Blk-iolatency: warn on negative inflight IO counter

[ Upstream commit 391f552af2 ]

This is to catch any unexpected negative value of inflight IO counter.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Liu Bo 2019-01-25 08:12:48 +08:00 committed by Greg Kroah-Hartman
parent 91a71a61da
commit 5f33e81250

View File

@ -560,6 +560,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
u64 now = ktime_to_ns(ktime_get());
bool issue_as_root = bio_issue_as_root_blkg(bio);
bool enabled = false;
int inflight = 0;
blkg = bio->bi_blkg;
if (!blkg)
@ -585,7 +586,8 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
}
rqw = &iolat->rq_wait;
atomic_dec(&rqw->inflight);
inflight = atomic_dec_return(&rqw->inflight);
WARN_ON_ONCE(inflight < 0);
if (iolat->min_lat_nsec == 0)
goto next;
iolatency_record_time(iolat, &bio->bi_issue, now,