On 09/20/2013 02:30 AM, Simo Sorce wrote:
On Thu, 2013-09-19 at 18:45 +0200, Jakub Hrozek wrote:
> On Wed, Sep 18, 2013 at 10:40:13PM +0200, Jakub Hrozek wrote:
>> On Wed, Sep 18, 2013 at 01:41:36PM -0400, Simo Sorce wrote:
>>> On Wed, 2013-09-18 at 17:58 +0200, Jakub Hrozek wrote:
>>>> Hi,
>>>>
>>>> the first patch fixes the bug that Jean-Baptiste Denis found earlier
>>>> today. In case the lookup was not done using a FQDN, the code would skip
>>>> setting the entries to the ncache.
>>>>
>>>> The second patch is an incremental improvement. I don't think we
should
>>>> abort the whole lookup if setting an entry in negcache would fail. The
>>>> negative cache is a performance optimization after all.
>>>
>>> It seem to me that with the first patch you are changing behavior as you
>>> leave 'ret' unchanged to whatever error is returned instead of
setting
>>> it to ENOENT before going to 'done'.
>>>
>>> Simo.
>>
>> Ugh, that is a bug.
>>
>> I was going back and forth on changing the particular return to goto
>> and when I made my mind, I forgot to set the errno.
>>
>> Thanks Simo for catching it, I'll prepare a new version.
>
> I think we were both confused by the poor label naming. The label actually,
> despite being named "done", made the function return ENOENT so the code
> was correct. But even I was confused couple of hours after sending the
> patch so the code had to be improved :)
>
> So in the attached patch I renamed the label to notfound. I hope that's
> OK if we don't use the commonly used "done" in this case. I think the
most
> important thing is that there is only a single label we jump to.
>
> Alternatively, if you prefer strictly one exit point, I could convert
> the function to only use goto done and set negcache based on errno value
> (if ENOENT->ncache) but I didn't see that as necessary.
I prefer the idiom:
ret = ENOENT;
goto done;
to:
goto notfound;
Simo.
I agree. We should not introduce new labels.