Enhanced File System Testing through Input and Output Coverage
Yifei Liu, Geoff Kuenning, Md. Kamal Parvez, Scott A. Smolka, Erez Zadok · 2025
Effective file system testing relies on coverage to detect bugs and enhance reliability. We analyzed real file system bugs and found a weak correlation between code coverage, the most commonly used metric, and test effectiveness; many bugs were in covered code but remained undetected. Our study also showed that covering diverse file system inputs and outputs---system call arguments and return values---can be key to detecting the majority of observed bugs.