OpenAFS Master Repository branch, master, updated. openafs-devel-1_5_76-3703-g2032845

[Gerrit Code Review]

The following commit has been merged in the master branch:
commit 3cf2d46a8c29039a6c8d33a952888370aa885801
Author: Jeffrey Altman <jaltman@your-file-system.com>
Date:   Mon Apr 8 08:56:31 2013 -0400

    Windows: hold locks during non-cached writes
    
    Writes can alter both the EndOfFile (Fcb FileSize) and the ValidDataLength
    which must remain synchronized with the data known to the service.
    Dropping the Fcb.Resource and the SectionObjectResource prior to
    performing non-cached writes opens the possibility of a race in which
    data changes and length updates can be altered independently.
    
    Efforts are made to avoid holding locks across calls to the service
    because they can result in deadlocks with object invalidation or extent
    management.  However, object invalidation for data version changes are
    now handled in a worker thread.  It should be safe to hold onto the
    Fcb Resource and SectionObjectResource across non-cached write processing.
    
    The locks are not held in the paging IO path so paging non-cached
    writes (which cannot be extending) will not prevent cached writes from
    taking place in parallel.
    
    The reason it is critical for the ValidDataLength and the FileSize to
    remain in sync with the data for non-paging non-cached writes is that
    these values are used to determine whether the Windows cache manager
    should trigger a page fault to read data from the service upon receiving
    an extending cached write that doesn't fill the page.
    
    Change-Id: If3edb2a7412623dbec10a6efd2ee8d3b92ac992d
    Reviewed-on: http://gerrit.openafs.org/9745
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Rod Widdowson <rdw@steadingsoftware.com>
    Reviewed-by: Peter Scott <pscott@kerneldrivers.com>
    Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>

 src/WINNT/afsrdr/kernel/lib/AFSWrite.cpp |   29 -----------------------------
 1 files changed, 0 insertions(+), 29 deletions(-)

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