From: "Andrew Dixie" <andrew-0FSrDVjkvKm9koe0gwxAeg@public.gmane.org>
Subject: Re: (fwd) nfs hang on 2.6.24
Date: Thu, 7 Feb 2008 10:19:06 +1300 (NZDT)
Message-ID: <37673.203.167.214.129.1202332746.squirrel@mail.orcon.net.nz>
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Cc: "Trond Myklebust" <trond.myklebust@netapp.com>,
	"Andrew Dixie" <andrew-0FSrDVjkvKm9koe0gwxAeg@public.gmane.org>, linux-nfs@vger.kernel.org,
	"maximilian attems" <max-U9r9yeDMy7A@public.gmane.org>
To: "J. Bruce Fields" <bfields@fieldses.org>
In-Reply-To: <20080206183128.GG5342@fieldses.org>
Sender: linux-nfs-owner@vger.kernel.org


> Oh, right, I was confusing client and server reboot and assuming the
> client would forget the uniquifier on server reboot.  That's obviously
> wrong!  The client will forget its own uniquifier on client reboot, but
> that's alright since it's happy enough just to let that old state time
> out at that point.  So the only possible problem is suboptimal behavior
> when the client reboot time is less than the lease time.

There is one client, a stable connection between client and server, and
neither client or server are being rebooted.
Are the "string in use by client" messages still expected?

Below is a program that attempts to open a file that is contained in a
directory that has been deleted by another client.

I'm not sure these are conditions that are normally occuring, it's just
something I encountered trying to reproduce the hang.

This reliably reproduces:
Feb  7 09:55:01 devfile kernel: NFSD: preprocess_seqid_op: bad seqid
(expected 20, got 22)

And about 1 in 10 times it also reproduces:
Feb  7 09:55:01 devfile kernel: NFSD: setclientid: string in use by
client(clientid 47a627bd/0000044b)

The server is 2.6.18-5 from debian.

---

#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <stdlib.h>

#define ASSERT(x) \
        if (!(x)) { fprintf(stderr, "%s:%i:assert:" #x "\n", __FILE__,
__LINE__); abort(); }

#define testdir "/home/andrewd/testdir"
#define testfile testdir "/fred"

int main(int argc, char *argv[])
{
        int fd;
        int rv;

        rv = mkdir(testdir,0777);
        ASSERT(rv == 0 || errno == EEXIST);

        fd = open(testfile, O_CREAT|O_WRONLY);
        ASSERT(fd != -1);
        rv = write(fd, "stuff\n", 6);
        ASSERT(rv == 6);
        close(fd);

        rv = access(testfile, 0);
        ASSERT(rv == 0);

        // Remove directory via another client (nfsv3)
        system("ssh devlin7 rm -r "testdir);

        // Try to open file
        fd = open(testfile, O_RDONLY);
        printf("got fd:%i errno:%i\n", fd, errno);
        // fd == -1, errno = ENOENT
        // This is expected, error on nfs server is not.
        return 0;
}