Testing File System Implementations on Layered Models

Generating high-quality system call sequences is not only important to testing file system implementations, but also challenging due to the astronomically large input space. This paper introduces a new approach to the workload generation problem by building layered models and abstract workloads refinement. This approach is instantiated as a three-layer file system model for file system workload generation. In a short-period experiment run, sequential workloads (system call sequences) manifested over a thousand crashes in mainline Linux Kernel file systems, with 12 previously unknown bugs being reported. We also provide evidence that such workloads benefit other domain-specific testing techniques including crash consistency testing and concurrency testing.