DEFAULT_IDX_LEB
mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
main_first + DEFAULT_IDX_LEB);
err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0);