int mdev_device_create()

in mdev/mdev_core.c [254:336]

• 66 lines of code
• 12 McCabe index (conditional complexity)

int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
{
	int ret;
	struct mdev_device *mdev, *tmp;
	struct mdev_parent *parent = type->parent;
	struct mdev_driver *drv = parent->ops->device_driver;

	mutex_lock(&mdev_list_lock);

	/* Check for duplicate */
	list_for_each_entry(tmp, &mdev_list, next) {
		if (guid_equal(&tmp->uuid, uuid)) {
			mutex_unlock(&mdev_list_lock);
			return -EEXIST;
		}
	}

	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
	if (!mdev) {
		mutex_unlock(&mdev_list_lock);
		return -ENOMEM;
	}

	device_initialize(&mdev->dev);
	mdev->dev.parent  = parent->dev;
	mdev->dev.bus = &mdev_bus_type;
	mdev->dev.release = mdev_device_release;
	mdev->dev.groups = parent->ops->mdev_attr_groups;
	mdev->type = type;
	/* Pairs with the put in mdev_device_release() */
	kobject_get(&type->kobj);

	guid_copy(&mdev->uuid, uuid);
	list_add(&mdev->next, &mdev_list);
	mutex_unlock(&mdev_list_lock);

	ret = dev_set_name(&mdev->dev, "%pUl", uuid);
	if (ret)
		goto out_put_device;

	/* Check if parent unregistration has started */
	if (!down_read_trylock(&parent->unreg_sem)) {
		ret = -ENODEV;
		goto out_put_device;
	}

	if (parent->ops->create) {
		ret = parent->ops->create(mdev);
		if (ret)
			goto out_unlock;
	}

	ret = device_add(&mdev->dev);
	if (ret)
		goto out_remove;

	if (!drv)
		drv = &vfio_mdev_driver;
	ret = device_driver_attach(&drv->driver, &mdev->dev);
	if (ret)
		goto out_del;

	ret = mdev_create_sysfs_files(mdev);
	if (ret)
		goto out_del;

	mdev->active = true;
	dev_dbg(&mdev->dev, "MDEV: created\n");
	up_read(&parent->unreg_sem);

	return 0;

out_del:
	device_del(&mdev->dev);
out_remove:
	if (parent->ops->remove)
		parent->ops->remove(mdev);
out_unlock:
	up_read(&parent->unreg_sem);
out_put_device:
	put_device(&mdev->dev);
	return ret;
}