Since three quarter term I've added NFS-level support for named attributes what means that virtually all important NFS version 4 feature are now implemented, as I described them in my blog posts during the coding period. What still needs to be done is to improve support of Haiku's extended attributes and a lot of bugfixing. There is also a room for performance improvement and several possibilities to organize code in a better way.
This is a companion discussion topic for the original entry at https://www.haiku-os.org/blog/pawe%C5%82_dziepak/2012-08-26_nfsv4_client_final_report/