net: bridge: mcast: destroy all entries via gc

Since each entry type has timers that can be running simultaneously we need
to make sure that entries are not freed before their timers have finished.
In order to do that generalize the src gc work to mcast gc work and use a
callback to free the entries (mdb, port group or src).

v3: add IPv6 support
v2: force mcast gc on port del to make sure all port group timers have
    finished before freeing the bridge port

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index fb35a73fc559..a23d2bae56e1 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -219,6 +219,11 @@ struct net_bridge_fdb_entry {
 #define BR_SGRP_F_DELETE	BIT(0)
 #define BR_SGRP_F_SEND		BIT(1)
 
+struct net_bridge_mcast_gc {
+	struct hlist_node		gc_node;
+	void				(*destroy)(struct net_bridge_mcast_gc *gc);
+};
+
 struct net_bridge_group_src {
 	struct hlist_node		node;
 
@@ -229,7 +234,7 @@ struct net_bridge_group_src {
 	struct timer_list		timer;
 
 	struct net_bridge		*br;
-	struct hlist_node		del_node;
+	struct net_bridge_mcast_gc	mcast_gc;
 	struct rcu_head			rcu;
 };
 
@@ -248,6 +253,7 @@ struct net_bridge_port_group {
 	struct timer_list		rexmit_timer;
 	struct hlist_node		mglist;
 
+	struct net_bridge_mcast_gc	mcast_gc;
 	struct rcu_head			rcu;
 };
 
@@ -261,6 +267,7 @@ struct net_bridge_mdb_entry {
 	struct timer_list		timer;
 	struct hlist_node		mdb_node;
 
+	struct net_bridge_mcast_gc	mcast_gc;
 	struct rcu_head			rcu;
 };
 
@@ -434,7 +441,7 @@ struct net_bridge {
 
 	struct rhashtable		mdb_hash_tbl;
 
-	struct hlist_head		src_gc_list;
+	struct hlist_head		mcast_gc_list;
 	struct hlist_head		mdb_list;
 	struct hlist_head		router_list;
 
@@ -448,7 +455,7 @@ struct net_bridge {
 	struct bridge_mcast_own_query	ip6_own_query;
 	struct bridge_mcast_querier	ip6_querier;
 #endif /* IS_ENABLED(CONFIG_IPV6) */
-	struct work_struct		src_gc_work;
+	struct work_struct		mcast_gc_work;
 #endif
 
 	struct timer_list		hello_timer;