[libvirt] [PATCH 5/5] qemu: Disable errors in qemudShutdownVMDaemon

[Cole Robinson]

On 01/12/2010 04:16 AM, Jim Meyering wrote:
> Cole Robinson wrote:
>> Signed-off-by: Cole Robinson <crobinso at redhat.com>
>> ---
>>  src/qemu/qemu_driver.c |   10 ++++++++++
>>  1 files changed, 10 insertions(+), 0 deletions(-)
>>
>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
>> index fc6b9fa..38be88f 100644
>> --- a/src/qemu/qemu_driver.c
>> +++ b/src/qemu/qemu_driver.c
>> @@ -2616,12 +2616,17 @@ static void qemudShutdownVMDaemon(virConnectPtr conn,
>>      int ret;
>>      int retries = 0;
>>      qemuDomainObjPrivatePtr priv = vm->privateData;
>> +    virErrorPtr origerr = NULL;
> 
> That assignment is technically what they call a dead store,
> since the very next use is to overwrite that just-stored value.
> So, to avoid warnings from the likes of the clang static checker,
> do this instead:
> 
>        virErrorPtr origerr;
> 

Will do.

>>      if (!virDomainObjIsActive(vm))
>>          return;
>>
>>      VIR_DEBUG("Shutting down VM '%s'", vm->def->name);
>>
>> +    /* This method is routinely used in clean up paths. Disable error
>> +     * reporting so we don't squash a legit error. */
>> +    origerr = virSaveLastError();
>> +
>>      if (driver->macFilter) {
>>          int i;
>>          virDomainDefPtr def = vm->def;
>> @@ -2701,6 +2706,11 @@ retry:
>>          vm->def->id = -1;
>>          vm->newDef = NULL;
>>      }
>> +
>> +    if (origerr) {
>> +        virSetError(origerr);
>> +        virFreeError(origerr);
>> +    }
>>  }
> 
> Hi Cole,
> This looks like a fine series.
> Is there an easy way to demonstrate the fix?
> Thinking it'd be nice to have a test that exercises at least one piece
> of the new code.
> 

Not that I can think of. Doing qemu migration to a host with a firewall
blocked migration port would previously return 'Unknown Error', where as
now it will return 'migration did not complete successfully'. Not easily
automated unfortunately.

> One tiny comment: people tend not to comprehend
> "wordsthatareattachedlikethis".
> So if you rename your "origerr" to e.g., "orig_err",
> it will be more readable.
> 
> If you decide to make the change, you can do it quickly by doing
> something like this (assuming the top 5 changes are the ones in this
> series, and they've been rebased to the latest master):
> 
>   git format-patch --stdout -5 | sed s/origerr/orig_err/ > patch
>   git co master
>   git co -b var-rename
>   git am patch

Sounds good, I'll make the adjustments and push.

Thanks,
Cole