RDS: TCP: rds_tcp_accept_worker() must exit gracefully when terminating rds-tcp

sowminiv · davem330 · commit 37e14f4fe299 · 2016-05-20T19:19:57.000-04:00
There are two instances where we want to terminate RDS-TCP: when
exiting the netns or during module unload. In either case, the
termination sequence is to stop the listen socket, mark the
rtn-&gt;rds_tcp_listen_sock as null, and flush any accept workqs.
Thus any workqs that get flushed at this point will encounter a
null rds_tcp_listen_sock, and must exit gracefully to allow
the RDS-TCP termination to complete successfully.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
@@ -80,6 +80,9 @@ int rds_tcp_accept_one(struct socket *sock)
 	int conn_state;
 	struct sock *nsk;
 
+	if (!sock) /* module unload or netns delete in progress */
+		return -ENETUNREACH;
+
 	ret = sock_create_kern(sock_net(sock->sk), sock->sk->sk_family,
 			       sock->sk->sk_type, sock->sk->sk_protocol,
 			       &new_sock);
