Backport #15193
Updated by Kefu Chai almost 8 years ago
https://github.com/ceph/ceph/pull/9090 (from PR 8990)
we have three PRs for #13990
# https://github.com/ceph/ceph/pull/8017
# https://github.com/ceph/ceph/pull/8990
# https://github.com/ceph/ceph/pull/9108
among which, 9108 is more critical