Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:
 "Some straggler bug fixes:

   1) Batman-adv DAT must consider VLAN IDs when choosing candidate
      nodes, from Antonio Quartulli.

   2) Fix botched reference counting of vlan objects and neigh nodes in
      batman-adv, from Sven Eckelmann.

   3) netem can crash when it sees GSO packets, the fix is to segment
      then upon ->enqueue.  Fix from Neil Horman with help from Eric
      Dumazet.

   4) Fix VXLAN dependencies in mlx5 driver Kconfig, from Matthew
      Finlay.

   5) Handle VXLAN ops outside of rcu lock, via a workqueue, in mlx5,
      since it can sleep.  Fix also from Matthew Finlay.

   6) Check mdiobus_scan() return values properly in pxa168_eth and macb
      drivers.  From Sergei Shtylyov.

   7) If the netdevice doesn't support checksumming, disable
      segmentation.  From Alexandery Duyck.

   8) Fix races between RDS tcp accept and sending, from Sowmini
      Varadhan.

   9) In macb driver, probe MDIO bus before we register the netdev,
      otherwise we can try to open the device before it is really ready
      for that.  Fix from Florian Fainelli.

  10) Netlink attribute size for ILA "tunnels" not calculated properly,
      fix from Nicolas Dichtel"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  ipv6/ila: fix nlsize calculation for lwtunnel
  net: macb: Probe MDIO bus before registering netdev
  RDS: TCP: Synchronize accept() and connect() paths on t_conn_lock.
  RDS:TCP: Synchronize rds_tcp_accept_one with rds_send_xmit when resetting t_sock
  vxlan: Add checksum check to the features check function
  net: Disable segmentation if checksumming is not supported
  net: mvneta: Remove superfluous SMP function call
  macb: fix mdiobus_scan() error check
  pxa168_eth: fix mdiobus_scan() error check
  net/mlx5e: Use workqueue for vxlan ops
  net/mlx5e: Implement a mlx5e workqueue
  net/mlx5: Kconfig: Fix MLX5_EN/VXLAN build issue
  net/mlx5: Unmap only the relevant IO memory mapping
  netem: Segment GSO packets on enqueue
  batman-adv: Fix reference counting of hardif_neigh_node object for neigh_node
  batman-adv: Fix reference counting of vlan object for tt_local_entry
  batman-adv: B.A.T.M.A.N V - make sure iface is reactivated upon NETDEV_UP event
  batman-adv: fix DAT candidate selection (must use vid)

4 files changed, 50 insertions, 19 deletions

diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 61ed2a8764ba..86187dad1440 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -127,7 +127,7 @@ void rds_tcp_restore_callbacks(struct socket *sock,
 
 /*
  * This is the only path that sets tc->t_sock.  Send and receive trust that
- * it is set.  The RDS_CONN_CONNECTED bit protects those paths from being
+ * it is set.  The RDS_CONN_UP bit protects those paths from being
  * called while it isn't set.
  */
 void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
@@ -216,6 +216,7 @@ static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 	if (!tc)
 		return -ENOMEM;
 
+	mutex_init(&tc->t_conn_lock);
 	tc->t_sock = NULL;
 	tc->t_tinc = NULL;
 	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
diff --git a/net/rds/tcp.h b/net/rds/tcp.h
index 64f873c0c6b6..41c228300525 100644
--- a/net/rds/tcp.h
+++ b/net/rds/tcp.h
@@ -12,6 +12,10 @@ struct rds_tcp_connection {
 
 	struct list_head	t_tcp_node;
 	struct rds_connection   *conn;
+	/* t_conn_lock synchronizes the connection establishment between
+	 * rds_tcp_accept_one and rds_tcp_conn_connect
+	 */
+	struct mutex		t_conn_lock;
 	struct socket		*t_sock;
 	void			*t_orig_write_space;
 	void			*t_orig_data_ready;
diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c
index 5cb16875c460..49a3fcfed360 100644
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -78,7 +78,14 @@ int rds_tcp_conn_connect(struct rds_connection *conn)
 	struct socket *sock = NULL;
 	struct sockaddr_in src, dest;
 	int ret;
+	struct rds_tcp_connection *tc = conn->c_transport_data;
+
+	mutex_lock(&tc->t_conn_lock);
 
+	if (rds_conn_up(conn)) {
+		mutex_unlock(&tc->t_conn_lock);
+		return 0;
+	}
 	ret = sock_create_kern(rds_conn_net(conn), PF_INET,
 			       SOCK_STREAM, IPPROTO_TCP, &sock);
 	if (ret < 0)
@@ -120,6 +127,7 @@ int rds_tcp_conn_connect(struct rds_connection *conn)
 	}
 
 out:
+	mutex_unlock(&tc->t_conn_lock);
 	if (sock)
 		sock_release(sock);
 	return ret;
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 0936a4a32b47..be263cdf268b 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -76,7 +76,9 @@ int rds_tcp_accept_one(struct socket *sock)
 	struct rds_connection *conn;
 	int ret;
 	struct inet_sock *inet;
-	struct rds_tcp_connection *rs_tcp;
+	struct rds_tcp_connection *rs_tcp = NULL;
+	int conn_state;
+	struct sock *nsk;
 
 	ret = sock_create_kern(sock_net(sock->sk), sock->sk->sk_family,
 			       sock->sk->sk_type, sock->sk->sk_protocol,
@@ -115,28 +117,44 @@ int rds_tcp_accept_one(struct socket *sock)
 	 * rds_tcp_state_change() will do that cleanup
 	 */
 	rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
-	if (rs_tcp->t_sock &&
-	    ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr)) {
-		struct sock *nsk = new_sock->sk;
-
-		nsk->sk_user_data = NULL;
-		nsk->sk_prot->disconnect(nsk, 0);
-		tcp_done(nsk);
-		new_sock = NULL;
-		ret = 0;
-		goto out;
-	} else if (rs_tcp->t_sock) {
-		rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp);
-		conn->c_outgoing = 0;
-	}
-
 	rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING);
+	mutex_lock(&rs_tcp->t_conn_lock);
+	conn_state = rds_conn_state(conn);
+	if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_UP)
+		goto rst_nsk;
+	if (rs_tcp->t_sock) {
+		/* Need to resolve a duelling SYN between peers.
+		 * We have an outstanding SYN to this peer, which may
+		 * potentially have transitioned to the RDS_CONN_UP state,
+		 * so we must quiesce any send threads before resetting
+		 * c_transport_data.
+		 */
+		wait_event(conn->c_waitq,
+			   !test_bit(RDS_IN_XMIT, &conn->c_flags));
+		if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr)) {
+			goto rst_nsk;
+		} else if (rs_tcp->t_sock) {
+			rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp);
+			conn->c_outgoing = 0;
+		}
+	}
 	rds_tcp_set_callbacks(new_sock, conn);
-	rds_connect_complete(conn);
+	rds_connect_complete(conn); /* marks RDS_CONN_UP */
+	new_sock = NULL;
+	ret = 0;
+	goto out;
+rst_nsk:
+	/* reset the newly returned accept sock and bail */
+	nsk = new_sock->sk;
+	rds_tcp_stats_inc(s_tcp_listen_closed_stale);
+	nsk->sk_user_data = NULL;
+	nsk->sk_prot->disconnect(nsk, 0);
+	tcp_done(nsk);
 	new_sock = NULL;
 	ret = 0;
-
 out:
+	if (rs_tcp)
+		mutex_unlock(&rs_tcp->t_conn_lock);
 	if (new_sock)
 		sock_release(new_sock);
 	return ret;