From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Gortmaker Subject: [PATCH net-next 03/15] tipc: Prevent broadcast link stalling in dual LAN environments Date: Mon, 6 Feb 2012 19:52:36 -0500 Message-ID: <1328575968-20643-4-git-send-email-paul.gortmaker@windriver.com> References: <1328575968-20643-1-git-send-email-paul.gortmaker@windriver.com> Cc: netdev@vger.kernel.org, allan.stephens@windriver.com, ying.xue@windriver.com, Paul Gortmaker To: davem@davemloft.net Return-path: Received: from mail.windriver.com ([147.11.1.11]:50170 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754529Ab2BGAxK (ORCPT ); Mon, 6 Feb 2012 19:53:10 -0500 In-Reply-To: <1328575968-20643-1-git-send-email-paul.gortmaker@windriver.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Allan Stephens Ensure that sequence number information about incoming broadcast link messages is initialized only by the activation of the first link to a given cluster node. Previously, a race condition allowed reset and/or activation messages for a second link to re-initialize this sequence number information with obsolete values. This could trigger TIPC to request the retransmission of previously acknowledged broadcast link messages from that node, resulting in broadcast link processing becoming stalled if the node had already released one or more of those messages and was unable to perform the required retransmission. Thanks to Laser for identifying this problem and assisting in the development of this fix. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/link.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index bee316c..4ea6cad 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -2128,14 +2128,15 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf) } l_ptr->owner->bclink.supported = (max_pkt_info != 0); + /* Synchronize broadcast link info, if not done previously */ + + if (!tipc_node_is_up(l_ptr->owner)) + l_ptr->owner->bclink.last_in = msg_last_bcast(msg); + link_state_event(l_ptr, msg_type(msg)); l_ptr->peer_session = msg_session(msg); l_ptr->peer_bearer_id = msg_bearer_id(msg); - - /* Synchronize broadcast sequence numbers */ - if (!tipc_node_redundant_links(l_ptr->owner)) - l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg)); break; case STATE_MSG: -- 1.7.9