From: Jeff King <peff@peff.net>
Date: Fri, 24 Jan 2014 02:28:22 GMT
Subject: Re: [PATCH] pack-objects: turn off bitmaps when skipping objects
Message-ID: <20140124022822.GC4521@sigill.intra.peff.net>
In-Reply-To: <52E1AB78.1000504@fb.com>

On Thu, Jan 23, 2014 at 03:53:28PM -0800, Siddharth Agarwal wrote:

> On 01/23/2014 03:45 PM, Siddharth Agarwal wrote:
> >
> >The worry is less certain objects not being packed and more the old
> >packs being deleted by git repack, isn't it? From the man page for
> >git-index-pack:
> 
> This should probably be "new pack" and not "old packs", I guess. Not
> knowing much about how this actually works, I'm assuming the scenario
> here is something like:
> 
> (1) git receive-pack receives a pack P.pack and writes it to disk
> (2) git index-pack runs on P.pack
> (3) git repack runs separately, finds pack P.pack with no refs
> pointing to it, and deletes it
> (4) everything goes wrong
> 
> With a keep file, this would be averted because
> 
> (1) git receive-pack receives a pack P.pack and writes it to disk
> (2) git index-pack writes a keep file for P.pack, called P.keep
> (3) git repack runs separately, finds pack P.pack with a keep file,
> doesn't touch it
> (4) git index-pack finishes, and something updates refs to point to
> P.pack and deletes P.keep

I think your understanding is accurate here. So we want repack to
respect keep files for deletion, but we _not_ necessarily want
pack-objects to avoid packing an object just because it's in a pack
marked by .keep (see my other email).

-Peff