From 3bff82b57564ffc1fe4fff23f9d121fcf410dd5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Bosdonnat?= <cbosdonnat@suse.com>
Date: Wed, 25 Nov 2015 11:43:56 +0100
Subject: [PATCH] Wait for udev events to be handled after removing veth

As per http://www.redhat.com/archives/libvir-list/2013-July/msg01279.html,
wait for udev events to be handled after removing a virtual NIC.
Any udev rule associated to NIC destroy could happen to run with a new
device with the same name that is being created.
---
 src/lxc/lxc_controller.c | 1 +
 src/lxc/lxc_driver.c     | 2 ++
 src/lxc/lxc_process.c    | 1 +
 3 files changed, 4 insertions(+)

Index: libvirt-4.0.0/src/lxc/lxc_controller.c
===================================================================
--- libvirt-4.0.0.orig/src/lxc/lxc_controller.c
+++ libvirt-4.0.0/src/lxc/lxc_controller.c
@@ -73,6 +73,7 @@
 #include "rpc/virnetdaemon.h"
 #include "virstring.h"
 #include "virgettext.h"
+#include "virutil.h"
 
 #define VIR_FROM_THIS VIR_FROM_LXC
 
@@ -1997,6 +1998,7 @@ static int virLXCControllerDeleteInterfa
         if (virNetDevVethDelete(ctrl->veths[i]) < 0)
             ret = -1;
     }
+    virWaitForDevices();
 
     return ret;
 }
Index: libvirt-4.0.0/src/lxc/lxc_driver.c
===================================================================
--- libvirt-4.0.0.orig/src/lxc/lxc_driver.c
+++ libvirt-4.0.0/src/lxc/lxc_driver.c
@@ -76,6 +76,7 @@
 #include "virtime.h"
 #include "virtypedparam.h"
 #include "viruri.h"
+#include "virutil.h"
 #include "virstring.h"
 #include "viraccessapicheck.h"
 #include "viraccessapichecklxc.h"
@@ -4007,6 +4008,7 @@ lxcDomainAttachDeviceNetLive(virConnectP
         case VIR_DOMAIN_NET_TYPE_NETWORK:
         case VIR_DOMAIN_NET_TYPE_ETHERNET:
             ignore_value(virNetDevVethDelete(veth));
+            virWaitForDevices();
             break;
 
         case VIR_DOMAIN_NET_TYPE_DIRECT:
@@ -4441,6 +4443,7 @@ lxcDomainDetachDeviceNetLive(virDomainOb
             virDomainAuditNet(vm, detach, NULL, "detach", false);
             goto cleanup;
         }
+        virWaitForDevices();
         break;
 
         /* It'd be nice to support this, but with macvlan
Index: libvirt-4.0.0/src/lxc/lxc_process.c
===================================================================
--- libvirt-4.0.0.orig/src/lxc/lxc_process.c
+++ libvirt-4.0.0/src/lxc/lxc_process.c
@@ -52,6 +52,7 @@
 #include "viratomic.h"
 #include "virprocess.h"
 #include "virsystemd.h"
+#include "virutil.h"
 #include "netdev_bandwidth_conf.h"
 
 #define VIR_FROM_THIS VIR_FROM_LXC
@@ -221,6 +222,7 @@ static void virLXCProcessCleanup(virLXCD
         }
         networkReleaseActualDevice(vm->def, iface);
     }
+    virWaitForDevices();
 
     virDomainConfVMNWFilterTeardown(vm);