[PATCH] blk: fix gendisk->in_flight accounting during barrier sequence

While executing barrrier sequence, the bar_rq which carries actual
write was accounted as normal IO on completion, while it wasn't on
queueing.  This caused gendisk->in_flight to be decremented by 1 after
each barrier thus messed up statistics.

This patch makes bar_rq not accounted as normal IO.  As the containing
barrier request as a whole is accounted, part of it shouldn't be.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Jens Axboe 2006-05-23 11:23:49 +02:00 committed by Linus Torvalds
parent 0f04108237
commit fd0ff8aa1d

View file

@ -3452,7 +3452,12 @@ void end_that_request_last(struct request *req, int uptodate)
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
if (disk && blk_fs_request(req)) {
/*
* Account IO completion. bar_rq isn't accounted as a normal
* IO on queueing nor completion. Accounting the containing
* request is enough.
*/
if (disk && blk_fs_request(req) && req != &req->q->bar_rq) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);