[libvirt] [PATCH 2/2] qemu_driver: remove duplicate code
Pavel Hrdina
phrdina at redhat.com
Fri Jul 3 13:28:25 UTC 2015
On Fri, Jul 03, 2015 at 02:01:46PM +0200, Erik Skultety wrote:
>
>
> On 01/07/15 12:05, Pavel Hrdina wrote:
> > The copy of persistent definition is already done in
> > virDomainLiveConfigHelperMethod few lines above.
> >
> > Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
> > ---
> > src/qemu/qemu_driver.c | 6 ------
> > 1 file changed, 6 deletions(-)
> >
> > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> > index 4cfae03..ca93a1a 100644
> > --- a/src/qemu/qemu_driver.c
> > +++ b/src/qemu/qemu_driver.c
> > @@ -10336,12 +10336,6 @@ qemuDomainSetSchedulerParametersFlags(virDomainPtr dom,
> > &vmdef) < 0)
> > goto endjob;
> >
> > - if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
> > - /* Make a copy for updated domain. */
> > - if (!(vmdef = virDomainObjCopyPersistentDef(vm, caps, driver->xmlopt)))
> > - goto endjob;
> > - }
> > -
> > if (flags & VIR_DOMAIN_AFFECT_LIVE) {
> > if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPU)) {
> > virReportError(VIR_ERR_OPERATION_INVALID,
> >
> NACK. It's not true, that a copy is made in
> virDomainLiveConfigHelperMethod, only a reference to domain definition
> is returned. The problem is that we free vmdef at the end of the API
> which might not result in a desired behavior, let's consider an inactive
> persistent domain and you try to set one of scheduler params, instead of
> modifying an freeing a copy, you manipulate and free the original
> instance, what happens then? Yep, daemon crashes in the next API (OK,
> not every time, it requires a bit of luck but after a couple of minutes
> I managed to do that as well).
True, I've missed that in the helper we don't create a copy, just take a
reference. This makes perfect sense and in fact it's an exception, where we use
a copy to update the domain and in case of failure just drop the copy and leave
the domain definition intact. I thought, that there is no API that have this
behavior.
I'll push only the first patch, thanks for review.
Pavel
>
> Erik
>
> --
> libvir-list mailing list
> libvir-list at redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list
More information about the libvir-list
mailing list