EROFS, exFAT and EXT4 file system updates are coming for Linux 5.19

Along with buttery Btrfs feature updates for the in-development Linux 5.19 kernel, exFAT, EXT4, and XFS filesystem changes all landed too far in the early days of the v5.19 merge window.

EXT4, exFAT, and EROFS file systems work in this cycle, ranging from bug fixes to cool features.

the exFAT updates for this Microsoft filesystem there are fixes and two things worth mentioning. A Sony engineer contributed to a performance improvement of about 73% when zeroing a cluster by reducing the number of block requests. This is a big improvement for exFAT.

The other exFAT change worth mentioning in Linux 5.19 is the new “sys_tz” mount option. This allows the system time zone to be used as the time offset when dealing with exFAT timestamps which are treated as a UTC offset from the current local time.

Then there is EROFS Updates for this read-only Linux file system used by some Android devices and originally developed by Huawei. The big change for EROFS with Linux 5.19 is demand loading for EROFS with the FSCACHE/CacheFiles framework. This introduces a new file-based back-end and other improvements. See the aforementioned Git merge for full details.

In addition to EROFS now adding on-demand load support via FSCACHE, Linux 5.19 now also adds support for IDMAPPED mounts, NFS export support, and various fixes.

EXT4 Updates focus on various bugfixes and cleanups. Bugfixes include stuff found through various fuzzers and error injection tools. All in all, a relatively light cycle for this widely used Linux filesystem.