SERVER-59866 Stop FCV from waiting for majority when currentCommitted…

(cherry picked from commit 7e5e6088eaf3ff2e01740cb52efa16c1fb8d360b)

3 files changed, 15 insertions, 2 deletions

diff --git a/src/mongo/db/commands/feature_compatibility_version.cpp b/src/mongo/db/commands/feature_compatibility_version.cpp
index b922e6f57e3..d7cfb0b21b0 100644
--- a/src/mongo/db/commands/feature_compatibility_version.cpp
+++ b/src/mongo/db/commands/feature_compatibility_version.cpp
@@ -265,8 +265,7 @@ void FeatureCompatibilityVersion::onReplicationRollback(OperationContext* opCtx)
                   "oldVersion"_attr = FeatureCompatibilityVersionParser::toString(memoryFcv));
             _setVersion(opCtx, diskFcv, boost::none);
             // The rollback FCV is already in the stable snapshot.
-            stdx::lock_guard lk(lastFCVUpdateTimestampMutex);
-            lastFCVUpdateTimestamp = Timestamp();
+            clearLastFCVUpdateTimestamp();
         }
     }
 }
@@ -316,6 +315,11 @@ void FeatureCompatibilityVersion::_runUpdateCommand(OperationContext* opCtx,
     uassertStatusOK(getStatusFromWriteCommandReply(updateResult));
 }
 
+void FeatureCompatibilityVersion::clearLastFCVUpdateTimestamp() {
+    stdx::lock_guard lk(lastFCVUpdateTimestampMutex);
+    lastFCVUpdateTimestamp = Timestamp();
+}
+
 /**
  * Read-only server parameter for featureCompatibilityVersion.
  */
diff --git a/src/mongo/db/commands/feature_compatibility_version.h b/src/mongo/db/commands/feature_compatibility_version.h
index 04e84587e5d..0cc79203c00 100644
--- a/src/mongo/db/commands/feature_compatibility_version.h
+++ b/src/mongo/db/commands/feature_compatibility_version.h
@@ -104,6 +104,14 @@ public:
      */
     static void onReplicationRollback(OperationContext* opCtx);
 
+    /**
+     * Used at rollback time.  The rollback FCV is always in the majority snapshot, so it is safe to
+     * clear the lastFCVUpdateTimestamp then.
+     *
+     * Also used in rare cases when the replication coordinator majority snapshot is cleared.
+     */
+    static void clearLastFCVUpdateTimestamp();
+
 private:
     /**
      * Validate version. Uasserts if invalid.
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index 834bd679109..f3193f6f178 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -967,6 +967,7 @@ void ReplicationCoordinatorExternalStateImpl::_dropAllTempCollections(OperationC
 void ReplicationCoordinatorExternalStateImpl::dropAllSnapshots() {
     if (auto manager = _service->getStorageEngine()->getSnapshotManager())
         manager->dropAllSnapshots();
+    FeatureCompatibilityVersion::clearLastFCVUpdateTimestamp();
 }
 
 void ReplicationCoordinatorExternalStateImpl::updateCommittedSnapshot(