From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [net 1/1] tipc: remove joining group member from congested list
Date: Wed, 20 Dec 2017 14:57:11 -0500 (EST)
Message-ID: <20171220.145711.1010973633205606282.davem@davemloft.net>
References: <1513764195-7731-1-git-send-email-jon.maloy@ericsson.com>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: netdev@vger.kernel.org,
        mohan.krishna.ghanta.krishnamurthy@ericsson.com,
        tung.q.nguyen@dektech.com.au, hoang.h.le@dektech.com.au,
        canh.d.luu@dektech.com.au, ying.xue@windriver.com,
        tipc-discussion@lists.sourceforge.net
To: jon.maloy@ericsson.com
Return-path: <netdev-owner@vger.kernel.org>
Received: from shards.monkeyblade.net ([184.105.139.130]:43254 "EHLO
        shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S932398AbdLTT5N (ORCPT
        <rfc822;netdev@vger.kernel.org>); Wed, 20 Dec 2017 14:57:13 -0500
In-Reply-To: <1513764195-7731-1-git-send-email-jon.maloy@ericsson.com>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

From: Jon Maloy <jon.maloy@ericsson.com>
Date: Wed, 20 Dec 2017 11:03:15 +0100

> When we receive a JOIN message from a peer member, the message may
> contain an advertised window value ADV_IDLE that permits removing the
> member in question from the tipc_group::congested list. However, since
> the removal has been made conditional on that the advertised window is
> *not* ADV_IDLE, we miss this case. This has the effect that a sender
> sometimes may enter a state of permanent, false, broadcast congestion.
> 
> We fix this by unconditinally removing the member from the congested
> list before calling tipc_member_update(), which might potentially sort
> it into the list again.
> 
> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>

I bet this bug wasn't fun to track down.

Applied, thanks Jon.