From: Zygo Blaxell <zblaxell@gibbs.hungrycats.org>
To: Jonathan Nieder <jrnieder@gmail.com>
Cc: git@vger.kernel.org, 569505-forwarded@bugs.debian.org
Subject: Re: Bug#569505: git-core: 'git add' corrupts repository if the working directory is modified as it runs
Date: Thu, 11 Feb 2010 20:23:14 -0500 [thread overview]
Message-ID: <20100212012314.GC24809@gibbs.hungrycats.org> (raw)
In-Reply-To: <20100212002741.GB9883@progeny.tock>
On Thu, Feb 11, 2010 at 06:27:41PM -0600, Jonathan Nieder wrote:
> Zygo Blaxell reported through http://bugs.debian.org/569505 that ???git
> update-index??? has some issues when the files it is adding change under
> its feet:
>
> My thoughts:
>
> - Low-hanging fruit: it should be possible for update-index to check
> the stat information to see if the file has changed between when it
> first opens it and when it finishes.
I don't think this is a good idea. stat() is very coarse-grained, and
provides accuracy of only a second on a lot of file systems where git
working directories might be found. If you run the test script on an
ext3 filesystem on a modern machine the stat() data won't change at all
even though the file contents change completely many times.
What would be a good idea is to make sure that the code that copies a
file into the index and calculates its hash does both in a single pass
over the same input data. That might require replacing a simple mmap()
of the input file with a read-hash-copy loop.
next prev parent reply other threads:[~2010-02-12 1:32 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100211234753.22574.48799.reportbug@gibbs.hungrycats.org>
2010-02-12 0:27 ` Bug#569505: git-core: 'git add' corrupts repository if the working directory is modified as it runs Jonathan Nieder
2010-02-12 1:23 ` Zygo Blaxell [this message]
2010-02-13 12:12 ` Jonathan Nieder
2010-02-13 13:39 ` Ilari Liusvaara
2010-02-13 14:39 ` Thomas Rast
2010-02-13 16:29 ` Ilari Liusvaara
2010-02-13 22:09 ` Dmitry Potapov
2010-02-13 22:37 ` Zygo Blaxell
2010-02-14 1:18 ` [PATCH] don't use mmap() to hash files Dmitry Potapov
2010-02-14 1:37 ` Junio C Hamano
2010-02-14 2:18 ` Dmitry Potapov
2010-02-14 3:14 ` Junio C Hamano
2010-02-14 11:14 ` Thomas Rast
2010-02-14 11:46 ` Junio C Hamano
2010-02-14 1:53 ` Johannes Schindelin
2010-02-14 2:00 ` Junio C Hamano
2010-02-14 2:42 ` Dmitry Potapov
2010-02-14 11:07 ` Jakub Narebski
2010-02-14 11:55 ` Paolo Bonzini
2010-02-14 18:10 ` Johannes Schindelin
2010-02-14 19:06 ` Dmitry Potapov
2010-02-14 19:22 ` Johannes Schindelin
2010-02-14 19:28 ` Johannes Schindelin
2010-02-14 19:56 ` Dmitry Potapov
2010-02-14 23:52 ` Zygo Blaxell
2010-02-15 5:05 ` Nicolas Pitre
2010-02-15 12:23 ` Dmitry Potapov
2010-02-15 7:48 ` Paolo Bonzini
2010-02-15 12:25 ` Dmitry Potapov
2010-02-14 19:55 ` Dmitry Potapov
2010-02-14 23:13 ` Avery Pennarun
2010-02-15 4:16 ` Nicolas Pitre
2010-02-15 5:01 ` Avery Pennarun
2010-02-15 5:48 ` Nicolas Pitre
2010-02-15 19:19 ` Avery Pennarun
2010-02-15 19:29 ` Nicolas Pitre
2010-02-14 3:05 ` [PATCH v2] " Dmitry Potapov
2010-02-18 1:16 ` [PATCH] Teach "git add" and friends to be paranoid Junio C Hamano
2010-02-18 1:20 ` Junio C Hamano
2010-02-18 15:32 ` Zygo Blaxell
2010-02-19 17:51 ` Junio C Hamano
2010-02-18 1:38 ` Jeff King
2010-02-18 4:55 ` Nicolas Pitre
2010-02-18 5:36 ` Junio C Hamano
2010-02-18 7:27 ` Wincent Colaiuta
2010-02-18 16:18 ` Zygo Blaxell
2010-02-18 18:12 ` Jonathan Nieder
2010-02-18 18:35 ` Junio C Hamano
2010-02-22 12:59 ` Paolo Bonzini
2010-02-22 13:33 ` Dmitry Potapov
2010-02-18 10:14 ` Thomas Rast
2010-02-18 18:16 ` Junio C Hamano
2010-02-18 19:58 ` Nicolas Pitre
2010-02-18 20:11 ` 16 gig, 350,000 file repository Bill Lear
2010-02-18 20:58 ` Nicolas Pitre
2010-02-19 9:27 ` Erik Faye-Lund
2010-02-22 22:20 ` Bill Lear
2010-02-22 22:31 ` Nicolas Pitre
2010-02-18 20:14 ` [PATCH] Teach "git add" and friends to be paranoid Peter Harris
2010-02-18 20:17 ` Junio C Hamano
2010-02-18 21:30 ` Nicolas Pitre
2010-02-19 1:04 ` Jonathan Nieder
2010-02-19 15:26 ` Zygo Blaxell
2010-02-19 17:52 ` Junio C Hamano
2010-02-19 19:08 ` Zygo Blaxell
2010-02-19 8:28 ` Dmitry Potapov
2010-02-19 17:52 ` Junio C Hamano
2010-02-20 19:23 ` Junio C Hamano
2010-02-21 7:21 ` Dmitry Potapov
2010-02-21 19:32 ` Junio C Hamano
2010-02-22 3:35 ` Dmitry Potapov
2010-02-22 6:59 ` Junio C Hamano
2010-02-22 12:25 ` Dmitry Potapov
2010-02-22 15:40 ` Nicolas Pitre
2010-02-22 16:01 ` Dmitry Potapov
2010-02-22 17:31 ` Zygo Blaxell
2010-02-22 18:01 ` Nicolas Pitre
2010-02-22 19:56 ` Junio C Hamano
2010-02-22 20:52 ` Nicolas Pitre
2010-02-22 18:05 ` Dmitry Potapov
2010-02-22 18:14 ` Nicolas Pitre
2010-02-14 1:36 ` mmap with MAP_PRIVATE is useless (was Re: Bug#569505: git-core: 'git add' corrupts repository if the working directory is modified as it runs) Paolo Bonzini
2010-02-14 1:53 ` mmap with MAP_PRIVATE is useless Junio C Hamano
2010-02-14 2:11 ` Paolo Bonzini
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