[libvirt] [PATCH v2] qemu: hotplug: Clean up memory backing files after failed memory hotplug

[Peter Krempa]

Libvirt provides full path to the backing file since commit
fec8f9c49afb479f6. This made qemu create the backend object but did not
delete it. This was fixed for unplug case in 4d83a6722f but not in case
of failure to hotplug the frontend. We'd leave the files behind which
would make memory unusable in case of hugepages.

https://bugzilla.redhat.com/show_bug.cgi?id=1553085

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---

Differences to v1:
- dropped mostly unhelpful comment
- moved the call slightly earlier so that the error of the original
hotplug operation is preserved

 src/qemu/qemu_hotplug.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index e0a5300f08..49af4d4ff0 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -2212,6 +2212,10 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver,
         ignore_value(qemuMonitorDelObject(priv->mon, objalias));
     if (qemuDomainObjExitMonitor(driver, vm) < 0)
         mem = NULL;
+
+    if (objAdded && mem)
+        ignore_value(qemuProcessDestroyMemoryBackingPath(driver, vm, mem));
+
     virErrorRestore(&orig_err);
     if (!mem)
         goto audit;
-- 
2.16.2