[OpenAFS] write permissions without locking?

Jeffrey Altman jaltman@secure-endpoints.com
Fri, 19 Feb 2010 13:09:51 -0500


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On 2/19/2010 1:01 PM, G=C3=A9mes G=C3=A9za wrote:
> Shortly, the answer is yes.
> A longer one the clients in question are Windows XP SP3 with KB955535
> and KB971421 applied, OpenAFS 1.5.7000
> The applications are mainly from MSOffice2003: mostly Word and Excel.

The answer is that Word and Excel explicitly request exclusive byte
range locks on the files that are open.  Since AFS does not support
byte range locks, these become exclusive full file locks which prevent
file sharing across machines.   The only way to disable this behavior
is to disable the acquisition of file locks from the file server.  There
is a registry key that will permit this.  It restores the behavior of
the pre-1.4 Windows clients.  However, doing so opens the door for two
copies of Word to write to the file at the same time and corrupt the
contents.  The registry key is documented in the release notes in
Appendix A.

The current version of OpenAFS for Windows is 1.5.7200.  This contains
an important fix to the Rx RPC library that will improve performance
and reliability.

Jeffrey Altman


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