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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 3E545C433ED for ; Fri, 9 Apr 2021 09:34:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F411A611BE for ; Fri, 9 Apr 2021 09:34:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232276AbhDIJeN (ORCPT ); Fri, 9 Apr 2021 05:34:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231402AbhDIJeL (ORCPT ); Fri, 9 Apr 2021 05:34:11 -0400 Received: from mail-vs1-xe29.google.com (mail-vs1-xe29.google.com [IPv6:2607:f8b0:4864:20::e29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA28BC061760 for ; Fri, 9 Apr 2021 02:33:58 -0700 (PDT) Received: by mail-vs1-xe29.google.com with SMTP id 2so2609907vsh.4 for ; Fri, 09 Apr 2021 02:33:58 -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=OO9iwsL0KDbtjIAGoYaz7sDHtq5BkOHEGXLIhrYn/Gc=; b=QNgB65wm8nudussgpnqTsTnY6OzfdhaIbY75sl0xLLWMkLDqiO2tPa88Sd//ZM3FNF 3cNp4y3ouiJfghiGt7Z7Fn0zduVsTrOxG+A41HCLFwSCnxcEjTOSJxsB4h0sLf+JKyNr sIRVTs/+jWkSiVHOxMij185IbkHm5IkL5chgQ= 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=OO9iwsL0KDbtjIAGoYaz7sDHtq5BkOHEGXLIhrYn/Gc=; b=LN/78afnZrD3+IjwexZQ7vKPO5Ghg/FsBe0alT/aqb51XpbHOvyKQS03hNEPPbp3QC 7Xroo+rhcrha/i+gSx7YE+1bvMyAmSNb9FBuoLPnqYBlisXOHQmyKTi/l3fOLnBqWUkL TxIhFkmCa2xJQSCWM5TOL00WrdBoUr9mTV3cjYrDZpsOAIkHkfLCvGinFO4OkT2WTFaO nrmOe79Qqk+v5sAC7oytG0kTdc2lq1mux/GS8QqxxJ2nP6igh46Jx9H7ETuASuR9F/2A 3XtDlDELHzj0SkgbpU3x28r3MZETKeJNT/lqWFwWIdJTwLLSpCmsOMbVVZzcgYmWhByR SVVA== X-Gm-Message-State: AOAM533EeIFpnecUR91AQIIpAONdTR7ljqyJLt8z2oSxzwVpGeaMUT+z bSQ5Xmeh2Ss72jyva7a2RBPx+krqo7m2toZORRGejw== X-Google-Smtp-Source: ABdhPJzSw9GxlWN91DIboH/hs+f1E/gx0AB/RwZCeNgWatXdXeFrf7k5sApQq2djiuifLESr6nZra8iW/j5i6NTe7aA= X-Received: by 2002:a67:6647:: with SMTP id a68mr7643351vsc.21.1617960838037; Fri, 09 Apr 2021 02:33:58 -0700 (PDT) MIME-Version: 1.0 References: <20210309162654.243184-1-amir73il@gmail.com> In-Reply-To: <20210309162654.243184-1-amir73il@gmail.com> From: Miklos Szeredi Date: Fri, 9 Apr 2021 11:33:47 +0200 Message-ID: Subject: Re: [PATCH] ovl: restrict lower null uuid for "xino=auto" To: Amir Goldstein Cc: Fabian , Kevin Locke , overlayfs Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Tue, Mar 9, 2021 at 5:27 PM Amir Goldstein wrote: > > Commit a888db310195 ("ovl: fix regression with re-formatted lower > squashfs") attempted to fix a regression with existing setups that > use a practice that we are trying to discourage. > > The discourage part was described this way in the commit message: > "To avoid the reported regression while still allowing the new features > with single lower squashfs, do not allow decoding origin with lower null > uuid unless user opted-in to one of the new features that require > following the lower inode of non-dir upper (index, xino, metacopy)." > > The three mentioned features are disabled by default in Kconfig, so > it was assumed that if they are enabled, the user opted-in for them. > Apparently, distros started to configure CONFIG_OVERLAY_FS_XINO_AUTO=y > some time ago, so users upgrading their kernels can still be affected > by said regression even though they never opted-in for any new feature. > > To fix this, treat "xino=on" as "user opted-in", but not "xino=auto". > Since we are changing the behavior of "xino=auto" to no longer follow > to lower origin with null uuid, take this one step further and disable > xino in that corner case. To be consistent, disable xino also in cases > of lower fs without file handle support and upper fs without xattr > support. > > Update documentation w.r.t the new "xino=auto" behavior and fix the out > dated bits of documentation regarding "xino" and regarding offline > modifications to lower layers. > > Link: https://lore.kernel.org/linux-unionfs/b36a429d7c563730c28d763d4d57a6fc30508a4f.1615216996.git.kevin@kevinlocke.name/ > Fixes: a888db310195 ("ovl: fix regression with re-formatted lower squashfs") > Signed-off-by: Amir Goldstein > --- > > Miklos, > > What do you think about this? Applied. I removed the Fixes: tag for fear of too eager backport bots, the said commit is mentioned in the header, so no information is lost. Thanks, Miklos