int lock_device_hotplug_sysfs(void)
{
	if (mutex_trylock(&device_hotplug_lock))
		return 0;

	/* Avoid busy looping (5 ms of sleep should do). */
	msleep(5);
	return restart_syscall();
}
int lock_device_hotplug_sysfs(void)
{
	if (mutex_trylock(&device_hotplug_lock))
		return 0;

	 
	msleep(5);
	return restart_syscall();
}