14 DAY TRIAL // As expected, the Linux 4.13 kernel series was made official this past weekend by none other than its creator, Linus Torvalds, which urges all Linux users to start migrating to this version as soon as possible.
Work on Linux kernel 4.13 started in mid-July with the first Release Candidate (RC) milestone, which already gave us a glimpse of the new features coming to this major kernel branch. There are, of course, numerous improvements and support for new hardware through updated drivers and core components.
Highlights of Linux kernel 4.13 include Intel's Cannon Lake and Coffee Lake CPUs, support for non-blocking buffered I/O operations to improve asynchronous I/O support, support for "lifetime hints" in the block layers and the virtual filesystem, AppArmor enhancements, and better power management.
There's also AMD Raven Ridge support implemented in the AMDGPU graphics driver, which received numerous improvements, support for five-level page tables was added in the s390 architecture, and the structure randomization plugin was added as part of the build system.
It's coming soon to a GNU/Linux distro near you
Among other noteworthy improvements included in the Linux 4.13 kernel, we can mention that the EXT4 file system, which is currently used by default on almost all GNU/Linux distributions, supports more files in a single directory, from 10 million to 2 billion, thanks to the implementation of a new "largedir" option.
The EXT4 file system also allows for more attributes to be stored per file. There's also disk quota support for the F2FS file system, better performance for HTTPS (HTTP Secure) and other protocols, supports for numerous new hardware components, and support for the SMB 3.0 protocol by default for CIFS mounts.
"This time it's not really a kernel security issue, but a generic protocol security issue," said Linus Torvalds. "The change in question is simply changing the default CIFS behavior: instead of defaulting to SMB 1.0, the default CIFS mount now defaults to a rather more modern SMB 3.0."
Other than that, it's now possible to re-export NFS filesystems over NFS (Network File System), as well as to execute copy-up operations on an OverlayFS file system, and the reporting of writeback errors was improved. More details can be found in the appended shortlog attached to Linus Torvalds' mailing list announcement.
Linux kernel 4.13 is now the latest stable kernel branch for GNU/Linux distributions, but it's currently tagged as "mainline" on kernel.org, from where you can download the source tarball if you want to compile it on your Linux OS. But it will take a couple of weeks until it is declared stable and ready for deployment, usually when the first maintenance update gets out, Linux 4.13.1.