From b44901cb8fa09fc78385e953b7e9e7e63289066f Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Thu, 28 Oct 2010 14:54:56 -0700 Subject: [PATCH] SubmittingPatches: initial version Largely based on Linux's version. Includes the Signed-off-by stuff at the top, and a bit more modern description of how to prepare/send patches using git format-patch and send-email. Signed-off-by: Sage Weil --- SubmittingPatches | 339 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 339 insertions(+) create mode 100644 SubmittingPatches diff --git a/SubmittingPatches b/SubmittingPatches new file mode 100644 index 0000000000000..1c2f1e6932563 --- /dev/null +++ b/SubmittingPatches @@ -0,0 +1,339 @@ + +========================== +Submitting Patches to Ceph +========================== + +This is based on Documentation/SubmittingPatches from the Linux kernel, +but has pared down significantly and updated slightly. The patch signing +procedures and definitions are unmodified. + + +--------------------- +SIGNING CONTRIBUTIONS +--------------------- + +In order to keep the record of code attribution clean within the +source repository, please follow these guidelines for signing +patches submitted to the project. These definitions are taken +from those used by the Linux kernel and many other open source +projects. + +1) Sign your work + +To improve tracking of who did what, especially with patches that can +percolate to their final resting place in the kernel through several +layers of maintainers, we've introduced a "sign-off" procedure on +patches that are being emailed around. + +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 a open-source patch. The rules are pretty simple: if you +can certify the below: + + Developer's Certificate of Origin 1.1 + + 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 saying + + Signed-off-by: Random J Developer + +using your real name (sorry, no pseudonyms or anonymous contributions.) + +Some people also put extra tags at the end. They'll just be ignored for +now, but you can do this to mark internal company procedures or just +point out some special detail about the sign-off. + +If you are a subsystem or branch maintainer, sometimes you need to slightly +modify patches you receive in order to merge them, because the code is not +exactly the same in your tree and the submitters'. If you stick strictly to +rule (c), you should ask the submitter to rediff, but this is a totally +counter-productive waste of time and energy. Rule (b) allows you to adjust +the code, but then it is very impolite to change one submitter's code and +make him endorse your bugs. To solve this problem, it is recommended that +you add a line between the last Signed-off-by header and yours, indicating +the nature of your changes. While there is nothing mandatory about this, it +seems like prepending the description with your mail and/or name, all +enclosed in square brackets, is noticeable enough to make it obvious that +you are responsible for last-minute changes. Example : + + Signed-off-by: Random J Developer + [lucky@maintainer.example.org: struct foo moved from foo.c to foo.h] + Signed-off-by: Lucky K Maintainer + +This practise is particularly helpful if you maintain a stable branch and +want at the same time to credit the author, track changes, merge the fix, +and protect the submitter from complaints. Note that under no circumstances +can you change the author's identity (the From header), as it is the one +which appears in the changelog. + +Special note to back-porters: It seems to be a common and useful practise +to insert an indication of the origin of a patch at the top of the commit +message (just after the subject line) to facilitate tracking. For instance, +here's what we see in 2.6-stable : + + Date: Tue May 13 19:10:30 2008 +0000 + + SCSI: libiscsi regression in 2.6.25: fix nop timer handling + + commit 4cf1043593db6a337f10e006c23c69e5fc93e722 upstream + +And here's what appears in 2.4 : + + Date: Tue May 13 22:12:27 2008 +0200 + + wireless, airo: waitbusy() won't delay + + [backport of 2.6 commit b7acbdfbd1f277c1eb23f344f899cfa4cd0bf36a] + +Whatever the format, this information provides a valuable help to people +tracking your trees, and to people trying to trouble-shoot bugs in your +tree. + + +2) When to use Acked-by: and Cc: + +The Signed-off-by: tag indicates that the signer was involved in the +development of the patch, or that he/she was in the patch's delivery path. + +If a person was not directly involved in the preparation or handling of a +patch but wishes to signify and record their approval of it then they can +arrange to have an Acked-by: line added to the patch's changelog. + +Acked-by: is often used by the maintainer of the affected code when that +maintainer neither contributed to nor forwarded the patch. + +Acked-by: is not as formal as Signed-off-by:. It is a record that the acker +has at least reviewed the patch and has indicated acceptance. Hence patch +mergers will sometimes manually convert an acker's "yep, looks good to me" +into an Acked-by:. + +Acked-by: does not necessarily indicate acknowledgement of the entire patch. +For example, if a patch affects multiple subsystems and has an Acked-by: from +one subsystem maintainer then this usually indicates acknowledgement of just +the part which affects that maintainer's code. Judgement should be used here. +When in doubt people should refer to the original discussion in the mailing +list archives. + +If a person has had the opportunity to comment on a patch, but has not +provided such comments, you may optionally add a "Cc:" tag to the patch. +This is the only tag which might be added without an explicit action by the +person it names. This tag documents that potentially interested parties +have been included in the discussion + + +3) Using Reported-by:, Tested-by: and Reviewed-by: + +If this patch fixes a problem reported by somebody else, consider adding a +Reported-by: tag to credit the reporter for their contribution. Please +note that this tag should not be added without the reporter's permission, +especially if the problem was not reported in a public forum. That said, +if we diligently credit our bug reporters, they will, hopefully, be +inspired to help us again in the future. + +A Tested-by: tag indicates that the patch has been successfully tested (in +some environment) by the person named. This tag informs maintainers that +some testing has been performed, provides a means to locate testers for +future patches, and ensures credit for the testers. + +Reviewed-by:, instead, indicates that the patch has been reviewed and found +acceptable according to the Reviewer's Statement: + + Reviewer's statement of oversight + + By offering my Reviewed-by: tag, I state that: + + (a) I have carried out a technical review of this patch to + evaluate its appropriateness and readiness for inclusion into + the mainline kernel. + + (b) Any problems, concerns, or questions relating to the patch + have been communicated back to the submitter. I am satisfied + with the submitter's response to my comments. + + (c) While there may be things that could be improved with this + submission, I believe that it is, at this time, (1) a + worthwhile modification to the kernel, and (2) free of known + issues which would argue against its inclusion. + + (d) While I have reviewed the patch and believe it to be sound, I + do not (unless explicitly stated elsewhere) make any + warranties or guarantees that it will achieve its stated + purpose or function properly in any given situation. + +A Reviewed-by tag is a statement of opinion that the patch is an +appropriate modification of the kernel without any remaining serious +technical issues. Any interested reviewer (who has done the work) can +offer a Reviewed-by tag for a patch. This tag serves to give credit to +reviewers and to inform maintainers of the degree of review which has been +done on the patch. Reviewed-by: tags, when supplied by reviewers known to +understand the subject area and to perform thorough reviews, will normally +increase the likelihood of your patch getting into the kernel. + + +----------------------------- +PREPARING AND SENDING PATCHES +----------------------------- + +The upstream repository is managed by Git. You will find that it +is easiest to work on the project and submit changes by using the +git tools, both for managing your own code and for preparing and +sending patches. + +1) "git format-patch" + +The best way to generate a patch is to work from a Git checkout of +the Ceph source code. You can then generate patches with the +'git format-patch' command. For example, + + $ git format-patch HEAD^^ -o mything + +will take the last two commits and generate patches in the mything/ +directory. The commit you specify on the command line is the +'upstream' commit that you are diffing against. Note that it does +not necesarily have to be an ancestor of your current commit. You +can do something like + + $ git checkout -b mything + $ ... do lots of stuff ... + $ git fetch + ...find out that origin/unstable has also moved forward... + $ git format-patch origin/unstable -o mything + +and the patches will be against origin/unstable. + +The -o dir is optional; if left off, the patch(es) will appear in +the current directory. This can quickly get messy. + +You can also add --cover-letter and get a '0000' patch in the +mything/ directory. That can be updated to include any overview +stuff for a multipart patch series. If it's a single patch, don't +bother. + +Make sure your patch does not include any extra files which do not +belong in a patch submission. Make sure to review your patch -after- +generated it with diff(1), to ensure accuracy. + +If your changes produce a lot of deltas, you may want to look into +splitting them into individual patches which modify things in +logical stages. This will facilitate easier reviewing by other +kernel developers, very important if you want your patch accepted. +There are a number of scripts which can aid in this: + + +2) Sending patches with "git send-email" + +The git send-email command make it super easy to send patches +(particularly those prepared with git format patch). It is careful to +format the emails correctly so that you don't have to worry about your +email client mangling whitespace or otherwise screwing things up. It +works like so: + + $ git send-email --to ceph-devel@vger.kernel.org my.patch + +for a single patch, or + + $ git send-email --to ceph-devel@vger.kernel.org mything + +to send a whole patch series (prepared with, say, git format-patch). + + +3) Describe your changes. + +Describe the technical detail of the change(s) your patch includes. + +Be as specific as possible. The WORST descriptions possible include +things like "update driver X", "bug fix for driver X", or "this patch +includes updates for subsystem X. Please apply." + +The maintainer will thank you if you write your patch description in a +form which can be easily pulled into Linux's source code management +system, git, as a "commit log". See #15, below. + +If your description starts to get long, that's a sign that you probably +need to split up your patch. See #3, next. + +When you submit or resubmit a patch or patch series, include the +complete patch description and justification for it. Don't just +say that this is version N of the patch (series). Don't expect the +patch merger to refer back to earlier patch versions or referenced +URLs to find the patch description and put that into the patch. +I.e., the patch (series) and its description should be self-contained. +This benefits both the patch merger(s) and reviewers. Some reviewers +probably didn't even receive earlier versions of the patch. + +If the patch fixes a logged bug entry, refer to that bug entry by +number and URL. + + +4) Separate your changes. + +Separate _logical changes_ into a single patch file. + +For example, if your changes include both bug fixes and performance +enhancements for a single driver, separate those changes into two +or more patches. If your changes include an API update, and a new +driver which uses that new API, separate those into two patches. + +On the other hand, if you make a single change to numerous files, +group those changes into a single patch. Thus a single logical change +is contained within a single patch. + +If one patch depends on another patch in order for a change to be +complete, that is OK. Simply note "this patch depends on patch X" +in your patch description. + +If you cannot condense your patch set into a smaller set of patches, +then only post say 15 or so at a time and wait for review and integration. + + + +5) Style check your changes. + +Check your patch for basic style violations, details of which can be +found in CodingStyle. + + + +6) No MIME, no links, no compression, no attachments. Just plain text. + +Developers need to be able to read and comment on the changes you are +submitting. It is important for a kernel developer to be able to +"quote" your changes, using standard e-mail tools, so that they may +comment on specific portions of your code. + +For this reason, all patches should be submitting e-mail "inline". +WARNING: Be wary of your editor's word-wrap corrupting your patch, +if you choose to cut-n-paste your patch. + +Do not attach the patch as a MIME attachment, compressed or not. +Many popular e-mail applications will not always transmit a MIME +attachment as plain text, making it impossible to comment on your +code. A MIME attachment also takes Linus a bit more time to process, +decreasing the likelihood of your MIME-attached change being accepted. + +Exception: If your mailer is mangling patches then someone may ask +you to re-send them using MIME. +