struct dmxdev_filter *dmxdevfilter=dvb_dmxdev_file_to_filter(file);
struct dmxdev_filter *dmxdevfilter= file->private_data;
dvb_demux_read(struct file *file, char __user *buf, size_t count, loff_t *ppos){	struct dmxdev_filter *dmxdevfilter=dvb_dmxdev_file_to_filter(file);	int ret=0;	if (down_interruptible(&dmxdevfilter->mutex))		return -ERESTARTSYS;	if (dmxdevfilter->type==DMXDEV_TYPE_SEC)		ret=dvb_dmxdev_read_sec(dmxdevfilter, file, buf, count, ppos);	else		ret=dvb_dmxdev_buffer_read(&dmxdevfilter->buffer,				     file->f_flags&O_NONBLOCK,				     buf, count, ppos);	up(&dmxdevfilter->mutex);	return ret;}