datapath: remove RCU annotation from flow->mask

After a mask is assigned to a flow, it will not change for the life of
the flow. Since flow access is protected by RCU lock, access to
flow->mask after getting a flow is always safe.

Suggested-by: Jesse Gross <jesse@nicira.com>
Reported-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 9a3a07b..4330ce3 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -1127,7 +1127,6 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
                                  u32 seq, u32 flags, u8 cmd)
 {
        const int skb_orig_len = skb->len;
-       struct sw_flow_mask *mask;
        struct nlattr *start;
        struct ovs_flow_stats stats;
        struct ovs_header *ovs_header;
@@ -1157,8 +1156,7 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
        if (!nla)
                goto nla_put_failure;
 
-       mask = rcu_dereference_check(flow->mask, lockdep_ovsl_is_held());
-       err = ovs_flow_to_nlattrs(&flow->key, &mask->key, skb);
+       err = ovs_flow_to_nlattrs(&flow->key, &flow->mask->key, skb);
        if (err)
                goto error;
 
@@ -1344,7 +1342,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
                }
 
                ovs_sw_flow_mask_add_ref(mask_p);
-               rcu_assign_pointer(flow->mask, mask_p);
+               flow->mask = mask_p;
                rcu_assign_pointer(flow->sf_acts, acts);
 
                /* Put flow in bucket. */

diff --git a/datapath/flow.c b/datapath/flow.c
index 95fea7f..c6a90b9 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -638,8 +638,7 @@ void ovs_flow_free(struct sw_flow *flow, bool deferred)
        if (!flow)
                return;
 
-       ovs_sw_flow_mask_del_ref((struct sw_flow_mask __force *)flow->mask,
-                                deferred);
+       ovs_sw_flow_mask_del_ref(flow->mask, deferred);
 
        if (deferred)
                call_rcu(&flow->rcu, rcu_free_flow_callback);
@@ -1073,9 +1072,8 @@ struct sw_flow *ovs_flow_lookup(struct flow_table *tbl,
 
 void ovs_flow_insert(struct flow_table *table, struct sw_flow *flow)
 {
-       flow->hash = ovs_flow_hash(&flow->key,
-                       ovsl_dereference(flow->mask)->range.start,
-                       ovsl_dereference(flow->mask)->range.end);
+       flow->hash = ovs_flow_hash(&flow->key, flow->mask->range.start,
+                       flow->mask->range.end);
        __tbl_insert(table, flow);
 }
 

diff --git a/datapath/flow.h b/datapath/flow.h
index 1a3764e..59c7f6e 100644 (file)
--- a/datapath/flow.h
+++ b/datapath/flow.h
@@ -120,7 +120,7 @@ struct sw_flow {
 
        struct sw_flow_key key;
        struct sw_flow_key unmasked_key;
-       struct sw_flow_mask __rcu *mask;
+       struct sw_flow_mask *mask;
        struct sw_flow_actions __rcu *sf_acts;
 
        spinlock_t lock;        /* Lock for values below. */