[NET]: Do sysfs registration as part of register_netdevice.

The last step of netdevice registration was being done by a delayed
call, but because it was delayed, it was impossible to return any error
code if the class_device registration failed.

Side effects:
 * one state in registration process is unnecessary.
 * register_netdevice can sleep inside class_device registration/hotplug
 * code in netdev_run_todo only does unregistration so it is simpler.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 36 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index ced57430f6d..2dce673a039 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2777,6 +2777,8 @@ int register_netdevice(struct net_device *dev)
         BUG_ON(dev_boot_phase);
         ASSERT_RTNL();
 
+        might_sleep();
+
         /* When net_device's are persistent, this will be fatal. */
         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
 
@@ -2863,6 +2865,11 @@ int register_netdevice(struct net_device *dev)
         if (!dev->rebuild_header)
                 dev->rebuild_header = default_rebuild_header;
 
+        ret = netdev_register_sysfs(dev);
+        if (ret)
+                goto out_err;
+        dev->reg_state = NETREG_REGISTERED;
+
         /*
          *      Default initial state at registry is that the
          *      device is present.
@@ -2878,14 +2885,11 @@ int register_netdevice(struct net_device *dev)
         hlist_add_head(&dev->name_hlist, head);
         hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
         dev_hold(dev);
-        dev->reg_state = NETREG_REGISTERING;
         write_unlock_bh(&dev_base_lock);
 
         /* Notify protocols, that a new device appeared. */
         raw_notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev);
 
-        /* Finish registration after unlock */
-        net_set_todo(dev);
         ret = 0;
 
 out:
@@ -3008,7 +3012,7 @@ static void netdev_wait_allrefs(struct net_device *dev)
  *
  * We are invoked by rtnl_unlock() after it drops the semaphore.
  * This allows us to deal with problems:
- * 1) We can create/delete sysfs objects which invoke hotplug
+ * 1) We can delete sysfs objects which invoke hotplug
  *    without deadlocking with linkwatch via keventd.
  * 2) Since we run with the RTNL semaphore not held, we can sleep
  *    safely in order to wait for the netdev refcnt to drop to zero.
@@ -3017,8 +3021,6 @@ static DEFINE_MUTEX(net_todo_run_mutex);
 void netdev_run_todo(void)
 {
         struct list_head list = LIST_HEAD_INIT(list);
-        int err;
-
 
         /* Need to guard against multiple cpu's getting out of order. */
         mutex_lock(&net_todo_run_mutex);
@@ -3041,40 +3043,29 @@ void netdev_run_todo(void)
                         = list_entry(list.next, struct net_device, todo_list);
                 list_del(&dev->todo_list);
 
-                switch(dev->reg_state) {
-                case NETREG_REGISTERING:
-                        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:
-                        netdev_unregister_sysfs(dev);
-                        dev->reg_state = NETREG_UNREGISTERED;
-
-                        netdev_wait_allrefs(dev);
+                if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
+                        printk(KERN_ERR "network todo '%s' but state %d\n",
+                               dev->name, dev->reg_state);
+                        dump_stack();
+                        continue;
+                }
 
-                        /* paranoia */
-                        BUG_ON(atomic_read(&dev->refcnt));
-                        BUG_TRAP(!dev->ip_ptr);
-                        BUG_TRAP(!dev->ip6_ptr);
-                        BUG_TRAP(!dev->dn_ptr);
+                netdev_unregister_sysfs(dev);
+                dev->reg_state = NETREG_UNREGISTERED;
 
+                netdev_wait_allrefs(dev);
 
-                        /* It must be the very last action, 
-                         * after this 'dev' may point to freed up memory.
-                         */
-                        if (dev->destructor)
-                                dev->destructor(dev);
-                        break;
+                /* paranoia */
+                BUG_ON(atomic_read(&dev->refcnt));
+                BUG_TRAP(!dev->ip_ptr);
+                BUG_TRAP(!dev->ip6_ptr);
+                BUG_TRAP(!dev->dn_ptr);
 
-                default:
-                        printk(KERN_ERR "network todo '%s' but state %d\n",
-                               dev->name, dev->reg_state);
-                        break;
-                }
+                /* It must be the very last action,
+                 * after this 'dev' may point to freed up memory.
+                 */
+                if (dev->destructor)
+                        dev->destructor(dev);
         }
 
 out: