OpenAFS Master Repository branch, openafs-stable-1_8_x, updated. openafs-stable-1_8_2-7-g3927292

[Gerrit Code Review]

The following commit has been merged in the openafs-stable-1_8_x branch:
commit 39272929fc528a4c6af05e74b98518a3bae18462
Author: Andrew Deason <adeason@sinenomine.net>
Date:   Thu May 10 16:22:52 2018 -0500

    ubik: Buffer log writes with stdio
    
    Currently, when we write ubik i/o operations to the db log, we tend to
    issue several syscalls involving small writes and fstat()s. This is
    because each "log" operation involves at least one write, and each log
    operation tends to be pretty small.
    
    Each logged operation hitting disk separately is unnecessary, since
    the db log does not need to hit the disk at all until we are ready to
    commit the transaction. So to reduce the number of syscalls when
    writing to the db, change our log writes to be buffered in memory
    (using stdio calls). This also avoids needing to fstat() the
    underlying log file, since we open the underlying file in append-only
    mode, since we only ever append to (and truncate) the log file.
    
    To implement this, we introduce a new 'buffered_append' phys
    operation, to explicitly separate our buffered and non-buffered
    operations, to try to avoid any bugs from mixing buffered and
    non-buffered i/o. This new operation is only used for the db log.
    
    Reviewed-on: https://gerrit.openafs.org/13070
    Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
    Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
    Reviewed-by: Joe Gorse <jhgorse@gmail.com>
    Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
    Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    (cherry picked from commit 800318b43fdf461ad95cd7f3940718f3f0a609a7)
    
    Change-Id: Ia40d75e7bdeb6a9f6c316aaea6fd20d5c8d80625
    Reviewed-on: https://gerrit.openafs.org/13353
    Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
    Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
    Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
    Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>

 src/ubik/disk.c   |   41 +++------------------------
 src/ubik/phys.c   |   78 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/ubik/ubik.c   |    1 +
 src/ubik/ubik.p.h |    3 ++
 4 files changed, 87 insertions(+), 36 deletions(-)

-- 
OpenAFS Master Repository