int vsock_core_register(const struct vsock_transport *t, int features)
{
	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
	int err = mutex_lock_interruptible(&vsock_register_mutex);

	if (err)
		return err;

	t_h2g = transport_h2g;
	t_g2h = transport_g2h;
	t_dgram = transport_dgram;
	t_local = transport_local;

	if (features & VSOCK_TRANSPORT_F_H2G) {
		if (t_h2g) {
			err = -EBUSY;
			goto err_busy;
		}
		t_h2g = t;
	}

	if (features & VSOCK_TRANSPORT_F_G2H) {
		if (t_g2h) {
			err = -EBUSY;
			goto err_busy;
		}
		t_g2h = t;
	}

	if (features & VSOCK_TRANSPORT_F_DGRAM) {
		if (t_dgram) {
			err = -EBUSY;
			goto err_busy;
		}
		t_dgram = t;
	}

	if (features & VSOCK_TRANSPORT_F_LOCAL) {
		if (t_local) {
			err = -EBUSY;
			goto err_busy;
		}
		t_local = t;
	}

	transport_h2g = t_h2g;
	transport_g2h = t_g2h;
	transport_dgram = t_dgram;
	transport_local = t_local;

err_busy:
	mutex_unlock(&vsock_register_mutex);
	return err;
}
int vsock_core_register(const struct vsock_transport *t, int features)
{
	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
	int err = mutex_lock_interruptible(&vsock_register_mutex);

	if (err)
		return err;

	t_h2g = transport_h2g;
	t_g2h = transport_g2h;
	t_dgram = transport_dgram;
	t_local = transport_local;

	if (features & VSOCK_TRANSPORT_F_H2G) {
		if (t_h2g) {
			err = -EBUSY;
			goto err_busy;
		}
		t_h2g = t;
	}

	if (features & VSOCK_TRANSPORT_F_G2H) {
		if (t_g2h) {
			err = -EBUSY;
			goto err_busy;
		}
		t_g2h = t;
	}

	if (features & VSOCK_TRANSPORT_F_DGRAM) {
		if (t_dgram) {
			err = -EBUSY;
			goto err_busy;
		}
		t_dgram = t;
	}

	if (features & VSOCK_TRANSPORT_F_LOCAL) {
		if (t_local) {
			err = -EBUSY;
			goto err_busy;
		}
		t_local = t;
	}

	transport_h2g = t_h2g;
	transport_g2h = t_g2h;
	transport_dgram = t_dgram;
	transport_local = t_local;

err_busy:
	mutex_unlock(&vsock_register_mutex);
	return err;
}