indx_read
err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
err = indx_read(indx, ni, de_get_vbn(e), &node);
err = indx_read(indx, ni, de_get_vbn(e), &n);
err = indx_read(indx, ni, next_used_vbn, &n);
err = indx_read(indx, ni, de_get_vbn(e), &n);
err = indx_read(indx, ni, vbn, &n);
err = indx_read(indx, ni, vbn, &n);