From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B56FDC433EF for ; Tue, 30 Nov 2021 16:26:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243837AbhK3Q3l (ORCPT ); Tue, 30 Nov 2021 11:29:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239752AbhK3Q3j (ORCPT ); Tue, 30 Nov 2021 11:29:39 -0500 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C2C9C061574; Tue, 30 Nov 2021 08:26:20 -0800 (PST) Received: by mail-pf1-x429.google.com with SMTP id 8so21146419pfo.4; Tue, 30 Nov 2021 08:26:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=c5SAYFCCSK5GacjcTQ47eQM20SEI2kSoxxYyDX/fm7g=; b=WuEA+bpfKYR9NLIIrwBgv9GJy2Sqs3GbI0IIf9pwMJMXsSCI1YQlAwXknLH/wTYAJD iGJxHYd9gWOMumxRX60SU8m9X3a96QJvwABQJSaLk/UwYX0oTzfvE1+mD/pTCPZVc0wX nwyTRT6H3nMscuCpww4ouTekbvVnImtzQkpCVviTPQrvcD3++XkUgRUtDbtMgc7kfIOS v9YgrBcEvackhH95vp53qGHa4xAKTe1iz3Dcs5hW3xJm1hr3bo+M8kG/vVt5vEAtyGLx pvSMzYNsPvDpfVl30+ppF1Aec1+VsyI9Ru7Iz3AJ2tJGdoavpTMIp8Og6Cbz837agOq1 KPdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=c5SAYFCCSK5GacjcTQ47eQM20SEI2kSoxxYyDX/fm7g=; b=JnJl4Y1JpgbmL+Xjl0/uNUm+a58z8sPdBTnsLwNVD8HE7LR2wUs3MtZhYKtDnzegJb 38XljqFB1hZIBQeWtYU5Ei3FtzD8dXoqMmKFJbGo3VrJ27Rm3mw19gs5rCh1ud4tC/W1 OsIXjtaVinTwcEt9uzPAJ7hbdWpmavX+LgVIgF4ceMu/j5YF4fBcsaq32C12m7oIcChI /CxqCjlg5Q0jMWUhb90dtVBkqZWgpPabwKji8M/gwfBSJE+q1DEtq0TmD+ksfAqM/FAO UtGOII/hK3CJQcBQThY4wR9y6eWGRuJ/QzuCX2755cKr7FB12qHEAOe6hcvMl/Na+PKT fOig== X-Gm-Message-State: AOAM53375HM5BGH848UKM/vCJUDTQ2Fn3bNY/xPot426i7REu61tJx0N cEizeNijI7UGRklte6W8cQs= X-Google-Smtp-Source: ABdhPJzkO44MwB9FWMocPI631L8m3xRRVHgB04ObRgITFxLjJHORH5qdg1/C4bh1hAr4YDR0Yy8zQA== X-Received: by 2002:a05:6a00:15c5:b0:4a0:3c1:4f43 with SMTP id o5-20020a056a0015c500b004a003c14f43mr47791127pfu.33.1638289579628; Tue, 30 Nov 2021 08:26:19 -0800 (PST) Received: from localhost (2603-800c-1a02-1bae-e24f-43ff-fee6-449f.res6.spectrum.com. [2603:800c:1a02:1bae:e24f:43ff:fee6:449f]) by smtp.gmail.com with ESMTPSA id p10sm20876523pff.173.2021.11.30.08.26.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Nov 2021 08:26:19 -0800 (PST) Sender: Tejun Heo Date: Tue, 30 Nov 2021 06:26:18 -1000 From: Tejun Heo To: Yu Kuai Cc: hch@infradead.org, axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com Subject: Re: [PATCH v2 2/2] block: cancel all throttled bios in del_gendisk() Message-ID: References: <20211130011730.2584339-1-yukuai3@huawei.com> <20211130011730.2584339-3-yukuai3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211130011730.2584339-3-yukuai3@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Nov 30, 2021 at 09:17:30AM +0800, Yu Kuai wrote: > +void blk_throtl_cancel_bios(struct request_queue *q) > +{ > + struct throtl_data *td = q->td; > + struct blkcg_gq *blkg; > + struct cgroup_subsys_state *pos_css; > + struct bio *bio; > + int rw; > + > + rcu_read_lock(); So, all of the draining is being performed without holding the q lock, which *might* be okay given that we're in the del_gendisk path but is likely risky - ie. there can still be timers or whatever racing against it. Thanks. -- tejun