tcp: Namespace-ify sysctl_tcp_app_win

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

include/net/netns/ipv4.h

@@ -139,6 +139,7 @@ struct netns_ipv4 {
 	int sysctl_tcp_fack;
 	int sysctl_tcp_max_reordering;
 	int sysctl_tcp_dsack;
+	int sysctl_tcp_app_win;
 	struct inet_timewait_death_row tcp_death_row;
 	int sysctl_max_syn_backlog;
 	int sysctl_tcp_fastopen;

include/net/tcp.h

@@ -247,7 +247,6 @@ extern int sysctl_tcp_max_orphans;
 extern long sysctl_tcp_mem[3];
 extern int sysctl_tcp_wmem[3];
 extern int sysctl_tcp_rmem[3];
-extern int sysctl_tcp_app_win;
 extern int sysctl_tcp_adv_win_scale;
 extern int sysctl_tcp_frto;
 extern int sysctl_tcp_nometrics_save;

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_app_win",
-		.data		= &sysctl_tcp_app_win,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
 	{
 		.procname	= "tcp_adv_win_scale",
 		.data		= &sysctl_tcp_adv_win_scale,
@@ -1145,6 +1138,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "tcp_app_win",
+		.data		= &init_net.ipv4.sysctl_tcp_app_win,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 

net/ipv4/tcp_input.c

@@ -79,7 +79,6 @@
 #include <linux/unaligned/access_ok.h>
 #include <linux/static_key.h>
 
-int sysctl_tcp_app_win __read_mostly = 31;
 int sysctl_tcp_adv_win_scale __read_mostly = 1;
 EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
 
@@ -428,6 +427,7 @@ static void tcp_fixup_rcvbuf(struct sock *sk)
  */
 void tcp_init_buffer_space(struct sock *sk)
 {
+	int tcp_app_win = sock_net(sk)->ipv4.sysctl_tcp_app_win;
 	struct tcp_sock *tp = tcp_sk(sk);
 	int maxwin;
 
@@ -446,14 +446,14 @@ void tcp_init_buffer_space(struct sock *sk)
 	if (tp->window_clamp >= maxwin) {
 		tp->window_clamp = maxwin;
 
-		if (sysctl_tcp_app_win && maxwin > 4 * tp->advmss)
+		if (tcp_app_win && maxwin > 4 * tp->advmss)
 			tp->window_clamp = max(maxwin -
-					       (maxwin >> sysctl_tcp_app_win),
+					       (maxwin >> tcp_app_win),
 					       4 * tp->advmss);
 	}
 
 	/* Force reservation of one segment. */
-	if (sysctl_tcp_app_win &&
+	if (tcp_app_win &&
 	    tp->window_clamp > 2 * tp->advmss &&
 	    tp->window_clamp + tp->advmss > maxwin)
 		tp->window_clamp = max(2 * tp->advmss, maxwin - tp->advmss);

net/ipv4/tcp_ipv4.c

@@ -2490,6 +2490,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_retrans_collapse = 1;
 	net->ipv4.sysctl_tcp_max_reordering = 300;
 	net->ipv4.sysctl_tcp_dsack = 1;
+	net->ipv4.sysctl_tcp_app_win = 31;
 
 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
 	spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);