[libvirt] [PATCH 2/2] qemuDomainUndefineFlags: unlink nvram file regardless of domain state

[Michal Privoznik]

On 08/09/2017 11:41 AM, Martin Kletzander wrote:
> On Mon, Aug 07, 2017 at 02:20:06PM +0200, Michal Privoznik wrote:
>> https://bugzilla.redhat.com/show_bug.cgi?id=1467245
>>
>> Currently, there's a bug when undefining a domain with NVRAM
>> store. Basically, the unlink() of the NVRAM store file happens
>> during the undefine procedure iff domain is inactive. So, if
>> domain is running and undefine is called the file is left behind.
>> It won't be removed in the domain cleanup process either
>> (qemuProcessStop). One of the solutions is to remove if
>> regardless of the domain state and rely on qemu having the file
>> opened. This still has a downside that if the domain is defined
>> back the NVRAM store file is going to be new, any changes to the
>> current one are lost (just like with any other file that is
>> deleted while a process has it opened). But is it really a
>> downside?
>>
> 
> It might be.  Why don't we disable removing it when the domain is
> running?  We have some precedence for this.  The place which already
> deals with this possibility is tools/virsh-domain.c in the cmdUndefine()
> where we handle --remove-all-storage.  If you look at the help of that
> command it also says:
> 
>  --nvram          remove nvram file, if inactive
> 
> And that makes sense to me.  What doesn't, on the other hand, is that it
> also says:
> 
>  --keep-nvram     keep nvram file, if inactive
> 
> I don't get the "if inactive" there.  But I'm not going to check who
> pushed that.  At least not again =)

Okay, I'll write a patch that:

a) forbids undefine for active domains, unless
b) KEEP_NVRAM flag is specified.

Michal