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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 501BBC04AB5 for ; Thu, 6 Jun 2019 12:32:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 243C8204FD for ; Thu, 6 Jun 2019 12:32:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Dbiovk8o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727498AbfFFMcu (ORCPT ); Thu, 6 Jun 2019 08:32:50 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:32968 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726717AbfFFMcu (ORCPT ); Thu, 6 Jun 2019 08:32:50 -0400 Received: by mail-lj1-f196.google.com with SMTP id v29so1854824ljv.0 for ; Thu, 06 Jun 2019 05:32:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=vaVAGfvIWmlk7NtGq1TPLC8ZKE6xRNld3Q7CKBoUXaw=; b=Dbiovk8ouunaJQRHMVqIJGlVObWaS7VVzG3itjvdtaBAlisSGpHCrhTW1XLyJCJxpP FNUpZoLUKiDRWNKBgTVeP3xhB4UZMqoefcdWr3LbfcZFRz/IjqOzyaesMDl3iW9lwUNO 7SrwhBArqdooHDmUBtbcLr4E5XIbMJuNEQD2QSPPVc1v3Ku0MqRo3esEblFfW9X985mK 17L3TuBctpvtQamvQpQkYcaGjWg+K5tmsQ86urGgDghsglYJu/yppXA/OtnGxW30yTIg rVWHIywZb2yJpWXSS1fhuarNEmKCWd1t6fJUGw95Us7HocoThFfxJCk3Y1W4XNVtTrLh YOiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=vaVAGfvIWmlk7NtGq1TPLC8ZKE6xRNld3Q7CKBoUXaw=; b=iHlluuMa0Qj/RVurKY0/wPKu6VwR3IvAsqfLMpA/kFCoC7OFs2fbYRRCU7IlzPE4H7 RBLGPcLBll1/sjbMA5Ix5kB8m2MQBdEqHbpinCK0vt6Eqc7xQQ1rxiJ6HcnxeOZ95Kti bnTT8UnYFrqfzyO+TeaQxMaYB+Dlezprz/fZnWMGCSYYvitdJD37UlBrzQfL7NcEI1vM z4Yaboyl5oJSbUVdUFl6nMtRS5YcMnvaL0ba/TblpoPp52boNT0b+z4DJuBv7zIVSTu6 C98fUAeUEh1Qua57d23kglgQ18Q3hBBrMh+Tp1p7aaGzT7NS5rs2E3zAoJ8i7enOZG45 gu4Q== X-Gm-Message-State: APjAAAWhimkCu9CXURXlLJSjn9GVoL8uxW2d8lSKLSsY5SjVXhRcEYwS ct2hK+NKrwzn3JM3VlzIlDF7kb/oa+c= X-Google-Smtp-Source: APXvYqwr/K+19LwU85dY7t5VMD74g6wqOViy63CATpp0NDfgRxx+R2Cbr3joSqFaXY7S+zwHhgLATQ== X-Received: by 2002:a2e:8591:: with SMTP id b17mr13682386lji.71.1559824368608; Thu, 06 Jun 2019 05:32:48 -0700 (PDT) Received: from [192.168.1.192] ([195.208.173.203]) by smtp.gmail.com with ESMTPSA id b18sm276929lfi.30.2019.06.06.05.32.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Jun 2019 05:32:47 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [HELP] What are the allocated blocks on a newly created ext4 fs ? From: Artem Blagodarenko In-Reply-To: Date: Thu, 6 Jun 2019 15:32:44 +0300 Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca Content-Transfer-Encoding: quoted-printable Message-Id: <7FD3148B-1E27-4BFA-965C-9FDC7FC8FD96@gmail.com> References: To: Jianchao Wang X-Mailer: Apple Mail (2.3273) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Hello Jianchao, Not enought input data to give an answer. It depends on mkfs options. = For example, if flex_bg option is enabled, then several block groups are = tied together as one logical block group; the bitmap spaces and the = inode table space in the first block group, so some groups are not = totally free just after FS creating. > On 6 Jun 2019, at 13:41, Jianchao Wang = wrote: >=20 > Dear all >=20 > After I newly created a ext4 fs and check the mb_group, >=20 > #group: free frags first [ 2^0 2^1 2^2 2^3 2^4 2^5 = 2^6 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ] > #0 : 23513 1 9255 [ 1 0 0 1 1 0 = 1 1 1 1 0 1 1 2 ] > #1 : 31743 1 1025 [ 1 1 1 1 1 1 = 1 1 1 1 0 1 1 3 ] > ^^^^ > #2 : 32768 1 0 [ 0 0 0 0 0 0 = 0 0 0 0 0 0 0 4 ] > #3 : 31743 1 1025 [ 1 1 1 1 1 1 = 1 1 1 1 0 1 1 3 ] > #4 : 32768 1 0 [ 0 0 0 0 0 0 = 0 0 0 0 0 0 0 4 ] > #5 : 31743 1 1025 [ 1 1 1 1 1 1 = 1 1 1 1 0 1 1 3 ] > #6 : 32768 1 0 [ 0 0 0 0 0 0 = 0 0 0 0 0 0 0 4 ] > #7 : 31743 1 1025 [ 1 1 1 1 1 1 = 1 1 1 1 0 1 1 3 ] > #8 : 32768 1 0 [ 0 0 0 0 0 0 = 0 0 0 0 0 0 0 4 ] > #9 : 31743 1 1025 [ 1 1 1 1 1 1 = 1 1 1 1 0 1 1 3 ] > #10 : 32768 1 0 [ 0 0 0 0 0 0 = 0 0 0 0 0 0 0 4 ] > #11 : 32768 1 0 [ 0 0 0 0 0 0 = 0 0 0 0 0 0 0 4 ] >=20 > There are some bgs that have 1024 blocks allocated. What are they for = ? >=20 BTW, I don=E2=80=99t see from mb_group output why 1024 blocks allocated = in group #1 > Many thanks in advance > Jianchao Best regards, Artem Blagodarenko.