vlan: Optimize multiple unregistration

Use unregister_netdevice_many() to speedup master device unregister.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 35 insertions, 16 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 8898cbebcf34..71a4870c09a9 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -85,6 +85,7 @@ struct vlan_group {
                                             * the vlan is attached to.
                                             */
         unsigned int            nr_vlans;
+        int                     killall;
         struct hlist_node       hlist;  /* linked list */
         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
         struct rcu_head         rcu;
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 6b5c9dddaa72..511afe72af31 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -159,11 +159,12 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
                 ops->ndo_vlan_rx_kill_vid(real_dev, vlan_id);
 
-        vlan_group_set_device(grp, vlan_id, NULL);
         grp->nr_vlans--;
 
-        synchronize_net();
-
+        if (!grp->killall) {
+                vlan_group_set_device(grp, vlan_id, NULL);
+                synchronize_net();
+        }
         unregister_netdevice_queue(dev, head);
 
         /* If the group is now empty, kill off the group. */
@@ -183,6 +184,34 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
         dev_put(real_dev);
 }
 
+void unregister_vlan_dev_alls(struct vlan_group *grp)
+{
+        LIST_HEAD(list);
+        int i;
+        struct net_device *vlandev;
+        struct vlan_group save;
+
+        memcpy(&save, grp, sizeof(save));
+        memset(&grp->vlan_devices_arrays, 0, sizeof(grp->vlan_devices_arrays));
+        grp->killall = 1;
+
+        synchronize_net();
+
+        /* Delete all VLANs for this dev. */
+        for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
+                vlandev = vlan_group_get_device(&save, i);
+                if (!vlandev)
+                        continue;
+
+                unregister_vlan_dev(vlandev, &list);
+                if (grp->nr_vlans == 0)
+                        break;
+        }
+        unregister_netdevice_many(&list);
+        for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
+                kfree(save.vlan_devices_arrays[i]);
+}
+
 static void vlan_transfer_operstate(const struct net_device *dev,
                                     struct net_device *vlandev)
 {
@@ -524,19 +553,7 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
                 break;
 
         case NETDEV_UNREGISTER:
-                /* Delete all VLANs for this dev. */
-                for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
-                        vlandev = vlan_group_get_device(grp, i);
-                        if (!vlandev)
-                                continue;
-
-                        /* unregistration of last vlan destroys group, abort
-                         * afterwards */
-                        if (grp->nr_vlans == 1)
-                                i = VLAN_GROUP_ARRAY_LEN;
-
-                        unregister_vlan_dev(vlandev, NULL);
-                }
+                unregister_vlan_dev_alls(grp);
                 break;
         }
 
diff --git a/net/core/dev.c b/net/core/dev.c
index 4513dfd5718e..09551cc143a9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5303,6 +5303,7 @@ void unregister_netdevice_many(struct list_head *head)
                         net_set_todo(dev);
         }
 }
+EXPORT_SYMBOL(unregister_netdevice_many);
 
 /**
  *      unregister_netdev - remove device from the kernel