rds: tcp: set linger to 1 when unloading a rds-tcp

If we are unloading the rds_tcp module, we can set linger to 1
and drop pending packets to accelerate reconnect. The peer will
end up resetting the connection based on new generation numbers
of the new incarnation, so hanging on to unsent TCP packets via
linger is mostly pointless in this case.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Jenny Xu <jenny.x.xu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 7 insertions, 2 deletions

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 382443b060cb..50a3789ac23e 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -412,6 +412,7 @@ void rds_conn_destroy(struct rds_connection *conn)
                  "%pI4\n", conn, &conn->c_laddr,
                  &conn->c_faddr);
 
+        conn->c_destroy_in_prog = 1;
         /* Ensure conn will not be scheduled for reconnect */
         spin_lock_irq(&rds_conn_lock);
         hlist_del_init_rcu(&conn->c_hash_node);
diff --git a/net/rds/rds.h b/net/rds/rds.h
index aa696b361e20..4a25db7075b1 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -137,7 +137,8 @@ struct rds_connection {
         __be32                  c_faddr;
         unsigned int            c_loopback:1,
                                 c_ping_triggered:1,
-                                c_pad_to_32:30;
+                                c_destroy_in_prog:1,
+                                c_pad_to_32:29;
         int                     c_npaths;
         struct rds_connection   *c_passive;
         struct rds_transport    *c_trans;
diff --git a/net/rds/tcp.h b/net/rds/tcp.h
index 56ea6620fcf9..f8800b7ce79c 100644
--- a/net/rds/tcp.h
+++ b/net/rds/tcp.h
@@ -71,6 +71,7 @@ void rds_tcp_listen_data_ready(struct sock *sk);
 int rds_tcp_accept_one(struct socket *sock);
 int rds_tcp_keepalive(struct socket *sock);
 void *rds_tcp_listen_sock_def_readable(struct net *net);
+void rds_tcp_set_linger(struct socket *sock);
 
 /* tcp_recv.c */
 int rds_tcp_recv_init(void);
diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c
index 5a62a083bb5a..cbe08a1fa4c7 100644
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -170,6 +170,8 @@ void rds_tcp_conn_path_shutdown(struct rds_conn_path *cp)
                  cp->cp_conn, tc, sock);
 
         if (sock) {
+                if (cp->cp_conn->c_destroy_in_prog)
+                        rds_tcp_set_linger(sock);
                 sock->ops->shutdown(sock, RCV_SHUTDOWN | SEND_SHUTDOWN);
                 lock_sock(sock->sk);
                 rds_tcp_restore_callbacks(sock, tc); /* tc->tc_sock = NULL */
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 6089e9a8e00a..c6dc8caaf5ca 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -112,7 +112,7 @@ struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn)
         return NULL;
 }
 
-static void rds_tcp_set_linger(struct socket *sock)
+void rds_tcp_set_linger(struct socket *sock)
 {
         struct linger no_linger = {
                 .l_onoff = 1,