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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 C9C26C433E6 for ; Fri, 19 Mar 2021 10:52:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8ED3864F38 for ; Fri, 19 Mar 2021 10:52:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229796AbhCSKwM (ORCPT ); Fri, 19 Mar 2021 06:52:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229767AbhCSKwH (ORCPT ); Fri, 19 Mar 2021 06:52:07 -0400 Received: from mail-vs1-xe2b.google.com (mail-vs1-xe2b.google.com [IPv6:2607:f8b0:4864:20::e2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F06AC06175F for ; Fri, 19 Mar 2021 03:52:06 -0700 (PDT) Received: by mail-vs1-xe2b.google.com with SMTP id h25so3220192vso.2 for ; Fri, 19 Mar 2021 03:52:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DyU0kfhyJ9K9PwDpeZgafjUaj5wayL2Dd1uu3ttNySA=; b=X8iKjZKkXYwh3BR84dUDizD/1NFrlbgZCIGwoUQIOsscM/6j6yFdalp+0zHlY0afLn 2TTOEZwIma6EHaZtjOqsTYsEb8tM38HBkrCQKxJekX0F6Gu8kT4t4O/jhs4t1r4qM08d IsqnUJVbVcdM3PYW9BAKdBv2zowZxdkW2mVcU= 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=DyU0kfhyJ9K9PwDpeZgafjUaj5wayL2Dd1uu3ttNySA=; b=BgoFe3ZbUrplAekT8TWqzz/IKy3ITFBSo6LQlfH8KRHr8qkS7/VMk/elWvInwS8Sut 1s9xoUO4ORJ0jkL550zHJh3EVunrPstJaNkr2ksppcriMoGX/tCJnQ6iE72YtI5Im2CL 6I4gaQb5HyYRjN8Q916KAJFy9S68ZX7/wfIdwMn7sFUQbxhF25VLJ6psHhqErntfwqOm VCKNkx+aHl7cfVPD3tXh/4wb5mTBRZ5b+nCmbwVdeAYLdo3Oka+CY3nyvGZv/szAVimW AGGI+ddmR+ZP1+CnrdtJo0Xv3o7ClRyDIgUg/TWFcX93E4r+rfGZ+AkIxtYuHx8r0X8E RO+g== X-Gm-Message-State: AOAM531eU1uSGgEpoI+PrnIY7R2POq4DIIgfAU/+AbU/M09jGOgt6u55 IHnu4dtLpS4nBFLsRnmQGSMdUdh544wImBRQqEUnUQ== X-Google-Smtp-Source: ABdhPJyKXHCKa1uQYDJ36wfBLGH7zSQQ4glHPyYkdKrk6MfMGZWPApUav49zfHhz35XD+Gis8mq8yciY5zILs46+sW0= X-Received: by 2002:a67:f7d2:: with SMTP id a18mr1977372vsp.21.1616151125453; Fri, 19 Mar 2021 03:52:05 -0700 (PDT) MIME-Version: 1.0 References: <20210316221921.1124955-1-harshadshirwadkar@gmail.com> In-Reply-To: From: Miklos Szeredi Date: Fri, 19 Mar 2021 11:51:54 +0100 Message-ID: Subject: Re: [PATCH] ext4: add rename whiteout support for fast commit To: Amir Goldstein Cc: harshad shirwadkar , Ext4 , Theodore Tso , overlayfs Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Fri, Mar 19, 2021 at 11:35 AM Amir Goldstein wrote: > One thing that we will probably need to do is use the RENAME_WHITEOUT > interface as the explicit way to create the shared whiteout instead of using > vfs_whiteout() for filesystems that support RENAME_WHITEOUT > (we check for RENAME_WHITEOUT support anyway). > > The only thing that bothered me in moving from per-ovl-instance singleton > to per-ext4-singleton is what happens if someone tries to (say) chown -R > the upper layer or some other offline modification that was working up to > now and seemed to make sense. Eek. > > Surely, the ext4 singleton whiteout cannot allow modifications like that, > so what do we do about this? Let those scripts fail (if they exist) and > let their owners fix them to skip errors on whiteouts? Might try that. But the no-regressions rule means we'd have to change that in case it breaks something. Thanks, Miklos > Thanks, > Amir.