdr(fid->vid);
x->vnode.lo = u64_to_xdr(fid->vnode);
x->mtime_client = u64_to_xdr(mtime);
x->owner = u64_to_xdr(0);