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=-0.8 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=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 538ECCA9EC3 for ; Thu, 31 Oct 2019 05:35:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E7C020650 for ; Thu, 31 Oct 2019 05:35:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UvRbsqnA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726370AbfJaFfI (ORCPT ); Thu, 31 Oct 2019 01:35:08 -0400 Received: from mail-ot1-f65.google.com ([209.85.210.65]:33047 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726321AbfJaFfI (ORCPT ); Thu, 31 Oct 2019 01:35:08 -0400 Received: by mail-ot1-f65.google.com with SMTP id u13so4351000ote.0 for ; Wed, 30 Oct 2019 22:35:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=qhr8CmMadr7RqtPcqLxf13TLSK+eNsp9nb4CWr3W31o=; b=UvRbsqnAFbzZb7VKq8aslazYwCvEdZKfhh6bmsBYZVfdlbifYazZTiidTqn3VuXlxq D9yvb5PcB0Ruil5OcesVdMJscLMbcyd+FFZNeFQdGrwQKlpG160bz/ME8Rfjg1bDtk6B iJMuJt4W5ni6Shx5oal855Qv3MRiRdtXagIfvW5rnMtU1Vm01WQ0C2NmW5B2WtJebGMY 01HNAUvL25a0yIll8RU+TzkbCgjwb5BVTkcCaAGm1aMxjH+JMEGFRbJSy7FqFmRO6dfX dUfmQSXW4Y717Oh2i2nPIlkzHp06V10HKOfwOvkZ4lMQcKt6WP069K1zReoUc7N2NFwR hTIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=qhr8CmMadr7RqtPcqLxf13TLSK+eNsp9nb4CWr3W31o=; b=A1jdFGi5RfWZZSSI+vufhTGE4C4lpZmiJwncOGoHxgUMxmIFoWS6UrI8m8jgcP0eCi 2i6fA5vAMirYdP5tEK4FRXBpOZDl1vYAWal/saxbAVTyXNye1elpusP2QTtNxS7UFDsB 9zKXTmZCQP1fpunFQ5WB5+XWBjKbe4fEXB67KUXsnARVbEFz33XpXUvzMUpEE6kyhXWE 8ukwWEeSQnGRQvMemfovJYGbbvRJ3t3YZs2gHCxhvtIBdG3iJz8TmWfJiErSk2Qp0fd3 SilGr9oJethsBwGCBXOXUYsVWUwbOLODNGbtRRNrLo5yeOoqiAM1Y0AM/kiDvzZKYTjS pFPA== X-Gm-Message-State: APjAAAU4VpQwHSlixApwxNyI5TbSGSvYYER7yrurnmCUk6xg20Dae/N8 43lYK23V/jQwd/sDEt/2ZhCjFMwvdKFbk1KDl98= X-Google-Smtp-Source: APXvYqxrETAgwgqDyOIut2BbkFcERr+0ruZYe5PRgsaRBamPSKYs+SljN9MSQbBp9DY9e2FF5uI137yKpLQYohaK38U= X-Received: by 2002:a9d:5f89:: with SMTP id g9mr2879670oti.227.1572500107066; Wed, 30 Oct 2019 22:35:07 -0700 (PDT) MIME-Version: 1.0 References: <20191001074101.256523-1-harshadshirwadkar@gmail.com> <20191001074101.256523-13-harshadshirwadkar@gmail.com> <20191018015655.GB21137@mit.edu> In-Reply-To: <20191018015655.GB21137@mit.edu> From: harshad shirwadkar Date: Wed, 30 Oct 2019 22:34:56 -0700 Message-ID: Subject: Re: [PATCH v3 12/13] docs: Add fast commit documentation To: "Theodore Y. Ts'o" Cc: Ext4 Developers List Content-Type: text/plain; charset="UTF-8" Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Thanks good point. I was trying to imitate how a jbd2 commit I guess. There's no reason really to do this in atomic way. I'll fix this in next version. On Thu, Oct 17, 2019 at 6:56 PM Theodore Y. Ts'o wrote: > > On Tue, Oct 01, 2019 at 12:41:01AM -0700, Harshad Shirwadkar wrote: > > + > > +Multiple fast commit blocks are a part of one sub-transaction. To > > +indicate the last block in a fast commit transaction, fc_flags field > > +in the last block in every subtransaction is marked with "LAST" (0x1) > > +flag. A subtransaction is valid only if all the following conditions > > +are met: > > + > > +1) SUBTID of all blocks is either equal to or greater than SUBTID of > > + the previous fast commit block. > > +2) For every sub-transaction, last block is marked with LAST flag. > > +3) There are no invalid blocks in between. > > I'm wondering why we need to support multiple inodes being modified in > a single transaction. As we currently have defined what can be done, > all updates to an inode should be free standing and not dependent on a > change to another inode, right? And today, one block only modifies > one inode. > > The only reason why we might want to define a sub-transaction as being > composed of multiple inodes, which must all be updated in an > all-or-nothing fashion, is the swap boot inode ioctl, and if that's > the only one, I wonder if it's worth the extra complexity. > > Am I missing anything? > > - Ted