Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935049AbcJZVUR (ORCPT ); Wed, 26 Oct 2016 17:20:17 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:42136 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932716AbcJZVUQ (ORCPT ); Wed, 26 Oct 2016 17:20:16 -0400 Date: Wed, 26 Oct 2016 17:20:14 -0400 (EDT) Message-Id: <20161026.172014.1445485460255687424.davem@davemloft.net> To: sven@narfation.org Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, linux-kernel@vger.kernel.org, jarod@redhat.com Subject: Re: [PATCH] batman-adv: Revert "use core MTU range checking in misc drivers" From: David Miller In-Reply-To: <20161022074624.30033-1-sven@narfation.org> References: <20161022074624.30033-1-sven@narfation.org> X-Mailer: Mew version 6.7 on Emacs 25.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 26 Oct 2016 14:20:15 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 822 Lines: 18 From: Sven Eckelmann Date: Sat, 22 Oct 2016 09:46:24 +0200 > The maximum MTU is defined via the slave devices of an batman-adv > interface. Thus it is not possible to calculate the max_mtu during the > creation of the batman-adv device when no slave devices are attached. Doing > so would for example break non-fragmentation setups which then > (incorrectly) allow an MTU of 1500 even when underlying device cannot > transport 1500 bytes + batman-adv headers. > > Checking the dynamically calculated max_mtu via the minimum of the slave > devices MTU during .ndo_change_mtu is also used by the bridge interface. > > Cc: Jarod Wilson > Fixes: b3e3893e1253 ("net: use core MTU range checking in misc drivers") > Signed-off-by: Sven Eckelmann Applied, thanks.