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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1C248C43331 for ; Thu, 26 Mar 2020 12:19:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E76AC2070A for ; Thu, 26 Mar 2020 12:19:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cumulusnetworks.com header.i=@cumulusnetworks.com header.b="ep4Y1Q/H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728218AbgCZMTc (ORCPT ); Thu, 26 Mar 2020 08:19:32 -0400 Received: from mail-lf1-f68.google.com ([209.85.167.68]:41366 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727560AbgCZMTc (ORCPT ); Thu, 26 Mar 2020 08:19:32 -0400 Received: by mail-lf1-f68.google.com with SMTP id z23so4619570lfh.8 for ; Thu, 26 Mar 2020 05:19:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cumulusnetworks.com; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=2Oxl8RbYwTpZ/gOLvMl9BnnFknBpsGUWXiaJDhErJBs=; b=ep4Y1Q/HLOHUIKHZ+X4l9DkCjY6OFyacVWkJZTFl39zyEVhGIApId4N86v9NoFsm0Y 371ctDWvhhC/Vs73GH4xIEQKuZg+uAnSKnbu2xY81lp8cmjqfNJmKoDSRTTrQy3wlE18 v+tEh5kXOrEfVHHzv6U7xe81CpeHzaqcEBlf0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=2Oxl8RbYwTpZ/gOLvMl9BnnFknBpsGUWXiaJDhErJBs=; b=PuafjpAvMqr4K+HrpoLFoo7LFjjtWepSXkkc7lHsU923URcex35qKWwzpKeZFUhCEy ZrGiBtWf02scDJD2Xt9vze7MV4zsaIaEyF0mElS/k92Yw4wT68wr8n82YhGummfwaKP3 gcxr7mxarhDpa75EQ4qeRfw0nQg1WsQbTOd2ggLUivR5OQm19hEY7SjVOp6Z93ec3QbD /jX1sbg5svElsZe0kvF82uwjCi5ED+GVE4Kt82Njodu/N7LsWtGYViZ0+ZpPFgykuOfo d9KNEvBWyryD/linHMIoYJ9PtFRxvALVsT79PaqES/uHFVOthdLqoAuL1UBtBeoKhDEP zaaw== X-Gm-Message-State: ANhLgQ1dIu+HloAY0PA4S3RlKY8f9t9lCbLgHyhUVRJ0fuxSlglYOxZG qEpXreJPiigrdrEyIRNQv+nFbt/6P40= X-Google-Smtp-Source: ADFU+vsZUov0dXtahGFXeM+oV5XeJyMkV3TB19LszIYDKb949GzB92zwm6kle9LKMKFECy1r0HgcHg== X-Received: by 2002:ac2:51bc:: with SMTP id f28mr5506252lfk.112.1585225168669; Thu, 26 Mar 2020 05:19:28 -0700 (PDT) Received: from [192.168.0.109] (84-238-136-197.ip.btc-net.bg. [84.238.136.197]) by smtp.gmail.com with ESMTPSA id k19sm1344903lfm.47.2020.03.26.05.19.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Mar 2020 05:19:28 -0700 (PDT) Subject: Re: [PATCH v2 net-next 10/10] net: bridge: implement auto-normalization of MTU for hardware datapath To: Vladimir Oltean Cc: Ido Schimmel , Andrew Lunn , Florian Fainelli , Vivien Didelot , "David S. Miller" , Jakub Kicinski , murali.policharla@broadcom.com, Stephen Hemminger , Jiri Pirko , Jakub Kicinski , netdev References: <20200325152209.3428-1-olteanv@gmail.com> <20200325152209.3428-11-olteanv@gmail.com> <20200326101752.GA1362955@splinter> <20200326113542.GA1383155@splinter> <83375385-7881-53b7-c685-e166c8bdeba4@cumulusnetworks.com> From: Nikolay Aleksandrov Message-ID: <25bc3bf2-0dea-5667-8aae-c57a2a693bec@cumulusnetworks.com> Date: Thu, 26 Mar 2020 14:19:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 26/03/2020 14:18, Vladimir Oltean wrote: > On Thu, 26 Mar 2020 at 14:06, Nikolay Aleksandrov > wrote: >> >> On 26/03/2020 13:35, Ido Schimmel wrote: >>> On Thu, Mar 26, 2020 at 12:25:20PM +0200, Vladimir Oltean wrote: >>>> Hi Ido, >>>> >>>> On Thu, 26 Mar 2020 at 12:17, Ido Schimmel wrote: >>>>> > [snip] >>> >>> I think you should be more explicit about it. Did you consider listening >>> to 'NETDEV_PRECHANGEMTU' notifications in relevant drivers and vetoing >>> unsupported configurations with an appropriate extack message? If you >>> can't veto (in order not to break user space), you can still emit an >>> extack message. >>> >> >> +1, this sounds more appropriate IMO >> > > And what does vetoing gain me exactly? The practical inability to > change the MTU of any interface that is already bridged and applies > length check on RX? > I was referring to moving the logic to NETDEV_PRECHANGEMTU, the rest is up to you.