ovs-vswitchd: Preserve datapath ports across graceful shutdown.

Until now, asking ovs-vswitchd to shut down gracefully, e.g. with
"ovs-appctl exit", would cause it to first remove all the ports from
kernel-based datapaths.  This has the unfortunate side effect that IP
addresses on any removed "internal" ports are lost, even if the ports are
added again when ovs-vswitchd is restarted.  This is long-standing
behavior, but it only became important when the OVS control scripts were
changed to try to do graceful shutdown first instead of using a signal.

This commit changes graceful shutdown so that it leaves ports in the
datapath, fixing the problem.

Fixes: 9b5422a98f8 (ovs-lib: Try to call exit before killing.)
Reported-by: Edgar Cantu <eocantu@us.ibm.com>
Reported-at: http://openvswitch.org/pipermail/discuss/2016-January/020024.html
Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Gurucharan Shetty <guru@ovn.org>

diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 904cc2a..adfaeb6 100644 (file)
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -1802,7 +1802,7 @@ port_construct(struct ofport *port_)
 }
 
 static void
-port_destruct(struct ofport *port_)
+port_destruct(struct ofport *port_, bool del)
 {
     struct ofport_dpif *port = ofport_dpif_cast(port_);
     struct ofproto_dpif *ofproto = ofproto_dpif_cast(port->up.ofproto);
@@ -1817,7 +1817,7 @@ port_destruct(struct ofport *port_)
 
     dp_port_name = netdev_vport_get_dpif_port(port->up.netdev, namebuf,
                                               sizeof namebuf);
-    if (dpif_port_exists(ofproto->backer->dpif, dp_port_name)) {
+    if (del && dpif_port_exists(ofproto->backer->dpif, dp_port_name)) {
         /* The underlying device is still there, so delete it.  This
          * happens when the ofproto is being destroyed, since the caller
          * assumes that removal of attached ports will happen as part of

diff --git a/ofproto/ofproto-provider.h b/ofproto/ofproto-provider.h
index 3ba97d0..5fa03b5 100644 (file)
--- a/ofproto/ofproto-provider.h
+++ b/ofproto/ofproto-provider.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Nicira, Inc.
+ * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -896,12 +896,36 @@ struct ofproto_class {
      *     initialization, and construct and destruct ofports to reflect all of
      *     the changes.
      *
+     *   - On graceful shutdown, the base ofproto code will destruct all
+     *     the ports.
+     *
      * ->port_construct() returns 0 if successful, otherwise a positive errno
      * value.
+     *
+     *
+     * ->port_destruct()
+     * =================
+     *
+     * ->port_destruct() takes a 'del' parameter.  If the provider implements
+     * the datapath itself (e.g. dpif-netdev, it can ignore 'del'.  On the
+     * other hand, if the provider is an interface to an external datapath
+     * (e.g. to a kernel module that implement the datapath) then 'del' should
+     * influence destruction behavior in the following way:
+     *
+     *   - If 'del' is true, it should remove the port from the underlying
+     *     implementation.  This is the common case.
+     *
+     *   - If 'del' is false, it should leave the port in the underlying
+     *     implementation.  This is used when Open vSwitch is performing a
+     *     graceful shutdown and ensures that, across Open vSwitch restarts,
+     *     the underlying ports are not removed and recreated.  That makes an
+     *     important difference for, e.g., "internal" ports that have
+     *     configured IP addresses; without this distinction, the IP address
+     *     and other configured state for the port is lost.
      */
     struct ofport *(*port_alloc)(void);
     int (*port_construct)(struct ofport *ofport);
-    void (*port_destruct)(struct ofport *ofport);
+    void (*port_destruct)(struct ofport *ofport, bool del);
     void (*port_dealloc)(struct ofport *ofport);
 
     /* Called after 'ofport->netdev' is replaced by a new netdev object.  If

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 939cb37..e1efedb 100644 (file)
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -217,7 +217,7 @@ static void learned_cookies_flush(struct ofproto *, struct ovs_list *dead_cookie
 
 /* ofport. */
 static void ofport_destroy__(struct ofport *) OVS_EXCLUDED(ofproto_mutex);
-static void ofport_destroy(struct ofport *);
+static void ofport_destroy(struct ofport *, bool del);
 
 static int update_port(struct ofproto *, const char *devname);
 static int init_ports(struct ofproto *);
@@ -1573,7 +1573,7 @@ ofproto_destroy_defer__(struct ofproto *ofproto)
 }
 
 void
-ofproto_destroy(struct ofproto *p)
+ofproto_destroy(struct ofproto *p, bool del)
     OVS_EXCLUDED(ofproto_mutex)
 {
     struct ofport *ofport, *next_ofport;
@@ -1592,7 +1592,7 @@ ofproto_destroy(struct ofproto *p)
 
     ofproto_flush__(p);
     HMAP_FOR_EACH_SAFE (ofport, next_ofport, hmap_node, &p->ports) {
-        ofport_destroy(ofport);
+        ofport_destroy(ofport, del);
     }
 
     HMAP_FOR_EACH_SAFE (usage, next_usage, hmap_node, &p->ofport_usage) {
@@ -2392,7 +2392,7 @@ ofport_remove(struct ofport *ofport)
 {
     connmgr_send_port_status(ofport->ofproto->connmgr, NULL, &ofport->pp,
                              OFPPR_DELETE);
-    ofport_destroy(ofport);
+    ofport_destroy(ofport, true);
 }
 
 /* If 'ofproto' contains an ofport named 'name', removes it from 'ofproto' and
@@ -2478,11 +2478,11 @@ ofport_destroy__(struct ofport *port)
 }
 
 static void
-ofport_destroy(struct ofport *port)
+ofport_destroy(struct ofport *port, bool del)
 {
     if (port) {
         dealloc_ofp_port(port->ofproto, port->ofp_port);
-        port->ofproto->ofproto_class->port_destruct(port);
+        port->ofproto->ofproto_class->port_destruct(port, del);
         ofport_destroy__(port);
      }
 }

diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index b99f0cd..2d5a481 100644 (file)
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Nicira, Inc.
+ * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -239,7 +239,7 @@ void ofproto_type_wait(const char *datapath_type);
 
 int ofproto_create(const char *datapath, const char *datapath_type,
                    struct ofproto **ofprotop);
-void ofproto_destroy(struct ofproto *);
+void ofproto_destroy(struct ofproto *, bool del);
 int ofproto_delete(const char *name, const char *type);
 
 int ofproto_run(struct ofproto *);

diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index c6fa445..25a0663 100644 (file)
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -227,7 +227,7 @@ static bool ifaces_changed = false;
 static void add_del_bridges(const struct ovsrec_open_vswitch *);
 static void bridge_run__(void);
 static void bridge_create(const struct ovsrec_bridge *);
-static void bridge_destroy(struct bridge *);
+static void bridge_destroy(struct bridge *, bool del);
 static struct bridge *bridge_lookup(const char *name);
 static unixctl_cb_func bridge_unixctl_dump_flows;
 static unixctl_cb_func bridge_unixctl_reconnect;
@@ -500,7 +500,7 @@ bridge_exit(void)
 
     if_notifier_destroy(ifnotifier);
     HMAP_FOR_EACH_SAFE (br, next_br, node, &all_bridges) {
-        bridge_destroy(br);
+        bridge_destroy(br, false);
     }
     ovsdb_idl_destroy(idl);
 }
@@ -633,7 +633,7 @@ bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
                 VLOG_ERR("failed to create bridge %s: %s", br->name,
                          ovs_strerror(error));
                 shash_destroy(&br->wanted_ports);
-                bridge_destroy(br);
+                bridge_destroy(br, true);
             } else {
                 /* Trigger storing datapath version. */
                 seq_change(connectivity_seq_get());
@@ -1713,7 +1713,7 @@ add_del_bridges(const struct ovsrec_open_vswitch *cfg)
         br->cfg = shash_find_data(&new_br, br->name);
         if (!br->cfg || strcmp(br->type, ofproto_normalize_type(
                                    br->cfg->datapath_type))) {
-            bridge_destroy(br);
+            bridge_destroy(br, true);
         }
     }
 
@@ -2909,7 +2909,7 @@ bridge_run(void)
                     (long int) getpid());
 
         HMAP_FOR_EACH_SAFE (br, next_br, node, &all_bridges) {
-            bridge_destroy(br);
+            bridge_destroy(br, false);
         }
         /* Since we will not be running system_stats_run() in this process
          * with the current situation of multiple ovs-vswitchd daemons,
@@ -3194,7 +3194,7 @@ bridge_create(const struct ovsrec_bridge *br_cfg)
 }
 
 static void
-bridge_destroy(struct bridge *br)
+bridge_destroy(struct bridge *br, bool del)
 {
     if (br) {
         struct mirror *mirror, *next_mirror;
@@ -3208,7 +3208,7 @@ bridge_destroy(struct bridge *br)
         }
 
         hmap_remove(&all_bridges, &br->node);
-        ofproto_destroy(br->ofproto);
+        ofproto_destroy(br->ofproto, del);
         hmap_destroy(&br->ifaces);
         hmap_destroy(&br->ports);
         hmap_destroy(&br->iface_by_name);