Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 26308eab authored by Jerome Marchand's avatar Jerome Marchand Committed by Jens Axboe
Browse files

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: default avatarJerome Marchand <jmarchan@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 6c7e8cee

block/blk-core.c

+4 −9
Original line number Diff line number Diff line
@@ -64,12 +64,11 @@ static struct workqueue_struct *kblockd_workqueue; 


static void drive_stat_acct(struct request *rq, int new_io)

{

	struct gendisk *disk = rq->rq_disk;

	struct hd_struct *part;

	int rw = rq_data_dir(rq);

	int cpu;



	if (!blk_fs_request(rq) || !disk || !blk_do_io_stat(disk->queue))

	if (!blk_fs_request(rq) || !blk_do_io_stat(rq))

		return;



	cpu = part_stat_lock();
@@ -1675,9 +1674,7 @@ EXPORT_SYMBOL(blkdev_dequeue_request); 


static void blk_account_io_completion(struct request *req, unsigned int bytes)

{

	struct gendisk *disk = req->rq_disk;



	if (!disk || !blk_do_io_stat(disk->queue))

	if (!blk_do_io_stat(req))

		return;



	if (blk_fs_request(req)) {
@@ -1694,9 +1691,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes) 


static void blk_account_io_done(struct request *req)

{

	struct gendisk *disk = req->rq_disk;



	if (!disk || !blk_do_io_stat(disk->queue))

	if (!blk_do_io_stat(req))

		return;



	/*
@@ -1711,7 +1706,7 @@ static void blk_account_io_done(struct request *req) 
		int cpu;



		cpu = part_stat_lock();

		part = disk_map_sector_rcu(disk, req->sector);

		part = disk_map_sector_rcu(req->rq_disk, req->sector);



		part_stat_inc(cpu, part, ios[rw]);

		part_stat_add(cpu, part, ticks[rw], duration);

block/blk-merge.c

+17 −12
Original line number Diff line number Diff line
@@ -338,6 +338,22 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, 
	return 1;

}



static void blk_account_io_merge(struct request *req)

{

	if (blk_do_io_stat(req)) {

		struct hd_struct *part;

		int cpu;



		cpu = part_stat_lock();

		part = disk_map_sector_rcu(req->rq_disk, req->sector);



		part_round_stats(cpu, part);

		part_dec_in_flight(part);



		part_stat_unlock();

	}

}



/*

 * Has to be called with the request spinlock acquired

 */
@@ -386,18 +402,7 @@ static int attempt_merge(struct request_queue *q, struct request *req, 


	elv_merge_requests(q, req, next);



	if (req->rq_disk) {

		struct hd_struct *part;

		int cpu;



		cpu = part_stat_lock();

		part = disk_map_sector_rcu(req->rq_disk, req->sector);



		part_round_stats(cpu, part);

		part_dec_in_flight(part);



		part_stat_unlock();

	}

	blk_account_io_merge(req);



	req->ioprio = ioprio_best(req->ioprio, next->ioprio);

	if (blk_rq_cpu_valid(next))

block/blk-sysfs.c

+4 −0
Original line number Diff line number Diff line
@@ -209,10 +209,14 @@ static ssize_t queue_iostats_store(struct request_queue *q, const char *page, 
	ssize_t ret = queue_var_store(&stats, page, count);



	spin_lock_irq(q->queue_lock);

	elv_quisce_start(q);



	if (stats)

		queue_flag_set(QUEUE_FLAG_IO_STAT, q);

	else

		queue_flag_clear(QUEUE_FLAG_IO_STAT, q);



	elv_quisce_end(q);

	spin_unlock_irq(q->queue_lock);



	return ret;

block/blk.h

+6 −4
Original line number Diff line number Diff line
@@ -112,12 +112,14 @@ static inline int blk_cpu_to_group(int cpu) 
#endif

}



static inline int blk_do_io_stat(struct request_queue *q)

static inline int blk_do_io_stat(struct request *rq)

{

	if (q)

		return blk_queue_io_stat(q);

	struct gendisk *disk = rq->rq_disk;



	if (!disk || !disk->queue)

		return 0;



	return blk_queue_io_stat(disk->queue) && (rq->cmd_flags & REQ_ELVPRIV);

}



#endif

block/elevator.c

+1 −1
Original line number Diff line number Diff line
@@ -573,7 +573,7 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) 
	elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE);

}



static void elv_drain_elevator(struct request_queue *q)

void elv_drain_elevator(struct request_queue *q)

{

	static int printed;

	while (q->elevator->ops->elevator_dispatch_fn(q, 1))