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=-7.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 C899DC433DB for ; Thu, 31 Dec 2020 19:43:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 85AA8207C7 for ; Thu, 31 Dec 2020 19:43:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726230AbgLaTnE (ORCPT ); Thu, 31 Dec 2020 14:43:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725968AbgLaTnD (ORCPT ); Thu, 31 Dec 2020 14:43:03 -0500 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 279AEC061573 for ; Thu, 31 Dec 2020 11:42:23 -0800 (PST) Received: by mail-lf1-x12a.google.com with SMTP id l11so45914896lfg.0 for ; Thu, 31 Dec 2020 11:42:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=Ys9f4ClpJL8HAcQlauKh3PDFZfSJYAi99SUSEOzYtRM=; b=Tc2ndKRC8axW3OTIHkxsPwVf5IRqhAxCo6lfSmQjR72GtceMIM/H5y0o1HYPkLMDcs oPKE2BCZsdssNv09+7Qmy04nn30jcQ6kKig8xe2tv5ROCsI3HIJqmBPkEJpZN6AR9rXm zC8sDzwn4wGFPTxDGC467UjqJGnjsqf3lmvKku0E8bYGB+gkZFEHGiUxJYF6Ay5LtSfX mJFTgKZgJPwfOIYv6qFINjwBXAHDM7Dg6ezXDMvkPu1MFYAP8dITs9mJCgNwcRSIgDuU dICodIKlYJRFT5Btj5zEMabfIt5dxfEDV/iXnmKACcPBfeA/pLpOhCx0q7BDKDmu+VCZ +4oA== 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:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=Ys9f4ClpJL8HAcQlauKh3PDFZfSJYAi99SUSEOzYtRM=; b=swzqTO2iO8R5Zq7wL1qqr6efzMRBDG6yd8HL1CQJSsRXNHjG0WVr4mwrhZsNxDf+Bb JCy7ZHkqzuC18gxGaPPsnUr5dj9ra+d/WId4nlGVx7+w1RynV5WMYT3yS/Qs8rNHRVz9 +0LLzhW92bDpmu62A0mB5IF/UECJCKj2f/kLOnf4OeNXCHAWRIe6OCOFnwuaYFBynLAY DwX3tgSkYja5lApF7lcB8CKQ2Y2B405IBO4AthCRchuYVWVEOJwMY27WYf/fKaSo8w+R 605HqhnZx4EmAcCLs8CpTdlZUOs8M8oa2ZqODU9C1Gb+nksBljCMk22XonRBrPA2gpY9 3JOg== X-Gm-Message-State: AOAM533WY/j067EQTlP8Awdi0n8oZYr/vbHiGZQbm3jKczq6Zao+DzvU sliojjBt5V/u6ciu0hLNj8NeaXI/E5Q= X-Google-Smtp-Source: ABdhPJxx13XVk64xvnPO+3ud+yF3yg74lB368M139cNQr4YAX7U5DMpyS69JCceEAW0TgbP8nY9cqw== X-Received: by 2002:a05:6512:248:: with SMTP id b8mr27060510lfo.371.1609443741557; Thu, 31 Dec 2020 11:42:21 -0800 (PST) Received: from ?IPv6:2a00:1370:812d:ecb3:590f:aaab:50ba:573b? ([2a00:1370:812d:ecb3:590f:aaab:50ba:573b]) by smtp.gmail.com with ESMTPSA id j2sm6303790lfe.213.2020.12.31.11.42.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 31 Dec 2020 11:42:21 -0800 (PST) Subject: Re: hierarchical, tree-like structure of snapshots To: john terragon , Zygo Blaxell Cc: sys , Btrfs BTRFS References: <20201231172812.GS31381@hungrycats.org> From: Andrei Borzenkov Autocrypt: addr=arvidjaar@gmail.com; prefer-encrypt=mutual; keydata= mQGiBDxiRwwRBAC3CN9wdwpVEqUGmSoqF8tWVIT4P/bLCSZLkinSZ2drsblKpdG7x+guxwts +LgI8qjf/q5Lah1TwOqzDvjHYJ1wbBauxZ03nDzSLUhD4Ms1IsqlIwyTLumQs4vcQdvLxjFs G70aDglgUSBogtaIEsiYZXl4X0j3L9fVstuz4/wXtwCg1cN/yv/eBC0tkcM1nsJXQrC5Ay8D /1aA5qPticLBpmEBxqkf0EMHuzyrFlqVw1tUjZ+Ep2LMlem8malPvfdZKEZ71W1a/XbRn8FE SOp0tUa5GwdoDXgEp1CJUn+WLurR0KPDf01E4j/PHHAoABgrqcOTcIVoNpv2gNiBySVsNGzF XTeY/Yd6vQclkqjBYONGN3r9R8bWA/0Y1j4XK61qjowRk3Iy8sBggM3PmmNRUJYgroerpcAr 2byz6wTsb3U7OzUZ1Llgisk5Qum0RN77m3I37FXlIhCmSEY7KZVzGNW3blugLHcfw/HuCB7R 1w5qiLWKK6eCQHL+BZwiU8hX3dtTq9d7WhRW5nsVPEaPqudQfMSi/Ux1kbQmQW5kcmV5IEJv cnplbmtvdiA8YXJ2aWRqYWFyQGdtYWlsLmNvbT6IYAQTEQIAIAUCSXs6NQIbAwYLCQgHAwIE FQIIAwQWAgMBAh4BAheAAAoJEEeizLraXfeMLOYAnj4ovpka+mXNzImeYCd5LqW5to8FAJ4v P4IW+Ic7eYXxCLM7/zm9YMUVbrQmQW5kcmVpIEJvcnplbmtvdiA8YXJ2aWRqYWFyQGdtYWls LmNvbT6IZQQTEQIAJQIbAwYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AFAliWAiQCGQEACgkQ R6LMutpd94wFGwCeNuQnMDxve/Fo3EvYIkAOn+zE21cAnRCQTXd1hTgcRHfpArEd/Rcb5+Sc uQENBDxiRyQQBACQtME33UHfFOCApLki4kLFrIw15A5asua10jm5It+hxzI9jDR9/bNEKDTK SciHnM7aRUggLwTt+6CXkMy8an+tVqGL/MvDc4/RKKlZxj39xP7wVXdt8y1ciY4ZqqZf3tmm SN9DlLcZJIOT82DaJZuvr7UJ7rLzBFbAUh4yRKaNnwADBwQAjNvMr/KBcGsV/UvxZSm/mdpv UPtcw9qmbxCrqFQoB6TmoZ7F6wp/rL3TkQ5UElPRgsG12+Dk9GgRhnnxTHCFgN1qTiZNX4YI FpNrd0au3W/Xko79L0c4/49ten5OrFI/psx53fhYvLYfkJnc62h8hiNeM6kqYa/x0BEddu92 ZG6IRgQYEQIABgUCPGJHJAAKCRBHosy62l33jMhdAJ48P7WDvKLQQ5MKnn2D/TI337uA/gCg n5mnvm4SBctbhaSBgckRmgSxfwQ= Message-ID: Date: Thu, 31 Dec 2020 22:42:19 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org 31.12.2020 21:19, john terragon пишет: > On Thu, Dec 31, 2020 at 6:28 PM Zygo Blaxell > wrote: > >> >> I think your confusion is that you are thinking of these as a tree. >> There is no tree, each subvol is an equal peer in the filesystem. >> >> "send -p A B" just walks over subvol A and B and sends a diff of the >> parts of B not in A. You can pick any subvol with -p as long as it's >> read-only and present on the receiving side. Obviously it's much more >> efficient if the two subvols have a lot of shared extents (e.g. because >> B and A were both snapshots made at different times of some other subvol >> C), but this is not required. > > Can you really use ANY subvol to use with -p. Because if I > > 1) create a subvol X > 2) create a subvol W with the exact same content of X (but created > independently) How exactly you create subvolume with the same content? There are many possible interpretations. > 3) do a RO snap X_RO of X > 4) do a RO snap W_RO of W > 5) send W_RO to the other FS Show actual command please. > 6) send -p W_RO X_RO to the other FS > Again show full command please. Which include also receive command. > I get this: > > At subvol X_RO > At snapshot X_RO > ERROR: chown o257-1648413-0 failed: No such file or directory > You get where? On source, on destination? > any idea? >