From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 59D6F8F57 for ; Sun, 16 Jul 2023 20:58:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D23F4C433C7; Sun, 16 Jul 2023 20:58:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689541089; bh=0rP2/jCBcjbswwtuDI399GFcDfrMxjV75FNm5xKNqHY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z/ltfMneO4my+DEECgpuetsinmWEaRempxLRtZ1xh75u+QibCBpzyoHaCWYCij/8p SeDlXXNseGpSUGWmFP96V3UQVvZfgi3RcppTf/dNRFwSrflOY6vsA3URSOfbSWDUgp 9XgwyuJSVvGphRk2Q8Bh5rLQd/qynqyZuPNflacE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shinichiro Kawasaki , Jay Shin , Tejun Heo , Waiman Long , Ming Lei , Jens Axboe Subject: [PATCH 6.1 585/591] block: make sure local irq is disabled when calling __blkcg_rstat_flush Date: Sun, 16 Jul 2023 21:52:04 +0200 Message-ID: <20230716194938.987630904@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194923.861634455@linuxfoundation.org> References: <20230716194923.861634455@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ming Lei commit 9c39b7a905d84b7da5f59d80f2e455853fea7217 upstream. When __blkcg_rstat_flush() is called from cgroup_rstat_flush*() code path, interrupt is always disabled. When we start to flush blkcg per-cpu stats list in __blkg_release() for avoiding to leak blkcg_gq's reference in commit 20cb1c2fb756 ("blk-cgroup: Flush stats before releasing blkcg_gq"), local irq isn't disabled yet, then lockdep warning may be triggered because the dependent cgroup locks may be acquired from irq(soft irq) handler. Fix the issue by disabling local irq always. Fixes: 20cb1c2fb756 ("blk-cgroup: Flush stats before releasing blkcg_gq") Reported-by: Shinichiro Kawasaki Closes: https://lore.kernel.org/linux-block/pz2wzwnmn5tk3pwpskmjhli6g3qly7eoknilb26of376c7kwxy@qydzpvt6zpis/T/#u Cc: stable@vger.kernel.org Cc: Jay Shin Cc: Tejun Heo Cc: Waiman Long Signed-off-by: Ming Lei Reviewed-by: Waiman Long Link: https://lore.kernel.org/r/20230622084249.1208005-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/blk-cgroup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -886,6 +886,7 @@ static void __blkcg_rstat_flush(struct b struct llist_head *lhead = per_cpu_ptr(blkcg->lhead, cpu); struct llist_node *lnode; struct blkg_iostat_set *bisc, *next_bisc; + unsigned long flags; rcu_read_lock(); @@ -899,7 +900,7 @@ static void __blkcg_rstat_flush(struct b * When flushing from cgroup, cgroup_rstat_lock is always held, so * this lock won't cause contention most of time. */ - raw_spin_lock(&blkg_stat_lock); + raw_spin_lock_irqsave(&blkg_stat_lock, flags); /* * Iterate only the iostat_cpu's queued in the lockless list. @@ -925,7 +926,7 @@ static void __blkcg_rstat_flush(struct b blkcg_iostat_update(parent, &blkg->iostat.cur, &blkg->iostat.last); } - raw_spin_unlock(&blkg_stat_lock); + raw_spin_unlock_irqrestore(&blkg_stat_lock, flags); out: rcu_read_unlock(); }