[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/8021q/vlanproc.c b/net/8021q/vlanproc.c
index bd08aa0..ac80e6b 100644
--- a/net/8021q/vlanproc.c
+++ b/net/8021q/vlanproc.c
@@ -33,6 +33,7 @@
 #include <linux/fs.h>
 #include <linux/netdevice.h>
 #include <linux/if_vlan.h>
+#include <net/net_namespace.h>
 #include "vlanproc.h"
 #include "vlan.h"
 
@@ -143,7 +144,7 @@
 		remove_proc_entry(name_conf, proc_vlan_dir);
 
 	if (proc_vlan_dir)
-		proc_net_remove(name_root);
+		proc_net_remove(&init_net, name_root);
 
 	/* Dynamically added entries should be cleaned up as their vlan_device
 	 * is removed, so we should not have to take care of it here...
@@ -156,7 +157,7 @@
 
 int __init vlan_proc_init(void)
 {
-	proc_vlan_dir = proc_mkdir(name_root, proc_net);
+	proc_vlan_dir = proc_mkdir(name_root, init_net.proc_net);
 	if (proc_vlan_dir) {
 		proc_vlan_conf = create_proc_entry(name_conf,
 						   S_IFREG|S_IRUSR|S_IWUSR,