2. XFS Maintainer Entry Profile¶
2.1. Overview¶
XFS is a well known high-performance filesystem in the Linux kernel. The aim of this project is to provide and maintain a robust and performant filesystem.
Patches are generally merged to the for-next branch of the appropriate git repository. After a testing period, the for-next branch is merged to the master branch.
Kernel code are merged to the xfs-linux tree[0]. Userspace code are merged to the xfsprogs tree[1]. Test cases are merged to the xfstests tree[2]. Ondisk format documentation are merged to the xfs-documentation tree[3].
All patchsets involving XFS must be cc’d in their entirety to the mailing list linux-xfs@vger.kernel.org.
2.2. Roles¶
There are eight key roles in the XFS project. A person can take on multiple roles, and a role can be filled by multiple people. Anyone taking on a role is advised to check in with themselves and others on a regular basis about burnout.
Outside Contributor: Anyone who sends a patch but is not involved in the XFS project on a regular basis. These folks are usually people who work on other filesystems or elsewhere in the kernel community.
Developer: Someone who is familiar with the XFS codebase enough to write new code, documentation, and tests.
Developers can often be found in the IRC channel mentioned by the
C:entry in the kernel MAINTAINERS file.Senior Developer: A developer who is very familiar with at least some part of the XFS codebase and/or other subsystems in the kernel. These people collectively decide the long term goals of the project and nudge the community in that direction. They should help prioritize development and review work for each release cycle.
Senior developers tend to be more active participants in the IRC channel.
Reviewer: Someone (most likely also a developer) who reads code submissions to decide:
Is the idea behind the contribution sound?
Does the idea fit the goals of the project?
Is the contribution designed correctly?
Is the contribution polished?
Can the contribution be tested effectively?
Reviewers should identify themselves with an
R:entry in the kernel and fstests MAINTAINERS files.Testing Lead: This person is responsible for setting the test coverage goals of the project, negotiating with developers to decide on new tests for new features, and making sure that developers and release managers execute on the testing.
The testing lead should identify themselves with an
M:entry in the XFS section of the fstests MAINTAINERS file.Bug Triager: Someone who examines incoming bug reports in just enough detail to identify the person to whom the report should be forwarded.
The bug triagers should identify themselves with a
B:entry in the kernel MAINTAINERS file.Release Manager: This person merges reviewed patchsets into an integration branch, tests the result locally, pushes the branch to a public git repository, and sends pull requests further upstream. The release manager is not expected to work on new feature patchsets. If a developer and a reviewer fail to reach a resolution on some point, the release manager must have the ability to intervene to try to drive a resolution.
The release manager should identify themselves with an
M:entry in the kernel MAINTAINERS file.Community Manager: This person calls and moderates meetings of as many XFS participants as they can get when mailing list discussions prove insufficient for collective decisionmaking. They may also serve as liaison between managers of the organizations sponsoring work on any part of XFS.
LTS Maintainer: Someone who backports and tests bug fixes from uptream to the LTS kernels. There tend to be six separate LTS trees at any given time.
The maintainer for a given LTS release should identify themselves with an
M:entry in the MAINTAINERS file for that LTS tree. Unmaintained LTS kernels should be marked with statusS: Orphanin that same file.
2.3. Submission Checklist Addendum¶
Please follow these additional rules when submitting to XFS:
Patches affecting only the filesystem itself should be based against the latest -rc or the for-next branch. These patches will be merged back to the for-next branch.
Authors of patches touching other subsystems need to coordinate with the maintainers of XFS and the relevant subsystems to decide how to proceed with a merge.
Any patchset changing XFS should be cc’d in its entirety to linux-xfs. Do not send partial patchsets; that makes analysis of the broader context of the changes unnecessarily difficult.
Anyone making kernel changes that have corresponding changes to the userspace utilities should send the userspace changes as separate patchsets immediately after the kernel patchsets.
Authors of bug fix patches are expected to use fstests[2] to perform an A/B test of the patch to determine that there are no regressions. When possible, a new regression test case should be written for fstests.
Authors of new feature patchsets must ensure that fstests will have appropriate functional and input corner-case test cases for the new feature.
When implementing a new feature, it is strongly suggested that the developers write a design document to answer the following questions:
What problem is this trying to solve?
Who will benefit from this solution, and where will they access it?
How will this new feature work? This should touch on major data structures and algorithms supporting the solution at a higher level than code comments.
What userspace interfaces are necessary to build off of the new features?
How will this work be tested to ensure that it solves the problems laid out in the design document without causing new problems?
The design document should be committed in the kernel documentation directory. It may be omitted if the feature is already well known to the community.
Patchsets for the new tests should be submitted as separate patchsets immediately after the kernel and userspace code patchsets.
Changes to the on-disk format of XFS must be described in the ondisk format document[3] and submitted as a patchset after the fstests patchsets.
Patchsets implementing bug fixes and further code cleanups should put the bug fixes at the beginning of the series to ease backporting.
2.4. Key Release Cycle Dates¶
Bug fixes may be sent at any time, though the release manager may decide to defer a patch when the next merge window is close.
Code submissions targeting the next merge window should be sent between -rc1 and -rc6. This gives the community time to review the changes, to suggest other changes, and for the author to retest those changes.
Code submissions also requiring changes to fs/iomap and targeting the next merge window should be sent between -rc1 and -rc4. This allows the broader kernel community adequate time to test the infrastructure changes.
2.5. Review Cadence¶
In general, please wait at least one week before pinging for feedback. To find reviewers, either consult the MAINTAINERS file, or ask developers that have Reviewed-by tags for XFS changes to take a look and offer their opinion.