Portable Userspace Virtual Filesystem Switch


  • Łukasz Faber AGH University of Science and Technology, Department of Computer Science
  • Krzysztof Boryczko AGH University of Science and Technology, Department of Computer Science




userspace virtual filesystem, operating systems, ptrace, FUSE


Multiple different filesystems — including disk-based, network, distributed, abstract — arean integral part of every operating system. They are usually written as kernel modules and abstracted to the user via a virtual filesystem switch. In this paper we analyse the feasibility of reimplementing the virtual filesystem switch as a userspace daemon and applicability of this approach in real-life usage. Such reimplementation will require a way to virtualise processes behaviour related to filesystem operations. The problem is non-trivial, as we assume limited capabilities of the VFS switch implemented in userspace. We present a layered architecture comprising of a monitoring process, the VFS abstraction and real filesystem implementations. All working in userspace. Then, we evaluate this solution in four areas: portability, feasibility, usability and performance. Our results demonstrate possible gains in using the userspace-based approach with monolithic kernels, but also underline problems that are encountered in this approach.


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How to Cite

Faber, Łukasz, & Boryczko, K. (2013). Portable Userspace Virtual Filesystem Switch. Computer Science, 14(3), 345. https://doi.org/10.7494/csci.2013.14.3.345




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