diff options
| author | Ming Lei <ming.lei@redhat.com> | 2023-02-02 10:18:04 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-02-01 19:26:41 -0700 |
| commit | 0416f3be58c6b1ea066cd52e354b857693feb01e (patch) | |
| tree | 4c92b2739ef71e6f525743a9bb5f5e1c2dda61e8 | |
| parent | 81ea42b9c3d61ea34d82d900ed93f4b4851f13b0 (diff) | |
blk-cgroup: don't update io stat for root cgroup
We source root cgroup stats from the system-wide stats, see blkcg_print_stat
and blkcg_rstat_flush, so don't update io state for root cgroup.
Fixes blkg leak issue introduced in commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()")
which starts to grab blkg's reference when adding iostat_cpu into percpu
blkcg list, but this state won't be consumed by blkcg_rstat_flush() where
the blkg reference is dropped.
Tested-by: Bart van Assche <bvanassche@acm.org>
Reported-by: Bart van Assche <bvanassche@acm.org>
Fixes: 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()")
Cc: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230202021804.278582-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-cgroup.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 4c94a6560f62..9ac1efb053e0 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -2001,6 +2001,10 @@ void blk_cgroup_bio_start(struct bio *bio) struct blkg_iostat_set *bis; unsigned long flags; + /* Root-level stats are sourced from system-wide IO stats */ + if (!cgroup_parent(blkcg->css.cgroup)) + return; + cpu = get_cpu(); bis = per_cpu_ptr(bio->bi_blkg->iostat_cpu, cpu); flags = u64_stats_update_begin_irqsave(&bis->sync); |