static int cgroup_file_open(struct kernfs_open_file *of)
{
	struct cftype *cft = of_cft(of);

	if (cft->open)
		return cft->open(of);
	return 0;
}
static int cgroup_file_open(struct kernfs_open_file *of)
{
	struct cftype *cft = of_cft(of);

	if (cft->open)
		return cft->open(of);
	return 0;
}