Merge PR #41385 into master

* refs/pull/41385/head:
	mon/FSCommands: add command to rename a file system
	qa/cephfs: split test_admin.TestAdminCommands
	mds: remove 'fs_name' from MDSRank

Reviewed-by: Rishabh Dave <ridave@redhat.com>
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>

diff --cc qa/tasks/cephfs/test_admin.py
Simple merge

diff --cc src/mds/MDSDaemon.cc
Simple merge

diff --cc src/mds/MDSRank.cc
Simple merge

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