[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/drivers/isdn/hysdn/hysdn_procconf.c b/drivers/isdn/hysdn/hysdn_procconf.c
index dc477e0..27d890b 100644
--- a/drivers/isdn/hysdn/hysdn_procconf.c
+++ b/drivers/isdn/hysdn/hysdn_procconf.c
@@ -16,6 +16,7 @@
 #include <linux/proc_fs.h>
 #include <linux/pci.h>
 #include <linux/smp_lock.h>
+#include <net/net_namespace.h>
 
 #include "hysdn_defs.h"
 
@@ -392,7 +393,7 @@
 	hysdn_card *card;
 	unsigned char conf_name[20];
 
-	hysdn_proc_entry = proc_mkdir(PROC_SUBDIR_NAME, proc_net);
+	hysdn_proc_entry = proc_mkdir(PROC_SUBDIR_NAME, init_net.proc_net);
 	if (!hysdn_proc_entry) {
 		printk(KERN_ERR "HYSDN: unable to create hysdn subdir\n");
 		return (-1);
@@ -437,5 +438,5 @@
 		card = card->next;	/* point to next card */
 	}
 
-	remove_proc_entry(PROC_SUBDIR_NAME, proc_net);
+	remove_proc_entry(PROC_SUBDIR_NAME, init_net.proc_net);
 }