Merge PR #19440 into master

* refs/pull/19440/head:
	mds: update mds option descriptions
	mds: obsolete MDSMap option configs
	mds: organize Filesystem class def

Reviewed-by: John Spray <john.spray@redhat.com>

diff --cc PendingReleaseNotes
index cd10c1362cfa925e0ec096e7efd9955eddd14cb2,e5e6c2cd63adcc51546c4b7489457c26a35a6b35..b48eb44cf70ba1cbc4adfe5be207e27253b34e2e
--- 1/PendingReleaseNotes
--- 2/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@@ -20,8 -20,12 +20,13 @@@
        - mds remove_data_pool -> fs rm_data_pool
        - mds rm_data_pool -> fs rm_data_pool
  
+   * New CephFS file system attributes session_timeout and session_autoclose
+     are configurable via `ceph fs set`. The MDS config options
+     mds_session_timeout, mds_session_autoclose, and mds_max_file_size are now
+     obsolete.
+ 
  
 +
  >= 12.2.2
  ---------