From: Luyao Huang <lhuang@redhat.com>
Date: Wed, 31 Dec 2014 01:34:39 +0000 (+0800)
Subject: qemu: Restore old bandwidth rules when setting new fails
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=565d049fd1a4f3264a12001467a0bbf3b87a6421;p=libvirt.git

qemu: Restore old bandwidth rules when setting new fails

https://bugzilla.redhat.com/show_bug.cgi?id=1177723

When setting new bandwidth limits via
virDomainSetInterfaceParameters, the old ones are cleared first.
However, if setting the new ones fails, the old are already gone
and interface is left in inconsistent state.  Therefore, right
before failing we ought to try to restore the old bandwidth.

Signed-off-by: Luyao Huang <lhuang@redhat.com>
---

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 1596d2bc25..cdf4173809 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10510,8 +10510,12 @@ qemuDomainSetInterfaceParameters(virDomainPtr dom,
                    sizeof(*newBandwidth->out));
         }
 
-        if (virNetDevBandwidthSet(net->ifname, newBandwidth, false) < 0)
+        if (virNetDevBandwidthSet(net->ifname, newBandwidth, false) < 0) {
+            ignore_value(virNetDevBandwidthSet(net->ifname,
+                                               net->bandwidth,
+                                               false));
             goto endjob;
+        }
 
         virNetDevBandwidthFree(net->bandwidth);
         if (newBandwidth->in || newBandwidth->out) {