3 files changed, 28 insertions, 6 deletions

diff --git a/net/Kconfig b/net/Kconfig
index d789d79551ae..8c3d97ca0d96 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
         bool "Network namespace support"
         default n
-        depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+        depends on EXPERIMENTAL && NAMESPACES
         help
           Allow user space to create what appear to be multiple instances
           of the network stack.
diff --git a/net/core/dev.c b/net/core/dev.c
index d9038e328cc1..3a2b8be9e67b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -924,10 +924,15 @@ int dev_change_name(struct net_device *dev, const char *newname)
                 strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-        ret = device_rename(&dev->dev, dev->name);
-        if (ret) {
-                memcpy(dev->name, oldname, IFNAMSIZ);
-                return ret;
+        /* For now only devices in the initial network namespace
+         * are in sysfs.
+         */
+        if (net == &init_net) {
+                ret = device_rename(&dev->dev, dev->name);
+                if (ret) {
+                        memcpy(dev->name, oldname, IFNAMSIZ);
+                        return ret;
+                }
         }
 
         write_lock_bh(&dev_base_lock);
@@ -4460,6 +4465,15 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
         if (dev->features & NETIF_F_NETNS_LOCAL)
                 goto out;
 
+#ifdef CONFIG_SYSFS
+        /* Don't allow real devices to be moved when sysfs
+         * is enabled.
+         */
+        err = -EINVAL;
+        if (dev->dev.parent)
+                goto out;
+#endif
+
         /* Ensure the device has been registrered */
         err = -EINVAL;
         if (dev->reg_state != NETREG_REGISTERED)
@@ -4517,6 +4531,8 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
          */
         dev_addr_discard(dev);
 
+        netdev_unregister_kobject(dev);
+
         /* Actually switch the network namespace */
         dev_net_set(dev, net);
 
@@ -4533,7 +4549,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
         }
 
         /* Fixup kobjects */
-        netdev_unregister_kobject(dev);
         err = netdev_register_kobject(dev);
         WARN_ON(err);
 
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 92d6b9467314..85cb8bdcfb8f 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -476,6 +476,10 @@ void netdev_unregister_kobject(struct net_device * net)
         struct device *dev = &(net->dev);
 
         kobject_get(&dev->kobj);
+
+        if (dev_net(net) != &init_net)
+                return;
+
         device_del(dev);
 }
 
@@ -501,6 +505,9 @@ int netdev_register_kobject(struct net_device *net)
 #endif
 #endif /* CONFIG_SYSFS */
 
+        if (dev_net(net) != &init_net)
+                return 0;
+
         return device_add(dev);
 }