Merge PR 16068 into master

* refs/remotes/upstream/pull/16068/head:
	mds: wait auth pinned objects when deactivating mds
	mds: fix "wait for stray manager to start"
	ceph: kick purge queue when mds active
	mds: properly do null snapflush
	mds: force client to flush data when waiting on LOCK_SNAP_SYNC lock
	mds: don't issue caps for frozen inode

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

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

diff --cc src/mds/Locker.h
Simple merge

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

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