Free netdev in rcu callback

2 files changed, 27 insertions, 23 deletions

diff --git a/fastd.c b/fastd.c
index c9afc67..00dd41e 100644
--- a/fastd.c
+++ b/fastd.c
@@ -89,6 +89,7 @@ struct fastd_struct {
 	struct list_head	sockets;
 
 	struct work_struct	destroy_work;
+	struct rcu_head		rcu;
 };
 
 struct fastd_socket {
@@ -204,27 +205,9 @@ static const struct ethtool_ops fastd_ethtool_ops = {
 };
 
 
-static void fastd_netdev_free(struct net_device *dev)
-{
-	struct fastd_struct *fastd = netdev_priv(dev);
-	struct fastd_socket *socket, *next;
-
-	list_for_each_entry_safe(socket, next, &fastd->sockets, list) {
-		list_del(&socket->list);
-		sock_release(socket->sock);
-		kfree(socket);
-	}
-
-	put_net(fastd->net);
-	free_netdev(dev);
-
-	module_put(THIS_MODULE);
-}
-
 static void fastd_netdev_setup(struct net_device *dev)
 {
 	dev->ethtool_ops = &fastd_ethtool_ops;
-	dev->destructor = fastd_netdev_free;
 }
 
 static inline u16 fastd_header_len(u16 mode)
@@ -262,6 +245,24 @@ static void fastd_netdev_init(struct net_device *dev)
 	dev->hard_header_len = fastd_header_len(fastd->mode);
 }
 
+static void fastd_netdev_free(struct rcu_head *rcu)
+{
+	struct fastd_struct *fastd = container_of(rcu, struct fastd_struct,
+						  rcu);
+	struct fastd_socket *socket, *next;
+
+	list_for_each_entry_safe(socket, next, &fastd->sockets, list) {
+		list_del(&socket->list);
+		sk_release_kernel(socket->sock->sk);
+		kfree(socket);
+	}
+
+	put_net(fastd->net);
+	free_netdev(fastd->dev);
+
+	module_put(THIS_MODULE);
+}
+
 static void fastd_destroy_work(struct work_struct *work)
 {
 	struct fastd_struct *fastd = container_of(work, struct fastd_struct,
@@ -273,6 +274,8 @@ static void fastd_destroy_work(struct work_struct *work)
 	unregister_netdevice(fastd->dev);
 
 	rtnl_unlock();
+
+	call_rcu(&fastd->rcu, fastd_netdev_free);
 }
 
 static int fastd_cmd_create(struct sk_buff *skb, struct genl_info *info)
@@ -413,7 +416,7 @@ err_unlock_rcu:
 	rcu_read_unlock();
 
 err_release_sock:
-	sock_release(socket->sock);
+	sk_release_kernel(socket->sock->sk);
 
 err_free_socket:
 	kfree(socket);
diff --git a/fastd.h b/fastd.h
index 55878cc..3017c18 100644
--- a/fastd.h
+++ b/fastd.h
@@ -40,15 +40,16 @@
 #define __LINUX_FASTD_H
 
 enum {
-	FASTD_MODE_ETH = 1,
-	FASTD_MODE_IP
+	FASTD_MODE_UNSPEC,
+	FASTD_MODE_ETH,
+	FASTD_MODE_IP,
 };
 
 enum {
 	FASTD_CMD_UNSPEC,
 	FASTD_CMD_CREATE,
 	FASTD_CMD_BIND,
-	__FASTD_CMD_MAX
+	__FASTD_CMD_MAX,
 };
 
 enum {
@@ -58,7 +59,7 @@ enum {
 	FASTD_A_MTU,
 	FASTD_A_LOCALADDR,
 	FASTD_A_REMOTEADDR,
-	__FASTD_A_MAX
+	__FASTD_A_MAX,
 };