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authorLiu Bo <bo.liu@linux.alibaba.com>2019-01-25 08:12:48 +0800
committerJens Axboe <axboe@kernel.dk>2019-02-08 12:42:27 -0700
commit391f552af213985d3d324c60004475759a7030c5 (patch)
treef4f2268199a07c7343b4989371140227358f51c2 /block
parent8c772a9bfc7c07c76f4a58b58910452fbb20843b (diff)
downloadlinux-stericsson-391f552af213985d3d324c60004475759a7030c5.tar.gz
Blk-iolatency: warn on negative inflight IO counter
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>
Diffstat (limited to 'block')
-rw-r--r--block/blk-iolatency.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 1893686a9c1f..2620baa1f699 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -592,6 +592,7 @@ 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 || !bio_flagged(bio, BIO_TRACKED))
@@ -613,7 +614,8 @@ 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,