3 files changed, 38 insertions, 50 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 97d30ac67c88..8aecf5df6656 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1316,26 +1316,12 @@ again:
 
                         hlist_del_init(&session->hlist);
 
-                        /* Since we should hold the sock lock while
-                         * doing any unbinding, we need to release the
-                         * lock we're holding before taking that lock.
-                         * Hold a reference to the sock so it doesn't
-                         * disappear as we're jumping between locks.
-                         */
                         if (session->ref != NULL)
                                 (*session->ref)(session);
 
                         write_unlock_bh(&tunnel->hlist_lock);
 
-                        if (tunnel->version != L2TP_HDR_VER_2) {
-                                struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
-
-                                spin_lock_bh(&pn->l2tp_session_hlist_lock);
-                                hlist_del_init_rcu(&session->global_hlist);
-                                spin_unlock_bh(&pn->l2tp_session_hlist_lock);
-                                synchronize_rcu();
-                        }
-
+                        __l2tp_session_unhash(session);
                         l2tp_session_queue_purge(session);
 
                         if (session->session_close != NULL)
@@ -1732,64 +1718,71 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);
  */
 void l2tp_session_free(struct l2tp_session *session)
 {
-        struct l2tp_tunnel *tunnel;
+        struct l2tp_tunnel *tunnel = session->tunnel;
 
         BUG_ON(atomic_read(&session->ref_count) != 0);
 
-        tunnel = session->tunnel;
-        if (tunnel != NULL) {
+        if (tunnel) {
                 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
+                if (session->session_id != 0)
+                        atomic_dec(&l2tp_session_count);
+                sock_put(tunnel->sock);
+                session->tunnel = NULL;
+                l2tp_tunnel_dec_refcount(tunnel);
+        }
+
+        kfree(session);
+
+        return;
+}
+EXPORT_SYMBOL_GPL(l2tp_session_free);
+
+/* Remove an l2tp session from l2tp_core's hash lists.
+ * Provides a tidyup interface for pseudowire code which can't just route all
+ * shutdown via. l2tp_session_delete and a pseudowire-specific session_close
+ * callback.
+ */
+void __l2tp_session_unhash(struct l2tp_session *session)
+{
+        struct l2tp_tunnel *tunnel = session->tunnel;
 
-                /* Delete the session from the hash */
+        /* Remove the session from core hashes */
+        if (tunnel) {
+                /* Remove from the per-tunnel hash */
                 write_lock_bh(&tunnel->hlist_lock);
                 hlist_del_init(&session->hlist);
                 write_unlock_bh(&tunnel->hlist_lock);
 
-                /* Unlink from the global hash if not L2TPv2 */
+                /* For L2TPv3 we have a per-net hash: remove from there, too */
                 if (tunnel->version != L2TP_HDR_VER_2) {
                         struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
-
                         spin_lock_bh(&pn->l2tp_session_hlist_lock);
                         hlist_del_init_rcu(&session->global_hlist);
                         spin_unlock_bh(&pn->l2tp_session_hlist_lock);
                         synchronize_rcu();
                 }
-
-                if (session->session_id != 0)
-                        atomic_dec(&l2tp_session_count);
-
-                sock_put(tunnel->sock);
-
-                /* This will delete the tunnel context if this
-                 * is the last session on the tunnel.
-                 */
-                session->tunnel = NULL;
-                l2tp_tunnel_dec_refcount(tunnel);
         }
-
-        kfree(session);
-
-        return;
 }
-EXPORT_SYMBOL_GPL(l2tp_session_free);
+EXPORT_SYMBOL_GPL(__l2tp_session_unhash);
 
 /* This function is used by the netlink SESSION_DELETE command and by
    pseudowire modules.
  */
 int l2tp_session_delete(struct l2tp_session *session)
 {
+        if (session->ref)
+                (*session->ref)(session);
+        __l2tp_session_unhash(session);
         l2tp_session_queue_purge(session);
-
         if (session->session_close != NULL)
                 (*session->session_close)(session);
-
+        if (session->deref)
+                (*session->ref)(session);
         l2tp_session_dec_refcount(session);
-
         return 0;
 }
 EXPORT_SYMBOL_GPL(l2tp_session_delete);
 
-
 /* We come here whenever a session's send_seq, cookie_len or
  * l2specific_len parameters are set.
  */
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 519b013f8b31..485a490fd990 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -242,6 +242,7 @@ extern int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_i
 extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
 extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
 extern struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
+extern void __l2tp_session_unhash(struct l2tp_session *session);
 extern int l2tp_session_delete(struct l2tp_session *session);
 extern void l2tp_session_free(struct l2tp_session *session);
 extern void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, unsigned char *ptr, unsigned char *optr, u16 hdrflags, int length, int (*payload_hook)(struct sk_buff *skb));
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 9d0eb8c13530..637a341c1e2d 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -466,19 +466,12 @@ static void pppol2tp_session_close(struct l2tp_session *session)
  */
 static void pppol2tp_session_destruct(struct sock *sk)
 {
-        struct l2tp_session *session;
-
-        if (sk->sk_user_data != NULL) {
-                session = sk->sk_user_data;
-                if (session == NULL)
-                        goto out;
-
+        struct l2tp_session *session = sk->sk_user_data;
+        if (session) {
                 sk->sk_user_data = NULL;
                 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
                 l2tp_session_dec_refcount(session);
         }
-
-out:
         return;
 }
 
@@ -509,6 +502,7 @@ static int pppol2tp_release(struct socket *sock)
 
         /* Purge any queued data */
         if (session != NULL) {
+                __l2tp_session_unhash(session);
                 l2tp_session_queue_purge(session);
                 sock_put(sk);
         }