During community bonding period, apart from reading specifications, I also analyzed other NFSv4 client implementations, looking for interesting ideas and solutions. One thing I noticed which may be worth using in my NFSv4 client implementation is caching of some parts of generated RPC request.
In addition to that I also got more familiar with what Haiku expects from file system modules. I have written a very simple dummy file system and check how things work.
My GSoC project is to implement a Network File System version 4 client. NFS since its early versions became one of the most popular way of sharing files among Unix-like (and not only) systems. The fourth version brings many changes to the protocol that both simplify implementation and make it more efficient. That includes better support of client side caching which can significantly improve performance. In addition to that neither mountd nor NLM needs to be used anymore since services they provide are now part of the protocol.