When installing a packfile, we place the .pack file before the .idx file. The intention is that Git scans for .idx files in the pack directory and then loads the .pack files from that list. However, when we delete packfiles, we do not do this in the reverse order as we should. The unlink_pack_path() method deletes the .pack followed by the .idx. This creates a window where the process could be interrupted between the .pack deletion and the .idx deletion, leaving the repository in a state that looks strange, but isn't actually too problematic if we assume the pack was safe to delete. The .idx without a .pack will cause some overhead, but will not interrupt other Git processes. This ordering was introduced into the 'git repack' builtin bya1bbc6c017(repack: rewrite the shell script in C, 2013-09-15), though we must be careful to track history through the code move in8434e85d5f(repack: refactor pack deletion for future use, 2019-06-10) to see that. This became more important after73320e49ad(builtin/repack.c: only collect fully-formed packs, 2023-06-07) changed how 'git repack' scanned for packfiles for use in the cruft pack process. It previously looked for .pack files, but that was problematic due to the order that packs are installed: repacks between the creation of a .pack and the creation of its .idx would result in hard failures. There is an independent proposal about what to do in the case of a .idx without a .pack during this 'git repack' scenario, but this change is focused on deleting .pack files more safely. Modify the order to delete the .idx before the .pack. The rest of the modifiers on the .pack should still come after the .pack so we know all of the presumed properties of the packfile as long as it exists in the filesystem, in case we wish to reinstate it by re-indexing the .pack file. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org (not the Git list). The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks