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

Orabug 23542064

Backport of upstream commit 37e14f4fe299 ("RDS: TCP: rds_tcp_accept_worker()
must exit gracefully when terminating rds-tcp")

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->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 <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 330c304853f7a38bc8ee45da1b1bd77b19b0bd62..38a6df62cdb7d41df86458628784076c17d3e129 100644 (file)
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -79,6 +79,9 @@ 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);