[openib-general] NFS/RDMA client *and server* release for Linux 2.6.15

[Talpey, Thomas]

Following up on the client release of Feb 8, we are releasing
a first-functional NFS/RDMA server for Linux 2.6.15, along with
client updates based on comments received.

These are both licensed under dual BSD/GPL2 terms, and available
at the project's Sourceforge site:

<http://sourceforge.net/projects/nfs-rdma/>

<http://sourceforge.net/project/showfiles.php?group_id=97628&package_id=182485&release_id=399220>

Both client and server employ the native OpenIB verbs API for
RDMA, and work equally for Infiniband and iWARP.

The client and server implement the IETF draft protocol (*) and fully
support direct (zero-copy, zero-touch) RDMA transfers at the RPC
layer. However, the write performance is not yet representative of
full RDMA operation, due to a bottleneck in the server's use of RDMA
Read, and at least one data copy in its handoff to the filesystem.
We will be rectifying the former, and investigating the latter.

Both the client and server have been tested with NFSv3 and pass
the Connectathon test suite.

Due to the additional components, the procedure for applying the
patches is substantially more involved, requiring several steps to
be followed in a particular sequence. Also, the server patches have
been separated into "framework" and "RDMA" sections, as already
been done for the client. The package README has details.

The RDMA support in this NFS server release was developed by
Tom Tucker of Open Grid Computing and we thank him for his efforts
on this.

At this time, the changes to the Linux NFS server svc framework are
in effect a first proposal for how RDMA support might be added to the
code. There are open issues in both how the module linkage should
be structured, and also how the linkage to existing code be done.

As before, we look forward to comments and feedback! Thanks for all
of it so far.

Tom Talpey, for the various NFS/RDMA projects.

(*) Protocol docs under "Internet-Drafts" at bottom of page:
<http://www.ietf.org/html.charters/nfsv4-charter.html>