SERVER-31030 Make sure that _getNextSessionMods will only contain oplog entries that are majority committed

1 files changed, 12 insertions, 2 deletions

diff --git a/src/mongo/db/s/migration_chunk_cloner_source_legacy_commands.cpp b/src/mongo/db/s/migration_chunk_cloner_source_legacy_commands.cpp
index d42c6bdaa99..a6f0f5c7f18 100644
--- a/src/mongo/db/s/migration_chunk_cloner_source_legacy_commands.cpp
+++ b/src/mongo/db/s/migration_chunk_cloner_source_legacy_commands.cpp
@@ -41,6 +41,7 @@
 #include "mongo/db/s/migration_chunk_cloner_source_legacy.h"
 #include "mongo/db/s/migration_source_manager.h"
 #include "mongo/db/s/sharding_state.h"
+#include "mongo/db/write_concern.h"
 
 /**
  * This file contains commands, which are specific to the legacy chunk cloner source.
@@ -259,8 +260,17 @@ public:
 
         BSONArrayBuilder arrBuilder;
 
-        AutoGetActiveCloner autoCloner(opCtx, migrationSessionId);
-        autoCloner.getCloner()->nextSessionMigrationBatch(opCtx, &arrBuilder);
+        repl::OpTime opTime;
+
+        {
+            AutoGetActiveCloner autoCloner(opCtx, migrationSessionId);
+            opTime = autoCloner.getCloner()->nextSessionMigrationBatch(opCtx, &arrBuilder);
+        }
+
+        WriteConcernResult wcResult;
+        WriteConcernOptions majorityWC(
+            WriteConcernOptions::kMajority, WriteConcernOptions::SyncMode::UNSET, 0);
+        uassertStatusOK(waitForWriteConcern(opCtx, opTime, majorityWC, &wcResult));
 
         result.appendArray("oplog", arrBuilder.arr());
         return true;