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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA8C0C0650E for ; Wed, 3 Jul 2019 15:14:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80CF62189E for ; Wed, 3 Jul 2019 15:14:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726473AbfGCPOU (ORCPT ); Wed, 3 Jul 2019 11:14:20 -0400 Received: from mail-pf1-f182.google.com ([209.85.210.182]:35716 "EHLO mail-pf1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725847AbfGCPOT (ORCPT ); Wed, 3 Jul 2019 11:14:19 -0400 Received: by mail-pf1-f182.google.com with SMTP id u14so250623pfn.2 for ; Wed, 03 Jul 2019 08:14:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=au819//Ef0qqAwi9QrrqFk91YA1jak3mu2OY38eDTaM=; b=r1LP2eiqOEpOQK6IyS5rPkcdcb4yWBnp3/G5K6erR49iTeoRPjQ1hR0O1c+DZWPaTp rIccFyDfuJpPPY3uhSXb6zeyxJWslWrOJIFcsMHk3cKSKqpg/7O3/NSSSFRpgchvTF9Z vGhDVOhqSiKrGyk0u5dyhRkX34ipJ2rzyUsAo+cF/uESsud+oNElcjzuA7MsFSnzDRAf VxESZW2lUTlVKRDeqy+H5Zj3hLxh+/10cEggZQVJ/qWJO8DgOTWIT5S8gIZfVrHzF1p0 z1rpDWV5xCKZCrnmYXNBWU+EK7qSPR9sl3LG9kcC9SvnY20n8qS+FQhx85ypfThejyq4 QYhA== X-Gm-Message-State: APjAAAUpau7/98VeAR2mDcXrx924fC7mWFfL+S73WVYZP1dGIEQvI68F +VqEMzXB9cYzopBv2Tcq/r7ZU0feCr0= X-Google-Smtp-Source: APXvYqz9VvijXSHi5BZSw++YraSQrfNjeusbaUWnJuoWQPiwAyzFOVx1qJjTm5JvzkoxfmmjvFqxWQ== X-Received: by 2002:a63:3f84:: with SMTP id m126mr36626586pga.213.1562166858702; Wed, 03 Jul 2019 08:14:18 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id g6sm2375362pgh.64.2019.07.03.08.14.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Jul 2019 08:14:17 -0700 (PDT) Subject: Re: [PATCH] block: Document the bio splitting functions To: Hannes Reinecke , Jens Axboe Cc: Christoph Hellwig , Christoph Hellwig , Ming Lei , Hannes Reinecke , linux-block@vger.kernel.org References: <20190701162328.216266-1-bvanassche@acm.org> From: Bart Van Assche Message-ID: <77f37e93-2b77-2540-7da8-322ff3c4ce4b@acm.org> Date: Wed, 3 Jul 2019 08:14:16 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 7/2/19 12:39 AM, Hannes Reinecke wrote: > Could you add a reference to the bio_set in those descriptions, too? > It's really non-obvious that 'split' will reference the bio_set of the > queue, and hence the queue _must not_ go away while the bio is allocated. > This becomes especially tricky if the bio is remapped to another queue > later on, as then we'll lose the reference to the original queue, and > have no idea that suddenly we have a bio with references to _two_ > request queues. Hi Hannes, Thanks for having taken a look. I will update this patch as proposed and repost it. Bart.