[PATCH 0/9] packfile: avoid .idx rename races

This series is a unification of [1] and [2] which together prevent a handful of races when code that writes packfiles moves the `.idx` into place before all other auxiliary files are properly renamed.

This can lead to races like not reading the `.rev` file even if one was generated and is about to be moved into place.

Credit goes to Ævar for preparing what is more-or-less sent here. I polished a few of the commit messages, and added the second patch on top of his result. It isn't necessary, but felt like good hygiene when I was reading the surrounding code.

Thanks in advance for reviewing.

[1]: https://lore.kernel.org/git/cover.1631139433.git.me@ttaylorr.com/ [2]: https://lore.kernel.org/git/cover-0.3-00000000000-20210907T193600Z-avarab@gmail.com/

Taylor Blau (4):
  bulk-checkin.c: store checksum directly
  pack-write.c: rename `.idx` files after `*.rev`
  builtin/repack.c: move `.idx` files into place last
  builtin/index-pack.c: move `.idx` files into place last

Ævar Arnfjörð Bjarmason (5):
  pack.h: line-wrap the definition of finish_tmp_packfile()
  pack-write: refactor renaming in finish_tmp_packfile()
  index-pack: refactor renaming in final()
  pack-write: split up finish_tmp_packfile() function
  pack-objects: rename .idx files into place after .bitmap files

 builtin/index-pack.c   | 48 +++++++++++++++++------------------
 builtin/pack-objects.c | 15 ++++++++---
 builtin/repack.c       |  2 +-
 bulk-checkin.c         | 31 +++++++++++++++++------
 pack-write.c           | 57 +++++++++++++++++++++---------------------
 pack.h                 | 10 +++++++-
 6 files changed, 96 insertions(+), 67 deletions(-)