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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00C76C433EF for ; Sat, 2 Oct 2021 07:05:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C704561AAD for ; Sat, 2 Oct 2021 07:05:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232487AbhJBHHJ (ORCPT ); Sat, 2 Oct 2021 03:07:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232355AbhJBHHI (ORCPT ); Sat, 2 Oct 2021 03:07:08 -0400 Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C6A6C061775 for ; Sat, 2 Oct 2021 00:05:23 -0700 (PDT) Received: by mail-lf1-x12d.google.com with SMTP id m3so47025003lfu.2 for ; Sat, 02 Oct 2021 00:05:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=ouMtmNsvfuf9w/XQR6PYGX4r+B/1/ZVrMZ+0k722Zm4=; b=pcMJH/iSZC00tQpKOsVvUN48ePO5tIkA4aKCMOCYznMLQjAnHwsTYob+kVoJG0cBcu vGCqNRwrqlZr2IaSSZ0NdxULG/CIoJwR+4gXc/RgyaDgOb3Luv1QyxAlXtlBLWx+vSbW j8qnNdhSEeaRmvdKk1VF6DWxvDgZF4xE/RyJxt3l+R2Soye4jWPo9moftMEYif7X0zC6 oO/uYYRbIW9v7kjvyqwdg3Z8GBowUTtA1awEwcFC2KjwtfqLuhK9flRM/dKKPgdEZYE/ F9ShZNJIG7rw39gCnR6NZAqjVk+b+N7ofjGNfIQb1yarPUBCFkzJb1X36UhrFNdgyhBa quzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ouMtmNsvfuf9w/XQR6PYGX4r+B/1/ZVrMZ+0k722Zm4=; b=TOmF/ddBc2po/gsR4btXULxrPDGJYlANml/qEYvRB9pljkX856A3KPeO+t0cyln0xl 43oJAkMQCT8LZHykYgkkFzrpXutYoNze2dFs3J4VmUeZs8yZ0RxTX1rqSWUaKj1Ct3Cv Nr1JBP95Ty5USodp+bpxH/iPRilXD0kEhykqNgbKiVFwI1H6WuajoOYaCmY35UxwEEqX Yi+7ugC8sUbwYM9Y9HLr1AHyTeuLKgwun08kRK9KBFm0T7OL+3vUZ/kbA9g1lwHobXgX TwTeM5X9qIR83lWMJUtaLLsv36uBqDolJm4aI6L0FTACUPWvb30bUaWhUhmHBZLVy8VC ae8Q== X-Gm-Message-State: AOAM531KFaLB3OyQroFfprp8sg9niQSzuYKOlMtqqOxuwlbDu0tLtwWY qOv2HSdhvinlt/nkQgHJbb2OL3tHJnY= X-Google-Smtp-Source: ABdhPJzVlNkgthK96Kh5kIOW/HHgGvRoMyymTBujFo+IEcTrsw1wECSZrhlCImJ5+AFcEqDT7zQVIg== X-Received: by 2002:a05:6512:acd:: with SMTP id n13mr2440484lfu.247.1633158321430; Sat, 02 Oct 2021 00:05:21 -0700 (PDT) Received: from ?IPv6:2a00:1370:812d:ceb2:544e:22a0:6fa3:2d83? ([2a00:1370:812d:ceb2:544e:22a0:6fa3:2d83]) by smtp.gmail.com with ESMTPSA id r3sm965307lfc.114.2021.10.02.00.05.20 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 02 Oct 2021 00:05:20 -0700 (PDT) Subject: Re: [PATCH 4/5] btrfs-progs: property: ro->rw and received_uuid To: linux-btrfs@vger.kernel.org References: <4c02eb0d00433fa95b77befecafcdf147c230f21.1633101904.git.dsterba@suse.com> From: Andrei Borzenkov Message-ID: Date: Sat, 2 Oct 2021 10:05:19 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <4c02eb0d00433fa95b77befecafcdf147c230f21.1633101904.git.dsterba@suse.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 01.10.2021 18:29, David Sterba wrote: > Implement safety check when a read-only subvolume is getting switched > to read-write and there's received_uuid set. > > This prevents accidental breakage of incremental send usecase but allows > user to do the rw change anyway but resets the received_uuid in that > case. > > As this is implemented entirely in userspace, it's racy and using the > raw ioctl won't prevent it nor reset the received_uuid. > Is it feasible to add "force" flag to ioctl itself?