F2FS With Linux 5.16 Will Let You Intentionally Fragment The Disk
The F2FS changes this cycle aren't particularly large but include a few enhancements and a number of bug fixes along with some code cleaning. One interesting new addition is adding a mount option to intentionally fragment the on-disk layout of F2FS file-systems.
F2FS' "mode=" mount option has added new options to simulate file-system fragmentation after garbage collection. The "fragment:segment" option will create a new segment in a random position while "fragment:block" will scatter block allocation. New sysfs nodes are added for further tuning the behavior of the "mode=fragment:block" option. Details in this commit.
The developers hope that by making it easier to fragment F2FS partitions it will be easier to understand the behavior and come up with ways to better handle real-world fragmentation and to optimize around it.
F2FS with Linux 5.16 also has direct I/O for multi-partition setups now working. F2FS previously added multi-device support but had missed out on handling of direct I/O for multiple devices.
Those enhancements plus a handful of bug fixes make up the F2FS changes for the Linux 5.16 kernel.