From: Dennis Kaarsemaker <dennis@kaarsemaker.net>
To: John Szakmeister <john@szakmeister.net>, git@vger.kernel.org
Subject: Re: "git fsck" not detecting garbage at the end of blob object files...
Date: Sat, 07 Jan 2017 22:47:03 +0100 [thread overview]
Message-ID: <1483825623.31837.9.camel@kaarsemaker.net> (raw)
In-Reply-To: <CAEBDL5Uc39JagdmXUxfxh1TPSK3H5wxoTfjK-pfLRYjciBnHpA@mail.gmail.com>
On Sat, 2017-01-07 at 07:50 -0500, John Szakmeister wrote:
> I was perusing StackOverflow this morning and ran across this
> question: http://stackoverflow.com/questions/41521143/git-fsck-full-only-checking-directories/
>
> It was a simple question about why "checking objects" was not
> appearing, but in it was another issue. The user purposefully
> corrupted a blob object file to see if `git fsck` would catch it by
> tacking extra data on at the end. `git fsck` happily said everything
> was okay, but when I played with things locally I found out that `git
> gc` does not like that extra garbage. I'm not sure what the trade-off
> needs to be here, but my expectation is that if `git fsck` says
> everything is okay, then all operations using that object (file)
> should work too.
>
> Is that unreasonable? What would be the impact of fixing this issue?
If you do this with a commit object or tree object, fsck does complain.
I think it's sensible to do so for blob objects as well.
Editing blob object:
hurricane:/tmp/moo (master)$ hexer .git/objects/a1/b3ebb97f10ff8d85a9472bcba50cb575dbd485
hurricane:/tmp/moo (master)$ git status
On branch master
nothing to commit, working tree clean
hurricane:/tmp/moo (master)$ git fsck
Checking object directories: 100% (256/256), done.
hurricane:/tmp/moo (master)$ git gc
Counting objects: 3, done.
error: garbage at end of loose object 'a1b3ebb97f10ff8d85a9472bcba50cb575dbd485'
fatal: loose object a1b3ebb97f10ff8d85a9472bcba50cb575dbd485 (stored in .git/objects/a1/b3ebb97f10ff8d85a9472bcba50cb575dbd485) is corrupt
error: failed to run repack
Editing tree object:
hurricane:/tmp/moo (master)$ hexer .git/objects/d4/eda486f02e3e862e23f6eb3739a25a2ca43f20
hurricane:/tmp/moo (master +)$ git status
error: garbage at end of loose object 'd4eda486f02e3e862e23f6eb3739a25a2ca43f20'
fatal: loose object d4eda486f02e3e862e23f6eb3739a25a2ca43f20 (stored in .git/objects/d4/eda486f02e3e862e23f6eb3739a25a2ca43f20) is corrupt
error: garbage at end of loose object 'd4eda486f02e3e862e23f6eb3739a25a2ca43f20'
fatal: loose object d4eda486f02e3e862e23f6eb3739a25a2ca43f20 (stored in .git/objects/d4/eda486f02e3e862e23f6eb3739a25a2ca43f20) is corrupt
hurricane:/tmp/moo (master +)$ git fsck
error: garbage at end of loose object 'd4eda486f02e3e862e23f6eb3739a25a2ca43f20'
fatal: loose object d4eda486f02e3e862e23f6eb3739a25a2ca43f20 (stored in .git/objects/d4/eda486f02e3e862e23f6eb3739a25a2ca43f20) is corrupt
error: garbage at end of loose object 'd4eda486f02e3e862e23f6eb3739a25a2ca43f20'
fatal: loose object d4eda486f02e3e862e23f6eb3739a25a2ca43f20 (stored in .git/objects/d4/eda486f02e3e862e23f6eb3739a25a2ca43f20) is corrupt
Editing commit object:
hurricane:/tmp/moo (master)$ echo test >> .git/objects/47/59a693f7e8362c724d3365fe6df398083fafa0
hurricane:/tmp/moo (master +)$ git status
error: garbage at end of loose object '4759a693f7e8362c724d3365fe6df398083fafa0'
fatal: loose object 4759a693f7e8362c724d3365fe6df398083fafa0 (stored in .git/objects/47/59a693f7e8362c724d3365fe6df398083fafa0) is corrupt
error: garbage at end of loose object '4759a693f7e8362c724d3365fe6df398083fafa0'
fatal: loose object 4759a693f7e8362c724d3365fe6df398083fafa0 (stored in .git/objects/47/59a693f7e8362c724d3365fe6df398083fafa0) is corrupt
!(128) hurricane:/tmp/moo (master +)$ git fsck
error: garbage at end of loose object '4759a693f7e8362c724d3365fe6df398083fafa0'
fatal: loose object 4759a693f7e8362c724d3365fe6df398083fafa0 (stored in .git/objects/47/59a693f7e8362c724d3365fe6df398083fafa0) is corrupt
error: garbage at end of loose object '4759a693f7e8362c724d3365fe6df398083fafa0'
fatal: loose object 4759a693f7e8362c724d3365fe6df398083fafa0 (stored in .git/objects/47/59a693f7e8362c724d3365fe6df398083fafa0) is corrupt
D.
next prev parent reply other threads:[~2017-01-07 21:47 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-07 12:50 "git fsck" not detecting garbage at the end of blob object files John Szakmeister
2017-01-07 21:47 ` Dennis Kaarsemaker [this message]
2017-01-08 5:26 ` Jeff King
2017-01-13 9:15 ` John Szakmeister
2017-01-13 17:52 ` [PATCH 0/6] loose-object fsck fixes/tightening Jeff King
2017-01-13 17:54 ` [PATCH 1/6] t1450: refactor loose-object removal Jeff King
2017-01-13 17:54 ` [PATCH 2/6] sha1_file: fix error message for alternate objects Jeff King
2017-01-13 17:55 ` [PATCH 3/6] t1450: test fsck of packed objects Jeff King
2017-01-13 17:58 ` [PATCH 4/6] sha1_file: add read_loose_object() function Jeff King
2017-01-13 17:59 ` [PATCH 5/6] fsck: parse loose object paths directly Jeff King
2018-10-30 20:03 ` Infinite loop regression in git-fsck in v2.12.0 Ævar Arnfjörð Bjarmason
2018-10-30 21:35 ` Jeff King
2018-10-30 22:28 ` Junio C Hamano
2018-10-30 22:56 ` Jeff King
2018-10-30 23:12 ` Jeff King
2018-10-30 23:18 ` [PATCH 1/3] t1450: check large blob in trailing-garbage test Jeff King
2018-10-30 23:23 ` [PATCH 2/3] check_stream_sha1(): handle input underflow Jeff King
2018-10-31 4:23 ` Junio C Hamano
2018-10-31 4:30 ` Jeff King
2018-10-31 4:44 ` Junio C Hamano
2018-10-31 5:03 ` Jeff King
2018-10-31 5:13 ` Jeff King
2018-10-31 5:31 ` Junio C Hamano
2018-10-30 23:23 ` [PATCH 3/3] cat-file: handle streaming failures consistently Jeff King
2018-10-31 12:42 ` [PATCH 0/3] Add a GIT_TEST_FSCK test mode Ævar Arnfjörð Bjarmason
2018-10-31 12:42 ` [PATCH 1/3] tests: add a "env-bool" helper to test-tool Ævar Arnfjörð Bjarmason
2018-10-31 12:42 ` [PATCH 2/3] tests: mark those tests where "git fsck" fails at the end Ævar Arnfjörð Bjarmason
2018-11-01 3:37 ` Junio C Hamano
2018-10-31 12:42 ` [PATCH 3/3] tests: add a special test setup that runs "git fsck" before exiting Ævar Arnfjörð Bjarmason
2018-10-31 13:33 ` [PATCH 3/3] cat-file: handle streaming failures consistently Torsten Bögershausen
2018-10-31 14:23 ` Junio C Hamano
2018-10-31 14:37 ` Jeff King
2018-10-31 17:38 ` Eric Sunshine
2018-10-31 20:29 ` Jeff King
2018-10-30 21:56 ` Infinite loop regression in git-fsck in v2.12.0 Ævar Arnfjörð Bjarmason
2018-10-30 23:08 ` Jeff King
2017-01-13 18:00 ` [PATCH 6/6] fsck: detect trailing garbage in all object types Jeff King
2017-01-19 11:18 ` [PATCH 0/6] loose-object fsck fixes/tightening John Szakmeister
2017-01-13 9:16 ` "git fsck" not detecting garbage at the end of blob object files John Szakmeister
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