datapath: Add ref counting for flows.

[sliver-openvswitch.git] / datapath / flow.c

diff --git a/datapath/flow.c b/datapath/flow.c
index 1f01166..dfbf769 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -132,36 +132,27 @@ struct sw_flow *flow_alloc(void)
                return ERR_PTR(-ENOMEM);
 
        spin_lock_init(&flow->lock);
+       atomic_set(&flow->refcnt, 1);
+       flow->dead = false;
 
        return flow;
 }
 
-void flow_free(struct sw_flow *flow)
-{
-       if (unlikely(!flow))
-               return;
-
-       kmem_cache_free(flow_cache, flow);
-}
-
-/* Frees the entire 'flow' (both base and actions) immediately. */
-static void flow_free_full(struct sw_flow *flow)
-{
-       kfree(flow->sf_acts);
-       flow_free(flow);
-}
-
 void flow_free_tbl(struct tbl_node *node)
 {
        struct sw_flow *flow = flow_cast(node);
-       flow_free_full(flow);
+
+       flow->dead = true;
+       flow_put(flow);
 }
 
 /* RCU callback used by flow_deferred_free. */
 static void rcu_free_flow_callback(struct rcu_head *rcu)
 {
        struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
-       flow_free_full(flow);
+
+       flow->dead = true;
+       flow_put(flow);
 }
 
 /* Schedules 'flow' to be freed after the next RCU grace period.
@@ -171,6 +162,22 @@ void flow_deferred_free(struct sw_flow *flow)
        call_rcu(&flow->rcu, rcu_free_flow_callback);
 }
 
+void flow_hold(struct sw_flow *flow)
+{
+       atomic_inc(&flow->refcnt);
+}
+
+void flow_put(struct sw_flow *flow)
+{
+       if (unlikely(!flow))
+               return;
+
+       if (atomic_dec_and_test(&flow->refcnt)) {
+               kfree(flow->sf_acts);
+               kmem_cache_free(flow_cache, flow);
+       }
+}
+
 /* RCU callback used by flow_deferred_free_acts. */
 static void rcu_free_acts_callback(struct rcu_head *rcu)
 {