tipc udp_bearer does not need to access struct socket itself in the fast path; it only reads struct sock, and struct socket is only used for tunnel setup and teardown. Let's store struct sock directly in struct udp_bearer. Note that cleanup_bearer() calls synchronize_net() after udp_tunnel_sock_release(), so udp_bearer is not freed until inflight fast paths finish. Note also that synchronize_rcu() is added in the error path of tipc_udp_enable() since udp_bearer will be kfree()d immediately once we remove synchronize_rcu() in udp_tunnel_sock_release(). This can be later converted to kfree_rcu(). Signed-off-by: Kuniyuki Iwashima --- Cc: Jon Maloy --- net/tipc/udp_media.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index 0db172f1a41a..988b8a7f953a 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -89,14 +89,14 @@ struct udp_replicast { /** * struct udp_bearer - ip/udp bearer data structure * @bearer: associated generic tipc bearer - * @ubsock: bearer associated socket + * @sk: bearer associated socket * @ifindex: local address scope * @work: used to schedule deferred work on a bearer * @rcast: associated udp_replicast container */ struct udp_bearer { struct tipc_bearer __rcu *bearer; - struct socket *ubsock; + struct sock *sk; u32 ifindex; struct work_struct work; struct udp_replicast rcast; @@ -194,7 +194,7 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, } ttl = ip4_dst_hoplimit(&rt->dst); - udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr, + udp_tunnel_xmit_skb(rt, ub->sk, skb, src->ipv4.s_addr, dst->ipv4.s_addr, 0, ttl, 0, src->port, dst->port, false, true, 0); #if IS_ENABLED(CONFIG_IPV6) @@ -206,7 +206,7 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, .saddr = src->ipv6, .flowi6_proto = IPPROTO_UDP }; - ndst = ip6_dst_lookup_flow(net, ub->ubsock->sk, + ndst = ip6_dst_lookup_flow(net, ub->sk, &fl6, NULL); if (IS_ERR(ndst)) { err = PTR_ERR(ndst); @@ -215,7 +215,7 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, dst_cache_set_ip6(cache, ndst, &fl6.saddr); } ttl = ip6_dst_hoplimit(ndst); - udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL, + udp_tunnel6_xmit_skb(ndst, ub->sk, skb, NULL, &src->ipv6, &dst->ipv6, 0, ttl, 0, src->port, dst->port, false, 0); #endif @@ -405,9 +405,9 @@ static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb) static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote) { - int err = 0; + struct sock *sk = ub->sk; struct ip_mreqn mreqn; - struct sock *sk = ub->ubsock->sk; + int err = 0; if (ntohs(remote->proto) == ETH_P_IP) { mreqn.imr_multiaddr = remote->ipv4; @@ -670,6 +670,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; u8 node_id[NODE_ID_LEN] = {0,}; struct net_device *dev; + struct socket *sock; int rmcast = 0; ub = kzalloc_obj(*ub, GFP_ATOMIC); @@ -764,14 +765,16 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, goto err; } udp_conf.local_udp_port = local.port; - err = udp_sock_create(net, &udp_conf, &ub->ubsock); + err = udp_sock_create(net, &udp_conf, &sock); if (err) goto err; + + ub->sk = sock->sk; tuncfg.sk_user_data = ub; tuncfg.encap_type = 1; tuncfg.encap_rcv = tipc_udp_recv; tuncfg.encap_destroy = NULL; - setup_udp_tunnel_sock(net, ub->ubsock->sk, &tuncfg); + setup_udp_tunnel_sock(net, ub->sk, &tuncfg); err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC); if (err) @@ -793,7 +796,8 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, free: dst_cache_destroy(&ub->rcast.dst_cache); - udp_tunnel_sock_release(ub->ubsock->sk); + udp_tunnel_sock_release(ub->sk); + synchronize_rcu(); err: kfree(ub); return err; @@ -812,10 +816,10 @@ static void cleanup_bearer(struct work_struct *work) kfree_rcu(rcast, rcu); } - tn = tipc_net(sock_net(ub->ubsock->sk)); + tn = tipc_net(sock_net(ub->sk)); dst_cache_destroy(&ub->rcast.dst_cache); - udp_tunnel_sock_release(ub->ubsock->sk); + udp_tunnel_sock_release(ub->sk); /* Note: could use a call_rcu() to avoid another synchronize_net() */ synchronize_net(); @@ -833,11 +837,11 @@ static void tipc_udp_disable(struct tipc_bearer *b) pr_err("UDP bearer instance not found\n"); return; } - sock_set_flag(ub->ubsock->sk, SOCK_DEAD); + sock_set_flag(ub->sk, SOCK_DEAD); RCU_INIT_POINTER(ub->bearer, NULL); /* sock_release need to be done outside of rtnl lock */ - atomic_inc(&tipc_net(sock_net(ub->ubsock->sk))->wq_count); + atomic_inc(&tipc_net(sock_net(ub->sk))->wq_count); INIT_WORK(&ub->work, cleanup_bearer); schedule_work(&ub->work); } -- 2.54.0.545.g6539524ca2-goog