Re: [PATCH 1/1] gc/repack: release packs when needed

[Junio C Hamano <gitster@pobox.com>]

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> On Windows, files cannot be removed nor renamed if there are still
> handles held by a process. To remedy that, we introduced the
> close_all_packs() function.
>
> Earlier, we made sure that the packs are released just before `git gc`
> is spawned, in case that gc wants to remove no-longer needed packs.
>
> But this developer forgot that gc itself also needs to let go of packs,
> e.g. when consolidating all packs via the --aggressive option.
>
> Likewise, `git repack -d` wants to delete obsolete packs and therefore
> needs to close all pack handles, too.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  builtin/gc.c     | 4 +++-
>  builtin/repack.c | 2 ++
>  2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/gc.c b/builtin/gc.c
> index 871a56f1c5..df90fd7f51 100644
> --- a/builtin/gc.c
> +++ b/builtin/gc.c
> @@ -659,8 +659,10 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
>  
>  	report_garbage = report_pack_garbage;
>  	reprepare_packed_git(the_repository);
> -	if (pack_garbage.nr > 0)
> +	if (pack_garbage.nr > 0) {
> +		close_all_packs(the_repository->objects);
>  		clean_pack_garbage();
> +	}

Closing before removing does make sense, but wouldn't we want to
move reprepare_packed_git() after clean_pack_garbage() while at it?
After all, the logical sequence is that we used the current set of
packs to figure out whihch ones are garbage, then now we are about
to discard.  We close the packs in the current set (i.e. the fix
made in this patch), discard the garbage packs.  It would make sense
to start using the new set (i.e. "reprepare") after all that is
done, no?  Especially, given that the next step (write-commit-graph)
still wants to read quite a lot of data from now the latest set of
packfiles...

>  	if (gc_write_commit_graph)
>  		write_commit_graph_reachable(get_object_directory(), 0,
> diff --git a/builtin/repack.c b/builtin/repack.c
> index 45583683ee..f9319defe4 100644
> --- a/builtin/repack.c
> +++ b/builtin/repack.c
> @@ -419,6 +419,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
>  	if (!names.nr && !po_args.quiet)
>  		printf("Nothing new to pack.\n");
>  
> +	close_all_packs(the_repository->objects);
> +

On the other hand, This one is added to the ideal and perfect
location, I think.

Thanks.

>  	/*
>  	 * Ok we have prepared all new packfiles.
>  	 * First see if there are packs of the same name and if so