Longtime FUSE developer Miklos Szeredi of Red Hat has been working on a new "FUSE2" FUSE kernel driver for implementing file-systems in user-space.

ZFS On Linux 0.8.2 is out with fixes in order to provide compatibility with the brand new Linux 5.3 stable kernel while retaining support still going back to the Linux 2.6.32 days.

VirtIO-FS as a better approach for sharing folders/files with guest VMs is set to debut in Linux 5.4.

Sent in and already landed on Monday were the PCI changes for Linux 5.4 and includes an interesting feature addition.

Added to the device mapper (DM) code with the Linux 5.4 kernel is an interesting addition that benefits those wanting to carry out some interesting use-cases around remote replication of block devices.

While most of the other Linux file-systems are seeing mostly mundane changes for the Linux 5.4 feature work, the F2FS activity is fairly notable.

The OpenZFS file-system could soon be seeing better data deduplication support.

Like the mostly mundane Btrfs and XFS changes with the Linux 5.4 merge window, the EXT4 file-system activity is mostly focused on fixes too but also new debugging ioctls.

The Linux 5.4 block subsystem changes brings the new blk-iocost model.

The mature XFS and Btrfs file-systems continue seeing more fixes and cleaning with the now in-development Linux 5.4 kernel.

In addition to submitting the FS-VERITY file authentication code for Linux 5.4, Google's Eric Biggers has sent out his big update to the fscrypt file encryption framework for this next kernel revision.

While the upcoming Linux 5.4 kernel cycle is finally bringing a driver for Microsoft exFAT file-system read/write support, it's dated on an old Samsung code drop that has seen little public work over the years. Since queued for staging-next, there has been a big uptick in clean-ups and other activity, but there also exists another alternative out-of-tree exFAT Linux driver.

A Phoronix reader pointed out recent patches by a SUSE engineer working on support for mounting root file-systems over SMB (Samba).

The EXT4 case-insensitive lookup optimization added to the file-system with the current Linux 5.3 cycle has been ported to the Flash-Friendly File-System (F2FS) for the upcoming Linux 5.4.

A Phoronix reader recently pointed out a little known kernel tunable option to adjust the number of I/O polling queues for NVMe solid-state drives that can potentially help improve the performance/latency. Here are some benchmarks from the NVMe poll_queues option.

Linux 5.4 will be a big kernel on the file-system front as in addition to introducing the new VirtIO-FS and exFAT file-system support, Huawei's EROFS file-system will be graduating from staging.

In addition to the initial exFAT driver landing for Linux 5.4, also slated to land for this next kernel cycle is the VirtIO-FS file-system driver.

Following Microsoft's approval of seeing exFAT support on Linux and at long last releasing public specifications to the file-system, the existing out-of-tree Linux driver code was quickly volleyed on the mailing list for review and hopeful inclusion into the kernel.

Up until today the newest Linux kernel version supported by the official Reiser4 out-of-tree file-system driver patch was Linux 5.0, but that has now changed with the belated Linux 5.1 kernel support arriving as well as a separate patch for Linux 5.2 kernel support.

Fscrypt is the common Linux kernel framework leveraged by the likes of the EXT4, F2FS, and UBIFS file-systems for providing native encryption support. While that Fscrypt-based file encryption has been part of the kernel for several releases now, there's been some shortcomings in how the encryption keys are handled but that should be cleared up for the upcoming Linux 5.4 cycle.

EXT4 set off the new trend for opt-in, per-directory case-insensitive file/folder support on Linux systems. EXT4 picked up that optional case-insensitive support for Linux 5.2 while the for Linux 5.4 kernel cycle the Flash-Friendly File-System (F2FS) is set to receive similar support.

While initially the user-space utility for Huawei's EROFS file-system was not publicly available, it came last November and this past April they began rewriting these EROFS user-space bits. Fortunately, since then they have done a better job of keeping EROFS-utils up-to-date against their latest kernel module changes for this read-only file-system.

IO_uring is designed to deliver fast and efficient I/O operations thanks to a re-designed interface introduced in Linux 5.1 with various efficiency improvements compared to the kernel's existing asynchronous I/O code. But it turns out there was a big bottleneck within the current IO_uring code up until now.

Sent out on Thursday were the NFS client updates for the Linux 5.3 kernel merge window. This time around are a few interesting changes.

Following EXT4 getting initial (and opt-in) support for case-insensitive directories/files, the Flash-Friendly File-System has a set of patches pending that extend the case-folding support to this F2FS file-system that is becoming increasingly used by Android smartphones and other devices.

In addition to Linux 5.3 bringing a VirtIO-IOMMU driver, this next kernel version is bringing another new VirtIO virtual device implementation: PMEM for para-virtualized persistent memory support for the likes of Intel Optane DC persistent memory.

For those making use of the Ceph fault-tolerant storage platform, a number of updated kernel bits are landing in Linux 5.3.

Those running ZFS On Linux (ZoL) on post-5.0 (and pre-5.0 supported LTS releases) have seen big performance hits to the ZFS encryption performance in particular. That came due to upstream breaking an interface used by ZFS On Linux and admittedly not caring about ZoL due to it being an out-of-tree user. But now several kernel releases later, a workaround has been devised.

David Sterba sent in the Btrfs file-system updates on Monday for the Linux 5.3 kernel.

The UBIFS file-system for usage on un-managed flash memory devices now has support for Zstd compression.