Re: Recovering from repository corruption

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Jun 10, 2008, 21:09 UTC
Message-ID: <alpine.LFD.1.10.0806101403080.3101@woody.linux-foundation.org>
In-Reply-To: <6dbd4d000806101328k1fc913f2ia55c3e44273ec5ad@mail.gmail.com>

On Tue, 10 Jun 2008, Denis Bueno wrote:

Show 7 quoted lines

> >
> > Hmm. Scary. That should *not* have been successful with a corrupt repo.
> >
> > Unless you have done a .grafts file to hide the corruption, or something
> > like that?
> 
> I intended to do that, yes, and I think I was successful.

Ahh, ok. Yes, we should probably re-think our 'grafts' file thing, or at least not document it, because it's actually a wondeful way to just cause more corruption by hiding things (ie if you clone a repo with a grafts file, the result will now have neither the grafts file _nor_ the state that was hidden by it, so the result is guaranteed to be corrupt).

But that explains why your clone worked, and why the resulting repo had different corruption - it avoided the original corruption, but because of the grafts file it avoided it by just not having those commits at all..

> I do have bunches of personal information in the repo, unfortunately.
> The particular *file* involved in the corruption, however, is fine for
> all to view.  Is that useful?

No, almost all the interest is basically in how the whole repo ties together. The individual corrupt files may be interesting, though, ie from your original report:

    error: 320bd6e82267b71dd2ca7043ea3f61dbbca16109: object corrupt or missing
    error: 4d0be2816d5eea5ae2b40990235e2225c1715927: object corrupt or missing

then *if* you have the files

	.git/objects/32/0bd6e82267b71dd2ca7043ea3f61dbbca16109
	.git/objects/4d/0be2816d5eea5ae2b40990235e2225c1715927

then those two files are interesting in themselves (most likely they are not there at all, or are zero-sized, but if you have them, please post them).

And as this was a result of a real filesystem crash, it *is* possible that you have something in the /lost+found directory for that filesystem. If so, those missing files may be found there.

		Linus