Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9f4ab017 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

blk-iocost: ioc_pd_free() shouldn't assume irq disabled 



commit 5aeac7c4b16069aae49005f0a8d4526baa83341b upstream.

ioc_pd_free() grabs irq-safe ioc->lock without ensuring that irq is disabled
when it can be called with irq disabled or enabled. This has a small chance
of causing A-A deadlocks and triggers lockdep splats. Use irqsave operations
instead.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Fixes: 7caa4715 ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f7880745

block/blk-iocost.c

+3 −2
Original line number Diff line number Diff line
@@ -2074,14 +2074,15 @@ static void ioc_pd_free(struct blkg_policy_data *pd) 
{

	struct ioc_gq *iocg = pd_to_iocg(pd);

	struct ioc *ioc = iocg->ioc;

	unsigned long flags;



	if (ioc) {

		spin_lock(&ioc->lock);

		spin_lock_irqsave(&ioc->lock, flags);

		if (!list_empty(&iocg->active_list)) {

			propagate_active_weight(iocg, 0, 0);

			list_del_init(&iocg->active_list);

		}

		spin_unlock(&ioc->lock);

		spin_unlock_irqrestore(&ioc->lock, flags);



		hrtimer_cancel(&iocg->waitq_timer);

		hrtimer_cancel(&iocg->delay_timer);