static int job_control(struct tty_struct *tty, struct file *file)
{
	/* Job control check -- must be done at start and after
	   every sleep (POSIX.1 7.1.1.4). */
	/* NOTE: not yet done after every sleep pending a thorough
	   check of the logic of this change. -- jlc */
	/* don't stop on /dev/console */
	if (file->f_op->write == redirected_tty_write)
		return 0;

	return __tty_check_change(tty, SIGTTIN);
}
static int job_control(struct tty_struct *tty, struct file *file)
{
	 
	 
	 
	if (file->f_op->write == redirected_tty_write)
		return 0;

	return __tty_check_change(tty, SIGTTIN);
}