4 files changed, 62 insertions, 47 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index d15c40c7bde7..505d4b71975f 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -26,6 +26,8 @@ enum tcf_block_binder_type {
 
 struct tcf_block_ext_info {
         enum tcf_block_binder_type binder_type;
+        tcf_chain_head_change_t *chain_head_change;
+        void *chain_head_change_priv;
 };
 
 struct tcf_block_cb;
@@ -37,12 +39,10 @@ struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 void tcf_chain_put(struct tcf_chain *chain);
 int tcf_block_get(struct tcf_block **p_block,
                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q);
-int tcf_block_get_ext(struct tcf_block **p_block,
-                      struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                       struct tcf_block_ext_info *ei);
 void tcf_block_put(struct tcf_block *block);
-void tcf_block_put_ext(struct tcf_block *block,
-                       struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
                        struct tcf_block_ext_info *ei);
 
 static inline struct Qdisc *tcf_block_q(struct tcf_block *block)
@@ -82,8 +82,7 @@ int tcf_block_get(struct tcf_block **p_block,
 }
 
 static inline
-int tcf_block_get_ext(struct tcf_block **p_block,
-                      struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                       struct tcf_block_ext_info *ei)
 {
         return 0;
@@ -94,8 +93,7 @@ static inline void tcf_block_put(struct tcf_block *block)
 }
 
 static inline
-void tcf_block_put_ext(struct tcf_block *block,
-                       struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
                        struct tcf_block_ext_info *ei)
 {
 }
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c23e938f5b19..f230269e0bfb 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -260,9 +260,12 @@ struct qdisc_skb_cb {
         unsigned char           data[QDISC_CB_PRIV_LEN];
 };
 
+typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
+
 struct tcf_chain {
         struct tcf_proto __rcu *filter_chain;
-        struct tcf_proto __rcu **p_filter_chain;
+        tcf_chain_head_change_t *chain_head_change;
+        void *chain_head_change_priv;
         struct list_head list;
         struct tcf_block *block;
         u32 index; /* chain index */
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 8d1885abee83..206e19f4fc01 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -195,12 +195,19 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
         return chain;
 }
 
+static void tcf_chain_head_change(struct tcf_chain *chain,
+                                  struct tcf_proto *tp_head)
+{
+        if (chain->chain_head_change)
+                chain->chain_head_change(tp_head,
+                                         chain->chain_head_change_priv);
+}
+
 static void tcf_chain_flush(struct tcf_chain *chain)
 {
         struct tcf_proto *tp;
 
-        if (chain->p_filter_chain)
-                RCU_INIT_POINTER(*chain->p_filter_chain, NULL);
+        tcf_chain_head_change(chain, NULL);
         while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) {
                 RCU_INIT_POINTER(chain->filter_chain, tp->next);
                 tcf_chain_put(chain);
@@ -242,13 +249,6 @@ void tcf_chain_put(struct tcf_chain *chain)
 }
 EXPORT_SYMBOL(tcf_chain_put);
 
-static void
-tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain,
-                               struct tcf_proto __rcu **p_filter_chain)
-{
-        chain->p_filter_chain = p_filter_chain;
-}
-
 static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q,
                                   struct tcf_block_ext_info *ei,
                                   enum tc_block_command command)
@@ -276,8 +276,7 @@ static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND);
 }
 
-int tcf_block_get_ext(struct tcf_block **p_block,
-                      struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                       struct tcf_block_ext_info *ei)
 {
         struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
@@ -295,7 +294,9 @@ int tcf_block_get_ext(struct tcf_block **p_block,
                 err = -ENOMEM;
                 goto err_chain_create;
         }
-        tcf_chain_filter_chain_ptr_set(chain, p_filter_chain);
+        WARN_ON(!ei->chain_head_change);
+        chain->chain_head_change = ei->chain_head_change;
+        chain->chain_head_change_priv = ei->chain_head_change_priv;
         block->net = qdisc_net(q);
         block->q = q;
         tcf_block_offload_bind(block, q, ei);
@@ -308,12 +309,23 @@ err_chain_create:
 }
 EXPORT_SYMBOL(tcf_block_get_ext);
 
+static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
+{
+        struct tcf_proto __rcu **p_filter_chain = priv;
+
+        rcu_assign_pointer(*p_filter_chain, tp_head);
+}
+
 int tcf_block_get(struct tcf_block **p_block,
                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q)
 {
-        struct tcf_block_ext_info ei = {0, };
+        struct tcf_block_ext_info ei = {
+                .chain_head_change = tcf_chain_head_change_dflt,
+                .chain_head_change_priv = p_filter_chain,
+        };
 
-        return tcf_block_get_ext(p_block, p_filter_chain, q, &ei);
+        WARN_ON(!p_filter_chain);
+        return tcf_block_get_ext(p_block, q, &ei);
 }
 EXPORT_SYMBOL(tcf_block_get);
 
@@ -334,8 +346,7 @@ static void tcf_block_put_final(struct work_struct *work)
  * actions should be all removed after flushing. However, filters are now
  * destroyed in tc filter workqueue with RTNL lock, they can not race here.
  */
-void tcf_block_put_ext(struct tcf_block *block,
-                       struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
+void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
                        struct tcf_block_ext_info *ei)
 {
         struct tcf_chain *chain, *tmp;
@@ -361,7 +372,7 @@ void tcf_block_put(struct tcf_block *block)
 
         if (!block)
                 return;
-        tcf_block_put_ext(block, NULL, block->q, &ei);
+        tcf_block_put_ext(block, block->q, &ei);
 }
 
 EXPORT_SYMBOL(tcf_block_put);
@@ -537,9 +548,8 @@ static void tcf_chain_tp_insert(struct tcf_chain *chain,
                                 struct tcf_chain_info *chain_info,
                                 struct tcf_proto *tp)
 {
-        if (chain->p_filter_chain &&
-            *chain_info->pprev == chain->filter_chain)
-                rcu_assign_pointer(*chain->p_filter_chain, tp);
+        if (*chain_info->pprev == chain->filter_chain)
+                tcf_chain_head_change(chain, tp);
         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
         rcu_assign_pointer(*chain_info->pprev, tp);
         tcf_chain_hold(chain);
@@ -551,8 +561,8 @@ static void tcf_chain_tp_remove(struct tcf_chain *chain,