[NET]: Make /proc/net per network namespace

This patch makes /proc/net per network namespace.  It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.

Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipvs/ip_vs_ctl.c b/net/ipv4/ipvs/ip_vs_ctl.c
index f656d41..61d023d 100644
--- a/net/ipv4/ipvs/ip_vs_ctl.c
+++ b/net/ipv4/ipvs/ip_vs_ctl.c
@@ -35,6 +35,7 @@
 #include <linux/netfilter_ipv4.h>
 #include <linux/mutex.h>
 
+#include <net/net_namespace.h>
 #include <net/ip.h>
 #include <net/route.h>
 #include <net/sock.h>
@@ -2356,8 +2357,8 @@
 		return ret;
 	}
 
-	proc_net_fops_create("ip_vs", 0, &ip_vs_info_fops);
-	proc_net_fops_create("ip_vs_stats",0, &ip_vs_stats_fops);
+	proc_net_fops_create(&init_net, "ip_vs", 0, &ip_vs_info_fops);
+	proc_net_fops_create(&init_net, "ip_vs_stats",0, &ip_vs_stats_fops);
 
 	sysctl_header = register_sysctl_table(vs_root_table);
 
@@ -2390,8 +2391,8 @@
 	cancel_work_sync(&defense_work.work);
 	ip_vs_kill_estimator(&ip_vs_stats);
 	unregister_sysctl_table(sysctl_header);
-	proc_net_remove("ip_vs_stats");
-	proc_net_remove("ip_vs");
+	proc_net_remove(&init_net, "ip_vs_stats");
+	proc_net_remove(&init_net, "ip_vs");
 	nf_unregister_sockopt(&ip_vs_sockopts);
 	LeaveFunction(2);
 }