tcp: Namespace-ify sysctl_tcp_min_rtt_wlen

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

include/net/netns/ipv4.h

@@ -149,6 +149,7 @@ struct netns_ipv4 {
 	int sysctl_tcp_limit_output_bytes;
 	int sysctl_tcp_challenge_ack_limit;
 	int sysctl_tcp_min_tso_segs;
+	int sysctl_tcp_min_rtt_wlen;
 	struct inet_timewait_death_row tcp_death_row;
 	int sysctl_max_syn_backlog;
 	int sysctl_tcp_fastopen;

include/net/tcp.h

@@ -250,7 +250,6 @@ extern int sysctl_tcp_rmem[3];
 
 #define TCP_RACK_LOSS_DETECTION  0x1 /* Use RACK to detect losses */
 
-extern int sysctl_tcp_min_rtt_wlen;
 extern int sysctl_tcp_autocorking;
 extern int sysctl_tcp_invalid_ratelimit;
 extern int sysctl_tcp_pacing_ss_ratio;

net/ipv4/sysctl_net_ipv4.c

@@ -437,13 +437,6 @@ static struct ctl_table ipv4_table[] = {
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= &one,
 	},
-	{
-		.procname	= "tcp_min_rtt_wlen",
-		.data		= &sysctl_tcp_min_rtt_wlen,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
 	{
 		.procname	= "tcp_low_latency",
 		.data		= &sysctl_tcp_low_latency,
@@ -1145,6 +1138,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra1		= &one,
 		.extra2		= &gso_max_segs,
 	},
+	{
+		.procname	= "tcp_min_rtt_wlen",
+		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 

net/ipv4/tcp_input.c

@@ -80,7 +80,6 @@
 #include <linux/static_key.h>
 
 int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
-int sysctl_tcp_min_rtt_wlen __read_mostly = 300;
 int sysctl_tcp_invalid_ratelimit __read_mostly = HZ/2;
 
 #define FLAG_DATA		0x01 /* Incoming frame contained data.		*/
@@ -2915,8 +2914,8 @@ static void tcp_fastretrans_alert(struct sock *sk, const int acked,
 
 static void tcp_update_rtt_min(struct sock *sk, u32 rtt_us)
 {
+	u32 wlen = sock_net(sk)->ipv4.sysctl_tcp_min_rtt_wlen * HZ;
 	struct tcp_sock *tp = tcp_sk(sk);
-	u32 wlen = sysctl_tcp_min_rtt_wlen * HZ;
 
 	minmax_running_min(&tp->rtt_min, wlen, tcp_jiffies32,
 			   rtt_us ? : jiffies_to_usecs(1));

net/ipv4/tcp_ipv4.c

@@ -2504,6 +2504,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	/* rfc5961 challenge ack rate limiting */
 	net->ipv4.sysctl_tcp_challenge_ack_limit = 1000;
 	net->ipv4.sysctl_tcp_min_tso_segs = 2;
+	net->ipv4.sysctl_tcp_min_rtt_wlen = 300;
 
 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
 	spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);