From: Jiufei Xue jiufei.xue@linux.alibaba.com
mainline inclusion from mainline-5.4-rc8 commit 8b37bc277fb459fa100808880a9d4e0641fff444 category: feature bugzilla: 38688 CVE: NA
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There is a bug that checking the same active_list over and over again in iocg_activate(). The intention of the code was checking whether all the ancestors and self have already been activated. So fix it.
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Acked-by: Tejun Heo tj@kernel.org Signed-off-by: Jiufei Xue jiufei.xue@linux.alibaba.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- block/blk-iocost.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index fa7da47bea2ef..295fcf7a52ac7 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1057,9 +1057,12 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) atomic64_set(&iocg->active_period, cur_period);
/* already activated or breaking leaf-only constraint? */ - for (i = iocg->level; i > 0; i--) - if (!list_empty(&iocg->active_list)) + if (!list_empty(&iocg->active_list)) + goto succeed_unlock; + for (i = iocg->level - 1; i > 0; i--) + if (!list_empty(&iocg->ancestors[i]->active_list)) goto fail_unlock; + if (iocg->child_active_sum) goto fail_unlock;
@@ -1101,6 +1104,7 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) ioc_start_period(ioc, now); }
+succeed_unlock: spin_unlock_irq(&ioc->lock); return true;