net: Introduce unregister_netdevice_many()
Introduce rollback_registered_many() and unregister_netdevice_many()
rollback_registered_many() is able to perform necessary steps at device dismantle
time, factorizing two expensive synchronize_net() calls.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index ff94e2b..04d3e30 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4637,59 +4637,76 @@
list_add_tail(&dev->todo_list, &net_todo_list);
}
-static void rollback_registered(struct net_device *dev)
+static void rollback_registered_many(struct list_head *head)
{
+ struct net_device *dev;
+
BUG_ON(dev_boot_phase);
ASSERT_RTNL();
- /* Some devices call without registering for initialization unwind. */
- if (dev->reg_state == NETREG_UNINITIALIZED) {
- printk(KERN_DEBUG "unregister_netdevice: device %s/%p never "
- "was registered\n", dev->name, dev);
+ list_for_each_entry(dev, head, unreg_list) {
+ /* Some devices call without registering
+ * for initialization unwind.
+ */
+ if (dev->reg_state == NETREG_UNINITIALIZED) {
+ pr_debug("unregister_netdevice: device %s/%p never "
+ "was registered\n", dev->name, dev);
- WARN_ON(1);
- return;
+ WARN_ON(1);
+ return;
+ }
+
+ BUG_ON(dev->reg_state != NETREG_REGISTERED);
+
+ /* If device is running, close it first. */
+ dev_close(dev);
+
+ /* And unlink it from device chain. */
+ unlist_netdevice(dev);
+
+ dev->reg_state = NETREG_UNREGISTERING;
}
- BUG_ON(dev->reg_state != NETREG_REGISTERED);
+ synchronize_net();
- /* If device is running, close it first. */
- dev_close(dev);
+ list_for_each_entry(dev, head, unreg_list) {
+ /* Shutdown queueing discipline. */
+ dev_shutdown(dev);
- /* And unlink it from device chain. */
- unlist_netdevice(dev);
- dev->reg_state = NETREG_UNREGISTERING;
+ /* Notify protocols, that we are about to destroy
+ this device. They should clean all the things.
+ */
+ call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
+
+ /*
+ * Flush the unicast and multicast chains
+ */
+ dev_unicast_flush(dev);
+ dev_addr_discard(dev);
+
+ if (dev->netdev_ops->ndo_uninit)
+ dev->netdev_ops->ndo_uninit(dev);
+
+ /* Notifier chain MUST detach us from master device. */
+ WARN_ON(dev->master);
+
+ /* Remove entries from kobject tree */
+ netdev_unregister_kobject(dev);
+ }
synchronize_net();
- /* Shutdown queueing discipline. */
- dev_shutdown(dev);
+ list_for_each_entry(dev, head, unreg_list)
+ dev_put(dev);
+}
+static void rollback_registered(struct net_device *dev)
+{
+ LIST_HEAD(single);
- /* Notify protocols, that we are about to destroy
- this device. They should clean all the things.
- */
- call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
-
- /*
- * Flush the unicast and multicast chains
- */
- dev_unicast_flush(dev);
- dev_addr_discard(dev);
-
- if (dev->netdev_ops->ndo_uninit)
- dev->netdev_ops->ndo_uninit(dev);
-
- /* Notifier chain MUST detach us from master device. */
- WARN_ON(dev->master);
-
- /* Remove entries from kobject tree */
- netdev_unregister_kobject(dev);
-
- synchronize_net();
-
- dev_put(dev);
+ list_add(&dev->unreg_list, &single);
+ rollback_registered_many(&single);
}
static void __netdev_init_queue_locks_one(struct net_device *dev,
@@ -5272,6 +5289,22 @@
EXPORT_SYMBOL(unregister_netdevice_queue);
/**
+ * unregister_netdevice_many - unregister many devices
+ * @head: list of devices
+ *
+ */
+void unregister_netdevice_many(struct list_head *head)
+{
+ struct net_device *dev;
+
+ if (!list_empty(head)) {
+ rollback_registered_many(head);
+ list_for_each_entry(dev, head, unreg_list)
+ net_set_todo(dev);
+ }
+}
+
+/**
* unregister_netdev - remove device from the kernel
* @dev: device
*