Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / net / bridge / br_vlan_tunnel.c

diff --git a/net/bridge/br_vlan_tunnel.c b/net/bridge/br_vlan_tunnel.c
index 0d3a8c0..0101744 100644 (file)
--- a/net/bridge/br_vlan_tunnel.c
+++ b/net/bridge/br_vlan_tunnel.c
@@ -41,26 +41,33 @@ static struct net_bridge_vlan *br_vlan_tunnel_lookup(struct rhashtable *tbl,
                                      br_vlan_tunnel_rht_params);
 }
 
+static void vlan_tunnel_info_release(struct net_bridge_vlan *vlan)
+{
+       struct metadata_dst *tdst = rtnl_dereference(vlan->tinfo.tunnel_dst);
+
+       WRITE_ONCE(vlan->tinfo.tunnel_id, 0);
+       RCU_INIT_POINTER(vlan->tinfo.tunnel_dst, NULL);
+       dst_release(&tdst->dst);
+}
+
 void vlan_tunnel_info_del(struct net_bridge_vlan_group *vg,
                          struct net_bridge_vlan *vlan)
 {
-       if (!vlan->tinfo.tunnel_dst)
+       if (!rcu_access_pointer(vlan->tinfo.tunnel_dst))
                return;
        rhashtable_remove_fast(&vg->tunnel_hash, &vlan->tnode,
                               br_vlan_tunnel_rht_params);
-       vlan->tinfo.tunnel_id = 0;
-       dst_release(&vlan->tinfo.tunnel_dst->dst);
-       vlan->tinfo.tunnel_dst = NULL;
+       vlan_tunnel_info_release(vlan);
 }
 
 static int __vlan_tunnel_info_add(struct net_bridge_vlan_group *vg,
                                  struct net_bridge_vlan *vlan, u32 tun_id)
 {
-       struct metadata_dst *metadata = NULL;
+       struct metadata_dst *metadata = rtnl_dereference(vlan->tinfo.tunnel_dst);
        __be64 key = key32_to_tunnel_id(cpu_to_be32(tun_id));
        int err;
 
-       if (vlan->tinfo.tunnel_dst)
+       if (metadata)
                return -EEXIST;
 
        metadata = __ip_tun_set_dst(0, 0, 0, 0, 0, TUNNEL_KEY,
@@ -69,8 +76,8 @@ static int __vlan_tunnel_info_add(struct net_bridge_vlan_group *vg,
                return -EINVAL;
 
        metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_BRIDGE;
-       vlan->tinfo.tunnel_dst = metadata;
-       vlan->tinfo.tunnel_id = key;
+       rcu_assign_pointer(vlan->tinfo.tunnel_dst, metadata);
+       WRITE_ONCE(vlan->tinfo.tunnel_id, key);
 
        err = rhashtable_lookup_insert_fast(&vg->tunnel_hash, &vlan->tnode,
                                            br_vlan_tunnel_rht_params);
@@ -79,9 +86,7 @@ static int __vlan_tunnel_info_add(struct net_bridge_vlan_group *vg,
 
        return 0;
 out:
-       dst_release(&vlan->tinfo.tunnel_dst->dst);
-       vlan->tinfo.tunnel_dst = NULL;
-       vlan->tinfo.tunnel_id = 0;
+       vlan_tunnel_info_release(vlan);
 
        return err;
 }
@@ -182,12 +187,15 @@ int br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
                                 struct net_bridge_vlan *vlan)
 {
+       struct metadata_dst *tunnel_dst;
+       __be64 tunnel_id;
        int err;
 
-       if (!vlan || !vlan->tinfo.tunnel_id)
+       if (!vlan)
                return 0;
 
-       if (unlikely(!skb_vlan_tag_present(skb)))
+       tunnel_id = READ_ONCE(vlan->tinfo.tunnel_id);
+       if (!tunnel_id || unlikely(!skb_vlan_tag_present(skb)))
                return 0;
 
        skb_dst_drop(skb);
@@ -195,7 +203,9 @@ int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
        if (err)
                return err;
 
-       skb_dst_set(skb, dst_clone(&vlan->tinfo.tunnel_dst->dst));
+       tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
+       if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
+               skb_dst_set(skb, &tunnel_dst->dst);
 
        return 0;
 }