static int process_msg_open()

in rnbd/rnbd-srv.c [693:827]

• 116 lines of code
• 13 McCabe index (conditional complexity)

static int process_msg_open(struct rnbd_srv_session *srv_sess,
			    const void *msg, size_t len,
			    void *data, size_t datalen)
{
	int ret;
	struct rnbd_srv_dev *srv_dev;
	struct rnbd_srv_sess_dev *srv_sess_dev;
	const struct rnbd_msg_open *open_msg = msg;
	fmode_t open_flags;
	char *full_path;
	struct rnbd_dev *rnbd_dev;
	struct rnbd_msg_open_rsp *rsp = data;

	pr_debug("Open message received: session='%s' path='%s' access_mode=%d\n",
		 srv_sess->sessname, open_msg->dev_name,
		 open_msg->access_mode);
	open_flags = FMODE_READ;
	if (open_msg->access_mode != RNBD_ACCESS_RO)
		open_flags |= FMODE_WRITE;

	mutex_lock(&srv_sess->lock);

	srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
	if (srv_sess_dev)
		goto fill_response;

	if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
	    >= PATH_MAX) {
		pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
		       srv_sess->sessname, dev_search_path, open_msg->dev_name,
		       PATH_MAX);
		ret = -EINVAL;
		goto reject;
	}
	if (strstr(open_msg->dev_name, "..")) {
		pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
		       srv_sess->sessname, open_msg->dev_name);
		ret = -EINVAL;
		goto reject;
	}
	full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
	if (IS_ERR(full_path)) {
		ret = PTR_ERR(full_path);
		pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
		       open_msg->dev_name, srv_sess->sessname, ret);
		goto reject;
	}

	rnbd_dev = rnbd_dev_open(full_path, open_flags,
				 &srv_sess->sess_bio_set);
	if (IS_ERR(rnbd_dev)) {
		pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %ld\n",
		       full_path, srv_sess->sessname, PTR_ERR(rnbd_dev));
		ret = PTR_ERR(rnbd_dev);
		goto free_path;
	}

	srv_dev = rnbd_srv_get_or_create_srv_dev(rnbd_dev, srv_sess,
						  open_msg->access_mode);
	if (IS_ERR(srv_dev)) {
		pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
		       full_path, srv_sess->sessname, PTR_ERR(srv_dev));
		ret = PTR_ERR(srv_dev);
		goto rnbd_dev_close;
	}

	srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
						     rnbd_dev, open_flags,
						     srv_dev);
	if (IS_ERR(srv_sess_dev)) {
		pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
		       full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
		ret = PTR_ERR(srv_sess_dev);
		goto srv_dev_put;
	}

	/* Create the srv_dev sysfs files if they haven't been created yet. The
	 * reason to delay the creation is not to create the sysfs files before
	 * we are sure the device can be opened.
	 */
	mutex_lock(&srv_dev->lock);
	if (!srv_dev->dev_kobj.state_in_sysfs) {
		ret = rnbd_srv_create_dev_sysfs(srv_dev, rnbd_dev->bdev,
						 rnbd_dev->name);
		if (ret) {
			mutex_unlock(&srv_dev->lock);
			rnbd_srv_err(srv_sess_dev,
				      "Opening device failed, failed to create device sysfs files, err: %d\n",
				      ret);
			goto free_srv_sess_dev;
		}
	}

	ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
	if (ret) {
		mutex_unlock(&srv_dev->lock);
		rnbd_srv_err(srv_sess_dev,
			      "Opening device failed, failed to create dev client sysfs files, err: %d\n",
			      ret);
		goto free_srv_sess_dev;
	}

	list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
	mutex_unlock(&srv_dev->lock);

	list_add(&srv_sess_dev->sess_list, &srv_sess->sess_dev_list);

	rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);

	kfree(full_path);

fill_response:
	rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
	mutex_unlock(&srv_sess->lock);
	return 0;

free_srv_sess_dev:
	xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
	synchronize_rcu();
	kfree(srv_sess_dev);
srv_dev_put:
	if (open_msg->access_mode != RNBD_ACCESS_RO) {
		mutex_lock(&srv_dev->lock);
		srv_dev->open_write_cnt--;
		mutex_unlock(&srv_dev->lock);
	}
	rnbd_put_srv_dev(srv_dev);
rnbd_dev_close:
	rnbd_dev_close(rnbd_dev);
free_path:
	kfree(full_path);
reject:
	mutex_unlock(&srv_sess->lock);
	return ret;
}