Re: What's cooking in git.git (Sep 2022, #08; Tue, 27)

From: Victoria Dye <vdye@github.com>
Date: Sep 28, 2022, 01:52 UTC
Message-ID: <be8f11f2-c4ad-0542-066b-3bbc99a16dae@github.com>
In-Reply-To: <xmqqtu4s1q1m.fsf@gitster.g>

Junio C Hamano wrote:

Show 11 quoted lines

> * vd/fix-unaligned-read-index-v4 (2022-09-23) 1 commit
>  - read-cache: avoid misaligned reads in index v4
> 
>  The codepath that reads from the index v4 had unaligned memory
>  accesses, which has been corrected.
> 
>  Expecting a reroll.
>  cf. <Yy4nkEnhuzt2iH+R@coredump.intra.peff.net>
>  cf. <bb3a2470-7ff5-e4a6-040a-96e0e3833978@gmail.com>
>  source: <pull.1366.git.1663962236069.gitgitgadget@gmail.com>
>

How drastic an update were you expecting for this re-roll? To keep the fix minimal (that is, focused on 'create_from_disk()'), I was planning to just add some comments explaining the implementation (in response to [1]). If the goal is to get this merged quickly, I'd want to avoid a larger refactor (suggested in [2] & [3]), since doing so would either make the implementations of "read from disk" ('create_from_disk()') and "write to disk" ('copy_cache_entry_to_ondisk()') different/difficult to compare, or would involve a more invasive refactor to update both functions [4].

However, if there's no time pressure (after all, this bug has existed since the introduction of index v4!), I'm happy to do that refactor. It would expand the series to 2 or 3 patches, but should address all of the suggestions made so far and make the code overall a bit clearer.

Let me know what you think!

Thanks,
- Victoria

[1] https://lore.kernel.org/git/bb3a2470-7ff5-e4a6-040a-96e0e3833978@gmail.com/ [2] https://lore.kernel.org/git/Yy4nkEnhuzt2iH+R@coredump.intra.peff.net/ [3] https://lore.kernel.org/git/YzH+IPFBGleIsAUe@coredump.intra.peff.net/ [4] https://lore.kernel.org/git/e5954e90-6b5c-46a6-0842-b3d7d1e06b33@github.com/