donporter
Part of our challenge is that we are also exploring non-standard extensions to the VFS API - largely supported by kallsyms + copied code to avoid kernel modifications. This makes rolling forward more labor intensive, but we are working to pay down this technical debt over time, or possibly make a broader case for a VFS API change.
For those who are curious, our initial goal is indeed to build a PoC and understand whether the data structures actually deliver the potential performance gains in a realistic implementation that one might expect on paper. I see a long arc from a new idea to a production-quality implementation, and several iterations of increasingly thorough evaluation and hardening.
Our current prototype is not production-ready; this is a long-term goal, but we appreciate how much work this is. More of our focus at the moment is on exploring other ways these algorithmic techniques may be useful in a storage system or how to address current problems---i.e., understanding the best way to design such a system before trying to build a production-quality version. Each of our papers has yielded significant overhauls to the design.
We would also consider it a success if other file systems adopted any ideas from our papers, or a new file system were designed by someone else that adopted these techniques.
The commenters are right that there is a gap between when an idea is exciting new research and fundable via grants versus funding the "maturing" phase of the prototype. I will hasten to say that the NSF has been supportive of maturing this system, for which we are most grateful. Nonetheless, like many projects, we could use more resources, and I would be happy to engage constructive conversations out-of-band about how to address this gap.