From f2f67390a4b961dae83733732e96e1a394a53c4e Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Tue, 28 Apr 2015 18:33:50 +0200 Subject: tipc: remove wrong use of NLM_F_MULTI NLM_F_MULTI must be used only when a NLMSG_DONE message is sent. In fact, it is sent only at the end of a dump. Libraries like libnl will wait forever for NLMSG_DONE. Fixes: 35b9dd7607f0 ("tipc: add bearer get/dump to new netlink api") Fixes: 7be57fc69184 ("tipc: add link get/dump to new netlink api") Fixes: 46f15c6794fb ("tipc: add media get/dump to new netlink api") CC: Richard Alpe CC: Jon Maloy CC: Ying Xue CC: tipc-discussion@lists.sourceforge.net Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/tipc/link.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net/tipc/link.c') diff --git a/net/tipc/link.c b/net/tipc/link.c index 57be6e6aff99..a11cc5e5e0ae 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -2013,7 +2013,7 @@ msg_full: /* Caller should hold appropriate locks to protect the link */ static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg, - struct tipc_link *link) + struct tipc_link *link, int nlflags) { int err; void *hdr; @@ -2022,7 +2022,7 @@ static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg, struct tipc_net *tn = net_generic(net, tipc_net_id); hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, - NLM_F_MULTI, TIPC_NL_LINK_GET); + nlflags, TIPC_NL_LINK_GET); if (!hdr) return -EMSGSIZE; @@ -2095,7 +2095,7 @@ static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg, if (!node->links[i]) continue; - err = __tipc_nl_add_link(net, msg, node->links[i]); + err = __tipc_nl_add_link(net, msg, node->links[i], NLM_F_MULTI); if (err) return err; } @@ -2209,7 +2209,7 @@ int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info) goto err_out; } - err = __tipc_nl_add_link(net, &msg, link); + err = __tipc_nl_add_link(net, &msg, link, 0); if (err) goto err_out; -- cgit v1.2.3 From 0d699f28ee5d0641470a603ab5904e463cb1532a Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Tue, 28 Apr 2015 16:59:04 -0400 Subject: tipc: fix problem with parallel link synchronization mechanism Currently, we try to accumulate arrived packets in the links's 'deferred' queue during the parallel link syncronization phase. This entails two problems: - With an unlucky combination of arriving packets the algorithm may go into a lockstep with the out-of-sequence handling function, where the synch mechanism is adding a packet to the deferred queue, while the out-of-sequence handling is retrieving it again, thus ending up in a loop inside the node_lock scope. - Even if this is avoided, the link will very often send out unnecessary protocol messages, in the worst case leading to redundant retransmissions. We fix this by just dropping arriving packets on the upcoming link during the synchronization phase, thus relying on the retransmission protocol to resolve the situation once the two links have arrived to a synchronized state. Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'net/tipc/link.c') diff --git a/net/tipc/link.c b/net/tipc/link.c index a11cc5e5e0ae..43a515dc97b0 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1145,11 +1145,8 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) } /* Synchronize with parallel link if applicable */ if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) { - link_handle_out_of_seq_msg(l_ptr, skb); - if (link_synch(l_ptr)) - link_retrieve_defq(l_ptr, &head); - skb = NULL; - goto unlock; + if (!link_synch(l_ptr)) + goto unlock; } l_ptr->next_in_no++; if (unlikely(!skb_queue_empty(&l_ptr->deferdq))) -- cgit v1.2.3