[libvirt] [PATCH 1/6] util: Prepare helpers for unpriv_sgio setting

[Osier Yang]

On 2013年01月03日 08:01, Eric Blake wrote:
> On 01/02/2013 07:37 AM, Osier Yang wrote:
>> "virGetDeviceID" could be used across the sources, but it doesn't
>> relate with this series, and could be done later.
>>
>> * src/util/virutil.h: (Declare virGetDeviceID, and
>>                         vir{Get,Set}DeviceUnprivSGIO)
>> * src/util/virutil.c: (Implement virGetDeviceID and
>>                         vir{Get,Set}DeviceUnprivSGIO)
>> * src/libvirt_private.syms: Export private symbols of upper helpers
>> ---
>>   src/libvirt_private.syms |    3 +
>>   src/util/virutil.c       |  140 ++++++++++++++++++++++++++++++++++++++++++++++
>>   src/util/virutil.h       |   11 ++++
>>   3 files changed, 154 insertions(+), 0 deletions(-)
>
> ACK.
>
>> +int
>> +virSetDeviceUnprivSGIO(const char *path,
>> +                       const char *sysfs_dir,
>> +                       int unpriv_sgio)
>> +{
>> +    char *sysfs_path = NULL;
>> +    char *val = NULL;
>> +    int ret = -1;
>> +    int rc;
>> +
>> +    if (!(sysfs_path = virGetUnprivSGIOSysfsPath(path, sysfs_dir)))
>> +        return -1;
>> +
>> +    if (!virFileExists(sysfs_path)) {
>> +        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
>> +                       _("unpriv_sgio is not supported by this kernel"));
>> +        goto cleanup;
>
> If 'unpriv_sgio' is 0 here, does it make the logic in any later patches
> easier to return success in that case (you are setting things to the
> default)?  But I'm okay with keeping it as a failure.
>

The "unpriv_sgio == 0" could be requested explicitly by user (not only
the from the default), and in this case I'd think an error is better.
Otherwise I could see one will raise bug like "sgio='filtered'
succeeded, but sgio='unfiltered' failed" unless we document it
somewhere.

Regards,
Osier