[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/ieee80211/ieee80211_module.c b/net/ieee80211/ieee80211_module.c
index 17ad278..69cb6aa 100644
--- a/net/ieee80211/ieee80211_module.c
+++ b/net/ieee80211/ieee80211_module.c
@@ -47,6 +47,7 @@
 #include <linux/wireless.h>
 #include <linux/etherdevice.h>
 #include <asm/uaccess.h>
+#include <net/net_namespace.h>
 #include <net/arp.h>
 
 #include <net/ieee80211.h>
@@ -264,7 +265,7 @@
 	struct proc_dir_entry *e;
 
 	ieee80211_debug_level = debug;
-	ieee80211_proc = proc_mkdir(DRV_NAME, proc_net);
+	ieee80211_proc = proc_mkdir(DRV_NAME, init_net.proc_net);
 	if (ieee80211_proc == NULL) {
 		IEEE80211_ERROR("Unable to create " DRV_NAME
 				" proc directory\n");
@@ -273,7 +274,7 @@
 	e = create_proc_entry("debug_level", S_IFREG | S_IRUGO | S_IWUSR,
 			      ieee80211_proc);
 	if (!e) {
-		remove_proc_entry(DRV_NAME, proc_net);
+		remove_proc_entry(DRV_NAME, init_net.proc_net);
 		ieee80211_proc = NULL;
 		return -EIO;
 	}
@@ -293,7 +294,7 @@
 #ifdef CONFIG_IEEE80211_DEBUG
 	if (ieee80211_proc) {
 		remove_proc_entry("debug_level", ieee80211_proc);
-		remove_proc_entry(DRV_NAME, proc_net);
+		remove_proc_entry(DRV_NAME, init_net.proc_net);
 		ieee80211_proc = NULL;
 	}
 #endif				/* CONFIG_IEEE80211_DEBUG */