24.06.2014 15:01, Markus Armbruster wrote:
> Kevin Wolf <kw...@redhat.com> writes:
>
>> Am 23.06.2014 um 17:28 hat Chen Gang geschrieben:
>>> When failure occurs, 'ret' need be set, or may return 0 to indicate success.
>>> And error_propagate() also need be called only one time within a function.
>>>
>>> It is abnormal to prevent bdrv_append_temp_snapshot() return value but still
>>> set errp when error occurs -- although it contents return value internally.
>>>
>>> So let bdrv_append_temp_snapshot() internal return value outside, and let
>>> all things normal, then fix the issue too.
>>>
>>> Signed-off-by: Chen Gang <gang.chen.5...@gmail.com>
>>
>> What does this fix?
>
> It fixes the return value of bdrv_open() when
> bdrv_append_temp_snapshot() fails. Before this patch, it returns a
> positive value, which is wrong. After the patch, it returns the
> negative error code bdrv_append_temp_snapshot() now returns.
So, what should be done there? Kevin, maybe you should pick this up
instead of going -trivial route?
>> Having both a return value and an Error* object is duplication and
>> only a sign that a function hasn't been fully converted to the Error
>> framework yet. We shouldn't introduce new instances of this without a
>> very good reason.
>
> Maybe. But I very much prefer
>
> ret = foo(arg, errp);
> if (ret < 0) {
> return ret;
> }
>
> over
>
> Error *local_err = NULL;
>
> foo(arg, &local_err);
> if (local_err) {
> error_propagate(errp, local_err);
> return;
> }
Yes, this new error propagation is a bit ugly, I dislike it too.
Thanks,
/mjt
