FLAGS_WRITE
flags &= (FLAGS_READ | FLAGS_WRITE);
flags = verto_get_flags(remote->io) & (FLAGS_READ | FLAGS_WRITE) & ~flags;
retval = remote_add_flags(req->rr, FLAGS_WRITE);
remote_del_flags(rr, FLAGS_WRITE);
retval = remote_add_flags(rr, FLAGS_WRITE);