Latest Half Dozen LWN Articles

posted by Roy Schestowitz on Mar 12, 2026

• Kernel Space / File Systems / Virtualization

  • LWN ☛ The ongoing quest for atomic buffered writes [LWN.net]

    There are many applications that need to be able to write multi-block chunks of data to disk with the assurance that the operation will either complete successfully or fail altogether — that the write will not be partially completed (or "torn"), in other words. For years, kernel developers have worked on providing atomic writes as a way of satisfying that need; see, for example, sessions from the Linux Storage, Filesystem, Memory Management, and BPF (LSFMM+BPF) Summit from 2023, 2024, and 2025 (twice). While atomic direct I/O is now supported by some filesystems, atomic buffered I/O still is not. Filling that gap seems certain to be a 2026 LSFMM+BPF topic but, thanks to an early discussion, the shape of a solution might already be coming into focus.

    Pankaj Raghav started that discussion on February 13, noting that both ext4 and XFS now have support for atomic writes when direct I/O is in use, but that supporting atomic buffered I/O ""remains a contentious topic"". There are a couple of outstanding proposals to add this feature: this 2024 series from John Garry and a more recent patch set from Ojaswin Mujoo. These proposals have stalled, partly out of concern about the amount of complexity added to the I/O paths and questions about whether there is really a need for atomic buffered writes.

• Free, Libre, and Open Source Software

  • LWN ☛ Free software needs free tools [LWN.net]

    One of the contradictions of the modern open-source movement is that projects which respect user freedoms often rely on proprietary tools that do not: communities often turn to non-free software for code hosting, communication, and more. At Configuration Management Camp (CfgMgmtCamp) 2026, Jan Ainali spoke about the need for open-source projects to adopt open tools; he hoped to persuade new and mature projects to switch to open alternatives, even if just one tool, to reduce their dependencies on tech giants and support community-driven infrastructure.

    Ainali does contract work for the Swedish chapter of the Wikimedia Foundation, called Wikimedia Sverige, through his company Open By Default. Wikimedia, of course, provides the MediaWiki software, hosts Wikipedia, and much more. He said that all of the tooling, everything in production, the analytics, and so forth is open source. ""There is a very strong ethos in the Wikimedia movement to do it like that.""

    However, that ethos weakens the farther away one gets from development. ""When you step away from development to the more peripheral parts of the workflow, it gets less and less open source in the tooling."" For example, Wikimedia uses the proprietary Figma software for design, and its annual conference uses Zoom to record talks and publishes them on YouTube. Even projects that have a strong drive to do something open, he said, struggle to do everything using only open-source software.

  • Licensing / Legal

    • LWN ☛ The exploitation paradox in open source [LWN.net]

      The free and open-source software (FOSS) movements have always been about giving freedom and power to individuals and organizations; throughout that history, though, there have also been actors trying to exploit FOSS to their own advantage. At Configuration Management Camp (CfgMgmtCamp) 2026 in Ghent, Belgium, Richard Fontana described the ""exploitation paradox"" of open source: the recurring pattern of crises when actors exploit loopholes to restrict freedoms or gain the upper hand over others in the community. He also talked about the attempts to close those loopholes as well as the need to look beyond licenses as a means of keeping freedom alive.

      Fontana is a lawyer who is well-known as an expert on FOSS licenses. He has worked for Red Hat for much of his career, and now works directly for IBM since it absorbed Red Hat's legal department in early 2026. He said that this would be an unusual talk for CfgMgmtCamp, as it was not about configuration management—though he had provided legal support to people working on related projects such as Ansible and Foreman. He would not be speaking for Red Hat or IBM in his talk, however, though he said it did draw on his work experiences over the years. ""I'm on vacation, seriously. I wanted to go to Ghent"".

  • Programming/Development

    • LWN ☛ Magit and Majutsu: discoverable version-control [LWN.net]

      Jujutsu is an increasingly popular Git-compatible version-control system. It has a focus on simplifying Git's conceptual model to produce a smoother, clearer command-line experience. Some people already have a preferred replacement for Git's usual command-line interface, though: Magit, an Emacs package for working with Git repositories that also tries to make the interface more discoverable. Now, a handful of people are working to implement a Magit-style interface for Jujutsu: Majutsu.

      Magit was started by Marius Vollmer in 2008; over time, the project grew organically to cover the users' needs for an intuitive Git interface. The current version is v4.5.0, and new releases come every few months. The project's statistics page shows that a majority of the code at this point has been written by Jonas Bernoulli, but many authors have contributed improvements for their specific workflows and use cases. The result is a startlingly comprehensive feature set, which Bernoulli calls ""essentially complete"", covering ""about 90% of what can be done using git"".

      Majutsu is much younger: it was started in November 2025 by Brandon Olivier and has had six contributors so far, reaching version 0.6.0 on February 12. Its interface is already fairly comprehensive, however, owing both to Jujutsu's fewer corner cases and to the libraries written for Magit. Both projects are licensed under version 3 of the GPL, and Majutsu reuses Magit's interface design and libraries for handling transient windows. (Emacs predates most graphical interfaces, and calls the things everyone else calls windows "frames". It calls panels that subdivide a frame "windows".)

    • Python

      • LWN ☛ The troubles with Boolean inversion in Python

        The Python bitwise-inversion (or complement) operator, "~", behaves pretty much as expected when it is applied to integers—it toggles every bit, from one to zero and vice versa. It might be expected that applying the operator to a non-integer, a bool for example, would raise a TypeError, but, because the bool type is really an int in disguise, the complement operator is allowed, at least for now. For nearly 15 years (and perhaps longer), there have been discussions about the oddity of that behavior and whether it should be changed. Eventually, that resulted in the "feature" being deprecated, producing a warning, with removal slated for Python 3.16 (due October 2027). That has led to some reconsideration and the deprecation may itself be deprecated.

  • Standards/Consortia

    • LWN ☛ IIIF: images and visual presentations for the web [LWN.net]

      The International Image Interoperability Framework, or IIIF ("triple-eye eff"), is a small set of standards that form a basis for serving, displaying, and reusing image data on the web. It consists of a number of API definitions that compose with each other to achieve a standard for providing, for example, presentations of high-resolution images at multiple zoom levels, as well as bundling multiple images together. Presentations may include metadata about details like authorship, dates, references to other representations of the same work, copyright information, bibliographic identifiers, etc. Presentations can be further grouped into collections, and metadata can be added in the form of transcriptions, annotations, or captions. IIIF is most popular with cultural-heritage organizations, such as libraries, universities, and archives.

      Collections and presentations can—and often do—link to images hosted at many different web sites. A key strength of the framework is standardizing complex, feature-rich image hosting with the explicit goal of interoperable referencing and grouping into combined presentations.