static int umount_nofollow_support(void)
{
	int res = umount2("", UMOUNT_UNUSED);
	if (res != -1 || errno != EINVAL)
		return 0;

	res = umount2("", UMOUNT_NOFOLLOW);
	if (res != -1 || errno != ENOENT)
		return 0;

	return 1;
}
Unknown