From 8b37bc277fb459fa100808880a9d4e0641fff444 Mon Sep 17 00:00:00 2001 From: Jiufei Xue Date: Wed, 13 Nov 2019 15:21:31 +0800 Subject: [PATCH] iocost: check active_list of all the ancestors in iocg_activate() 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 Signed-off-by: Jiufei Xue Signed-off-by: Jens Axboe --- 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 a7ed434eae03..e01267f99183 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;