If smbd writes "client failure in oplock break in file" into log file,
it locks file for any operations. Client reboot doesn't help in this
situation. For release of file one needs restart smbd.
Example:
1. Open big Excel file (test.xls) from windows client.
2. Excel opens it OK. Smbd writes: "client failure in oplock break
in file test.xls".
3. Close Excel file.
4. Open Excel file again. Excel writes: "file is open by another
user".
5. Reboot windows.
6. Open Excel file again. Oops... Excel writes: "file is open by
another user".
7. Restart smbd.
8. Go to 1.
