[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/llc/llc_proc.c b/net/llc/llc_proc.c
index 49be6c9..4865d82 100644
--- a/net/llc/llc_proc.c
+++ b/net/llc/llc_proc.c
@@ -17,6 +17,7 @@
 #include <linux/proc_fs.h>
 #include <linux/errno.h>
 #include <linux/seq_file.h>
+#include <net/net_namespace.h>
 #include <net/sock.h>
 #include <net/llc.h>
 #include <net/llc_c_ac.h>
@@ -231,7 +232,7 @@
 	int rc = -ENOMEM;
 	struct proc_dir_entry *p;
 
-	llc_proc_dir = proc_mkdir("llc", proc_net);
+	llc_proc_dir = proc_mkdir("llc", init_net.proc_net);
 	if (!llc_proc_dir)
 		goto out;
 	llc_proc_dir->owner = THIS_MODULE;
@@ -254,7 +255,7 @@
 out_core:
 	remove_proc_entry("socket", llc_proc_dir);
 out_socket:
-	remove_proc_entry("llc", proc_net);
+	remove_proc_entry("llc", init_net.proc_net);
 	goto out;
 }
 
@@ -262,5 +263,5 @@
 {
 	remove_proc_entry("socket", llc_proc_dir);
 	remove_proc_entry("core", llc_proc_dir);
-	remove_proc_entry("llc", proc_net);
+	remove_proc_entry("llc", init_net.proc_net);
 }