VD_COPYIN
rv = (iop->convert)(vdc, arg, mem_p, mode, VD_COPYIN);
if (dir == VD_COPYIN)
uvtoc = (dir == VD_COPYIN)? from : to;
uvtoc = (dir == VD_COPYIN)? from : to;
if (dir != VD_COPYIN)
if (dir == VD_COPYIN) {