From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Soltys Subject: Re: [PATCH next] bonding: pass link-local packets to bonding master also. Date: Tue, 17 Jul 2018 11:55:02 +0200 Message-ID: References: <20180716011246.225647-1-mahesh@bandewar.net> <20180716163353.2fe5659c@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: Mahesh Bandewar , Jay Vosburgh , Andy Gospodarek , Veaceslav Falico , David Miller , Netdev To: =?UTF-8?B?TWFoZXNoIEJhbmRld2FyICjgpK7gpLngpYfgpLYg4KSs4KSC4KSh4KWH4KS1?= =?UTF-8?B?4KS+4KSwKQ==?= , Stephen Hemminger Return-path: Received: from drutsystem.com ([84.10.39.251]:39179 "EHLO drutsystem.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729060AbeGQK07 (ORCPT ); Tue, 17 Jul 2018 06:26:59 -0400 In-Reply-To: Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 07/17/2018 01:57 AM, Mahesh Bandewar (महेश बंडेवार) wrote: > On Mon, Jul 16, 2018 at 4:33 PM, Stephen Hemminger > wrote: >> On Sun, 15 Jul 2018 18:12:46 -0700 >> Mahesh Bandewar wrote: >> >>> From: Mahesh Bandewar >>> >>> Commit b89f04c61efe ("bonding: deliver link-local packets with >>> skb->dev set to link that packets arrived on") changed the behavior >>> of how link-local-multicast packets are processed. The change in >>> the behavior broke some legacy use cases where these packets are >>> expected to arrive on bonding master device also. >>> >>> This patch passes the packet to the stack with the link it arrived >>> on as well as passes to the bonding-master device to preserve the >>> legacy use case. >>> >>> Reported-by: Michal Soltys >>> Signed-off-by: Mahesh Bandewar >> >> Thanks for fixing this. >> >> Why not add a Fixes: tag instead of just talking about the commit? >> That helps the stable maintainers know which versions of the kernel >> need the patch. > Well, I thought about it. It's definitely 'related' but not sure it > 'fixes' in true sense. It definitely fixes the broken legacy case > though. Is that sufficient to add 'fixes' tag? > It's __not__ broken legacy case. It's normal behavior, starting with specification covering LLDP itself (IEEE Std 802.1AB-2016, page 18, '6.8 LLDP and Link Aggregation') and ending with a linux bridge actively doing stp via in-kernel implementation or with userspace helper (or inactively passing) and being blind to bpdus. Not mentioning a very recent kernel feature like per-port group_fwd_mask rendered useless in this case. Unless you also consider attaching a bond to a linux bridge as a broken legacy use case. Among other things mentioned in the other thread. In this context, the comment in code/log message IMHO (of the attached patch), should be changed - as it will be just confusing for anyone reading it in the future. (and I'd very much like the fix to hit relevant stable kernels as well)