extern int elevator_init(request_queue_t *, char *);
extern void elevator_exit(elevator_t *);
extern int elv_rq_merge_ok(struct request *, struct bio *);
-extern int elv_try_merge(struct request *, struct bio *);
-extern int elv_try_last_merge(request_queue_t *, struct bio *);
/*
* Return values from elevator merger