All of lore.kernel.org
 help / color / mirror / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Taylor Blau <me@ttaylorr.com>
Cc: Gregory Szorc <gregory.szorc@gmail.com>,
	git@vger.kernel.org, stolee@gmail.com
Subject: Re: Race condition between repack and loose-objects maintenance task
Date: Thu, 30 Jun 2022 13:12:20 -0700	[thread overview]
Message-ID: <xmqqletdewrf.fsf@gitster.g> (raw)
In-Reply-To: <Yr0XMWWyD5C9uhlb@nand.local> (Taylor Blau's message of "Wed, 29 Jun 2022 23:23:29 -0400")

Taylor Blau <me@ttaylorr.com> writes:

> On Wed, Jun 29, 2022 at 11:19:09PM -0400, Taylor Blau wrote:
>> > However, I think there is yet another bug at play: running
>> > `incremental-repack` appears to be able to repack the cruft packfile.
>> > In doing so, it deletes its .mtimes file and the metadata inside.
>>
>> That sounds like a bug to me. I'll take a look into it and see what I
>> can find.
>
> I actually think that there are two bugs here.
>
> One is that we run a MIDX repack and expire, which could lead to us
> repacking the entire contents of the cruft pack and then expiring the
> metadata file. This is a bug, and we should exclude cruft packs from
> this computation.
>
> Another bug can happen when the cruft pack gets written into the MIDX
> and is MIDX-expireable (meaning that no objects are selected from the
> cruft pack). In that case, the `git multi-pack-index expire` step would
> remove the cruft pack entirely, which is also incorrect.
>
> I'll take a look at fixing both of these, and thanks for pointing them
> out!

Thanks, both.

The fact that the semantics of the .mtimes file being not equivalent
to the mtime on individual loose objects does not help thinking
about the possible ways the "cruft" pack can break, and both of the
possible issues you discuss above are indeed tricky ones.



  reply	other threads:[~2022-06-30 20:12 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-29 16:55 Race condition between repack and loose-objects maintenance task Gregory Szorc
2022-06-29 17:03 ` Taylor Blau
2022-06-29 17:10   ` Taylor Blau
2022-06-29 17:16   ` Gregory Szorc
2022-06-29 17:21     ` Taylor Blau
2022-06-30  0:44       ` Gregory Szorc
2022-06-30  3:19         ` Taylor Blau
2022-06-30  3:23           ` Taylor Blau
2022-06-30 20:12             ` Junio C Hamano [this message]
2022-07-05 18:43               ` Gregory Szorc
2022-07-06  8:50                 ` Ævar Arnfjörð Bjarmason
2022-07-20  1:40             ` Gregory Szorc
2022-07-20  9:52               ` Ævar Arnfjörð Bjarmason
2022-07-26 16:22                 ` Gregory Szorc
2022-07-26 18:11                   ` Ævar Arnfjörð Bjarmason
2022-07-20  1:41             ` Gregory Szorc

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqqletdewrf.fsf@gitster.g \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=gregory.szorc@gmail.com \
    --cc=me@ttaylorr.com \
    --cc=stolee@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.