For those making use of Linux's modern exFAT file-system, a significant optimization is on the way for when deleting files with the "dirsync" mount option set.

While the Flash-Friendly File-System (F2FS) allows selecting between your choice of optional compression algorithms like LZO, LZ4, and Zstd -- plus even specifying specific file extensions to optionally limit the transparent file-system compression to -- it doesn't allow easily specifying a compression level. That is fortunately set to change with the Linux 5.12 kernel this spring.

Released at the end of November was the much anticipated OpenZFS 2.0 open-source ZFS file-system implementation for Linux and FreeBSD systems. Today that has been succeeded by OpenZFS 2.0.1 with support for newer Linux kernels and many bug fixes.

The Linux kernel has been seeing incredible innovations and optimizations in the I/O area in recent times from IO_uring to numerous performance enhancements. One of the recent performance enhancements seeing activity and promising results is the no-copy bvec behavior.

One of the pleasant kernel surprises in 2020 was Paragon Software looking to upstream their previously commercial NTFS driver. This driver offers read-write support and more advanced capabilities than the current read-focused NTFS driver presently in the mainline kernel and better off than the other FUSE-based driver. This driver hasn't been mainlined yet but Paragon published new patches on Christmas.

Linux 5.10 as a Long-Term Support (LTS) kernel has been off to a rocky start after an immediate point release due to a RAID issue, some reporting AMDGPU problems, and also a staggering Btrfs performance regression hitting some users.

The out-of-tree Reiser4 file-system has now been ported to the week-old Linux 5.10 kernel code-base. This also comes days ahead of the one year anniversary since the "Version 5" announcement.

The main feature change for the XFS driver code in Linux 5.11 is adding a new "needs repair" feature flag. When the XFS code marks a file-system as needing repair, it will refuse to mount until the xfs_repair operation is run on it.

This first week of the Linux 5.11 merge window continues to be very active with many of the kernel maintainers looking to land their changes ahead of the Christmas week where they are often taking time off work.

The Flash-Friendly File-System (F2FS) continues seeing new work around its transparent data compression, optional case insensitive behavior, and native encryption support with the new code queued for Linux 5.11.

Kent Overstreet who developed the Bcachefs file-system out of the Linux kernel's block cache code has sent out the latest patches for review and to also serve as a possible pull request for mainlining the code.

The first set of major file-system material submitted for the newly opened Linux 5.11 merge window are the Btrfs updates.

Announced earlier this year by Micron was the HSE open-source storage engine aimed for low-latency, speed-performance on modern SSD storage and ideal for powering the likes of NoSQL databases. In squeezing out one more major release before year's end, HSE 1.9 was released on Friday.

Following the recent OpenZFS 2.0 release, a new feature that has landed in the latest OpenZFS development code is the ability to respond to CPU and memory hot-plugging.

One of the NVMe specification additions that was ratified this year is the "simple copy" command that allows for copying multiple contiguous ranges to a single destination. That simple copy operation is offloaded to the SSD controller. The Linux kernel support for NVMe simple copy is now being prepared.

Back in October there were engineers from Tencent proposing DMEMFS as the "Direct Memory File-System" for Linux. DMEMFS is about reserving some RAM that is not managed by the kernel to avoid that overhead and in turn expose it directly to virtual machines in the cloud. Those initial DMEMFS kernel patches have now been updated by Tencent as they continue working to get this functionality into the Linux kernel.

One of the surprises this year in the Linux kernel world was Paragon Software wanting to upstream their "NTFS3" kernel driver that supports read-write operations on Microsoft NTFS file-systems and is much more full-featured than the existing read-focused NTFS kernel driver or the user-space NTFS FUSE driver. The driver hasn't yet been mainlined but continues to be updated in preparing for that milestone.

In addition to OpenZFS 2.0 releasing and Bcachefs hitting up more performance optimizations, some further next-gen Linux storage news is Red Hat's Stratis Storage 2.3 being released.

Bcachefs was sent out for another round of review at the end of October. While it doesn't look like this file-system born out of Linux's block cache code will be mainlined in the immediate near future, it's still on a nice trajectory.

The Flash-Friendly File-System (F2FS) already supports LZO, LZ4, and Zstd compression while a proposal would also add support for LZ4HC.

OpenZFS 2.0 has been officially released! OpenZFS 2.0 marks a major step forward for open-source ZFS file-system support for what started out as ZFSOnLinux but is now OpenZFS with unified FreeBSD and Linux support (macOS support is still being pursued as well) and this release also bringing many new features.

FUSE is well known to longtime Linux users for allowing file-systems to be implemented in user-space for where a Linux kernel port isn't feasible for portability or licensing restrictions, among other factors. There is also CUSE for character devices in user-space. Now being based on FUSE, there is "MUSE" being worked on for MTD in user-space.

OpenZFS 2.0 is getting quite close to release but isn't over the finish line yet and this week brings the seventh release candidate.

This New Year's Eve will mark one year since the announcement of the in-development Reiser5 file-system. While the outlook for getting Reiser5 upstreamed into the mainline kernel remains murky given the out-of-tree status of Reiser4, Edward Shishkin does continue advancing this latest Reiser file-system iteration.

For over one year the Flash-Friendly File-System (F2FS) has supported case-folding for optional case-insensitive file/folder support. The past number of years F2FS has also supported FSCRYPT-based file encryption. But now as we roll into 2021, support is finally seemingly ready for mainline in supporting casefolding with encryption enabled.

A new Linux I/O scheduler has been proposed that is optimized for batching such as for MMC and TCP-based/remote storage.

Just one week after OpenZFS 2.0-RC5, a sixth release candidate is now available for this open-source ZFS file-system implementation currently geared for Linux and FreeBSD systems.

A set of Linux kernel patches posted on friday allow peer-to-peer DMA (P2PDMA) transfers between NVMe drives using existing O_DIRECT operations or the NVMe pass-through interface from user-space.

The trek to OpenZFS 2.0 continues with the fifth release candidate now being outed.

For any of you that happen to still be relying on the out-of-tree Reiser4 file-system or interested in the technical design of Reiser5, these file-system drivers have been updated for Linux 5.9 compatibility.