A list of options from a report:
https://www.fsl.cs.sunysb.edu/docs/secfs-rpe/index.html#tth_...
VersionFS:
https://www.fsl.cs.sunysb.edu/docs/versionfs-msthesis/index....
Elephant:
https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.70....
https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.129...
Silver:
https://www.usenix.org/system/files/conference/hotstorage16/...
Also possibly of interest, vfs:
https://github.com/FooSoft/vfs