tunnel: Recreate tunnel port only when the netdev status change.

On current master, the 'struct tnl_port' in tunnel module will be
recreated whenever the global connectivity sequence number changes
(e.g. when adding unrelated flow).  This is unnecessary and could
cause drop of tunnel packet if a lookup happens between the removal
and recreate.

This commit fixes the above issue by only checking the netdev's own
sequence number.

Found by code inspection.

Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Joe Stringer <joestringer@nicira.com>

diff --git a/ofproto/tunnel.c b/ofproto/tunnel.c
index 2b5aa50..dcbbfb5 100644 (file)
--- a/ofproto/tunnel.c
+++ b/ofproto/tunnel.c
@@ -52,7 +52,7 @@ struct tnl_port {
     struct hmap_node match_node;
 
     const struct ofport_dpif *ofport;
-    unsigned int change_seq;
+    uint64_t change_seq;
     struct netdev *netdev;
 
     struct tnl_match match;
@@ -138,7 +138,7 @@ tnl_port_add__(const struct ofport_dpif *ofport, const struct netdev *netdev,
     tnl_port = xzalloc(sizeof *tnl_port);
     tnl_port->ofport = ofport;
     tnl_port->netdev = netdev_ref(netdev);
-    tnl_port->change_seq = seq_read(connectivity_seq_get());
+    tnl_port->change_seq = netdev_get_change_seq(tnl_port->netdev);
 
     tnl_port->match.in_key = cfg->in_key;
     tnl_port->match.ip_src = cfg->ip_src;
@@ -206,7 +206,7 @@ tnl_port_reconfigure(const struct ofport_dpif *ofport,
         changed = tnl_port_add__(ofport, netdev, odp_port, false);
     } else if (tnl_port->netdev != netdev
                || tnl_port->match.odp_port != odp_port
-               || tnl_port->change_seq != seq_read(connectivity_seq_get())) {
+               || tnl_port->change_seq != netdev_get_change_seq(tnl_port->netdev)) {
         VLOG_DBG("reconfiguring %s", tnl_port_get_name(tnl_port));
         tnl_port_del__(ofport);
         tnl_port_add__(ofport, netdev, odp_port, true);