CONTENTS Sending Patches Patching Process Email Format Coding Style Options Various Notes Standards Compliance Sending Patches * send your patches to the mailing list (see ../README) or by github.com pull request. * email is accepted as an inline patch with, or without, a git pull request. Pull request emails need to include the patch set for review purposes. See howto-pull-request.txt and ../README for git repository instructions. * email attachments are difficult to review and not recommended. Hint: use git send-email. * one patch per email. See Email Format. * many small patches are preferred over a single large patch. Split patch sets based upon logical functionality. For example: #endif mark ups, compiler warnings, and exit code fixes should all be individual small patches. * don't include generated (autotools) files in your patches. Hint: use 'git clean -Xd'. * don't include po/ (translations) changes to the upstream patches. The po/ stuff is maintained on https://translationproject.org/domain/util-linux.html and updated always before the next release. * neutrality: the files in util-linux should be distribution-neutral. Packages like RPMs, DEBs, and the rest, are not provided. They should be available from the distribution. Repositories & Branches * Primary repository is on kernel.org: git clone git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git * Backup repository at github.com: git clone https://github.com/util-linux/util-linux.git We use this repository to backup kernel.org and for PULL REQUESTS, issues tracking. The master and stable branches are always pushed to the both repositories in the same time. It's recommended to use github.com for development. * Branches: master - continuous development stable/vX.Y - stable releases Since version 2.40, the "master" branch remains continuously open and is never subjected to feature freezes. The stabilization process for the upcoming release is exclusively conducted within the "stable/" branches. Upon branching from "master" to "stable/vX.Y," a new tag vX.Y+1-devel is generated to serve as placeholder for git-based versioning (refer to tools/git-version-gen). Subsequently, changes specific to the new release (such as po/ updates) are selectively cherry-picked from "stable/vX.Y" to "master" after the final release. Patching Process * announce it on the mailing list when you are going to work with some particular piece of code for a long time. This helps others to avoid massive merge conflicts. Small or quick work, does not need to be announced. * make sure that after applying your patch the file(s) will compile without errors. * test that the previously existing program behavior is not altered. If the patch intentionally alters the behavior explain what changed, and the reason for it, in the changelog/commit message. * only submit changes that you believe are ready to merge. To post a patch for peer review only, state it clearly in the email and use the Subject: [PATCH RFC] ... * incorporate reviewer comments in the patches. Resubmitting without changes is neither recommended nor polite. * resubmission can be partial or complete. If only a few alterations are needed then resubmit those particular patches. When comments cause a greater effect then resubmit the entire patch set. * When resubmitting use the email Subject: [PATCH v2] ... Hint: use the --subject-prefix='PATCH v2' option with 'git format-patch' * using a git repository for (re)submissions can make life easier. See howto-pull-request.txt and ../README. * all patch submissions are either commented, rejected, or accepted. If the maintainer rejects a patch set it is pointless to resubmit it. Email Format * Subject: [PATCH] subsystem: description. * Start the message body with an explanation of the patch, that is, a changelog/commit entry. * if someone else wrote the patch, they should be credited (and blamed) for it. To communicate this, add a line like: From: John Doe * add a Signed-off-by line. Hint: use git commit -s The sign-off is a simple line at the end of the explanation for the patch; which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple; if you can certify the following: By making a contribution to this project, I certify that: (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it. (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved. Then you just add a line like: Signed-off-by: Random J Developer Use your real name (sorry, no pseudonyms or anonymous contributions.) * Next a single line beginning with three hyphen-minus characters (---) and nothing else. * Followed by the unified diff patch. Note: the mailing list will reject certain content. See ../README. Coding Style * the preferred coding style is based on the linux kernel coding-style. Available here: https://docs.kernel.org/process/coding-style.html * use 'FIXME:' with a good description, if you want to inform others that something is not quite right, and you are unwilling to fix the issue in the submitted change. * do not use `else' after non-returning functions. For example: if (this) err(EXIT_FAIL, "this failed"); else err(EXIT_FAIL, "that failed"); Is wrong and should be written: if (this) err(EXIT_FAIL, "this failed"); err(EXIT_FAIL, "that failed"); * when you use 'if' short-shorthand make sure it does not wrap into multiple lines. In case the shorthand does not look good on one line use the normal "if () else" syntax. Options * The rule of thumb for options is that once they exist, you may not change them, nor change how they work, nor remove them. * The following options are well-known, and should not be used for any other purpose: -h, --help display usage and exit -V, --version display version and exit * Some commands use peculiar options and arguments. These will continue to be supported, but anything like them will not be accepted as new additions. A short list of examples: Characters other than '-' to start an option. See '+' in 'more'. Using a number as an option. See '-' in 'more'. Long options that start with a single '-'. See 'setterm'. '-?' is not a synonym for '--help', but is an unknown option resulting in a suggestion to try --help due to a getopt failure. Various Notes * util-linux does not use kernel headers for file system super blocks structures. * patches relying on kernel features that are not in Linus Torvalds's tree are not accepted. Standards Compliance Some of the commands maintained in this package have Open Group requirements. These commands are: cal col ipcrm ipcs kill line logger mesg more newgrp pg renice If you change these tools please make sure it does not create a conflict with the latest standard. For example, it is not recommended to add short command line options before they are part of the standard. Introducing new long options is acceptable. The Single UNIX(TM) Specification, Version 2 Copyright (C) 1997 The Open Group https://pubs.opengroup.org/onlinepubs/7908799/xcuix.html