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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 CBBC3C32792 for ; Thu, 3 Oct 2019 16:19:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E325222BE for ; Thu, 3 Oct 2019 16:19:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hyp83+4j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389687AbfJCQTG (ORCPT ); Thu, 3 Oct 2019 12:19:06 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:32792 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389673AbfJCQTC (ORCPT ); Thu, 3 Oct 2019 12:19:02 -0400 Received: by mail-pg1-f196.google.com with SMTP id q1so2098856pgb.0 for ; Thu, 03 Oct 2019 09:19:02 -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=xwJ+goq56V61KKdUp1nXU3PcbR5cWKTPI7JwjuelYXM=; b=hyp83+4jBvXpvboY1Q8WaQ1GiZC66yMNhix38Mq6ItRsEHKNnztY8eLYiaPlROtMiO 6oCrTF0iPbEgOB1yIfYXwZUNntXHpcgbqYMHdsrSpU//1oFcoVUMi6FdT1qDJ4oU5ZuE YGUquHvTdaL75XGy8rtdvQuw6+sC0ov/E2wa4PLsscBpLmLXxVJH+5K6oThVWNml2dcb wGmPc9wWRn6eFsxfQSH21Qr0k7DWt44yZ3bFzcWcQh+taOcZLlNT966/TdVvaKC9Wpqk X8+F4+HlLub7GFezI7CYgWMI9L66oD8/nsrQTIdzeCl6JGH8VgvzUNj4WQzY3FBxTAxI M0vQ== 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=xwJ+goq56V61KKdUp1nXU3PcbR5cWKTPI7JwjuelYXM=; b=kigFhJeiFK6O7/m1zOAFjwCr2aWJ7Uu2arCRsyQDmjXtM59vmJfuH1taBylXEAHOop fR3y7+j5Sq/f3gOqIatKiBD1yAZHQREAj2jjd/TXCPpfk/b6MXBwlGdp3vaz+2Tqo7mW 1P7njb3C7wNjCWBRQs2dupEjTc7e9ZgKt8kAMC0txk828vvKQHWptPBDssbC6w2evFz3 z0kR9LOcZb8EVkwqHwsOa5UoJ4d2FtGeHNOyeNvQRP+PlMEeo51IrcuRp3WPwAJz+ako FcupXxNJOsMRNLMRU88GIQOx7/NVjxOUr2TAnLRZq81yEMgcvHWzbegcFMc2BczgvbNW PU5g== X-Gm-Message-State: APjAAAXT6fdnQUYbVlZBzT624HMHtN99E2WanvMpY+OEbLeLvI4l1MJN K74Bv+BsfY6Ac1KIrablc6VuH9zLhEE= X-Google-Smtp-Source: APXvYqwWbEvPNnOSmoZ+Tj+A9qU3f3+vAVMOEdC4/oW4WXBs3yc1fSoo+bYhaxQX/uUKcaOpKpkEBg== X-Received: by 2002:a17:90a:3d03:: with SMTP id h3mr11611819pjc.49.1570119541664; Thu, 03 Oct 2019 09:19:01 -0700 (PDT) Received: from [192.168.248.234] ([63.239.150.218]) by smtp.gmail.com with ESMTPSA id t9sm2749051pgj.89.2019.10.03.09.18.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Oct 2019 09:19:00 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [PATCH] ext2fs: add ext2fs_read_sb that returns superblock From: =?utf-8?B?0JHQu9Cw0LPQvtC00LDRgNC10L3QutC+INCQ0YDRgtGR0Lw=?= In-Reply-To: <20191003160122.GB13093@magnolia> Date: Thu, 3 Oct 2019 19:18:47 +0300 Cc: linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca Content-Transfer-Encoding: quoted-printable Message-Id: References: <20190905110110.32627-1-c17828@cray.com> <20191003160122.GB13093@magnolia> To: "Darrick J. Wong" 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 Darrick, thanks for feedback. > On 3 Oct 2019, at 19:01, Darrick J. Wong = wrote: >=20 > On Thu, Sep 05, 2019 at 02:01:10PM +0300, Artem Blagodarenko wrote: >> tune2fs is used to make e2label duties. ext2fs_open2() reads group >> descriptors which are not used during disk label obtaining, but takes >> a lot of time on large partitions. >>=20 >> This patch adds ext2fs_read_sb(), there only initialized superblock >> is returned This saves time dramatically. >>=20 >> Signed-off-by: Artem Blagodarenko >> Cray-bug-id: LUS-5777 >> --- >> lib/ext2fs/ext2fs.h | 2 ++ >> lib/ext2fs/openfs.c | 16 ++++++++++++++++ >> misc/tune2fs.c | 23 +++++++++++++++-------- >> 3 files changed, 33 insertions(+), 8 deletions(-) >>=20 >> diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h >> index 59fd9742..3a63b74d 100644 >> --- a/lib/ext2fs/ext2fs.h >> +++ b/lib/ext2fs/ext2fs.h >> @@ -1630,6 +1630,8 @@ extern int ext2fs_journal_sb_start(int = blocksize); >> extern errcode_t ext2fs_open(const char *name, int flags, int = superblock, >> unsigned int block_size, io_manager = manager, >> ext2_filsys *ret_fs); >> +extern errcode_t ext2fs_read_sb(const char *name, io_manager = manager, >> + struct ext2_super_block * super); >> extern errcode_t ext2fs_open2(const char *name, const char = *io_options, >> int flags, int superblock, >> unsigned int block_size, io_manager = manager, >> diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c >> index 51b54a44..95f45d84 100644 >> --- a/lib/ext2fs/openfs.c >> +++ b/lib/ext2fs/openfs.c >> @@ -99,6 +99,22 @@ static void block_sha_map_free_entry(void *data) >> return; >> } >>=20 >> +errcode_t ext2fs_read_sb(const char *name, io_manager manager, >> + struct ext2_super_block * super) >> +{ >> + io_channel io; >> + errcode_t retval =3D 0; >> + >> + retval =3D manager->open(name, 0, &io); >> + if (!retval) { >> + retval =3D io_channel_read_blk(io, 1, -SUPERBLOCK_SIZE, >> + super); >> + io_channel_close(io); >> + } >> + >> + return retval; >> +} >> + >> /* >> * Note: if superblock is non-zero, block-size must also be = non-zero. >> * Superblock and block_size can be zero to use the default size. >> diff --git a/misc/tune2fs.c b/misc/tune2fs.c >> index 7d2d38d7..fea607e1 100644 >> --- a/misc/tune2fs.c >> +++ b/misc/tune2fs.c >> @@ -2879,6 +2879,21 @@ int tune2fs_main(int argc, char **argv) >> #endif >> io_ptr =3D unix_io_manager; >>=20 >> + if (print_label) { >> + /* For e2label emulation */ >> + struct ext2_super_block sb; >> + >> + /* Read only superblock. Nothing else metters.*/ >=20 > matters. */ >=20 >> + retval =3D ext2fs_read_sb(device_name, io_ptr, &sb); >> + if (!retval) { >> + printf("%.*s\n", (int) sizeof(sb.s_volume_name), >> + sb.s_volume_name); >> + } >=20 > Um, does this drop the error without making a report? No error message to output, but error code is returned to pointer. I believe user expect only disk label, no other output. >=20 >> + >> + remove_error_table(&et_ext2_error_table); >> + return retval; >> + } >=20 > I wonder if ext[24] should implement FS_IOC_[GS]ETFSLABEL for mounted > filesystems =E2=80=A6 ? Probably not very useful for Lustre FS, there disk label is not needed = during cluster work. Darrick, can you suggest any use case for this? Also such features need to be added in separate patch. This patch is = about performance optimisation.=20 Best regards, Artem Blagodarenko. >=20 > --D >=20 >> + >> retry_open: >> if ((open_flag & EXT2_FLAG_RW) =3D=3D 0 || f_flag) >> open_flag |=3D EXT2_FLAG_SKIP_MMP; >> @@ -2972,14 +2987,6 @@ retry_open: >> sb =3D fs->super; >> fs->flags &=3D ~EXT2_FLAG_MASTER_SB_ONLY; >>=20 >> - if (print_label) { >> - /* For e2label emulation */ >> - printf("%.*s\n", (int) sizeof(sb->s_volume_name), >> - sb->s_volume_name); >> - remove_error_table(&et_ext2_error_table); >> - goto closefs; >> - } >> - >> retval =3D ext2fs_check_if_mounted(device_name, &mount_flags); >> if (retval) { >> com_err("ext2fs_check_if_mount", retval, >> --=20 >> 2.14.3