[libvirt] [PATCH] network: prevent infinite hang if ovs-vswitchd isn't running

This fixes https://bugzilla.redhat.com/show_bug.cgi?id=852984 If a network or interface is configured to use Open vSwitch, but ovs-vswitchd (the Open vSwitch database service) isn't running, the ovs-vsctl add-port/del-port commands will hang indefinitely rather than returning an error. There is a --nowait option, but that appears to have no effect on add-port and del-port commands, so instead we add a --timeout=5 to the commands - they will retry for up to 5 seconds, then fail if there is no response. --- I'm not sure if 5 seconds is a reasonable timeout for this, but it seems to work okay for me (in a very lightly loaded environment, but a successful return is always effectively instantaneous...). Unfortunately there doesn't seem to be another way to bound the wait time of ovs-vsctl. :-( src/util/virnetdevopenvswitch.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c index 764f478..97b9d52 100644 --- a/src/util/virnetdevopenvswitch.c +++ b/src/util/virnetdevopenvswitch.c @@ -105,7 +105,7 @@ int virNetDevOpenvswitchAddPort(const char *brname, const char *ifname, cmd = virCommandNew(OVSVSCTL); - virCommandAddArgList(cmd, "--", "--may-exist", "add-port", + virCommandAddArgList(cmd, "--timeout=5", "--", "--may-exist", "add-port", brname, ifname, NULL); if (virBufferUse(&buf) != 0) @@ -166,7 +166,7 @@ int virNetDevOpenvswitchRemovePort(const char *brname ATTRIBUTE_UNUSED, const ch virCommandPtr cmd = NULL; cmd = virCommandNew(OVSVSCTL); - virCommandAddArgList(cmd, "--", "--if-exists", "del-port", ifname, NULL); + virCommandAddArgList(cmd, "--timeout=5", "--", "--if-exists", "del-port", ifname, NULL); if (virCommandRun(cmd, NULL) < 0) { virReportSystemError(VIR_ERR_INTERNAL_ERROR, -- 1.7.11.4