2 files changed, 16 insertions, 27 deletions

diff --git a/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp b/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp
index ec4588624f6..28377ec41a0 100644
--- a/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp
+++ b/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp
@@ -677,7 +677,8 @@ void MigrationChunkClonerSourceLegacy::_nextCloneBatchFromIndexScan(OperationCon
                            Milliseconds(internalQueryExecYieldPeriodMS.load()));
 
     if (!_jumboChunkCloneState->clonerExec) {
-        auto exec = uassertStatusOK(_getIndexScanExecutor(opCtx, collection));
+        auto exec = uassertStatusOK(_getIndexScanExecutor(
+            opCtx, collection, InternalPlanner::IndexScanOptions::IXSCAN_FETCH));
         _jumboChunkCloneState->clonerExec = std::move(exec);
     } else {
         _jumboChunkCloneState->clonerExec->reattachToOperationContext(opCtx);
@@ -685,39 +686,24 @@ void MigrationChunkClonerSourceLegacy::_nextCloneBatchFromIndexScan(OperationCon
     }
 
     BSONObj obj;
-    RecordId recordId;
     PlanExecutor::ExecState execState;
-
     while (PlanExecutor::ADVANCED ==
-           (execState = _jumboChunkCloneState->clonerExec->getNext(
-                &obj, _jumboChunkCloneState->stashedRecordId ? nullptr : &recordId))) {
+           (execState = _jumboChunkCloneState->clonerExec->getNext(&obj, nullptr))) {
 
         stdx::unique_lock<Latch> lk(_mutex);
         _jumboChunkCloneState->clonerState = execState;
         lk.unlock();
 
         opCtx->checkForInterrupt();
-
         // Use the builder size instead of accumulating the document sizes directly so
         // that we take into consideration the overhead of BSONArray indices.
         if (arrBuilder->arrSize() &&
             (arrBuilder->len() + obj.objsize() + 1024) > BSONObjMaxUserSize) {
             _jumboChunkCloneState->clonerExec->enqueue(obj);
-
-            // Stash the recordId we just read to add to the next batch.
-            if (!recordId.isNull()) {
-                invariant(!_jumboChunkCloneState->stashedRecordId);
-                _jumboChunkCloneState->stashedRecordId = std::move(recordId);
-            }
-
             break;
         }
 
-        Snapshotted<BSONObj> doc;
-        invariant(collection->findDoc(
-            opCtx, _jumboChunkCloneState->stashedRecordId.value_or(recordId), &doc));
-        arrBuilder->append(doc.value());
-        _jumboChunkCloneState->stashedRecordId = boost::none;
+        arrBuilder->append(obj);
 
         lk.lock();
         _jumboChunkCloneState->docsCloned++;
@@ -885,8 +871,10 @@ StatusWith<BSONObj> MigrationChunkClonerSourceLegacy::_callRecipient(const BSONO
 }
 
 StatusWith<std::unique_ptr<PlanExecutor, PlanExecutor::Deleter>>
-MigrationChunkClonerSourceLegacy::_getIndexScanExecutor(OperationContext* opCtx,
-                                                        Collection* const collection) {
+MigrationChunkClonerSourceLegacy::_getIndexScanExecutor(
+    OperationContext* opCtx,
+    Collection* const collection,
+    InternalPlanner::IndexScanOptions scanOption) {
     // Allow multiKey based on the invariant that shard keys must be single-valued. Therefore, any
     // multi-key index prefixed by shard key cannot be multikey over the shard key fields.
     const IndexDescriptor* idx =
@@ -913,7 +901,9 @@ MigrationChunkClonerSourceLegacy::_getIndexScanExecutor(OperationContext* opCtx,
                                       min,
                                       max,
                                       BoundInclusion::kIncludeStartKeyOnly,
-                                      PlanExecutor::YIELD_AUTO);
+                                      PlanExecutor::YIELD_AUTO,
+                                      InternalPlanner::Direction::FORWARD,
+                                      scanOption);
 }
 
 Status MigrationChunkClonerSourceLegacy::_storeCurrentLocs(OperationContext* opCtx) {
@@ -925,7 +915,8 @@ Status MigrationChunkClonerSourceLegacy::_storeCurrentLocs(OperationContext* opC
                 str::stream() << "Collection " << _args.getNss().ns() << " does not exist."};
     }
 
-    auto swExec = _getIndexScanExecutor(opCtx, collection);
+    auto swExec =
+        _getIndexScanExecutor(opCtx, collection, InternalPlanner::IndexScanOptions::IXSCAN_DEFAULT);
     if (!swExec.isOK()) {
         return swExec.getStatus();
     }
diff --git a/src/mongo/db/s/migration_chunk_cloner_source_legacy.h b/src/mongo/db/s/migration_chunk_cloner_source_legacy.h
index 7990615e38f..9d438d20eb0 100644
--- a/src/mongo/db/s/migration_chunk_cloner_source_legacy.h
+++ b/src/mongo/db/s/migration_chunk_cloner_source_legacy.h
@@ -224,7 +224,9 @@ private:
     StatusWith<BSONObj> _callRecipient(const BSONObj& cmdObj);
 
     StatusWith<std::unique_ptr<PlanExecutor, PlanExecutor::Deleter>> _getIndexScanExecutor(
-        OperationContext* opCtx, Collection* const collection);
+        OperationContext* opCtx,
+        Collection* const collection,
+        InternalPlanner::IndexScanOptions scanOption);
 
     void _nextCloneBatchFromIndexScan(OperationContext* opCtx,
                                       Collection* collection,
@@ -387,10 +389,6 @@ private:
         // The current state of 'clonerExec'.
         PlanExecutor::ExecState clonerState;
 
-        // RecordId of the last doc read in by 'clonerExec' if collection scan yields during
-        // cloning.
-        boost::optional<RecordId> stashedRecordId;
-
         // Number docs in jumbo chunk cloned so far
         int docsCloned = 0;
     };