static int uio_open()

in uio.c [461:518]

• 46 lines of code
• 7 McCabe index (conditional complexity)

static int uio_open(struct inode *inode, struct file *filep)
{
	struct uio_device *idev;
	struct uio_listener *listener;
	int ret = 0;

	mutex_lock(&minor_lock);
	idev = idr_find(&uio_idr, iminor(inode));
	mutex_unlock(&minor_lock);
	if (!idev) {
		ret = -ENODEV;
		goto out;
	}

	get_device(&idev->dev);

	if (!try_module_get(idev->owner)) {
		ret = -ENODEV;
		goto err_module_get;
	}

	listener = kmalloc(sizeof(*listener), GFP_KERNEL);
	if (!listener) {
		ret = -ENOMEM;
		goto err_alloc_listener;
	}

	listener->dev = idev;
	listener->event_count = atomic_read(&idev->event);
	filep->private_data = listener;

	mutex_lock(&idev->info_lock);
	if (!idev->info) {
		mutex_unlock(&idev->info_lock);
		ret = -EINVAL;
		goto err_infoopen;
	}

	if (idev->info->open)
		ret = idev->info->open(idev->info, inode);
	mutex_unlock(&idev->info_lock);
	if (ret)
		goto err_infoopen;

	return 0;

err_infoopen:
	kfree(listener);

err_alloc_listener:
	module_put(idev->owner);

err_module_get:
	put_device(&idev->dev);

out:
	return ret;
}