tcp: Namespace-ify sysctl_tcp_thin_linear_timeouts

Note that sysctl_tcp_thin_dupack was not used, I deleted it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ipv4.h

@@ -130,6 +130,7 @@ struct netns_ipv4 {
 	int sysctl_tcp_timestamps;
 	int sysctl_tcp_early_retrans;
 	int sysctl_tcp_recovery;
+	int sysctl_tcp_thin_linear_timeouts;
 	struct inet_timewait_death_row tcp_death_row;
 	int sysctl_max_syn_backlog;
 	int sysctl_tcp_fastopen;

include/net/tcp.h

@@ -263,8 +263,6 @@ extern int sysctl_tcp_moderate_rcvbuf;
 extern int sysctl_tcp_tso_win_divisor;
 extern int sysctl_tcp_workaround_signed_windows;
 extern int sysctl_tcp_slow_start_after_idle;
-extern int sysctl_tcp_thin_linear_timeouts;
-extern int sysctl_tcp_thin_dupack;
 
 #define TCP_RACK_LOSS_DETECTION  0x1 /* Use RACK to detect losses */
 

net/ipv4/sysctl_net_ipv4.c

@@ -620,13 +620,6 @@ static struct ctl_table ipv4_table[] = {
 		.mode		= 0644,
 		.proc_handler   = proc_allowed_congestion_control,
 	},
-	{
-		.procname       = "tcp_thin_linear_timeouts",
-		.data           = &sysctl_tcp_thin_linear_timeouts,
-		.maxlen         = sizeof(int),
-		.mode           = 0644,
-		.proc_handler   = proc_dointvec
-	},
 	{
 		.procname	= "tcp_min_tso_segs",
 		.data		= &sysctl_tcp_min_tso_segs,
@@ -1145,6 +1138,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+	{
+		.procname       = "tcp_thin_linear_timeouts",
+		.data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec
+	},
 	{ }
 };
 

net/ipv4/tcp_timer.c

@@ -22,8 +22,6 @@
 #include <linux/gfp.h>
 #include <net/tcp.h>
 
-int sysctl_tcp_thin_linear_timeouts __read_mostly;
-
 /**
  *  tcp_write_err() - close socket and save error info
  *  @sk:  The socket the error has appeared on.
@@ -522,7 +520,7 @@ void tcp_retransmit_timer(struct sock *sk)
 	 * linear-timeout retransmissions into a black hole
 	 */
 	if (sk->sk_state == TCP_ESTABLISHED &&
-	    (tp->thin_lto || sysctl_tcp_thin_linear_timeouts) &&
+	    (tp->thin_lto || net->ipv4.sysctl_tcp_thin_linear_timeouts) &&
 	    tcp_stream_is_thin(tp) &&
 	    icsk->icsk_retransmits <= TCP_THIN_LINEAR_RETRIES) {
 		icsk->icsk_backoff = 0;