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=-0.6 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 74792C5518A for ; Fri, 24 Apr 2020 06:02:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D1D02076C for ; Fri, 24 Apr 2020 06:02:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fhpQv0G7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726562AbgDXGCM (ORCPT ); Fri, 24 Apr 2020 02:02:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725823AbgDXGCM (ORCPT ); Fri, 24 Apr 2020 02:02:12 -0400 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14657C09B045 for ; Thu, 23 Apr 2020 23:02:12 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id e9so9159319iok.9 for ; Thu, 23 Apr 2020 23:02:11 -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=Lhm//PRyLWRG3+Zw7tpwTG96zUqrHWxhgVRttPdiOAY=; b=fhpQv0G7B7gAZjHYt4Y+cmgPYJ4+GTLDXLoumcyywIi0c9F7dPWI5EaeVxOOrz2WIl HmIwcS9/hLWa2etqa9QjmlAEcAF8klm+VWLuOybEm1D9efLe16q3TvnwoZierFJLPs1q ic12ukLwmtvvwBXAhmJaZbPbd0yLuOKVg3HtBxLVx4WsnS1X3EmAeFNLcm3T5llYXjmJ V+epodTfslLxEUo0esJxO6Q7+kf7j4NasFCjBYNMzFBthG/aXea3kgQMf2CTELwz7DuW 6xzLSvfFcqI+EpJn6dzsYh2lnQPpPiLBnWV+l0AosYPx6tx27Az85f714bhXPQVGIYZw g7lA== 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=Lhm//PRyLWRG3+Zw7tpwTG96zUqrHWxhgVRttPdiOAY=; b=hofsMIRbknYyCcIYIBb54z6b+VV3XA1uc6JigZzRRNaqGeKNacfJcX2ywnHUCFQpPR hmwKb8msNoC9OjpRib7l8nmM8ciATCpGpYDbGhxsSXFPaCU2RkK5A3Va8ueTEupQV1XJ UXx+qckarhG3H7LG0lqdvfRK9kGt+aqg4vZ0BMaeQhr47J8+xmwpCza2jyF/gPZG4NTJ 9w4sLsIbEdDASZmYiDG+XlKxT4mAxyywZsqFsI8Xgr3xh0ZVbKi3ndj1pDOmiiI/O0XT jZWu6gdKEpsr5Ku7ZowY/rPDs5XU0qlLYctcMxFpn46dbuuoVaX5+EBCq3txjWseKhpf ibVA== X-Gm-Message-State: AGi0Pub1bfsac4KOkenvGbkYXztEbKvFoQ9LW+LuNSolkHYNo9fGTfE/ WzWGMBMOmEzkUkbVWGPm/Po0tAoOP6NSzs01ODYq/II3 X-Google-Smtp-Source: APiQypIm1OrCW+yv4mWPbus/7gYDecDZ7XD0jB/nUOqdUlxGoLN2TidjvbHQ3dm9DWVTHxC4FaaC83vP07sR2mMWma0= X-Received: by 2002:a02:4b03:: with SMTP id q3mr6657270jaa.30.1587708131238; Thu, 23 Apr 2020 23:02:11 -0700 (PDT) MIME-Version: 1.0 References: <20200422102740.6670-1-cgxu519@mykernel.net> <171a49cb02a.e6962d897896.4484083556616944063@mykernel.net> In-Reply-To: <171a49cb02a.e6962d897896.4484083556616944063@mykernel.net> From: Amir Goldstein Date: Fri, 24 Apr 2020 09:02:00 +0300 Message-ID: Subject: Re: [PATCH v4] ovl: whiteout inode sharing To: Chengguang Xu Cc: Miklos Szeredi , overlayfs Content-Type: text/plain; charset="UTF-8" Sender: linux-unionfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org > > > + case OPT_WHITEOUT_LINK_MAX: > > > + if (match_int(&args[0], &link_max)) > > > + return -EINVAL; > > > + if (link_max < ovl_whiteout_link_max_def) > > > + config->whiteout_link_max = link_max; > > > > Why not allow link_max > ovl_whiteout_link_max_def? > > admin may want to disable ovl_whiteout_link_max_def by default > > in module parameter, but allow it for specific overlay instances. > > > > In this use case, seems we don't need module param any more, we just need to set default value for option. > > I would like to treate module param as a total switch, so that it could disable the feathre for all instances at the same time. > I think sometimes it's helpful for lazy admin(like me). > I am not convinced. lazy admin could very well want to disable whiteout_link_max by default, but allow user to specify whiteout_link_max for a specific mount. In fact, in order to preserve existing behavior and not cause regression with some special filesystems, distros could decide that default disabled is a reasonable choice. I don't understand at all what the purpose of this limitation is. Thanks, Amir.