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 C0CC3137752; Tue, 23 Apr 2024 11:40:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713872429; cv=none; b=gmlouNwc/T8aBtNcG/Idr8w49Nn0IOJWw9HysLBzonghOOmQTxkyYZikOYtS4Fz5Lwcc0Nwod3PRvUw/Jg8Adg1XsyxIhfSE0cEMQ/qvBfALjEzyGvIXW8WWE2LxUHBZ+KZX1N/KWl/GobJx5Gu9uYcewipeJbvqpsFCpGf9E8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713872429; c=relaxed/simple; bh=/Lwk9cGiFCTAlohZ1IS3e7lAjH6XXaUG0XDKhwUfqE0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r/ls7EkQ72pffBnT9n+7uCfm11AnRZDj4RXXdKuFJ7LItjMbSXnYOh3F+L/S/xWpjRWiDSs35NIBoCoeR2ygm869VAWMJv2FY4N9HHUJCN6Cp4g2JAQ1saLnKtrvB+U2bRHuE/E9cMOfZeoExCyU5oXvPJqrsWOUHeaN4keg9JA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZPyOaXPP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZPyOaXPP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39B97C32783; Tue, 23 Apr 2024 11:40:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713872429; bh=/Lwk9cGiFCTAlohZ1IS3e7lAjH6XXaUG0XDKhwUfqE0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZPyOaXPPSxJkCaf0ULLQ4rtUSdaY6o+65mAJo/XAR7BC3fwyldE2y/Yh2/pqq8tO9 Xw1fbGaz7bdjyAw1mAKD/QiDxg/pLaTaNKQvhIkgSaUAdo71TAXVmRM4o4/GiApPTw phMtvT8Dnc8o0zxu7bSvJYt71ONSwI7ZMpEly4HrF8zqfH4nvouMKgZijnzgd/8DKD xAm1e4FmfTlF5a5pWh0rc7+Vxu3E8Esq25UGNeJSsB1zRz+Tu5p/Vg6lf5uLukctSY 8tceywj+fFU+rdHRZbx35cBGrhYsznJckVP+xvo1+MLbffuDMnecczGZHmr8M3FkA+ h5llPNR+/YNOg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Li Nan , Yu Kuai , Tejun Heo , Jens Axboe , Sasha Levin , josef@toxicpanda.com, cgroups@vger.kernel.org, linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 6.8 18/18] blk-iocost: do not WARN if iocg was already offlined Date: Tue, 23 Apr 2024 07:01:14 -0400 Message-ID: <20240423110118.1652940-18-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240423110118.1652940-1-sashal@kernel.org> References: <20240423110118.1652940-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.8.7 Content-Transfer-Encoding: 8bit From: Li Nan [ Upstream commit 01bc4fda9ea0a6b52f12326486f07a4910666cf6 ] In iocg_pay_debt(), warn is triggered if 'active_list' is empty, which is intended to confirm iocg is active when it has debt. However, warn can be triggered during a blkcg or disk removal, if iocg_waitq_timer_fn() is run at that time: WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190 Call trace: iocg_pay_debt+0x14c/0x190 iocg_kick_waitq+0x438/0x4c0 iocg_waitq_timer_fn+0xd8/0x130 __run_hrtimer+0x144/0x45c __hrtimer_run_queues+0x16c/0x244 hrtimer_interrupt+0x2cc/0x7b0 The warn in this situation is meaningless. Since this iocg is being removed, the state of the 'active_list' is irrelevant, and 'waitq_timer' is canceled after removing 'active_list' in ioc_pd_free(), which ensures iocg is freed after iocg_waitq_timer_fn() returns. Therefore, add the check if iocg was already offlined to avoid warn when removing a blkcg or disk. Signed-off-by: Li Nan Reviewed-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20240419093257.3004211-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-iocost.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 04d44f0bcbc85..9a70aaf2b0d84 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1438,8 +1438,11 @@ static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay, lockdep_assert_held(&iocg->ioc->lock); lockdep_assert_held(&iocg->waitq.lock); - /* make sure that nobody messed with @iocg */ - WARN_ON_ONCE(list_empty(&iocg->active_list)); + /* + * make sure that nobody messed with @iocg. Check iocg->pd.online + * to avoid warn when removing blkcg or disk. + */ + WARN_ON_ONCE(list_empty(&iocg->active_list) && iocg->pd.online); WARN_ON_ONCE(iocg->inuse > 1); iocg->abs_vdebt -= min(abs_vpay, iocg->abs_vdebt); -- 2.43.0