Re: Repository corruption if objects pushed in the middle of repack

From: Taylor Blau <me@ttaylorr.com>
Date: Jun 13, 2022, 21:18 UTC
Message-ID: <YqepoUMb3rkKgWqB@nand.local>
In-Reply-To: <20220613203145.wbpi2m3ys3hchw6c@meerkat.local>

Hi Konstantin,

On Mon, Jun 13, 2022 at 04:31:45PM -0400, Konstantin Ryabitsev wrote:

Show 5 quoted lines

> As far as I know, the maintenance steps we are running shouldn't result in any
> missing objects, so I'm curious if it's something we're doing wrong (using
> unsafe flags) or if git isn't properly accounting for some objects that come
> in during the repack stage. We're seeing this happen fairly routinely, so it's
> not just a random fluke.

Interesting. From what you described, it does suggest that `repack` is deleting things too eagerly.

But I would be quite surprised if that were the case, since `repack` is *very* careful to only delete packs which it knew about at the start of the repack. Likewise, when it cleans up loose objects, it only unlinks objects which can be found in some (non-deleted) pack that will remain in the repository.

So I doubt that repack is doing something weird here, though it would be extremely interseting if you were able to pause the `repack` process at a specific point, push new objects into the repository, and reliably demonstrate the corruption.

Thanks, Taylor