if(test_and_set_bit(0, &timer_alive))
if (test_and_set_bit(0, &driver_open))
static int softdog_open(struct inode *inode, struct file *file){	if(test_and_set_bit(0, &timer_alive))		return -EBUSY;	if (nowayout)		__module_get(THIS_MODULE);	/*	 *	Activate timer	 */	softdog_keepalive();	return nonseekable_open(inode, file);}