tcp: Namespace-ify sysctl_tcp_max_reordering

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index f0e792b..3f68446 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -137,6 +137,7 @@
 	int sysctl_tcp_rfc1337;
 	int sysctl_tcp_abort_on_overflow;
 	int sysctl_tcp_fack;
+	int sysctl_tcp_max_reordering;
 	struct inet_timewait_death_row tcp_death_row;
 	int sysctl_max_syn_backlog;
 	int sysctl_tcp_fastopen;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index fc134ba..8cd2862 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -244,7 +244,6 @@
 
 /* sysctl variables for tcp */
 extern int sysctl_tcp_max_orphans;
-extern int sysctl_tcp_max_reordering;
 extern int sysctl_tcp_dsack;
 extern long sysctl_tcp_mem[3];
 extern int sysctl_tcp_wmem[3];
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 1f23be1..18cd228 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -415,13 +415,6 @@
 		.proc_handler	= proc_dointvec_jiffies,
 	},
 	{
-		.procname	= "tcp_max_reordering",
-		.data		= &sysctl_tcp_max_reordering,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
-	{
 		.procname	= "tcp_dsack",
 		.data		= &sysctl_tcp_dsack,
 		.maxlen		= sizeof(int),
@@ -1145,6 +1138,13 @@
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "tcp_max_reordering",
+		.data		= &init_net.ipv4.sysctl_tcp_max_reordering,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c5b9446..c118657 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -79,7 +79,6 @@
 #include <linux/unaligned/access_ok.h>
 #include <linux/static_key.h>
 
-int sysctl_tcp_max_reordering __read_mostly = 300;
 int sysctl_tcp_dsack __read_mostly = 1;
 int sysctl_tcp_app_win __read_mostly = 31;
 int sysctl_tcp_adv_win_scale __read_mostly = 1;
@@ -889,7 +888,7 @@
 		return;
 
 	if (metric > tp->reordering) {
-		tp->reordering = min(sysctl_tcp_max_reordering, metric);
+		tp->reordering = min(sock_net(sk)->ipv4.sysctl_tcp_max_reordering, metric);
 
 #if FASTRETRANS_DEBUG > 1
 		pr_debug("Disorder%d %d %u f%u s%u rr%d\n",
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2bc6ba2..c379a24 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2488,6 +2488,8 @@
 	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_max_reordering = 300;
+
 	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;