[Unionfs] [ANNOUNCE] Unionfs-ODF 2.1.10 release (NFS problems)

[Jesse I Pollard]

Thanks for the patch.

Apologies for the really late followup...

In reference to linux-2.6.24-rc3 + unionfs-2.1.10-odf_for_2.6.24-rc3:

1. Mounts locally:

        mount -t unionfs \
              -odirs=/mnt/a=rw/mnt/torpedo-old=ro,odf=/odf \
                        none /mnt/torpedo

2. Local operations appear normal.

3. NFS exporting fails:

        mount lint:/mnt/torpedo /mnt/torpedo
        mount: lint:/mnt/torpedo failed, reason given by server: Permission
                        denied

4. NFS in general works when the export is not part of a unionfs mount point
   and using the same client:

        mount lint:/mnt/a /mnt/u
        df
        Filesystem           1K-blocks      Used Available Use% Mounted on
        /dev/mapper/VolGroup00-LogVol00
                             234476168  11406680 210966628   6% /
        /dev/hda1               101086     27863     68004  30% /boot
        tmpfs                   481748         0    481748   0% /dev/shm
        lint:/mnt/a           15227008   7793152   6647936  54% /mnt/u

5. export list on server:

        /mnt/torpedo    tabby(rw,fsid=10,crossmnt,no_root_squash,nohide)
        /mnt/a          tabby(rw)

        I have also tried without the fsid=10 and crossmnt without success

6. NFS investigations has shown that the server believes the mount
   succeded (IP number entries have been removed):

        /usr/sbin/showmount -a
        tabby.nrl.navy.mil:/mnt/a
        tabby.nrl.navy.mil:/mnt/torpedo

The last time I traced through the logic, the problem appeared to be 
because
unionfs did not locate the root directory of the volume being mounted. 
Mountd
checks all passed, but the first filehandle read seems to be failing. 
(Perhaps
on either fsstat/fsinfo NFS operations). I do know the "Permission deinied"
message is used for any error that occurs during the mount that are not
otherwise labeled.

I have not traced this activity to see exactly where the failure arises yet
(I think it will call for some printks in the export.c functions...), but I
will be looking into it later next week and into january.