[libvirt] [PATCH] qemu: fix the error cover issue in qemuDomainAddCgroupForThread

[lhuang]

On 08/19/2015 01:40 AM, John Ferlan wrote:
>
> On 08/14/2015 02:59 AM, Luyao Huang wrote:
>> Just like commit 704cf06, the error already will be set in
>> virCgroup* function, and virCgroupAddTask will return -1,
>> so We will always report error "Operation not permitted"
>> in this place.
>>
>> Signed-off-by: Luyao Huang <lhuang at redhat.com>
>> ---
>>   src/qemu/qemu_driver.c | 3 ---
>>   1 file changed, 3 deletions(-)
>>
>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
>> index fa655b5..e0d7fa5 100644
>> --- a/src/qemu/qemu_driver.c
>> +++ b/src/qemu/qemu_driver.c
>> @@ -4606,9 +4606,6 @@ qemuDomainAddCgroupForThread(virCgroupPtr cgroup,
>>       /* Add pid/thread to the cgroup */
>>       rv = virCgroupAddTask(new_cgroup, pid);
>>       if (rv < 0) {
>> -        virReportSystemError(-rv,
>> -                             _("unable to add id %d task %d to cgroup"),
>> -                             idx, pid);
>>           virCgroupRemove(new_cgroup);
> Apparently virCgroupRemove can also overwrite a message, see
> virCgroupNewMachineSystemd for an example of how to save the error
> message and restore it..
> Perhaps all the callers that fail would need a similar sequence

You are right, maybe we could introduce a macro maybe named 
virErrorAvoidRecover for these case.

> John
>
> I'm at KVM Forum this week so digging and finding out the answer myself
> is a challenge with the flakiness of our network connection...

So lucky you are (of course i mean KVM Forum), i will fix them in 
another patches.

Thanks a lot for your review.

Luyao

>>           goto error;
>>       }
>>