[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_lblcr.c b/net/ipv4/ipvs/ip_vs_lblcr.c
index 6225aca..6a1fec4 100644
--- a/net/ipv4/ipvs/ip_vs_lblcr.c
+++ b/net/ipv4/ipvs/ip_vs_lblcr.c
@@ -50,6 +50,7 @@
 #include <linux/sysctl.h>
 /* for proc_net_create/proc_net_remove */
 #include <linux/proc_fs.h>
+#include <net/net_namespace.h>
 
 #include <net/ip_vs.h>
 
@@ -843,7 +844,7 @@
 	INIT_LIST_HEAD(&ip_vs_lblcr_scheduler.n_list);
 	sysctl_header = register_sysctl_table(lblcr_root_table);
 #ifdef CONFIG_IP_VS_LBLCR_DEBUG
-	proc_net_create("ip_vs_lblcr", 0, ip_vs_lblcr_getinfo);
+	proc_net_create(&init_net, "ip_vs_lblcr", 0, ip_vs_lblcr_getinfo);
 #endif
 	return register_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
 }
@@ -852,7 +853,7 @@
 static void __exit ip_vs_lblcr_cleanup(void)
 {
 #ifdef CONFIG_IP_VS_LBLCR_DEBUG
-	proc_net_remove("ip_vs_lblcr");
+	proc_net_remove(&init_net, "ip_vs_lblcr");
 #endif
 	unregister_sysctl_table(sysctl_header);
 	unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler);