[libvirt] [PATCH 4/3] qemu: don't leave vm in table on failure to attach

[Eric Blake]

On 09/04/2013 06:13 AM, Michal Privoznik wrote:
> On 28.08.2013 22:56, Eric Blake wrote:
>> Failure to attach to a domain during 'virsh qemu-attach' left
>> the list of domains in an odd state:
>>
>> $ virsh qemu-attach 4176
>> error: An error occurred, but the cause is unknown
>>
>> $ virsh list --all
>>  Id    Name                           State
>> ----------------------------------------------------
>>  2     foo                            shut off
>>

>> +++ b/src/qemu/qemu_driver.c
>> @@ -13623,8 +13623,11 @@ static virDomainPtr qemuDomainQemuAttach(virConnectPtr conn,
>>
>>      if (qemuProcessAttach(conn, driver, vm, pid,
>>                            pidfile, monConfig, monJSON) < 0) {
>> +        if (qemuDomainObjEndJob(driver, vm) > 0)
>> +            qemuDomainRemoveInactive(driver, vm);
>> +        vm = NULL;
>>          monConfig = NULL;
>> -        goto endjob;
>> +        goto cleanup;
>>      }
>>
> 
> While this part looks okay ...

This change exactly mirros what qemuDomainCreateXML was doing (as
mentioned in the commit message)...

> 
>>      monConfig = NULL;
>> @@ -13632,7 +13635,6 @@ static virDomainPtr qemuDomainQemuAttach(virConnectPtr conn,
>>      dom = virGetDomain(conn, vm->def->name, vm->def->uuid);
>>      if (dom) dom->id = vm->def->id;
>>
>> -endjob:
>>      if (qemuDomainObjEndJob(driver, vm) == 0) {
>>          vm = NULL;
>>          goto cleanup;
>>

...which left endjob as an unused label.

> 
> ... I am not convinced about this part. I mean, in the context, we
> create Domain and store it into @dom. But if qemu process dies
> meanwhile, so the qemuDomainObjEndJob() returns zero, the @dom refers to
> a stale process. Or am I missing something here? I think these lines
> should be swapped.

If there is still a bug here, then it is pre-existing, and probably a
similar bug in qemuDomainCreateXML.  I'll take another look.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 621 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130906/64f32ece/attachment-0001.sig>