inet: remove some sk_listener dependencies

listener can be source of false sharing. request sock has some
useful information like : ireq->ir_iif, ireq->ir_num, ireq->ireq_net

This patch does not solve the major problem of having to read
sk->sk_protocol which is sharing a cache line with sk->sk_wmem_alloc.
(This same field is read later in ip_build_and_send_pkt())

One idea would be to move sk_protocol close to sk_family
(using 8 bits instead of 16 for sk_family seems enough)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index a12b973164d038e8036ba488e700c15278338993..711ab143d4cb1cb5b26b30d71e209b4c832c9aad 100644 (file)
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -403,18 +403,17 @@ struct dst_entry *inet_csk_route_req(struct sock *sk,
                                     struct flowi4 *fl4,
                                     const struct request_sock *req)
 {
-       struct rtable *rt;
        const struct inet_request_sock *ireq = inet_rsk(req);
-       struct ip_options_rcu *opt = inet_rsk(req)->opt;
-       struct net *net = sock_net(sk);
-       int flags = inet_sk_flowi_flags(sk);
+       struct net *net = read_pnet(&ireq->ireq_net);
+       struct ip_options_rcu *opt = ireq->opt;
+       struct rtable *rt;
 
-       flowi4_init_output(fl4, sk->sk_bound_dev_if, ireq->ir_mark,
+       flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
                           RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
-                          sk->sk_protocol,
-                          flags,
+                          sk->sk_protocol, inet_sk_flowi_flags(sk),
                           (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
-                          ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
+                          ireq->ir_loc_addr, ireq->ir_rmt_port,
+                          htons(ireq->ir_num));
        security_req_classify_flow(req, flowi4_to_flowi(fl4));
        rt = ip_route_output_flow(net, fl4, sk);
        if (IS_ERR(rt))
@@ -436,9 +435,9 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
                                            const struct request_sock *req)
 {
        const struct inet_request_sock *ireq = inet_rsk(req);
+       struct net *net = read_pnet(&ireq->ireq_net);
        struct inet_sock *newinet = inet_sk(newsk);
        struct ip_options_rcu *opt;
-       struct net *net = sock_net(sk);
        struct flowi4 *fl4;
        struct rtable *rt;
 
@@ -446,11 +445,12 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
 
        rcu_read_lock();
        opt = rcu_dereference(newinet->inet_opt);
-       flowi4_init_output(fl4, sk->sk_bound_dev_if, inet_rsk(req)->ir_mark,
+       flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
                           RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
                           sk->sk_protocol, inet_sk_flowi_flags(sk),
                           (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
-                          ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
+                          ireq->ir_loc_addr, ireq->ir_rmt_port,
+                          htons(ireq->ir_num));
        security_req_classify_flow(req, flowi4_to_flowi(fl4));
        rt = ip_route_output_flow(net, fl4, sk);
        if (IS_ERR(rt))