tipc: purge backlog queue counters when broadcast link is reset (7d967b67) · Commits · 戴 / test

In commit ("tipc: introduce starvation free send algorithm") we introduced a counter per priority level for buffers in the link backlog queue. We also introduced a new function tipc_link_purge_backlog(), to reset these counters to zero when the link is reset. Unfortunately, we missed to call this function when the broadcast link is reset, with the result that the values of these counters might be permanently skewed when new nodes are attached. This may in the worst case lead to permananent, but spurious, broadcast link congestion, where no broadcast packets can be sent at all. We fix this bug with this commit. Signed-off-by:

Jon Maloy <jon.maloy@ericsson.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/tipc/bcast.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -108,6 +108,11 @@ void tipc_bclink_remove_node(struct net *net, u32 addr)

		tipc_bclink_lock(net);
		tipc_nmap_remove(&tn->bclink->bcast_nodes, addr);

		/* Last node? => reset backlog queue */
		if (!tn->bclink->bcast_nodes.count)
		tipc_link_purge_backlog(&tn->bclink->link);

		tipc_bclink_unlock(net);
		}

net/tipc/link.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -404,7 +404,7 @@ void tipc_link_reset_fragments(struct tipc_link *l_ptr)
		l_ptr->reasm_buf = NULL;
		}

		static void tipc_link_purge_backlog(struct tipc_link *l)
		void tipc_link_purge_backlog(struct tipc_link *l)
		{
		__skb_queue_purge(&l->backlogq);
		l->backlog[TIPC_LOW_IMPORTANCE].len = 0;

net/tipc/link.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -218,6 +218,7 @@ void tipc_link_reset_fragments(struct tipc_link *l_ptr);
		int tipc_link_is_up(struct tipc_link *l_ptr);
		int tipc_link_is_active(struct tipc_link *l_ptr);
		void tipc_link_purge_queues(struct tipc_link *l_ptr);
		void tipc_link_purge_backlog(struct tipc_link *l);
		void tipc_link_reset_all(struct tipc_node *node);
		void tipc_link_reset(struct tipc_link *l_ptr);
		int tipc_link_xmit_skb(struct net net, struct sk_buff skb, u32 dest,

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