inet: move ipv6only in sock_common

When an UDP application switches from AF_INET to AF_INET6 sockets, we
have a small performance degradation for IPv4 communications because of
extra cache line misses to access ipv6only information.

This can also be noticed for TCP listeners, as ipv6_only_sock() is also
used from __inet_lookup_listener()->compute_score()

This is magnified when SO_REUSEPORT is used.

Move ipv6only into struct sock_common so that it is available at
no extra cost in lookups.

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

5 files changed, 8 insertions, 11 deletions

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index c69eb9c4fbb8..b50dc436db1f 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -55,11 +55,9 @@ void dccp_time_wait(struct sock *sk, int state, int timeo)
 		const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
 #if IS_ENABLED(CONFIG_IPV6)
 		if (tw->tw_family == PF_INET6) {
-			const struct ipv6_pinfo *np = inet6_sk(sk);
-
 			tw->tw_v6_daddr = sk->sk_v6_daddr;
 			tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
-			tw->tw_ipv6only = np->ipv6only;
+			tw->tw_ipv6only = sk->sk_ipv6only;
 		}
 #endif
 		/* Linkage updates. */
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index e68e0d4af6c9..1649988bd1b6 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -298,7 +298,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 			tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 			tw->tw_tclass = np->tclass;
 			tw->tw_flowlabel = np->flow_label >> 12;
-			tw->tw_ipv6only = np->ipv6only;
+			tw->tw_ipv6only = sk->sk_ipv6only;
 		}
 #endif
 
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 7cb4392690dd..a426cd7099bb 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -197,7 +197,7 @@ lookup_protocol:
 	np->mcast_hops	= IPV6_DEFAULT_MCASTHOPS;
 	np->mc_loop	= 1;
 	np->pmtudisc	= IPV6_PMTUDISC_WANT;
-	np->ipv6only	= net->ipv6.sysctl.bindv6only;
+	sk->sk_ipv6only	= net->ipv6.sysctl.bindv6only;
 
 	/* Init the ipv4 part of the socket since we can have sockets
 	 * using v6 API for ipv4.
@@ -294,7 +294,7 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		/* Binding to v4-mapped address on a v6-only socket
 		 * makes no sense
 		 */
-		if (np->ipv6only) {
+		if (sk->sk_ipv6only) {
 			err = -EINVAL;
 			goto out;
 		}
@@ -371,7 +371,7 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	if (addr_type != IPV6_ADDR_ANY) {
 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 		if (addr_type != IPV6_ADDR_MAPPED)
-			np->ipv6only = 1;
+			sk->sk_ipv6only = 1;
 	}
 	if (snum)
 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index edb58aff4ae7..cc34f65179e4 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -235,7 +235,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		if (optlen < sizeof(int) ||
 		    inet_sk(sk)->inet_num)
 			goto e_inval;
-		np->ipv6only = valbool;
+		sk->sk_ipv6only = valbool;
 		retv = 0;
 		break;
 
@@ -1058,7 +1058,7 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 	}
 
 	case IPV6_V6ONLY:
-		val = np->ipv6only;
+		val = sk->sk_ipv6only;
 		break;
 
 	case IPV6_RECVPKTINFO:
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 95c834799288..c2bd28fd43e4 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -79,7 +79,6 @@ static unsigned int udp6_ehashfn(struct net *net,
 int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
 {
 	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
-	int sk_ipv6only = ipv6_only_sock(sk);
 	int sk2_ipv6only = inet_v6_ipv6only(sk2);
 	int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
 	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
@@ -95,7 +94,7 @@ int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
 		return 1;
 
 	if (addr_type == IPV6_ADDR_ANY &&
-	    !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
+	    !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
 		return 1;
 
 	if (sk2_rcv_saddr6 &&