[DLM] Fix lowcomms socket closing

This patch fixes the slight mess made in lowcomms closing by previous patches
and fixes all sorts of DLM hangs.

Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/dlm/lowcomms.c

@@ -334,18 +334,8 @@ static void close_connection(struct connection *con, bool and_other)
 		con->rx_page = NULL;
 	}
 
-	/* If we are an 'othercon' then NULL the pointer to us
-	   from the parent and tidy ourself up */
-	if (test_bit(CF_IS_OTHERCON, &con->flags)) {
-		struct connection *parent = __nodeid2con(con->nodeid, 0);
-		parent->othercon = NULL;
-		kmem_cache_free(con_cache, con);
-	}
-	else {
-		/* Parent connections get reused */
-		con->retries = 0;
-		mutex_unlock(&con->sock_mutex);
-	}
+	con->retries = 0;
+	mutex_unlock(&con->sock_mutex);
 }
 
 /* We only send shutdown messages to nodes that are not part of the cluster */
@@ -731,6 +721,8 @@ static int tcp_accept_from_sock(struct connection *con)
 			INIT_WORK(&othercon->swork, process_send_sockets);
 			INIT_WORK(&othercon->rwork, process_recv_sockets);
 			set_bit(CF_IS_OTHERCON, &othercon->flags);
+		}
+		if (!othercon->sock) {
 			newcon->othercon = othercon;
 			othercon->sock = newsock;
 			newsock->sk->sk_user_data = othercon;