OpenAFS Master Repository branch, master, updated. openafs-devel-1_5_76-4094-g64d7715

[Gerrit Code Review]

The following commit has been merged in the master branch:
commit 64d7715c0247734731ef4cc8be5de32ee7c4a1f6
Author: Michael Meffie <mmeffie@sinenomine.net>
Date:   Mon Dec 23 12:10:36 2013 -0500

    vol: reset nextVnodeUnique when uniquifier rolls over
    
    The on disk uniquifier counter is set to 200 more than the current
    nextVnodeUnique counter when the volume information is updated to disk. When
    the nextVnodeUnique is near UINT32_MAX, then the uniquifier counter rolls
    over.  This can happen during a volume header update due to
    VBumpVolumeUsage_r().
    
    With this change, the nextVnodeUnique customer is reset to 2 and the
    uniquifier is reset to 202 when a roll over occurs. (uniquifier of 1 is
    reserved for the root vnode.)
    
    With this change, the number of possible uniquifier numbers is limited to
    200 less than UINT32_MAX.
    
    The following shows a series of vnode creation/deletions to illustrate
    the uniquifier rollover before this commit:
    
    fid = 536870918.4.4294967114, nextVnodeUnique = 4294967115, uniquifier = 4294967295
    fid = 536870918.4.4294967115, nextVnodeUnique = 4294967116, uniquifier = 4294967295
    fid = 536870918.4.4294967116, nextVnodeUnique = 4294967117, uniquifier = 21
    fid = 536870918.4.4294967117, nextVnodeUnique = 4294967118, uniquifier = 22
    
    and after this commit:
    
    fid = 536870918.4.4294967115, nextVnodeUnique = 4294967116, uniquifier = 4294967295
    fid = 536870918.4.4294967116, nextVnodeUnique = 2, uniquifier = 202
    fid = 536870918.4.2, nextVnodeUnique = 3, uniquifier = 202
    fid = 536870918.4.3, nextVnodeUnique = 4, uniquifier = 202
    
    Change-Id: I93c8a7cf47e39b8701265d6507cfc4f8c1352ddc
    Reviewed-on: http://gerrit.openafs.org/10617
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
    Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
    Reviewed-by: Derrick Brashear <shadow@your-file-system.com>

 src/vol/volume.c |   24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)

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