Merge pull request #181 from ceph/wip_4510

Scrub/repair should correctly handle truncation and EIO

Fixes #4510
Reviewed-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

diff --cc src/common/config_opts.h
Simple merge

diff --cc src/osd/osd_types.cc
Simple merge

diff --cc src/osd/osd_types.h
Simple merge