Merge PR #20132 into master

Merge PR #20132 into master

* refs/pull/20132/head:
	qa/cephfs: update TestDamage for open file table
	mds: allow storing open file table in multiple omaps
	mds: differentiate Anchor types to clarify purpose
	mds: add perf counter for 'open ino' operation
	mds: protect open file table against partial omap update
	mds: add dirfrags whose child inodes have caps to open file table
	mds: don't try prefetching destroyed inodes
	mds: don't try opening inodes that haven't been created
	mds: don't re-requeue open files to head of log
	mds: use open file table to speed up mds recovery
	mds: introduce open file table
	mds: track how many clients/mds want caps for each inode
	mds: cleanup MDCache::opening_inodes access
	mds: cleanup CInode/CDir states definition

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