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=-5.1 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,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 8A8C6C433DF for ; Sat, 22 Aug 2020 11:48:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A51320720 for ; Sat, 22 Aug 2020 11:48:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rYqPweQk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727927AbgHVLs1 (ORCPT ); Sat, 22 Aug 2020 07:48:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727113AbgHVLsZ (ORCPT ); Sat, 22 Aug 2020 07:48:25 -0400 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55A32C061573 for ; Sat, 22 Aug 2020 04:48:24 -0700 (PDT) Received: by mail-wm1-x332.google.com with SMTP id u18so4135922wmc.3 for ; Sat, 22 Aug 2020 04:48:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:from:subject:message-id:date:user-agent:mime-version :content-transfer-encoding:content-language; bh=4yJHaYpjE/wU21AzHFhuCS+5+CAMg7UJu+9ysNFIZag=; b=rYqPweQkMHJc2sFy3J3xfQcuCLIDyM2/orTaTPLEQujE0+sjHXwUjCPM79LOa7cM3q MYstzlsj/rJNqormwm/+b0IMG/gQkMUovyTllhFShiH9NA8arjyemS+v/g1MAJYpQ9dx VrokLOnNKU4N6g1Eg65Yktwnoe/nJOHlBYFxD2G/JgXjP5YXc3lFHm0rpTVbsGFBR6ZU c1h560LNIjqfTm0pMXBGjtkyA0hC+nhk/a4g49wYbEJWrqWqxLqqHs2f/Pmmt0DUUApM sSEGkAz5yiMdjrquhVrXR8KUA3/k2C0oVZIVvgk8mjnu6mP3q8ZJcsdfUlzIQjRfY5ul 3LwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-transfer-encoding:content-language; bh=4yJHaYpjE/wU21AzHFhuCS+5+CAMg7UJu+9ysNFIZag=; b=XMmOlam2VgVa6FMbnnjad0TGP2j7Hy0LSl4J+137cYvLaL/moflobKQl2UbsV60emo 3TlTP8qaTTWCHFPqFap1+g1Wt8tgFbaKRggf2sYvDWkQrLc+ElBTQ0nHgoHHlCohU1yk T9oDaYPF1maqLOT7BTv39I0BnDf1PR7deAEyDrKfAOerXTOr6+Ks2zjZckSpXQnqLyPn KixpE1tlQj0TDwAtnHKizn8o0deAK/H+8x6mpORmS1cIdEjo31YdO8tYbQZUmEO3FiTc cUHyAWlGt81vChoEXI8V6fqlgXQRiIbu69j5NfHKx0IgCayhQ91XEiWPZUtnwdObA1FW wySQ== X-Gm-Message-State: AOAM533XxcT2XTtKEEV1V52fXX0KYtL3tvp2hIl2D3v9p+L+8Leg51I+ 2CtTl0MdNISLTuzo5zmOoCE6rVDhDbnRPw== X-Google-Smtp-Source: ABdhPJycCoH7lqCQd0+OtYSgCuSy6FiWWN8Fu4AMMbcKaRWhbIzrNyZsJ3Tg6N14TUo+XhaKc8Jsng== X-Received: by 2002:a1c:3c87:: with SMTP id j129mr7893295wma.176.1598096900281; Sat, 22 Aug 2020 04:48:20 -0700 (PDT) Received: from [192.168.0.42] ([65.18.223.249]) by smtp.googlemail.com with ESMTPSA id r11sm10391639wrw.78.2020.08.22.04.48.19 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 22 Aug 2020 04:48:19 -0700 (PDT) To: linux-btrfs@vger.kernel.org From: George Shuklin Subject: Replacing or merging last snapshot Message-ID: <878539b1-b8eb-f547-fb4a-9026f1d51cf7@gmail.com> Date: Sat, 22 Aug 2020 14:48:18 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org I wonder if there is a way to free space if there is only one snapshot available. The problem is that there is a hidden top-level (id=5) subvolume, and there was ever switch from top-level to another subvolume as 'default'. If top-level subvolume have some data (not present in 'default' snapshot), this space is wasted. Are there way to 'merge' snapshot into top-level subvolume, or a way to completely remove subvolume 5 (without breaking fs)?