1 files changed, 16 insertions, 7 deletions

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 27970a58d29b..0553a6158dcb 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -260,7 +260,7 @@ static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
 static void lowcomms_data_ready(struct sock *sk, int count_unused)
 {
 	struct connection *con = sock2con(sk);
-	if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
+	if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
 		queue_work(recv_workqueue, &con->rwork);
 }
 
@@ -268,7 +268,7 @@ static void lowcomms_write_space(struct sock *sk)
 {
 	struct connection *con = sock2con(sk);
 
-	if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
+	if (con && !test_and_set_bit(CF_WRITE_PENDING, &con->flags))
 		queue_work(send_workqueue, &con->swork);
 }
 
@@ -720,11 +720,17 @@ static int tcp_accept_from_sock(struct connection *con)
 			INIT_WORK(&othercon->rwork, process_recv_sockets);
 			set_bit(CF_IS_OTHERCON, &othercon->flags);
 			newcon->othercon = othercon;
+			othercon->sock = newsock;
+			newsock->sk->sk_user_data = othercon;
+			add_sock(newsock, othercon);
+			addcon = othercon;
+		}
+		else {
+			printk("Extra connection from node %d attempted\n", nodeid);
+			result = -EAGAIN;
+			mutex_unlock(&newcon->sock_mutex);
+			goto accept_err;
 		}
-		othercon->sock = newsock;
-		newsock->sk->sk_user_data = othercon;
-		add_sock(newsock, othercon);
-		addcon = othercon;
 	}
 	else {
 		newsock->sk->sk_user_data = newcon;
@@ -1400,8 +1406,11 @@ void dlm_lowcomms_stop(void)
 	down(&connections_lock);
 	for (i = 0; i <= max_nodeid; i++) {
 		con = __nodeid2con(i, 0);
-		if (con)
+		if (con) {
 			con->flags |= 0xFF;
+			if (con->sock)
+				con->sock->sk->sk_user_data = NULL;
+		}
 	}
 	up(&connections_lock);