[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>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a461b51d6076387386aee2284679ab4390d2c31f..f4169bbb60eb8036d021ba64e9270f6b5ffcaabb 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -433,8 +433,7 @@ struct net_device
 
        /* register/unregister state machine */
        enum { NETREG_UNINITIALIZED=0,
-              NETREG_REGISTERING,      /* called register_netdevice */
-              NETREG_REGISTERED,       /* completed register todo */
+              NETREG_REGISTERED,       /* completed register_netdevice */
               NETREG_UNREGISTERING,    /* called unregister_netdevice */
               NETREG_UNREGISTERED,     /* completed unregister todo */
               NETREG_RELEASED,         /* called free_netdev */

diff --git a/net/core/dev.c b/net/core/dev.c
index ced57430f6d873cb48f6a867960476c424c71db2..2dce673a039b6f4f71888e4780678b35924e7d3e 100644 (file)
--- 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: