Please test this build

Jeffrey Altman <[email protected]> Thu, 01 Jun 2006 09:48:51 -0400
Newsgroups gmane.comp.file-systems.openafs.devel.win32
Organization Secure Endpoints Inc.
Message-ID <[email protected]>
Over the last two weeks in response to the openafs-info thread
describing "delayed write errors" from Microsoft Office applications
I have made three changes to OpenAFS for Windows:

(1) Removed the deadlock that was the cause of the "delayed write
    errors" that initiated the thread.  The "delayed write errors"
    in this case were being caused by a deadlock on one smb_fid_t
    object that prevented reads, writes, etc from being performed
    on the file that Microsoft Office was attempting to write to.

(2) In the more general case, delayed write errors can occur when
    a smb_Server thread that is processing a Windows CIFS request
    is starved for CPU time because it is simply incredibly unlucky
    when trying to obtain a mutex, lock, etc.   To help prevent this
    situation thread priorities are now dynamically adjusted based
    upon the age of the CIFS request.  This helps older requests
    win out over younger requests when attempting to obtain resources.

(3) It was observed that when multiple requests on the same file
    are being processed that the smb_Server threads spend most of
    their time fighting over mutex objects and not performing I/O.
    This was because the mutex objects were being held across
    cm_SyncOp() and AFS RPC calls which tend to block.  Releasing
    the mutex across these calls will allow for simultaneous requests
    to the AFS File Server on the same file.  This is turn will
    improve performance.

I have tagged a set of sources in cvs as openafs-stable-1_4_1c.
Installers for this build are available at

http://web.mit.edu/jaltman/Public/OpenAFS/1.4.1/
/afs/athena.mit.edu/user/j/a/jaltman/Public/OpenAFS/1.4.1/
\\afs\athena.mit.edu\user\j\a\jaltman\Public\OpenAFS\1.4.1\

Please test this build and report back your experiences.  If things
look good, 1.4.2 will be released shortly.

Jeffrey Altman
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