--- /dev/null
+Submitting Patches to Ceph - Backports
+======================================
+
+Most likely you're reading this because you intend to submit a GitHub pull
+request ("PR") targeting one of the stable branches ("nautilus", etc.) at
+https://github.com/ceph/ceph.
+
+Before you open that PR, please read this entire document or, at the very least,
+the following two sections: `General principles`_ and `Cherry-picking rules`_.
+
+
+.. contents::
+ :depth: 3
+
+
+General principles
+------------------
+
+To help the people who will review your backport, please state either in the
+backport PR, or in the backport tracker issue, or in the master tracker issue:
+
+1. what bug is fixed
+2. why this fix is the minimal way to do it
+3. why does this need to be fixed in <release>
+
+The above should be followed especially in cases when the backport could be seen
+as introducing, into a stable branch, code that is not related to a particular
+bug or issue.
+
+Rationale: every modification of a stable branch carries a certain risk of
+introducing a regression. To minimize this risk, backports should be as
+straightforward and narrowly-targeted as possible. As a stable release series
+ages, the importance of following these general principles rises.
+
+
+Cherry-picking rules
+--------------------
+
+The following rules, which have been codified from "best practices" developed
+over years of backporting, apply to the actual backport implementation:
+
+* all fixes should land in master first
+* commits to stable branches should be cherry-picked from master
+* before starting to cherry-pick a set of commits from master, grep the master git history for the SHA1 of each master commit (using ``git log --grep``) to check for follow-up fixes. Include any follow-up fixes found in the set of commits to be cherry-picked.
+* cherry-picks must be done using ``git cherry-pick -x``
+* if a commit could not be cherry-picked from master, the commit message must explain why that was not possible
+* the commit message generated by ``git cherry-pick -x`` must not be modified, except to add a "Conflicts" section below the "cherry picked from commit ..." line added by git
+* the "Conflicts" section must mention all files where changes had to be made manually (not just conflicts flagged by git)
+* the "Conflicts" section should also describe the manual changes that were made
+* if a change is to be backported to multiple stable branches, a tracker issue is needed, so the backports can be tracked (if a change is only to be backported to the most recent stable branch, a tracker issue is not strictly required)
+
+For more information on tracker issues, see `Tracker workflow`_.
+
+For more information on conflict resolution and writing the "Conflicts" section,
+see `Conflict resolution`_.
+
+Adhering to these rules will make your backport easier for reviewers to
+understand. Not adhering to these rules creates additional work for reviewers
+and may cause your backport PR to be rejected.
+
+Notes on the cherry-picking rules
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+What does "all fixes should land in master first" mean? What if I just need to
+fix the issue in <release>?
+
+As the person fixing the issue, you are required to first check whether the
+issue exists in master. If it does, then the proper course of action is to
+create a master tracker (see `Tracker workflow`_) and fix the issue in master,
+first, and only then cherry-pick the fix to the stable branches that have the
+issue.
+
+If the issue exists in the stable branch, but not in master, there are several
+possibilities:
+
+1. it's a regression introduced into the stable branch by a bad backport
+2. the issue was fixed in master by some massive refactoring that cannot be backported
+3. the issue was already fixed in master by a cherry-pickable commit
+
+In cases 1 and 2, it's permissible to fix the issue directly in the most recent
+stable branch, subject to the rule "if a commit could not be cherry-picked from
+master, the commit message must explain why that was not possible". Once the
+fix has landed in the most recent stable branch, it can be cherry-picked to
+older stable branches from there.
+
+In case 3, the issue should be handled like any other backport - read on.
+
+
+Tracker workflow
+----------------
+
+Any change that is to be backported to multiple stable branches should have
+an associated tracker issue at https://tracker.ceph.com.
+
+For fixes already merged to master, this may have already been done - see the
+``Fixes:`` line in the master PR. If the master PR has already been merged and
+there is no associated master tracker issue, you can create a master tracker
+issue and fill in the fields as described below.
+
+This master tracker issue should be in the "Bug" or "Feature"
+trackers of the relevant subproject under the "Ceph" parent project (or
+in the "Ceph" project itself if none of the subprojects are a good fit).
+The stable branches to which the master changes are to be cherry-picked should
+be listed in the "Backport" field. For example::
+
+ Backport: mimic, nautilus
+
+Once the PR targeting master is open, add the PR number assigned by GitHub to
+the tracker issue. For example, if the PR number is 99999::
+
+ Pull request ID: 99999
+
+Once the master PR has been merged, after checking that the change really needs
+to be backported and the Backport field has been populated, change the master
+tracker issue's ``Status`` field to "Pending Backport".
+
+ Status: Pending Backport
+
+If you do not have sufficient permissions to modify any field of the tracker
+issue, just add a comment describing what changes you would like to make.
+Someone with permissions will make the necessary modifications on your behalf.
+
+For straightforward backports, that's all that you (as the developer of the fix)
+need to do. Volunteers from the `Stable Releases and Backports team`_ will
+proceed to create Backport issues to track the necessary backports and stage the
+backports by opening GitHub PRs with the cherry-picks. If you don't want to
+wait, and provided you have sufficient permissions at https://tracker.ceph.com,
+you can `create Backport tracker issues` and `stage backports`_ yourself. In
+that case, read on.
+
+
+.. _`create backport tracker issues`:
+.. _`backport tracker issue`:
+
+Creating Backport tracker issues
+--------------------------------
+
+To track backporting efforts, "backport tracker issues" can be created from
+a parent "master tracker issue". The master tracker issue is described in the
+previous section, `Tracker workflow`_. This section focuses the backport tracker
+issue.
+
+Once the entire `Tracker workflow`_ has been completed for the master issue,
+issues can be created in the Backport tracker for tracking the backporting work.
+
+Under ordinary circumstances, the developer who merges the master PR will flag
+the master tracker issue for backport by changing the Status to "Pending
+Backport", and volunteers from the `Stable Releases and Backports team`_
+periodically create backport tracker issues by running the
+``backport-create-issue`` script. They also do the actual backporting. But that
+does take time and you may not want to wait.
+
+You might be tempted to forge ahead and create the backport issues yourself.
+Please don't do that - it is difficult (bordering on impossible) to get all the
+fields correct when creating backport issues manually, and why even try when
+there is a script that gets it right every time? Setting up the script requires
+a small up-front time investment. Once that is done, creating backport issues
+becomes trivial.
+
+The backport-create-issue script
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The script used to create backport issues is located at
+``src/script/backport-create-issue`` in the master branch. Though there might be
+an older version of this script in a stable branch, do not use it. Only use the
+most recent version from master.
+
+Once you have the script somewhere in your PATH, you can proceed to install the
+dependencies.
+
+The dependencies are:
+
+* python3
+* python-redmine
+
+Python 3 should already be present on any recent Linux installation. The second
+dependency, `python-redmine`_, can be obtained from PyPi::
+
+ pip install --user python-redmine
+
+.. _`python-redmine`: https://pypi.org/project/python-redmine/
+
+Then, try to run the script::
+
+ backport-create-issue --help
+
+This should produce a usage message.
+
+Finally, run the script to actually create the Backport issues::
+
+ backport-create-issue --user <tracker_username> --password <tracker_password> 99999
+
+The script needs to know your https://tracker.ceph.com credentials in order to
+authenticate to Redmine. In lieu of providing your literal username and password
+on the command line, you could also obtain a REST API key ("My account" -> "API
+access key") and run the script like so::
+
+ backport-create-issue --key <tracker_api_key> 99999
+
+
+.. _`stage backports`:
+.. _`stage the backport`:
+.. _`staging a backport`:
+
+Opening a backport PR
+---------------------
+
+Once the `Tracker workflow`_ is completed and the `backport tracker issue`_ has
+been created, it's time to open a backport PR. One possibility is to do this
+manually, while taking care to follow the `cherry-picking rules`_. However, this
+can result in a backport that is not properly staged. For example, the PR
+description might not contain a link to the `backport tracker issue`_ (a common
+oversight). You might even forget to update the `backport tracker issue`_.
+
+In the past, much time was lost, and much frustration caused, by the necessity
+of staging backports manually. Now, fortunately, there is a script available
+which automates the process and takes away most of the guesswork.
+
+The ceph-backport.sh script
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Similar to the case of creating the `Backport tracker issues`_, staging the actual
+backport PR and updating the Backport tracker issue is difficult - if not
+impossible - to get right if you're doing it manually, and quickly becomes
+tedious if you do it more than once in a long while.
+
+The ``ceph-backport.sh`` script automates the entire process of cherry-picking
+the commits from the master PR, opening the GitHub backport PR, and
+cross-linking the GitHub backport PR with the correct Backport tracker issue.
+The script can also be used to good effect if you have already manually prepared
+the backport branch with the cherry-picks in it.
+
+The script is located at ``src/script/ceph-backport.sh`` in the ``master``
+branch. Though there might be an older version of this script in a stable
+branch, do not use it. Only use the most recent version from master.
+
+This is just a bash script, so the only dependency is ``bash`` itself, but it
+does need to be run in the top level of a local clone of ``ceph/ceph.git``.
+A small up-front time investment is required to get the script working in your
+environment. This is because the script needs to autenticate itself (i.e., as
+you) in order to use the GitHub and Redmine REST API services.
+
+The script is self-documenting. Just run the script and proceed from there.
+
+Once the script has been set up properly, you can validate the setup like so::
+
+ ceph-backport.sh --setup
+
+Once you have this saying "Overall setup is OK", you have two options for
+staging the backport: either leave everything to the script, or prepare the
+backport branch yourself and use the script only for creating the PR and
+updating the Backport tracker issue.
+
+If you prefer to leave everything to the script, just provide the Backport
+tracker issue number to the script::
+
+ ceph-backport.sh 55555
+
+The script will start by creating the backport branch in your local git clone.
+The script always uses the following format for naming the branch::
+
+ wip-<backport_issue_number>-<name_of_stable_branch>
+
+For example, if the Backport tracker issue number is 55555 and it's targeting
+the stable branch "nautilus", the backport branch would be named::
+
+ wip-55555-nautilus
+
+If you prefer to create the backport branch yourself, just do that. Be sure to
+name the backport branch as described above. (It's a good idea to use this
+branch naming convention for all your backporting work.) Then, run the script::
+
+ ceph-backport.sh 55555
+
+The script will see that the backport branch already exists, and use it.
+
+Conflict resolution
+^^^^^^^^^^^^^^^^^^^
+
+If git reports conflicts, the script will abort to allow you to resolve the
+conflicts manually.
+
+Once the conflicts are resolved, complete the cherry-pick ::
+
+ git cherry-pick --continue
+
+Git will present a draft commit message with a "Conflicts" section.
+
+Unfortunately, in recent versions of git, the Conflicts section is commented
+out. Since the Conflicts section is mandatory for Ceph backports that do not
+apply cleanly, you will need to uncomment the entire "Conflicts" section
+of the commit message before committing the cherry-pick. You can also
+include commentary on what the conflicts were and how you resolved
+them. For example::
+
+ Conflicts:
+ src/foo/bar.cc
+ - mimic does not have blatz; use batlo instead
+
+When editing the cherry-pick commit message, leave everything before the
+"cherry picked from" line unchanged. Any edits you make should be in the part
+following that line. Here is an example::
+
+ osd: check batlo before setting blatz
+
+ Setting blatz requires special precautions. Check batlo first.
+
+ Fixes: https://tracker.ceph.com/issues/99999
+ Signed-off-by: Random J Developer <random@developer.example.com>
+ (cherry picked from commit 01d73020da12f40ccd95ea1e49cfcf663f1a3a75)
+
+ Conflicts:
+ src/osd/batlo.cc
+ - add_batlo_check has an extra arg in newer code
+
+Naturally, the ``Fixes`` line points to the master issue. You might be tempted
+to modify it so it points to the backport issue, but - please - don't do that.
+First, the master issue points to all the backport issues, and second, *any*
+editing of the original commit message calls the entire backport into doubt,
+simply because there is no good reason for such editing.
+
+The part below the ``(cherry picked from commit ...)`` line is fair game for
+editing. If you need to add additional information to the cherry-pick commit
+message, append that information below this line. Once again: do not modify the
+original commit message.
+
+
+Labelling of backport PRs
+-------------------------
+
+Once the backport PR is open, the first order of business is to set the
+Milestone tag to the stable release the backport PR is targeting. For example,
+if the PR is targeting "nautilus", set the Milestone tag to "nautilus".
+
+If you don't have sufficient GitHub permissions to set the Milestone, add
+a comment to the PR with the following content::
+
+ @ceph/backport-admins
+
+This will alert the `Stable Releases and Backports team`_ to your PR, and
+someone will ensure your PR gets the proper labels.
+
+
+.. _`backport PR reviewing`:
+.. _`backport PR testing`:
+.. _`backport PR merging`:
+
+Reviewing, testing, and merging of backport PRs
+-----------------------------------------------
+
+Once your backport PR is open and the Milestone is set properly, the
+`Stable Releases and Backports team` will take care of getting the PR
+reviewed and tested. Once the PR is reviewed and tested, it will be merged.
+
+If you would like to facilitate this process, you can solicit reviews and run
+integration tests on the PR. In this case, add comments to the PR describing the
+tests you ran and their results.
+
+Once the PR has been reviewed and deemed to have undergone sufficient testing,
+it will be merged. Even if you have sufficient GitHub permissions to merge the
+PR, please do *not* merge it yourself. (Uncontrolled merging to stable branches
+unnecessarily complicates the release preparation process, which is done by
+volunteers.)
+
+
+Stable Releases and Backports team
+----------------------------------
+
+Ceph has a `Stable Releases and Backports`_ team, staffed by volunteers,
+which is charged with maintaining the stable releases and backporting bugfixes
+from the master branch to them. (That team maintains a wiki, accessible by
+clicking the `Stable Releases and Backports`_ link, which describes various
+workflows in the backporting lifecycle.)
+
+.. _`Stable Releases and Backports`: http://tracker.ceph.com/projects/ceph-releases/wiki
+
+Ordinarily, it is enough to fill out the "Backport" field in the bug (tracker
+issue). The volunteers from the Stable Releases and Backports team will
+backport the fix, run regression tests on it, and include it in one or more
+future point releases.
+
+
--- /dev/null
+Submitting Patches to Ceph - Kernel Components
+==============================================
+
+Submission of patches to the Ceph kernel code is subject to the same rules
+and guidelines as any other patches to the Linux Kernel. These are set out in
+``Documentation/process/submitting-patches.rst`` in the kernel source tree.
+
+What follows is a condensed version of those rules and guidelines, updated based
+on the Ceph project's best practices.
+
+
+.. contents::
+ :depth: 3
+
+
+Signing contributions
+---------------------
+
+In order to keep the record of code attribution clean within the source
+repository, 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 <random@developer.example.org>
+
+
+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 them 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 <random@developer.example.org>
+ [lucky@maintainer.example.org: struct foo moved from foo.c to foo.h]
+ Signed-off-by: Lucky K Maintainer <lucky@maintainer.example.org>
+
+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. 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
+-----------------------------
+
+For the kernel client, patches are expected to be emailed directly to the
+email list ``ceph-devel@vger.kernel.org`` (note: *not* ``dev@ceph.io``) and reviewed
+in the email list.
+
+The best way to generate a patch for manual submission is to work from
+a Git checkout of the Ceph kernel client (kernel modules) repository located at
+https://github.com/ceph/ceph-client. You can then generate patches
+with the 'git format-patch' command. For example,
+
+.. code-block:: bash
+
+ $ 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 necessarily have to be an ancestor of your current commit. You
+can do something like
+
+.. code-block:: bash
+
+ $ 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.
+
+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:
+
+.. code-block:: bash
+
+ $ git send-email --to ceph-devel@vger.kernel.org my.patch
+
+for a single patch, or
+
+.. code-block:: bash
+
+ $ git send-email --to ceph-devel@vger.kernel.org mything
+
+to send a whole patch series (prepared with, say, git format-patch).
+
+
+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.
+
+
+Style Guide
+-----------
+
+The Linux Kernel has coding style conventions, which are set forth in
+``Documentation/process/coding-style.rst``. Please adhere to these conventions.
Submitting Patches to Ceph
==========================
-This is based on Documentation/SubmittingPatches from the Linux kernel,
-but has pared down significantly and updated based on the Ceph project's
-best practices.
+Patches to Ceph can be divided into three categories:
-The patch signing procedures and definitions are unmodified.
+ 1. patches targeting Ceph kernel code
+ 2. patches targeting the "master" branch
+ 3. patches targeting stable branches (e.g.: "nautilus")
+Some parts of Ceph - notably the RBD and CephFS kernel clients - are maintained
+within the Linux Kernel. For patches targeting this code, please refer to the
+file ``SubmittingPatches-kernel.rst``.
-SIGNING CONTRIBUTIONS
-=====================
+The rest of this document assumes that your patch relates to Ceph code that is
+maintained in the GitHub repository https://github.com/ceph/ceph
-In order to keep the record of code attribution clean within the source
-repository, 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.
+If you have a patch that fixes an issue, feel free to open a GitHub pull request
+("PR") targeting the "master" branch, but do read this document first, as it
+contains important information for ensuring that your PR passes code review
+smoothly.
+For patches targeting stable branches (e.g. "nautilus"), please also see
+the file ``SubmittingPatches-backports.rst``.
+
+.. contents::
+ :depth: 3
-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.
+Sign your work
+--------------
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
+commit, 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:
Signed-off-by: Random J Developer <random@developer.example.org>
-
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 them 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 <random@developer.example.org>
- [lucky@maintainer.example.org: struct foo moved from foo.c to foo.h]
- Signed-off-by: Lucky K Maintainer <lucky@maintainer.example.org>
-
-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. 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.
-
-The project will generally accept code either by pulling code directly from
-a published git tree (usually on github), or via patches emailed directly
-to the email list (ceph-devel@vger.kernel.org). For the kernel client,
-patches are expected to be reviewed in the email list. And for everything
-else, github is preferred due to the convenience of the 'pull request'
-feature.
-
-
-1. Github pull request
-----------------------
-
-The preferred way to submit code is by publishing your patches in a branch
-in your github fork of the ceph repository and then submitting a github
-pull request.
-
-For example, prepare your changes
-
-.. code-block:: bash
-
- # ...code furiously...
- $ git commit # git gui is also quite convenient
- $ git push origin mything
+Git can sign off on your behalf
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Then submit a pull request at
+Please note that git makes it trivially easy to sign commits. First, set the
+following config options::
- https://github.com/ceph/ceph/pulls
+ $ git config --list | grep user
+ user.email=my_real_email_address@example.com
+ user.name=My Real Name
-and click 'New pull request'. See :ref:`_title_of_commit` for our naming
-convention of pull requests. The 'hub' command-line tool, available from
+Then just remember to use ``git commit -s``. Git will add the ``Signed-off-by``
+line automatically.
- https://github.com/github/hub
-allows you to submit pull requests directly from the command line
+Separate your changes
+---------------------
-.. code-block:: bash
+Group *logical changes* into individual commits.
- $ hub pull-request -b ceph:master -h you:mything
+If you have a series of bulleted modifications, consider separating each of
+those into its own commit.
-Pull requests appear in the review queue at
+For example, if your changes include both bug fixes and performance enhancements
+for a single component, separate those changes into two or more commits. If your
+changes include an API update, and a new feature which uses that new API,
+separate those into two patches.
- https://github.com/organizations/ceph/dashboard/pulls
+On the other hand, if you make a single change that affects numerous
+files, group those changes into a single commit. Thus a single logical change is
+contained within a single patch. (If the change needs to be backported, that
+might change the calculus, because smaller commits are easier to backport.)
-You may want to ping a developer in #ceph-devel on irc.oftc.net or on the
-email list to ensure your submission is noticed.
-When addressing review comments, can should either add additional patches to
-your branch or (better yet) squash those changes into the relevant commits so
-that the sequence of changes is "clean" and gets things right the first time.
-The ``git rebase -i`` command is very helpful in this process. Once you have
-updated your local branch, you can simply force-push to the existing branch
-in your public repository that is referenced by the pull request with
+Describe your changes
+---------------------
-.. code-block:: bash
+Each commit has an associated commit message that is stored in git. The first
+line of the commit message is the `commit title`_. The second line should be
+left blank. The lines that follow constitute the `commit message`_.
- $ git push -f origin mything
+A commit and its message should be focused around a particular change.
-and your changes will be visible from the existing pull-request. You may want
-to ping the reviewer again or comment on the pull request to ensure the updates
-are noticed.
+Commit title
+^^^^^^^^^^^^
-Sometimes your change could be based on an outdated parent commit and has
-conflicts with the latest target branch, then you need to fetch the updates
-from the remote branch, rebase your change onto it, and resolve the conflicts
-before doing the force-push
-
-.. code-block:: bash
-
- $ git pull --rebase origin target-branch
-
-So that the pull request does not contain any "merge" commit. Instead of "merging"
-the target branch, we expect a linear history in a pull request where you
-commit on top of the remote branch.
-
-Q: Which branch should I target in my pull request?
-
-A: The target branch depends on the nature of your change:
-
- If you are adding a feature, target the "master" branch in your pull
- request.
-
- If you are fixing a bug, target the named branch corresponding to the
- major version that is currently in development. For example, if
- Infernalis is the latest stable release and Jewel is development, target
- the "jewel" branch for bugfixes. The Ceph core developers will
- periodically merge this named branch into "master". When this happens,
- the master branch will contain your fix as well.
-
- If you are fixing a bug (see above) *and* the bug exists in older stable
- branches (for example, the "hammer" or "infernalis" branches), then you
- should file a Redmine ticket describing your issue and fill out the
- "Backport: <branchname>" form field. This will notify other developers that
- your commit should be cherry-picked to one or more stable branches. Then,
- target the "master" branch in your pull request.
-
- For example, you should set "Backport: jewel, kraken" in your Redmine ticket
- to indicate that you are fixing a bug that exists on the "jewel" and
- "kraken" branches and that you desire that your change be cherry-picked to
- those branches after it is merged into master.
-
-Q: How to include ``Reviewed-by: tag(s)`` in my pull request?
-
-A: You don't. If someone reviews your pull request, they should indicate they
- have done so by commenting on it with "+1", "looks good to me", "LGTM",
- and/or the entire "Reviewed-by: ..." line with their name and email address.
+The text up to the first empty line in a commit message is the commit
+title. It should be a single short line of at most 72 characters,
+summarizing the change, and prefixed with the
+subsystem or module you are changing. Also, it is conventional to use the
+imperative mood in the commit title. Positive examples include::
- The developer merging the pull request should note positive reviews and
- include the appropriate Reviewed-by: lines in the merge commit.
+ mds: add perf counter for finisher of MDSRank
+ osd: make the ClassHandler::mutex private
+More positive examples can be obtained from the git history of the ``master``
+branch::
-2. Patch submission via ceph-devel@vger.kernel.org
---------------------------------------------------
+ git log
-The best way to generate a patch for manual submission 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,
+Some negative examples (how *not* to title a commit message)::
-.. code-block:: bash
+ update driver X
+ bug fix for driver X
+ fix issue 99999
- $ git format-patch HEAD^^ -o mything
+Further to the last negative example ("fix issue 99999"), see `Fixes line`_.
-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 necessarily have to be an ancestor of your current commit. You
-can do something like
+Commit message
+^^^^^^^^^^^^^^
-.. code-block:: bash
+(This section is about the body of the commit message. Please also see
+the preceding section, `Commit title`_, for advice on titling commit messages.)
- $ 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
+In the body of your commit message, be as specific as possible. If the commit
+message title was too short to fully state what the commit is doing, use the
+body to explain not just the "what", but also the "why".
-and the patches will be against origin/unstable.
+For positive examples, peruse ``git log`` in the ``master`` branch. A negative
+example would be a commit message that merely states the obvious. For example:
+"this patch includes updates for subsystem X. Please apply."
-The ``-o`` dir is optional; if left off, the patch(es) will appear in
-the current directory. This can quickly get messy.
+.. _`fixes line`:
-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.
+Fixes line(s)
+^^^^^^^^^^^^^
-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 the commit fixes one or more issues tracked by http://tracker.ceph.com,
+add a ``Fixes:`` line (or lines) to the commit message, to connect this change
+to addressed issue(s) - for example::
-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.
+ Fixes: http://tracker.ceph.com/issues/12345
-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:
+This line should be added just before the ``Signed-off-by:`` line (see `Sign
+your work`_).
-.. code-block:: bash
+It helps reviewers to get more context of this bug and facilitates updating of
+the bug tracker. Also, anyone perusing the git history will see this line and be
+able to refer to the bug tracker easily.
- $ git send-email --to ceph-devel@vger.kernel.org my.patch
+Here is an example showing a properly-formed commit message::
-for a single patch, or
+ doc: add "--foo" option to bar
-.. code-block:: bash
+ This commit updates the man page for bar with the newly added "--foo"
+ option.
- $ git send-email --to ceph-devel@vger.kernel.org mything
+ Fixes: http://tracker.ceph.com/issues/12345
+ Signed-off-by: Random J Developer <random@developer.example.org>
-to send a whole patch series (prepared with, say, git format-patch).
+If a commit fixes a regression introduced by a different commit, please also
+(in addition to the above) add a line referencing the SHA1 of the commit that
+introduced the regression. For example::
+ Fixes: 9dbe7a003989f8bb45fe14aaa587e9d60a392727
-3. Describe your changes
-------------------------
-Describe the technical detail of the change(s) your patch includes.
+PR best practices
+-----------------
-.. _title_of_commit:
+PRs should be opened on branches contained in your fork of
+https://github.com/ceph/ceph.git - do not push branches directly to
+``ceph/ceph.git``.
-Title of pull requests and title of commits
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+PRs should target "master". If you need to add a patch to a stable branch, such
+as "nautilus", see the file ``SubmittingPatches-backports.rst``.
-The text up to the first empty line in a commit message is the commit
-title. Ideally it is a single short line of at most 72 characters,
-summarizing the change. It is required to prefix it with the
-subsystem or module you are changing. For instance, the prefix
-could be "doc:", "osd:", or "common:". One can use::
+In addition to a base, or "target" branch, PRs have several other components:
+the `PR title`_, the `PR description`_, labels, comments, etc. Of these, the PR
+title and description are relevant for new contributors.
- git log
+PR title
+^^^^^^^^
-for more examples. It is also conventional to use the imperative mood in the
-commit title. For example::
+If your PR has only one commit, the PR title can be the same as the commit title
+(and GitHub will suggest this). If the PR has multiple commits, do not accept
+the title GitHub suggest. Either use the title of the most relevant commit, or
+write your own title. In the latter case, use the same "subsystem: short
+description" convention described in `Commit title`_ for the PR title, with
+the following difference: the PR title describes the entire set of changes,
+while the `Commit title`_ describes only the changes in a particular commit.
- mds: add perf counter for finisher of MDSRank
+Keep in mind that the PR titles feed directly into the script that generates
+release notes and it is tedious to clean up non-conformant PR titles at release
+time. This document places no limit on the length of PR titles, but be aware
+that they are subject to editing as part of the release process.
-or::
+PR description
+^^^^^^^^^^^^^^
- osd: make the ClassHandler::mutex private
+In addition to a title, the PR also has a description field, or "body".
-For GitHub, please use this "subsystem: short description" convention for
-naming pull requests (PRs). These titles feed directly into the script that
-generates release notes and it is tedious to clean up non-conformant PR titles
-at release time. This document places no limit on the length of PR titles, but
-be aware that they are subject to editing as part of the release process.
+The PR description is a place for summarizing the PR as a whole. It need not
+duplicate information that is already in the commit messages. It can contain
+notices to maintainers, links to tracker issues and other related information,
+to-do lists, etc. The PR title and description should give readers a high-level
+notion of what the PR is about, quickly enabling them to decide whether they
+should take a closer look.
-Commit message
-^^^^^^^^^^^^^^
-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."
+Flag your changes for backport
+------------------------------
-If your description starts to get long, that's a sign that you probably
-need to split up your patch. See :ref:`split_changes`.
+If you believe your changes should be backported to stable branches after the PR
+is merged, open a tracker issue at https://tracker.ceph.com explaining:
-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.
+1. what bug is fixed
+2. why does the bug need to be fixed in <release>
-Tag the commit
-^^^^^^^^^^^^^^
+and fill out the Backport field in the tracker issue. For example::
-If the patch fixes a logged bug entry, refer to that bug entry by
-URL. In particular, if this patch fixes one or more issues
-tracked by http://tracker.ceph.com, consider adding a ``Fixes:`` tag to
-connect this change to addressed issue(s). So a line saying ::
+ Backport: mimic, nautilus
- Fixes: http://tracker.ceph.com/issues/12345
+For information on how backports are done in the Ceph project, refer to the
+document ``SubmittingPatches-backports.rst``.
-is added before the ``Signed-off-by:`` line stating that this commit
-addresses http://tracker.ceph.com/issues/12345. It helps the reviewer to
-get more context of this bug, so she/he can hence update the issue on
-the bug tracker accordingly.
-So a typical commit message for revising the document could look like::
+Test your changes
+-----------------
- doc: add "--foo" option to bar
+Before opening your PR, it's a good idea to run tests on your patchset. Doing
+that is simple, though the process can take a long time to complete, especially
+on older machines with less memory and spinning disks.
- * update the man page for bar with the newly added "--foo" option.
- * fix a typo
+The most simple test is to verify that your patchset builds, at least in your
+own development environment. The commands for this are::
- Fixes: http://tracker.ceph.com/issues/12345
- Signed-off-by: Random J Developer <random@developer.example.org>
+ ./install-deps.sh
+ ./do_cmake.sh
+ make
-.. _split_changes:
+Ceph comes with a battery of tests that can be run on a single machine. These
+are collectively referred to as "make check", and can be run by executing the
+following command::
-4. Separate your changes
-------------------------
+ ./run-make-check.sh
-Separate *logical changes* into a single patch file.
+If your patchset does not build, or if one or more of the "make check" tests
+fails, but the error shown is not obviously related to your patchset, don't let
+that dissuade you from opening a PR. The Ceph project has a Jenkins instance
+which will build your PR branch and run "make check" on it in a controlled
+environment.
-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.
+Once your patchset builds and passes "make check", you can run even more tests
+on it by issuing the following commands::
-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.
+ cd build
+ ../qa/run-standalone.sh
-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.
+Like "make check", the standalone tests take a long time to run. They also
+produce voluminous output. If one or more of the standalone tests fails, it's
+likely the relevant part of the output will have scrolled off your screen or
+gotten swapped out of your buffer. Therefore, it makes sense to capture the
+output in a file for later analysis.
-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. Document your changes
-------------------------
+Document your changes
+---------------------
-If you have added or modified any user-facing functionality, such
-as CLI commands or their output, then the patch series or pull request
-must include appropriate updates to documentation.
+If you have added or modified any user-facing functionality, such as CLI
+commands or their output, then the pull request must include appropriate updates
+to documentation.
It is the submitter's responsibility to make the changes, and the reviewer's
responsibility to make sure they are not merging changes that do not
have the needed updates to documentation.
-Where there are areas that have absent documentation, or there is no
-clear place to note the change that is being made, the reviewer should
-contact the component lead, who should arrange for the missing section
-to be created with sufficient detail for the patch submitter to
-document their changes.
+Where there are areas that have absent documentation, or there is no clear place
+to note the change that is being made, the reviewer should contact the component
+lead, who should arrange for the missing section to be created with sufficient
+detail for the PR submitter to document their changes.
When writing and/or editing documentation, follow the Google Developer
Documentation Style Guide: https://developers.google.com/style/
-
-6. Style check your changes
----------------------------
-
-Check your patch for basic style violations, details of which can be
-found in CodingStyle.
-
-
-7. 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.
-
projects / ceph.git / commitdiff