1 files changed, 46 insertions, 14 deletions

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index e7ee65dc20bf..cbd677f48c00 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -448,10 +448,15 @@ out:
  *  possibly free it
  * @softif_vlan: the vlan object to release
  */
-void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *softif_vlan)
+void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *vlan)
 {
-        if (atomic_dec_and_test(&softif_vlan->refcount))
-                kfree_rcu(softif_vlan, rcu);
+        if (atomic_dec_and_test(&vlan->refcount)) {
+                spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock);
+                hlist_del_rcu(&vlan->list);
+                spin_unlock_bh(&vlan->bat_priv->softif_vlan_list_lock);
+
+                kfree_rcu(vlan, rcu);
+        }
 }
 
 /**
@@ -505,6 +510,7 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
         if (!vlan)
                 return -ENOMEM;
 
+        vlan->bat_priv = bat_priv;
         vlan->vid = vid;
         atomic_set(&vlan->refcount, 1);
 
@@ -516,6 +522,10 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
                 return err;
         }
 
+        spin_lock_bh(&bat_priv->softif_vlan_list_lock);
+        hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
+        spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
+
         /* add a new TT local entry. This one will be marked with the NOPURGE
          * flag
          */
@@ -523,10 +533,6 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
                             bat_priv->soft_iface->dev_addr, vid,
                             BATADV_NULL_IFINDEX, BATADV_NO_MARK);
 
-        spin_lock_bh(&bat_priv->softif_vlan_list_lock);
-        hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
-        spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
-
         return 0;
 }
 
@@ -538,18 +544,13 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
 static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv,
                                        struct batadv_softif_vlan *vlan)
 {
-        spin_lock_bh(&bat_priv->softif_vlan_list_lock);
-        hlist_del_rcu(&vlan->list);
-        spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
-
-        batadv_sysfs_del_vlan(bat_priv, vlan);
-
         /* explicitly remove the associated TT local entry because it is marked
          * with the NOPURGE flag
          */
         batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr,
                                vlan->vid, "vlan interface destroyed", false);
 
+        batadv_sysfs_del_vlan(bat_priv, vlan);
         batadv_softif_vlan_free_ref(vlan);
 }
 
@@ -567,6 +568,8 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
                                     unsigned short vid)
 {
         struct batadv_priv *bat_priv = netdev_priv(dev);
+        struct batadv_softif_vlan *vlan;
+        int ret;
 
         /* only 802.1Q vlans are supported.
          * batman-adv does not know how to handle other types
@@ -576,7 +579,36 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
 
         vid |= BATADV_VLAN_HAS_TAG;
 
-        return batadv_softif_create_vlan(bat_priv, vid);
+        /* if a new vlan is getting created and it already exists, it means that
+         * it was not deleted yet. batadv_softif_vlan_get() increases the
+         * refcount in order to revive the object.
+         *
+         * if it does not exist then create it.
+         */
+        vlan = batadv_softif_vlan_get(bat_priv, vid);
+        if (!vlan)
+                return batadv_softif_create_vlan(bat_priv, vid);
+
+        /* recreate the sysfs object if it was already destroyed (and it should
+         * be since we received a kill_vid() for this vlan
+         */
+        if (!vlan->kobj) {
+                ret = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan);
+                if (ret) {
+                        batadv_softif_vlan_free_ref(vlan);
+                        return ret;
+                }
+        }
+
+        /* add a new TT local entry. This one will be marked with the NOPURGE
+         * flag. This must be added again, even if the vlan object already
+         * exists, because the entry was deleted by kill_vid()
+         */
+        batadv_tt_local_add(bat_priv->soft_iface,
+                            bat_priv->soft_iface->dev_addr, vid,
+                            BATADV_NULL_IFINDEX, BATADV_NO_MARK);
+
+        return 0;
 }
 
 /**