Re: [PATCH 9/9] pack-objects: rename .idx files into place after .bitmap files

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 9, 2021, 19:52 UTC
Message-ID: <xmqqr1dxy1b0.fsf@gitster.g>
In-Reply-To: <878s06fa14.fsf@evledraar.gmail.com>

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

Show 12 quoted lines

>     We fsync() the file descriptors we're writing out for all the
>     auxiliary files, but we don't yet fsync() the file descriptor for
>     the containing directory. Therefore our data might have been written
>     out, but it's anyone's guess what the state of the directory
>     containing the file is after we write the *.idx.
>
>     In practice modern OS's are known to be forgiving on that point, so
>     this will probably solve races in practice for most users. It will
>     almost certainly make them better than they were before when we
>     didn't write *.idx files last. We should more generally improve our
>     use of fsync() to cover containing directories, but that'll
>     hopefully be addressed by some follow-up series.

I'd probably drop the last paragraph, and replace it with a single sentence "we may want to fsync the containing directory once after placing *.idx file in place, but it is outside of the scope of this series", if I were doing this series.

Other than that (and I made a few comments on other patches), these were pleasant read.

Thanks.