From: Jeff King <peff@peff.net>
Date: Wed, 12 Jun 2013 12:01:56 GMT
Subject: Re: [PATCH 04/12] refs: implement simple transactions for the packed-refs file
Message-ID: <20130612120156.GB20461@sigill.intra.peff.net>
In-Reply-To: <1370987312-6761-5-git-send-email-mhagger@alum.mit.edu>

On Tue, Jun 11, 2013 at 11:48:24PM +0200, Michael Haggerty wrote:

> The API docs are not clear about whether it is kosher to read
> lock_file::fd directly.  It is only done in one file outside of
> lockfile.c.  So this patch stores the fd of the lockfile separately in
> struct packed_ref_cache, even though the same struct also has a
> pointer to the struct lock_file.
> 
> So please let me know if it is OK to read lock_file::fd directly.  If
> so, then I will drop the fd member of struct packed_ref_cache, as well
> as the local variable "fd" in lock_packed_refs().

I think it's fine; the fact that you have such an fd is a public part of
the interface, so you are only relying on the struct member being there.
And since the lock_file must hold the fd itself somewhere, I don't think
that's unreasonable.

I'm not sure how you got your "in one file" list, but it appears to
happen in credential-store.c, bundle.c, fast-import.c, and read-cache.c.

-Peff