Re: GIT 1.6.0-rc1

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 29, 2008, 22:03 UTC
Message-ID: <7vmyk0bb5r.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20080729211745.GA3879@blimp.local>

Alex Riesen <raa.lkml@gmail.com> writes:

Show 20 quoted lines

> Junio C Hamano, Tue, Jul 29, 2008 10:36:19 +0200:
>> Junio C Hamano <gitster@pobox.com> writes:
>> >
>> > Ok, I took a deeper look at the codepaths involved.  Although it does work
>> > around the issue, I do not think your patch alone is the "correct" one in
>> > the longer term.
>
> Thought so. I just didn't know the code around
>
>> > It needs a bit of explanation, and the explanation won't be exactly
>> > "plain, small and short", unfortunately.
>> 
>> Alex, I ran the full test with this, but only on Linux boxes; obviously
>> not on any flavor of Windows.  I think it is correct, and the "first line
>> of defence" fix is the same as your patch, so I'd assume it would work for
>> you as well.  But extra eyeballs are always appreciated.
>
> Well, it works on Cygwin too. And I had my eyeballs on the code
> (wondered first if it will cause more fs accesses than before: it
> will, in the racy check. Which is correct, AFAICT)

I thought racy check won't even trigger for gitlinks, no?

ce_modified_check_fs() has 3 call sites:

 - the call site in ie_match_stat() is protected with is_racy_timestamp()
   that is always false for gitlinks;

 - the call site in ie_modified() we just took care of in the current
   thread;

 - the other call site is in ce_smudge_racily_clean_entry(), which is
   called from write_index() but it also is protected with
   is_racy_timestamp() that is always false for gitlinks.