Merge pull request #28778 from myoungwon/wip-chunk-flush-op

src/osd: add tier-flush op

Reviewed-by: Sage Weil <sage@redhat.com>

diff --cc src/librados/librados_cxx.cc
Simple merge

diff --cc src/osdc/Objecter.h
Simple merge

diff --cc src/test/osd/RadosModel.h
Simple merge

diff --cc src/test/osd/TestRados.cc
Simple merge