Provided by: systemtap-doc_2.3-1ubuntu1.4_all 

NAME
probe::nfsd.proc.read - NFS server reading file for client
SYNOPSIS
nfsd.proc.read
VALUES
fh
file handle (the first part is the length of the file handle)
vec
struct kvec, includes buf address in kernel address and length of each buffer
count
read bytes
gid
requester's group id
uid
requester's user id
offset
the offset of file
vlen
read blocks
client_ip
the ip address of client
proto
transfer protocol
version
nfs version
size
read bytes
SystemTap Tapset Reference March 2016 PROBE::NFSD.PROC(3stap)