[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/irda/irproc.c b/net/irda/irproc.c
index 181cb51..cae24fb 100644
--- a/net/irda/irproc.c
+++ b/net/irda/irproc.c
@@ -28,6 +28,7 @@
 #include <linux/seq_file.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <net/net_namespace.h>
 
 #include <net/irda/irda.h>
 #include <net/irda/irlap.h>
@@ -66,7 +67,7 @@
 	int i;
 	struct proc_dir_entry *d;
 
-	proc_irda = proc_mkdir("irda", proc_net);
+	proc_irda = proc_mkdir("irda", init_net.proc_net);
 	if (proc_irda == NULL)
 		return;
 	proc_irda->owner = THIS_MODULE;
@@ -92,7 +93,7 @@
 		for (i=0; i<ARRAY_SIZE(irda_dirs); i++)
 			remove_proc_entry(irda_dirs[i].name, proc_irda);
 
-		remove_proc_entry("irda", proc_net);
+		remove_proc_entry("irda", init_net.proc_net);
 		proc_irda = NULL;
 	}
 }