Subject: [PATCH 2/2] rtl8192su: Fix procfs code for interfaces not named wlan0

From: Ben Hutchings <[email-masked]>
Date: Tue, 25 May 2010 04:25:57 +0100

The current code creates directories in procfs named after interfaces,
but doesn't handle renaming.  This can result in name collisions and
consequent WARNINGs.  It also means that the interface name cannot
reliably be used to remove the directory - in fact the current code
doesn't even try, and always uses "wlan0"!

Since the name of a proc_dir_entry is embedded in it, use that when
removing it.

Add a netdev notifier to catch interface renaming, and remove and
re-add the directory at this point.

Signed-off-by: Ben Hutchings <[email-masked]>
---
This is compile-tested only.

All this procfs crap should really be replaced - stats should be exposed
through the proper wireless stats interface and registers through
debugfs or not at all.  But for now let's patch it up to avoid the
WARNING.

Ben.

 drivers/staging/rtl8192su/r8192U_core.c |   35 ++++++++++++++++++++++++++++--
 1 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/rtl8192su/r8192U_core.c b/drivers/staging/rtl8192su/r8192U_core.c
index 90f2df4..4bd3710 100644
--- a/drivers/staging/rtl8192su/r8192U_core.c
+++ b/drivers/staging/rtl8192su/r8192U_core.c
@@ -27,6 +27,7 @@
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/eeprom_93cx6.h>
+#include <linux/notifier.h>
 
 #undef LOOP_TEST
 #undef DUMP_RX
@@ -161,6 +162,8 @@ MODULE_PARM_DESC(channels," Channel bitmask for specific locales. NYI");
 static int __devinit rtl8192_usb_probe(struct usb_interface *intf,
 			 const struct usb_device_id *id);
 static void __devexit rtl8192_usb_disconnect(struct usb_interface *intf);
+static const struct net_device_ops rtl8192_netdev_ops;
+static struct notifier_block proc_netdev_notifier;
 
 static struct usb_driver rtl8192_usb_driver = {
 	.name		= RTL819xU_MODULE_NAME,	          /* Driver name   */
@@ -992,14 +995,22 @@ static int proc_get_stats_rx(char *page, char **start,
 
 int rtl8192_proc_module_init(void)
 {
+	int ret;
+
 	RT_TRACE(COMP_INIT, "Initializing proc filesystem");
 	rtl8192_proc=create_proc_entry(RTL819xU_MODULE_NAME, S_IFDIR, init_net.proc_net);
-	return rtl8192_proc ? 0 : -ENOMEM;
+	if (!rtl8192_proc)
+		return -ENOMEM;
+	ret = register_netdevice_notifier(&proc_netdev_notifier);
+	if (ret)
+		remove_proc_entry(RTL819xU_MODULE_NAME, init_net.proc_net);
+	return ret;
 }

 void rtl8192_proc_module_remove(void)
 {
+	unregister_netdevice_notifier(&proc_netdev_notifier);
 	remove_proc_entry(RTL819xU_MODULE_NAME, init_net.proc_net);
 }
 
@@ -1027,8 +1038,7 @@ void rtl8192_proc_remove_one(struct net_device *dev)
 		remove_proc_entry("registers-e", priv->dir_dev);
 	//	remove_proc_entry("cck-registers",priv->dir_dev);
 	//	remove_proc_entry("ofdm-registers",priv->dir_dev);
-		//remove_proc_entry(dev->name, rtl8192_proc);
-		remove_proc_entry("wlan0", rtl8192_proc);
+		remove_proc_entry(priv->dir_dev->name, rtl8192_proc);
 		priv->dir_dev = NULL;
 	}
 }
@@ -1145,6 +1155,25 @@ void rtl8192_proc_init_one(struct net_device *dev)
 		      dev->name);
 	}
 }
+
+static int proc_netdev_event(struct notifier_block *this,
+			     unsigned long event, void *ptr)
+{
+	struct net_device *net_dev = ptr;
+
+	if (net_dev->netdev_ops == &rtl8192_netdev_ops &&
+	    event == NETDEV_CHANGENAME) {
+		rtl8192_proc_remove_one(net_dev);
+		rtl8192_proc_init_one(net_dev);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block proc_netdev_notifier = {
+	.notifier_call = proc_netdev_event,
+};
+
 /****************************************************************************
    -----------------------------MISC STUFF-------------------------
 *****************************************************************************/
-- 
1.7.1