Merge pull request #3295 from majianpeng/fix2

osd: add per-pool fadvise-dontneed flag

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

diff --cc src/include/rados.h
Simple merge

diff --cc src/mon/OSDMonitor.cc
Simple merge

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

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