1 files changed, 72 insertions, 55 deletions

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index ccf70bed0d0c..c59aff5ccac8 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2009-2015 B.A.T.M.A.N. contributors:
+/* Copyright (C) 2009-2016  B.A.T.M.A.N. contributors:
  *
  * Marek Lindner
  *
@@ -28,6 +28,7 @@
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/kernel.h>
+#include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/rculist.h>
@@ -59,12 +60,28 @@
  */
 #define BATADV_DHCP_CHADDR_OFFSET	28
 
-static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
+/**
+ * batadv_gw_node_release - release gw_node from lists and queue for free after
+ *  rcu grace period
+ * @ref: kref pointer of the gw_node
+ */
+static void batadv_gw_node_release(struct kref *ref)
 {
-	if (atomic_dec_and_test(&gw_node->refcount)) {
-		batadv_orig_node_free_ref(gw_node->orig_node);
-		kfree_rcu(gw_node, rcu);
-	}
+	struct batadv_gw_node *gw_node;
+
+	gw_node = container_of(ref, struct batadv_gw_node, refcount);
+
+	batadv_orig_node_put(gw_node->orig_node);
+	kfree_rcu(gw_node, rcu);
+}
+
+/**
+ * batadv_gw_node_put - decrement the gw_node refcounter and possibly release it
+ * @gw_node: gateway node to free
+ */
+static void batadv_gw_node_put(struct batadv_gw_node *gw_node)
+{
+	kref_put(&gw_node->refcount, batadv_gw_node_release);
 }
 
 static struct batadv_gw_node *
@@ -77,7 +94,7 @@ batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
 	if (!gw_node)
 		goto out;
 
-	if (!atomic_inc_not_zero(&gw_node->refcount))
+	if (!kref_get_unless_zero(&gw_node->refcount))
 		gw_node = NULL;
 
 out:
@@ -100,14 +117,14 @@ batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
 	if (!orig_node)
 		goto unlock;
 
-	if (!atomic_inc_not_zero(&orig_node->refcount))
+	if (!kref_get_unless_zero(&orig_node->refcount))
 		orig_node = NULL;
 
 unlock:
 	rcu_read_unlock();
 out:
 	if (gw_node)
-		batadv_gw_node_free_ref(gw_node);
+		batadv_gw_node_put(gw_node);
 	return orig_node;
 }
 
@@ -118,14 +135,14 @@ static void batadv_gw_select(struct batadv_priv *bat_priv,
 
 	spin_lock_bh(&bat_priv->gw.list_lock);
 
-	if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
+	if (new_gw_node && !kref_get_unless_zero(&new_gw_node->refcount))
 		new_gw_node = NULL;
 
 	curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
 	rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);
 
 	if (curr_gw_node)
-		batadv_gw_node_free_ref(curr_gw_node);
+		batadv_gw_node_put(curr_gw_node);
 
 	spin_unlock_bh(&bat_priv->gw.list_lock);
 }
@@ -170,7 +187,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 		if (!router_ifinfo)
 			goto next;
 
-		if (!atomic_inc_not_zero(&gw_node->refcount))
+		if (!kref_get_unless_zero(&gw_node->refcount))
 			goto next;
 
 		tq_avg = router_ifinfo->bat_iv.tq_avg;
@@ -186,9 +203,9 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 			    ((tmp_gw_factor == max_gw_factor) &&
 			     (tq_avg > max_tq))) {
 				if (curr_gw)
-					batadv_gw_node_free_ref(curr_gw);
+					batadv_gw_node_put(curr_gw);
 				curr_gw = gw_node;
-				atomic_inc(&curr_gw->refcount);
+				kref_get(&curr_gw->refcount);
 			}
 			break;
 
@@ -201,9 +218,9 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 			  */
 			if (tq_avg > max_tq) {
 				if (curr_gw)
-					batadv_gw_node_free_ref(curr_gw);
+					batadv_gw_node_put(curr_gw);
 				curr_gw = gw_node;
-				atomic_inc(&curr_gw->refcount);
+				kref_get(&curr_gw->refcount);
 			}
 			break;
 		}
@@ -214,12 +231,12 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 		if (tmp_gw_factor > max_gw_factor)
 			max_gw_factor = tmp_gw_factor;
 
-		batadv_gw_node_free_ref(gw_node);
+		batadv_gw_node_put(gw_node);
 
 next:
-		batadv_neigh_node_free_ref(router);
+		batadv_neigh_node_put(router);
 		if (router_ifinfo)
-			batadv_neigh_ifinfo_free_ref(router_ifinfo);
+			batadv_neigh_ifinfo_put(router_ifinfo);
 	}
 	rcu_read_unlock();
 
@@ -255,7 +272,7 @@ void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
 	 */
 	batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, NULL);
 
-	batadv_gw_node_free_ref(curr_gw);
+	batadv_gw_node_put(curr_gw);
 }
 
 void batadv_gw_election(struct batadv_priv *bat_priv)
@@ -330,13 +347,13 @@ void batadv_gw_election(struct batadv_priv *bat_priv)
 
 out:
 	if (curr_gw)
-		batadv_gw_node_free_ref(curr_gw);
+		batadv_gw_node_put(curr_gw);
 	if (next_gw)
-		batadv_gw_node_free_ref(next_gw);
+		batadv_gw_node_put(next_gw);
 	if (router)
-		batadv_neigh_node_free_ref(router);
+		batadv_neigh_node_put(router);
 	if (router_ifinfo)
-		batadv_neigh_ifinfo_free_ref(router_ifinfo);
+		batadv_neigh_ifinfo_put(router_ifinfo);
 }
 
 void batadv_gw_check_election(struct batadv_priv *bat_priv,
@@ -397,15 +414,15 @@ reselect:
 	batadv_gw_reselect(bat_priv);
 out:
 	if (curr_gw_orig)
-		batadv_orig_node_free_ref(curr_gw_orig);
+		batadv_orig_node_put(curr_gw_orig);
 	if (router_gw)
-		batadv_neigh_node_free_ref(router_gw);
+		batadv_neigh_node_put(router_gw);
 	if (router_orig)
-		batadv_neigh_node_free_ref(router_orig);
+		batadv_neigh_node_put(router_orig);
 	if (router_gw_tq)
-		batadv_neigh_ifinfo_free_ref(router_gw_tq);
+		batadv_neigh_ifinfo_put(router_gw_tq);
 	if (router_orig_tq)
-		batadv_neigh_ifinfo_free_ref(router_orig_tq);
+		batadv_neigh_ifinfo_put(router_orig_tq);
 }
 
 /**
@@ -423,12 +440,12 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
 	if (gateway->bandwidth_down == 0)
 		return;
 
-	if (!atomic_inc_not_zero(&orig_node->refcount))
+	if (!kref_get_unless_zero(&orig_node->refcount))
 		return;
 
 	gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
 	if (!gw_node) {
-		batadv_orig_node_free_ref(orig_node);
+		batadv_orig_node_put(orig_node);
 		return;
 	}
 
@@ -436,7 +453,7 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
 	gw_node->orig_node = orig_node;
 	gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
 	gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);
-	atomic_set(&gw_node->refcount, 1);
+	kref_init(&gw_node->refcount);
 
 	spin_lock_bh(&bat_priv->gw.list_lock);
 	hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
@@ -456,7 +473,7 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
  * @bat_priv: the bat priv with all the soft interface information
  * @orig_node: originator announcing gateway capabilities
  *
- * Returns gateway node if found or NULL otherwise.
+ * Return: gateway node if found or NULL otherwise.
  */
 static struct batadv_gw_node *
 batadv_gw_node_get(struct batadv_priv *bat_priv,
@@ -469,7 +486,7 @@ batadv_gw_node_get(struct batadv_priv *bat_priv,
 		if (gw_node_tmp->orig_node != orig_node)
 			continue;
 
-		if (!atomic_inc_not_zero(&gw_node_tmp->refcount))
+		if (!kref_get_unless_zero(&gw_node_tmp->refcount))
 			continue;
 
 		gw_node = gw_node_tmp;
@@ -529,7 +546,7 @@ void batadv_gw_node_update(struct batadv_priv *bat_priv,
 		spin_lock_bh(&bat_priv->gw.list_lock);
 		if (!hlist_unhashed(&gw_node->list)) {
 			hlist_del_init_rcu(&gw_node->list);
-			batadv_gw_node_free_ref(gw_node);
+			batadv_gw_node_put(gw_node);
 		}
 		spin_unlock_bh(&bat_priv->gw.list_lock);
 
@@ -538,12 +555,12 @@ void batadv_gw_node_update(struct batadv_priv *bat_priv,
 			batadv_gw_reselect(bat_priv);
 
 		if (curr_gw)
-			batadv_gw_node_free_ref(curr_gw);
+			batadv_gw_node_put(curr_gw);
 	}
 
 out:
 	if (gw_node)
-		batadv_gw_node_free_ref(gw_node);
+		batadv_gw_node_put(gw_node);
 }
 
 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
@@ -566,7 +583,7 @@ void batadv_gw_node_free(struct batadv_priv *bat_priv)
 	hlist_for_each_entry_safe(gw_node, node_tmp,
 				  &bat_priv->gw.list, list) {
 		hlist_del_init_rcu(&gw_node->list);
-		batadv_gw_node_free_ref(gw_node);
+		batadv_gw_node_put(gw_node);
 	}
 	spin_unlock_bh(&bat_priv->gw.list_lock);
 }
@@ -603,12 +620,12 @@ static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
 	ret = seq_has_overflowed(seq) ? -1 : 0;
 
 	if (curr_gw)
-		batadv_gw_node_free_ref(curr_gw);
+		batadv_gw_node_put(curr_gw);
 out:
 	if (router_ifinfo)
-		batadv_neigh_ifinfo_free_ref(router_ifinfo);
+		batadv_neigh_ifinfo_put(router_ifinfo);
 	if (router)
-		batadv_neigh_node_free_ref(router);
+		batadv_neigh_node_put(router);
 	return ret;
 }
 
@@ -645,7 +662,7 @@ int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
 
 out:
 	if (primary_if)
-		batadv_hardif_free_ref(primary_if);
+		batadv_hardif_put(primary_if);
 	return 0;
 }
 
@@ -656,13 +673,13 @@ out:
  * @chaddr: buffer where the client address will be stored. Valid
  *  only if the function returns BATADV_DHCP_TO_CLIENT
  *
- * Returns:
+ * This function may re-allocate the data buffer of the skb passed as argument.
+ *
+ * Return:
  * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
  *   while parsing it
  * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
  * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
- *
- * This function may re-allocate the data buffer of the skb passed as argument.
  */
 enum batadv_dhcp_recipient
 batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
@@ -777,11 +794,11 @@ batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
  * server. Due to topology changes it may be the case that the GW server
  * previously selected is not the best one anymore.
  *
- * Returns true if the packet destination is unicast and it is not the best gw,
- * false otherwise.
- *
  * This call might reallocate skb data.
  * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
+ *
+ * Return: true if the packet destination is unicast and it is not the best gw,
+ * false otherwise.
  */
 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
 			    struct sk_buff *skb)
@@ -839,7 +856,7 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
 			goto out;
 
 		curr_tq_avg = curr_ifinfo->bat_iv.tq_avg;
-		batadv_neigh_ifinfo_free_ref(curr_ifinfo);
+		batadv_neigh_ifinfo_put(curr_ifinfo);
 
 		break;
 	case BATADV_GW_MODE_OFF:
@@ -857,18 +874,18 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
 
 	if ((curr_tq_avg - old_ifinfo->bat_iv.tq_avg) > BATADV_GW_THRESHOLD)
 		out_of_range = true;
-	batadv_neigh_ifinfo_free_ref(old_ifinfo);
+	batadv_neigh_ifinfo_put(old_ifinfo);
 
 out:
 	if (orig_dst_node)
-		batadv_orig_node_free_ref(orig_dst_node);
+		batadv_orig_node_put(orig_dst_node);
 	if (curr_gw)
-		batadv_gw_node_free_ref(curr_gw);
+		batadv_gw_node_put(curr_gw);
 	if (gw_node)
-		batadv_gw_node_free_ref(gw_node);
+		batadv_gw_node_put(gw_node);
 	if (neigh_old)
-		batadv_neigh_node_free_ref(neigh_old);
+		batadv_neigh_node_put(neigh_old);
 	if (neigh_curr)
-		batadv_neigh_node_free_ref(neigh_curr);
+		batadv_neigh_node_put(neigh_curr);
 	return out_of_range;
 }