doc: document cap revoke non-responders client eviction

Fixes: http://tracker.ceph.com/issues/25188
Signed-off-by: Venky Shankar <vshankar@redhat.com>
(cherry picked from commit 28a52d6fa14425fc877a69055dabe4e7c00f6b14)

diff --git a/doc/cephfs/eviction.rst b/doc/cephfs/eviction.rst
index 1bab7a127e325bbea30ff5b0dd2c3ad190994799..8f0f20b8448c300ce8fa4fb7df7c79ef5f77e33c 100644 (file)
--- a/doc/cephfs/eviction.rst
+++ b/doc/cephfs/eviction.rst
@@ -21,12 +21,16 @@ libcephfs.
 Automatic client eviction
 =========================
 
-There are two situations in which a client may be evicted automatically:
+There are three situations in which a client may be evicted automatically:
 
 On an active MDS daemon, if a client has not communicated with the MDS for
 over ``mds_session_autoclose`` seconds (300 seconds by default), then it
 will be evicted automatically.
 
+On an active MDS daemon, if a client has not responded to cap revoke messages
+for over ``mds_cap_revoke_eviction_timeout`` (configuration option) seconds.
+This is disabled by default.
+
 During MDS startup (including on failover), the MDS passes through a
 state called ``reconnect``.  During this state, it waits for all the
 clients to connect to the new MDS daemon.  If any clients fail to do