I would recommend as a starter the Persistence section of the U Wisc Operating Systems open text book. https://pages.cs.wisc.edu/~remzi/OSTEP/. In particular the cited papers are foundations of major file system approaches of used many (probably most) systems today.

In the non-textbook sources, I would also recommend archives of the Usenix FAST conferences (File and Storage Technologies), where you often see newer and experimental approaches to file systems.

e.g. F2FS, https://www.usenix.org/conference/fast15/technical-sessions/...