mds: force replay sessionmap version

When expiring the MDLog Segments will it persist the sessionmap,
but what if the number of Segments doesn't reach up to the max
segment threshhold the expiring may won't happen.

So if the MDS failover then the sessionmap won't be persist and
couldn't be replayed by the standby MDS when it starting. We should
just force replay the sessionmap version just the inotable does.

Fixes: https://tracker.ceph.com/issues/58489
Signed-off-by: Xiubo Li <xiubli@redhat.com>

src/mds/journal.cc

@@ -1583,13 +1583,12 @@ void EMetaBlob::replay(MDSRank *mds, LogSegment *logseg, MDPeerUpdate *peerup)
     }
   }
   if (sessionmapv) {
-    unsigned diff = (used_preallocated_ino && !preallocated_inos.empty()) ? 2 : 1;
     if (mds->sessionmap.get_version() >= sessionmapv) {
       dout(10) << "EMetaBlob.replay sessionmap v " << sessionmapv
 	       << " <= table " << mds->sessionmap.get_version() << dendl;
-    } else if (mds->sessionmap.get_version() + diff == sessionmapv) {
+    } else {
       dout(10) << "EMetaBlob.replay sessionmap v " << sessionmapv
-	       << " - " << diff << " == table " << mds->sessionmap.get_version()
+	       << ", table " << mds->sessionmap.get_version()
 	       << " prealloc " << preallocated_inos
 	       << " used " << used_preallocated_ino
 	       << dendl;
@@ -1609,7 +1608,6 @@ void EMetaBlob::replay(MDSRank *mds, LogSegment *logseg, MDPeerUpdate *peerup)
 	  session->info.prealloc_inos.insert(preallocated_inos);
           mds->sessionmap.replay_dirty_session(session);
 	}
-
       } else {
 	dout(10) << "EMetaBlob.replay no session for " << client_name << dendl;
 	if (used_preallocated_ino)
@@ -1618,13 +1616,17 @@ void EMetaBlob::replay(MDSRank *mds, LogSegment *logseg, MDPeerUpdate *peerup)
 	if (!preallocated_inos.empty())
 	  mds->sessionmap.replay_advance_version();
       }
-      ceph_assert(sessionmapv == mds->sessionmap.get_version());
-    } else {
-      mds->clog->error() << "EMetaBlob.replay sessionmap v " << sessionmapv
-			 << " - " << diff << " > table " << mds->sessionmap.get_version();
-      ceph_assert(g_conf()->mds_wipe_sessions);
-      mds->sessionmap.wipe();
-      mds->sessionmap.set_version(sessionmapv);
+
+      // [repair bad sessionmap updates]
+      if (sessionmapv > mds->sessionmap.get_version()) {
+        mds->clog->error() << "EMetaBlob.replay sessionmapv mismatch "
+            << sessionmapv << " -> " << mds->sessionmap.get_version();
+        if (g_conf()->mds_wipe_sessions) {
+          mds->sessionmap.wipe();
+        }
+        // force replay sessionmap version
+        mds->sessionmap.set_version(sessionmapv);
+      }
     }
   }