iocost: check active_list of all the ancestors in iocg_activate() (8b37bc27) · Commits · 戴 / test

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: ("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>

block/blk-iocost.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -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))
		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;

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