block: fix inconsistency in I/O stat accounting code
This forces in_flight to be zero when turning off or on the I/O stat
accounting and stops updating I/O stats in attempt_merge() when
accounting is turned off.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 7a20425..c59b769 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -116,6 +116,7 @@
extern void elv_completed_request(struct request_queue *, struct request *);
extern int elv_set_request(struct request_queue *, struct request *, gfp_t);
extern void elv_put_request(struct request_queue *, struct request *);
+extern void elv_drain_elevator(struct request_queue *);
/*
* io scheduler registration