//ust// init_waitqueue_head(&buf->read_wait);
kref_init(&buf->kref);
//ust// setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf);
//ust// init_waitqueue_head(&buf->read_wait);
kref_init(&buf->kref);
//ust// setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf);