[NET]: Create netdev attribute_groups with class_device_add

Atomically create attributes when class device is added. This avoids
the race between registering class_device (which generates hotplug
event), and the creation of attribute groups.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 15 insertions, 38 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 01db7b88a2b1..309f9190a922 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -506,6 +506,8 @@ struct net_device
 
         /* class/net/name entry */
         struct class_device     class_dev;
+        /* space for optional statistics and wireless sysfs groups */
+        struct attribute_group  *sysfs_groups[3];
 };
 
 #define NETDEV_ALIGN            32
diff --git a/net/core/dev.c b/net/core/dev.c
index 3bad1afc89fa..9ab3cfa58466 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3043,11 +3043,11 @@ void netdev_run_todo(void)
 
                 switch(dev->reg_state) {
                 case NETREG_REGISTERING:
-                        dev->reg_state = NETREG_REGISTERED;
                         err = netdev_register_sysfs(dev);
                         if (err)
                                 printk(KERN_ERR "%s: failed sysfs registration (%d)\n",
                                        dev->name, err);
+                        dev->reg_state = NETREG_REGISTERED;
                         break;
 
                 case NETREG_UNREGISTERING:
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index c12990c9c603..47a6fceb6771 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -29,7 +29,7 @@ static const char fmt_ulong[] = "%lu\n";
 
 static inline int dev_isalive(const struct net_device *dev) 
 {
-        return dev->reg_state == NETREG_REGISTERED;
+        return dev->reg_state <= NETREG_REGISTERED;
 }
 
 /* use same locking rules as GIF* ioctl's */
@@ -445,58 +445,33 @@ static struct class net_class = {
 
 void netdev_unregister_sysfs(struct net_device * net)
 {
-        struct class_device * class_dev = &(net->class_dev);
-
-        if (net->get_stats)
-                sysfs_remove_group(&class_dev->kobj, &netstat_group);
-
-#ifdef WIRELESS_EXT
-        if (net->get_wireless_stats || (net->wireless_handlers &&
-                        net->wireless_handlers->get_wireless_stats))
-                sysfs_remove_group(&class_dev->kobj, &wireless_group);
-#endif
-        class_device_del(class_dev);
-
+        class_device_del(&(net->class_dev));
 }
 
 /* Create sysfs entries for network device. */
 int netdev_register_sysfs(struct net_device *net)
 {
         struct class_device *class_dev = &(net->class_dev);
-        int ret;
+        struct attribute_group **groups = net->sysfs_groups;
 
+        class_device_initialize(class_dev);
         class_dev->class = &net_class;
         class_dev->class_data = net;
+        class_dev->groups = groups;
 
+        BUILD_BUG_ON(BUS_ID_SIZE < IFNAMSIZ);
         strlcpy(class_dev->class_id, net->name, BUS_ID_SIZE);
-        if ((ret = class_device_register(class_dev)))
-                goto out;
 
-        if (net->get_stats &&
-            (ret = sysfs_create_group(&class_dev->kobj, &netstat_group)))
-                goto out_unreg; 
+        if (net->get_stats)
+                *groups++ = &netstat_group;
 
 #ifdef WIRELESS_EXT
-        if (net->get_wireless_stats || (net->wireless_handlers &&
-                        net->wireless_handlers->get_wireless_stats)) {
-                ret = sysfs_create_group(&class_dev->kobj, &wireless_group);
-                if (ret)
-                        goto out_cleanup;
-        }
-        return 0;
-out_cleanup:
-        if (net->get_stats)
-                sysfs_remove_group(&class_dev->kobj, &netstat_group);
-#else
-        return 0;
+        if (net->get_wireless_stats
+            || (net->wireless_handlers && net->wireless_handlers->get_wireless_stats))
+                *groups++ = &wireless_group;
 #endif
 
-out_unreg:
-        printk(KERN_WARNING "%s: sysfs attribute registration failed %d\n",
-               net->name, ret);
-        class_device_unregister(class_dev);
-out:
-        return ret;
+        return class_device_add(class_dev);
 }
 
 int netdev_sysfs_init(void)