tcp: Namespace-ify sysctl_tcp_retrans_collapse

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

include/net/netns/ipv4.h

@@ -132,6 +132,7 @@ struct netns_ipv4 {
 	int sysctl_tcp_recovery;
 	int sysctl_tcp_thin_linear_timeouts;
 	int sysctl_tcp_slow_start_after_idle;
+	int sysctl_tcp_retrans_collapse;
 	struct inet_timewait_death_row tcp_death_row;
 	int sysctl_max_syn_backlog;
 	int sysctl_tcp_fastopen;

include/net/tcp.h

@@ -243,7 +243,6 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
 
 
 /* sysctl variables for tcp */
-extern int sysctl_tcp_retrans_collapse;
 extern int sysctl_tcp_stdurg;
 extern int sysctl_tcp_rfc1337;
 extern int sysctl_tcp_abort_on_overflow;

net/ipv4/sysctl_net_ipv4.c

@@ -386,13 +386,6 @@ static int proc_tcp_available_ulp(struct ctl_table *ctl,
 }
 
 static struct ctl_table ipv4_table[] = {
-	{
-		.procname	= "tcp_retrans_collapse",
-		.data		= &sysctl_tcp_retrans_collapse,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
 	{
 		.procname	= "tcp_max_orphans",
 		.data		= &sysctl_tcp_max_orphans,
@@ -1145,6 +1138,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "tcp_retrans_collapse",
+		.data		= &init_net.ipv4.sysctl_tcp_retrans_collapse,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 

net/ipv4/tcp_ipv4.c

@@ -2487,7 +2487,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_early_retrans = 3;
 	net->ipv4.sysctl_tcp_recovery = TCP_RACK_LOSS_DETECTION;
 	net->ipv4.sysctl_tcp_slow_start_after_idle = 1; /* By default, RFC2861 behavior.  */
-
+	net->ipv4.sysctl_tcp_retrans_collapse = 1;
 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
 	spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
 	net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 60 * 60;

net/ipv4/tcp_output.c

@@ -45,9 +45,6 @@
 
 #include <trace/events/tcp.h>
 
-/* People can turn this off for buggy TCP's found in printers etc. */
-int sysctl_tcp_retrans_collapse __read_mostly = 1;
-
 /* People can turn this on to work with those rare, broken TCPs that
  * interpret the window field as a signed quantity.
  */
@@ -2804,7 +2801,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 	struct sk_buff *skb = to, *tmp;
 	bool first = true;
 
-	if (!sysctl_tcp_retrans_collapse)
+	if (!sock_net(sk)->ipv4.sysctl_tcp_retrans_collapse)
 		return;
 	if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)
 		return;