From: Sage Weil <sage@newdream.net>
Date: Wed, 14 Jul 2021 16:15:15 +0000 (-0400)
Subject: mon/LogMonitor: tolerate external_log_to in the future
X-Git-Tag: v17.1.0~1381^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F42338%2Fhead;p=ceph.git

mon/LogMonitor: tolerate external_log_to in the future

This can be fast-forwarded by a sync_force or other mon thrashing events.

In any case, if we see it in the future, it is easy to rewind.

Signed-off-by: Sage Weil <sage@newdream.net>
---

diff --git a/src/mon/LogMonitor.cc b/src/mon/LogMonitor.cc
index 33f3e9d07fcd..96d0a6181db5 100644
--- a/src/mon/LogMonitor.cc
+++ b/src/mon/LogMonitor.cc
@@ -454,7 +454,11 @@ void LogMonitor::log_external_backlog()
     }
   }
   // we may have logged ahead of summary.version, but never ahead of paxos
-  assert(external_log_to <= get_last_committed());
+  if (external_log_to > get_last_committed()) {
+    derr << __func__ << " rewinding external_log_to from " << external_log_to
+	 << " -> " << get_last_committed() << " (sync_force? mon rebuild?)" << dendl;
+    external_log_to = get_last_committed();
+  }
   if (external_log_to >= summary.version) {
     return;
   }