net: Make RFS socket operations not be inet specific.

Idea from Eric Dumazet.

As for placement inside of struct sock, I tried to choose a place
that otherwise has a 32-bit hole on 64-bit systems.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

include/net/inet_sock.h

@@ -102,7 +102,6 @@ struct rtable;
  * @uc_ttl - Unicast TTL
  * @inet_sport - Source port
  * @inet_id - ID counter for DF pkts
- * @rxhash - flow hash received from netif layer
  * @tos - TOS
  * @mc_ttl - Multicasting TTL
  * @is_icsk - is this an inet_connection_sock?
@@ -126,9 +125,6 @@ struct inet_sock {
 	__u16			cmsg_flags;
 	__be16			inet_sport;
 	__u16			inet_id;
-#ifdef CONFIG_RPS
-	__u32			rxhash;
-#endif
 
 	struct ip_options	*opt;
 	__u8			tos;
@@ -224,37 +220,4 @@ static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 	return inet_sk(sk)->transparent ? FLOWI_FLAG_ANYSRC : 0;
 }
 
-static inline void inet_rps_record_flow(const struct sock *sk)
-{
-#ifdef CONFIG_RPS
-	struct rps_sock_flow_table *sock_flow_table;
-
-	rcu_read_lock();
-	sock_flow_table = rcu_dereference(rps_sock_flow_table);
-	rps_record_sock_flow(sock_flow_table, inet_sk(sk)->rxhash);
-	rcu_read_unlock();
-#endif
-}
-
-static inline void inet_rps_reset_flow(const struct sock *sk)
-{
-#ifdef CONFIG_RPS
-	struct rps_sock_flow_table *sock_flow_table;
-
-	rcu_read_lock();
-	sock_flow_table = rcu_dereference(rps_sock_flow_table);
-	rps_reset_sock_flow(sock_flow_table, inet_sk(sk)->rxhash);
-	rcu_read_unlock();
-#endif
-}
-
-static inline void inet_rps_save_rxhash(struct sock *sk, u32 rxhash)
-{
-#ifdef CONFIG_RPS
-	if (unlikely(inet_sk(sk)->rxhash != rxhash)) {
-		inet_rps_reset_flow(sk);
-		inet_sk(sk)->rxhash = rxhash;
-	}
-#endif
-}
 #endif	/* _INET_SOCK_H */

include/net/sock.h

@@ -198,6 +198,7 @@ struct sock_common {
   *	@sk_rcvlowat: %SO_RCVLOWAT setting
   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
   *	@sk_sndtimeo: %SO_SNDTIMEO setting
+  *	@sk_rxhash: flow hash received from netif layer
   *	@sk_filter: socket filtering instructions
   *	@sk_protinfo: private area, net family specific, when not using slab
   *	@sk_timer: sock cleanup timer
@@ -279,6 +280,9 @@ struct sock {
 	int			sk_gso_type;
 	unsigned int		sk_gso_max_size;
 	int			sk_rcvlowat;
+#ifdef CONFIG_RPS
+	__u32			sk_rxhash;
+#endif
 	unsigned long 		sk_flags;
 	unsigned long	        sk_lingertime;
 	struct sk_buff_head	sk_error_queue;
@@ -620,6 +624,40 @@ static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 	return sk->sk_backlog_rcv(sk, skb);
 }
 
+static inline void sock_rps_record_flow(const struct sock *sk)
+{
+#ifdef CONFIG_RPS
+	struct rps_sock_flow_table *sock_flow_table;
+
+	rcu_read_lock();
+	sock_flow_table = rcu_dereference(rps_sock_flow_table);
+	rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
+	rcu_read_unlock();
+#endif
+}
+
+static inline void sock_rps_reset_flow(const struct sock *sk)
+{
+#ifdef CONFIG_RPS
+	struct rps_sock_flow_table *sock_flow_table;
+
+	rcu_read_lock();
+	sock_flow_table = rcu_dereference(rps_sock_flow_table);
+	rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
+	rcu_read_unlock();
+#endif
+}
+
+static inline void sock_rps_save_rxhash(struct sock *sk, u32 rxhash)
+{
+#ifdef CONFIG_RPS
+	if (unlikely(sk->sk_rxhash != rxhash)) {
+		sock_rps_reset_flow(sk);
+		sk->sk_rxhash = rxhash;
+	}
+#endif
+}
+
 #define sk_wait_event(__sk, __timeo, __condition)			\
 	({	int __rc;						\
 		release_sock(__sk);					\

net/ipv4/af_inet.c

@@ -419,7 +419,7 @@ int inet_release(struct socket *sock)
 	if (sk) {
 		long timeout;
 
-		inet_rps_reset_flow(sk);
+		sock_rps_reset_flow(sk);
 
 		/* Applications forget to leave groups before exiting */
 		ip_mc_drop_socket(sk);
@@ -722,7 +722,7 @@ int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 {
 	struct sock *sk = sock->sk;
 
-	inet_rps_record_flow(sk);
+	sock_rps_record_flow(sk);
 
 	/* We may need to bind the socket. */
 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
@@ -737,7 +737,7 @@ static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 {
 	struct sock *sk = sock->sk;
 
-	inet_rps_record_flow(sk);
+	sock_rps_record_flow(sk);
 
 	/* We may need to bind the socket. */
 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
@@ -755,7 +755,7 @@ int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 	int addr_len = 0;
 	int err;
 
-	inet_rps_record_flow(sk);
+	sock_rps_record_flow(sk);
 
 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
 				   flags & ~MSG_DONTWAIT, &addr_len);

net/ipv4/tcp_ipv4.c

@@ -1672,7 +1672,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
 
 	skb->dev = NULL;
 
-	inet_rps_save_rxhash(sk, skb->rxhash);
+	sock_rps_save_rxhash(sk, skb->rxhash);
 
 	bh_lock_sock_nested(sk);
 	ret = 0;

net/ipv4/udp.c

@@ -1217,7 +1217,7 @@ int udp_disconnect(struct sock *sk, int flags)
 	sk->sk_state = TCP_CLOSE;
 	inet->inet_daddr = 0;
 	inet->inet_dport = 0;
-	inet_rps_save_rxhash(sk, 0);
+	sock_rps_save_rxhash(sk, 0);
 	sk->sk_bound_dev_if = 0;
 	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 		inet_reset_saddr(sk);
@@ -1262,7 +1262,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	int rc;
 
 	if (inet_sk(sk)->inet_daddr)
-		inet_rps_save_rxhash(sk, skb->rxhash);
+		sock_rps_save_rxhash(sk, skb->rxhash);
 
 	rc = sock_queue_rcv_skb(sk, skb);
 	if (rc < 0) {