SERVER-50145 Collection instances are modified using copy-on-write

When a writable collection is requested from the catalog a cloned instance will be returned.
Its lifetime is managed by default in a WriteUnitOfWork and committed into the catalog in a commit handler.
In the case of a rollback the cloned and modified collection instance is simply discarded.

This removes the need to setup rollback handlers to restore any state written to a collection in the case of a rollback.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mongo/db/system_index.cpp b/src/mongo/db/system_index.cpp
index 09521feda5a..6f3ad2a4410 100644
--- a/src/mongo/db/system_index.cpp
+++ b/src/mongo/db/system_index.cpp
@@ -199,7 +199,7 @@ Status verifySystemIndexes(OperationContext* opCtx) {
     return Status::OK();
 }
 
-void createSystemIndexes(OperationContext* opCtx, const CollectionPtr& collection) {
+void createSystemIndexes(OperationContext* opCtx, CollectionWriter& collection) {
     invariant(collection);
     const NamespaceString& ns = collection->ns();
     BSONObj indexSpec;
@@ -219,7 +219,7 @@ void createSystemIndexes(OperationContext* opCtx, const CollectionPtr& collectio
         auto fromMigrate = false;
         try {
             IndexBuildsCoordinator::get(opCtx)->createIndexesOnEmptyCollection(
-                opCtx, collection->uuid(), {indexSpec}, fromMigrate);
+                opCtx, collection, {indexSpec}, fromMigrate);
         } catch (DBException& ex) {
             fassertFailedWithStatus(40456, ex.toStatus());
         }