xenserver: Avoid errors from ovs-vsctl at system shutdown.

Commit 823c5699 "interface-reconfigure: callout to datapath backend class
method on rewrite" changed "interface-reconfigure rewrite" to update
bridge external-ids in the vswitch database.  But this had the side effect
of causing errors at system shutdown, since ovsdb-server gets shut down
before the rewrite action is called.  This commit fixes the problem by
skipping the update if the database socket does not exist.  (It's just
fine to skip the update, since the external-ids will be re-set the next
time the system boots anyhow.)

This commit fixed the problem on 5.6.810-34773p for me.  I don't see the
problem at all on 5.5.0.  Presumably system shutdown order has changed.

NIC-136.

CC: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/xenserver/opt_xensource_libexec_InterfaceReconfigureVswitch.py b/xenserver/opt_xensource_libexec_InterfaceReconfigureVswitch.py
index b7375555f20a86a4612a767c3ece8e4d9aab91ab..1e45759adf15ffcb006c13bf13c46598a6049872 100644 (file)
--- a/xenserver/opt_xensource_libexec_InterfaceReconfigureVswitch.py
+++ b/xenserver/opt_xensource_libexec_InterfaceReconfigureVswitch.py
@@ -12,6 +12,7 @@
 # GNU Lesser General Public License for more details.
 #
 from InterfaceReconfigure import *
+import os
 import re
 
 #
@@ -367,6 +368,13 @@ class DatapathVswitch(Datapath):
 
     @classmethod
     def rewrite(cls):
+        if not os.path.exists("/var/run/openvswitch/db.sock"):
+            # ovsdb-server is not running, so we can't update the database.
+            # Probably we are being called as part of system shutdown.  Just
+            # skip the update, since the external-ids will be updated on the
+            # next boot anyhow.
+            return
+
         vsctl_argv = []
         for pif in db().get_all_pifs():
             pifrec = db().get_pif_record(pif)