Linux 5.0 has already been released, it is the first of this new numbering since 4.x was dropped in 2019 and we already have a Linux 5.0.1 with updates on kernel.org already. But that's just one more step in kernel development, and the hustle to improve the open-source project continues with work on the next Release Cadidates of the Linux 5.1 that will come soon. In fact, we already know some of the improvements that will be included in that new kernel.
Among them we will have important changes in what refers to the file systems or FS as they are EXT4 and also for Btrfs, two of the most used FS in the Linux world, as you know. Specifically there will be patches to correct some issues of these systems in the future kernel. They are not going to offer big changes in terms of features, but they do promise to improve the current system and also fix some bugs and make some optimizations.
The only new feature for EXT4 in Linux 5.1 would be the attribute / sys / fs / ext4 / [disk] / journal_task to expose the filesystem journal system, which may be good for developers and administrators who come up with other possibilities to move it to cgroup or for tracing purposes. We have learned that thanks to Ted Ts'o, who has confirmed it, and on the other hand, the developer Dave Sterba has been in charge of Btrfs.
About this other FS we know that there will be some changes for him, including the possibility to configure Zstd compression. That would be a great and remarkable feature for end users. Besides that, some bugs found that affect some extensions, some deadlocks and other minor errors that are now suffered if we have the current kernels and this file system in our favorite distributions will also be patched.
two of the most used FS in the Linux world, as you know ... these file systems are very hairy !!! :)