Re: [PATCH 00/12] Fix some reference-related races

From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Jun 19, 2013, 05:51 UTC
Message-ID: <51C146DA.5000500@alum.mit.edu>
In-Reply-To: <51C0A33A.7060802@ramsay1.demon.co.uk>

On 06/18/2013 08:13 PM, Ramsay Jones wrote:

Show 19 quoted lines

> Michael Haggerty wrote:
>> On 06/15/2013 10:13 PM, Ramsay Jones wrote:
>>> Now, turning to the new code, t3211-peel-ref.sh test #7 now works, but
>>> test #8 still fails...
> 
> [ ... ]
> 
>>             It should be impossible, because the current process is
>> holding packed-refs.lock, and therefore other git processes should
>> refuse to change the packed-refs file.
> 
> :-P You are assuming that a single process can't lie to itself ...
> 
> [ ... ]
> 
> I should not have assumed that you knew what I meant by "schizophrenic
> stat() functions" above; sorry about that! If you are interested, then
> the following commits may be useful reading: adbc0b6, 7faee6b, 7974843,
> 05bab3ea, 924aaf3e and b8a97333.

Thanks, that helps.

Show 10 quoted lines

>>> I haven't checked the remaining test failures to see if they are
>>> caused by this code (I don't think so, but ...), but this failure
>>> is clearly a cygwin specific issue.
>>
>> Thanks again for the testing and analysis,
> 
> So, unless you feel the need to fix this yourself, you can probably
> ignore this issue for now. I will hopefully find time to fix it up
> before this topic progresses to next. (Although I don't have any
> feeling for the time-frame of this topic).

Despite reading the commits that you referenced, I still don't feel competent to fix this myself so I gratefully accept your offer. Ideally, whatever complexity is needed would be hidden in the functions stat_validity_check() and stat_validity_update() added by patch 09/12 of my series, and possibly match_stat_data() from 08/12.

Let me know if I can help.

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/