Chuck Lever led a filesystem session at the2023 Linux Storage, Filesystem,Memory-Management and BPF Summit on the Linux NFS server, which is alsoknown as NFSD. He wanted to talk about converting the network filesystemto use iomap; that kind ofconversionwas the topic of the previous session atthe summit. Beyond that, he wanted to discuss using folios, which has beena frequent topic at recent LSFMM+BPF gatherings, including this year.
Security updates have been issued by Debian (ghostscript), Fedora (apache-ivy, chromium, golang-github-schollz-croc, golang-github-schollz-mnemonicode, and webkitgtk), SUSE (amazon-ecs-init, dnsdist, libcap, python-tornado, terraform, and xmltooling), and Ubuntu (imagemagick, openldap, php7.4, php8.1, and screen).
The C language is expressive in many ways, but it still does not have waysto express many of the relationships between fields in a data structure.That gap can be at least partially filled, though, if one is willing tocreate and use non-standard extensions. The adoption of of thoseextensions, in the form of the __counted_by() macro, has beenmerged for the 6.5 kernel release, even though the compiler feature itdepends on has not yet been finalized.
Version 5.38.0 of the Perl language is out. "Perl 5.38.0 representsapproximately 12 months of development since Perl 5.36.0 and containsapproximately 290,000 lines of changes across 1,500 files from 100authors." Significant changes include a new class feature,Unicode 15.0 support, a new API for hooking into functions, and more; seethe5.38.0 perldelta page for details.
Security updates have been issued by Debian (cups, gst-plugins-bad1.0, gst-plugins-base1.0, gst-plugins-good1.0, python3.7, and yajl), Fedora (chromium, kubernetes, pcs, and webkitgtk), Scientific Linux (open-vm-tools), SUSE (iniparser, keepass, libvirt, prometheus-ha_cluster_exporter, prometheus-sap_host_exporter, rekor, terraform-provider-aws, terraform-provider-helm, and terraform-provider-null), and Ubuntu (python-reportlab and vim).
The first days of the 6.5 merge window have been a bit calmer than usual,with "only" 4,000 non-merge changesets having been pulled into the mainlinerepository. Those changesets include a fair amount of significant work,though. Read on for LWN's summary of the first set of changes merged forthe next major kernel release.
The Emacs editor is not tied to the Linux kernel; indeed, it was createdsome years before Linux existed. The Emacs code base is intended to beportable, and the editor runs, with varying levels of support, on a widevariety of systems. Recently, an energetic developer has worked to extendthe set of supported systems to Android; the result is a working port, butwhether that port will be accepted into the Emacs mainline is the topic ofongoing conversation.
Security updates have been issued by Debian (chromium and maradns), SUSE (iniparser, kubernetes1.23, python-reportlab, and python-sqlparse), and Ubuntu (accountsservice and linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2, linux-snapdragon).
JupyterLab is aweb-based development environment widely used by data scientists,engineers, and educators for data visualization, data analysis,prototyping, and interactive learning materials. The Jupyter community has recently announced therelease of JupyterLab4.0, introducing lots of new features and performanceimprovements to enhance its capabilities both in research and educationalsettings.
A discussion that largely centered around the documentation ofiomap, which provides a block-mapping interface for modern filesystems,was led by Luis Chamberlain at the2023 Linux Storage, Filesystem,Memory-Management and BPF Summit. There is an ongoing process ofconverting filesystems to use iomap, in order to leave buffer heads behind and to better support folios, sothe intent was to get feedback on the documentation from developers who areworking on those conversions. One of the concrete outcomes of the sessionwas a plan to move that documentation from its current location on theKernelNewbies wiki intothe kernel documentation.
Security updates have been issued by Debian (c-ares and libx11), Fedora (chromium and kubernetes), Red Hat (python3 and python38:3.8, python38-devel:3.8), and SUSE (amazon-ssm-agent, kernel, kubernetes1.24, libvirt, nodejs16, openssl-1_1, and webkit2gtk3).
The 6.4 kernel was releasedon June25 after a nine-week development cycle. By that point, 14,835non-merge changesets had been pulled into the mainline kernel, a slightincrease from 6.3 (14,424 changesets) but still lower than many otherdevelopment cycles. As usual, LWN has taken a look at those changesets,who contributed them, and what the most active developers were up to.
Security updates have been issued by Debian (bind9 and owslib), Fedora (dav1d, dotnet6.0, dotnet7.0, mingw-dbus, vim, and wabt), and SUSE (cloud-init and golang-github-vpenso-prometheus_slurm_exporter).
Over on the Software Freedom Conservancy blog, Policy Fellow and Hacker-in-Residence Bradley M. Kuhn analyzes the recent changes to Red Hat Enterprise Linux (RHEL) source availability in light of the GPL. It contains some interesting information about two alleged GPL violations that came about because the company's business model is structured in a way that brings it too close to non-compliance with the license, he said:
The final day of the2023 Linux Storage, Filesystem,Memory-Management and BPF Summit featured three separate sessions led byLuis Chamberlain (he also led a plenary onday two); the first of those was a filesystem session on the status of thekthread-freezer-removal effort. The kthread freezer is meant to helpfilesystems freeze their state in order tosuspend or hibernate the system, but since at least2015, the freezer has been targeted for removal. Thingsdid not change much a year later, nor by LSFMM in2018 when Chamberlain had picked up Jiri Kosina's removaleffort; this year, Chamberlain was back to try to push things along.
The fifth conference on PowerManagement and Scheduling in the Linux Kernel (abbreviated "OSPM") washeld on April17 to19 in Ancona, Italy. LWN was not there,unfortunately, but the attendees of the event have gotten together to writeup summaries of the discussions that took place and LWN has the privilegeof being able to publish them. Reports from the third and final day of theevent appear below.
Security updates have been issued by Debian (asterisk, lua5.3, and trafficserver), Fedora (tang and trafficserver), Oracle (.NET 7.0, c-ares, firefox, openssl, postgresql, python3, texlive, and thunderbird), Red Hat (python27:2.7 and python39:3.9 and python39-devel:3.9), Scientific Linux (c-ares), Slackware (cups), SUSE (cups, dav1d, google-cloud-sap-agent, java-1_8_0-openjdk, libX11, openssl-1_0_0, openssl-1_1, openssl-3, openvswitch, and python-sqlparse), and Ubuntu (cups, dotnet6, dotnet7, and openssl).
The AlmaLinux organization has posted a messagedescribing the impact of Red Hat's decision to stop releasing the source tothe RHEL distribution and how AlmaLinux will respond.
The quest to enable limited use of BPF features in unprivileged processescontinues. In the previous episode, anattempt to use authoritative Linux security module (LSM) hooks for thispurpose was strongly rejected by the LSM developers. BPF developer AndriiNakryiko has now returned with a new mechanism based on aprivilege-conveying token. That approach, too, has run into someresistance, but a solution for the strongest concerns might be in sight.
Kernel support for copy offload is a feature that has been floating aroundin limbo for a decade or more at this point; it has been implemented along the way, but never merged. The idea is that the hostsystem can simply ask a block storage device to copy some data within the deviceand it will do so without further involving the host; instead of reading data intothe host so that it can be written back out again, the device circumventsthat process. At the2023 Linux Storage, Filesystem,Memory-Management and BPF Summit, Nitesh Shetty led a storage andfilesystem session to discuss the current status of a patch set that he andothers have been working on, with aneye toward getting something merged fairly soon.
The6.3.9,6.1.35,5.15.118,5.10.185,5.4.248,4.19.287, and4.14.319stable kernel updates have all been released; each contains another set ofimportant fixes.
Running a Linux distribution on Arm-based single-board computers (SBCs)is still not as easy as on x86 systems because many Arm devices require avendor-supplied kernel, a patched bootloader, and other device-specificcomponents. One distribution that addresses this problem is Armbian, which offers Debian- andUbuntu-based distributions formany devices. The headline feature in the recent release, Armbian23.05, which came at the end of May, is a major rework of the buildframework that has been made faster and more reliable after three years ofdevelopment.
Security updates have been issued by Debian (libfastjson, libx11, opensc, python-mechanize, and wordpress), SUSE (salt and terraform-provider-helm), and Ubuntu (firefox, libx11, pngcheck, python-werkzeug, ruby3.1, and vlc).
Backporting fixes to stable kernels is an ongoing process that, in general,is handled by the stable maintainers or the developers of the fixes.However, due to some unhappiness in the XFS developmentcommunity with the process of handling stable fixes for that filesystem,a different process has come about for backporting XFS patches to thestable kernels. The three developers doing that work, Leah Rumancik, AmirGoldstein, and Chandan Babu Rajendra, led a plenary session at the 2023 Linux Storage, Filesystem,Memory-Management and BPF Summit (with Rajendraparticipating remotely) to discuss that process.
The Rust project has announcedthe formation of the Rust Leadership Council, which will take the place ofthe existing Core Team and Leadership Chat groups.
Security updates have been issued by Debian (libxpm and php7.3), Fedora (chromium), Mageia (kernel, kernel-linus, and sysstat), Red Hat (c-ares), SUSE (libwebp), and Ubuntu (cups-filters, libjettison-java, and libsvgpp-dev).
In the fast-moving open-source world, programs can come and go quickly; atool that has many users today can easily be eclipsed by something betternext week. Even in this environment, though, some programs endure for along time. As an example, consider thePostgreSQL database system, which traces itshistory back to 1986. Making fundamental changes to a large code basewith that much history is never an easy task. As fundamental changes go,moving PostgreSQL away from its process-oriented model is not a small one,but it is one that the project is considering seriously.
The 6.4-rc7 kernel prepatch is out fortesting. "Nothing particular stands out in the rc this week,unless you count the mptcp selftest changes that are about making the testswork on stable kernels too."
The registration for this year's Linux Plumbers Conference (LPC) is now open. It will be held November 13-15 in Richmond, Virginia in the US. The attend page has all of the details. Meanwhile, some of the calls for proposals are still open, though the microconferences CFP is closed; this year's proposed microconference topics are listed here. Those who want to attend should note:"As usual we expect to sell [out] rather quickly so don't delay your registration for too long!"
The bcachefs filesystem, and theprocess for getting it upstream, were the topicsof a session led remotely by Kent Overstreet, creator of bcachefs, at the 2023 Linux Storage, Filesystem,Memory-Management and BPF Summit. He has also discussed bcachefs inprevious editions of the summit, firstin2018 and at last year's event;in both of those cases, the question of getting bcachefs mergedinto the mainline kernel came up, but that merge has not happened yet.This time around, though, Overstreet seemed closer than ever to being ready to actually start that process.
The fifth conference on PowerManagement and Scheduling in the Linux Kernel (abbreviated "OSPM") washeld on April17 to19 in Ancona, Italy. LWN was not there,unfortunately, but the attendees of the event have gotten together to writeup summaries of the discussions that took place and LWN has the privilegeof being able to publish them. Reports from the second day of the eventappear below.
Security updates have been issued by Debian (chromium, openjdk-17, and wireshark), Fedora (iniparser, mariadb, mingw-glib2, perl-HTML-StripScripts, php, python3.7, and syncthing), Oracle (.NET 6.0, c-ares, kernel, nodejs, and python3.9), Slackware (libX11), SUSE (amazon-ssm-agent and chromium), and Ubuntu (gsasl, libx11, and sssd).
The developers working on improving the speed of the CPython interpreterhave posteda plan describing their objectives for the Python 3.13 release. Thebiggest piece appears to be the tier-2optimizer, which will optimize larger chunks of Python code:"https://github.com/faster-cpython/ideas/issues/557".
The C language does not provide the sort of resource-management featuresfound in more recent languages. As a result, bugs involvingleaked memory or failure to release a lock are relatively common inprograms written in C — including the kernel. The kernel project has neverlimited itself to the language features found in the C standard, though;kernel developers will happilyuse extensions provided by compilers if they prove helpful. It looks likea relatively simple compiler-provided feature may lead to a significantchange in some common kernel coding patterns.
Darrick Wong has been doing work on XFS onlinerepair for a number of years and things are getting to the point where most of the filesystem-internal workhas been completed and is under review. The work remaining mostly concernsthe user-space side to set up a periodic scan and repair cycle, so he wanted to discuss whatuser space needs from this kind of feature in a filesystem session at the 2023 Linux Storage, Filesystem,Memory-Management and BPF Summit that he led remotely. The session maynot have gone quite as he hoped, as it got somewhat derailed by topics thatspilled over from the earlier session onunprivileged image mounts.
Security updates have been issued by Debian (webkit2gtk), Fedora (python-django-filter and qt), Mageia (cups, firefox/nss, httpie, thunderbird, and webkit2), Red Hat (.NET 6.0, .NET 7.0, c-ares, firefox, jenkins and jenkins-2-plugins, nodejs, nodejs:18, python3, python3.11, python3.9, and thunderbird), Scientific Linux (firefox and thunderbird), SUSE (frr, opensc, python3, and rekor), and Ubuntu (c-ares, glib2.0, libcap2, linux-intel-iotg-5.15, pano13, and requests).
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