I am reporting a problem that was originally posted to the samba list by Philip Ong: http://lists.samba.org/archive/samba/2011-October/164564.html

Scenario:
Server with Samba 3.5.12, exporting a share that is mounted via NFS.
Samba config includes (default setting):
-------
kernel oplocks = yes
-------

Problem:
Kernel commit (for SLES11 SP1 http://kernel.opensuse.org/cgit/kernel/commit/?h=SLE11-SP1&id=dd143426eaaadea159c8dd2d3c9ff5e9da94bcfd) seems to break the copying/saving of files to such a share, which was possible before this commit.

Steps to reproduce:
0) use kernel that include above mentioned commit
1) mount NFS share without "nolock" option
2) share NFS mount via Samba
3) copy or save a file on Samba share

Actual result:
Error Message when saving or copying a file to such a share:
 - Windows client: "The process cannot access the file because another process has locked a portion of the file"
 - In log.smbd: "smbd/oplock_linux.c:120(linux_set_kernel_oplock)
  linux_set_kernel_oplock: Refused oplock on file <FILENAME>, fd = 32, file_id = 15:100811:0. (Invalid argument)"

Expected result: 
Saving/copying files on share works without problems.

Possible solutions:
a) revert to a kernel without the mentioned patch
b) turn off kernel oplocks with: "kernel oplocks = yes"
c) mount NFS share with "nolock" option

Please find attached:
- smb.conf
- debug level 10 log of working kernel without mentioned patch
- debug level 10 log of non-working kernel including the patch
- strace of smbd on non-working kernel (taken at different time instance with different user)