read/write delegation, share deny

[Shirish Pargaonkar]

I have a small program like this

#include <stdio.h>
#include <fcntl.h>


#define FILE1NAME "/mnt/fs1/file1"
#define BUFSIZE 5

main()
{
        int fd1, fd2;
        int rc1, rc2;
        char buf[BUFSIZE+1] = {};

        fd1 = open(FILE1NAME, O_RDWR);
        read(fd1, buf, BUFSIZE);
        fd2 = open(FILE1NAME, O_RDWR);
        write(fd1, "something", sizeof("something"));
        rc1 = close(fd1);
        rc2 = close(fd2);
}

In tcpdump, all I see is OPEN_DELGATION_NONE being sent by server, twice,
for both the open I guess!
How do I make server issue READ/WRITE delegation during the first open?
I have just mounted the filesystem on the client.

I would like to see read/write delegation revoked when I issue open for the
very same file on the server from another client, which I can't verify
unless I can see first client receiving read/write open delegation I guess.
I am trying to verify what kinds of open delegations Linux server
issues to clients.

Also, instead of this during open
            share_access: OPEN4_SHARE_ACCESS_BOTH (3)
            share_deny: OPEN4_SHARE_DENY_NONE (0)
I want something to have something like this
            share_access: OPEN4_SHARE_ACCESS_BOTH (3)
            share_deny: OPEN4_SHARE_DENY_WRITE  or READ or BOTH
How do I go about doing that? During open call?  How?
Did not find relevant info on open manpage on the linux box.

I am using 2.6.22-bigsmp on both, nfsv4 RHEL5 client and server and 1.1.0
of nfs-utils.

Your help is appreciated.