In Memory FUSE filesystem

Question

Write a simple FUSE filesystem that is stored in memory. The filesystem has to support the following commands:

ls, mkdir, cp

This question was recently asked in an interview, I wasn't able answer it. So I have decided to learn it.

Did some searching and found some guides on building my own FUSE filesystem. I am really clueless on how to implement the filesystem in memory.

My questions are

• Am I heading in the right direction ?
• What else should I read up on ?
• What is the solution ?

Links that I am reading:

• http://fuse.sourceforge.net/
• http://www.ibm.com/developerworks/linux/library/l-fuse/
• http://pramode.net/articles/lfy/fuse/pramode.html
• http://revista.python.org.ar/3/en/html/python_en_tu_fs.html
• http://pysnippet.blogspot.com/2009/11/fuse-filesystem-in-userspace-part-1.html
• creating a temporary file in python with FUSE
• http://www.willmcgugan.com/blog/tech/2011/3/20/creating-a-virtual-filesystem-with-python-and-why-you-need-one/

In the last link the there is a mention on in-memory caching with PyFileSystem. I am not sure on how that might help.

PS : This was a written interview Question, So the answer has to simple enough to write on paper within 10-15 mins.

Answer 1

I had taken a course where we had to build an in-memory distributed file system similar in design to Frangipani. The course was heavily inspired by MIT's Distributed Systems course. Doing their first few lab assignments would be a good exercise.

This tutorial is also quite helpful.