SERVER-67845 Acquire critical section in rename "check preconditions" phase only if target not sharded

4 files changed, 61 insertions, 7 deletions

diff --git a/src/mongo/db/s/rename_collection_coordinator.cpp b/src/mongo/db/s/rename_collection_coordinator.cpp
index 294dfc61bf3..79dcaa4254d 100644
--- a/src/mongo/db/s/rename_collection_coordinator.cpp
+++ b/src/mongo/db/s/rename_collection_coordinator.cpp
@@ -39,6 +39,7 @@
 #include "mongo/db/ops/insert.h"
 #include "mongo/db/persistent_task_store.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
+#include "mongo/db/s/recoverable_critical_section_service.h"
 #include "mongo/db/s/sharding_ddl_util.h"
 #include "mongo/db/s/sharding_logging.h"
 #include "mongo/db/s/sharding_state.h"
@@ -189,6 +190,9 @@ ExecutorFuture<void> RenameCollectionCoordinator::_runImpl(
                 const auto& fromNss = nss();
                 const auto& toNss = _request.getTo();
 
+                const auto criticalSectionReason =
+                    sharding_ddl_util::getCriticalSectionReasonForRename(fromNss, toNss);
+
                 try {
                     // Make sure the source collection exists
                     const auto optSourceCollType = getShardedCollection(opCtx, fromNss);
@@ -206,6 +210,28 @@ ExecutorFuture<void> RenameCollectionCoordinator::_runImpl(
                         sharding_ddl_util::checkDbPrimariesOnTheSameShard(opCtx, fromNss, toNss);
                     }
 
+                    const auto optTargetCollType = getShardedCollection(opCtx, toNss);
+                    const bool targetIsSharded = (bool)optTargetCollType;
+                    _doc.setTargetIsSharded(targetIsSharded);
+                    _doc.setTargetUUID(getCollectionUUID(
+                        opCtx, toNss, optTargetCollType, /*throwNotFound*/ false));
+
+                    auto criticalSection = RecoverableCriticalSectionService::get(opCtx);
+                    if (!targetIsSharded) {
+                        // (SERVER-67325) Acquire critical section on the target collection in order
+                        // to disallow concurrent `createCollection`
+                        criticalSection->acquireRecoverableCriticalSectionBlockWrites(
+                            opCtx,
+                            toNss,
+                            criticalSectionReason,
+                            ShardingCatalogClient::kLocalWriteConcern);
+                        criticalSection->promoteRecoverableCriticalSectionToBlockAlsoReads(
+                            opCtx,
+                            toNss,
+                            criticalSectionReason,
+                            ShardingCatalogClient::kLocalWriteConcern);
+                    }
+
                     // Make sure the target namespace is not a view
                     {
                         Lock::DBLock dbLock(opCtx, toNss.db(), MODE_IS);
@@ -218,15 +244,36 @@ ExecutorFuture<void> RenameCollectionCoordinator::_runImpl(
                         }
                     }
 
-                    const auto optTargetCollType = getShardedCollection(opCtx, toNss);
-                    _doc.setTargetIsSharded((bool)optTargetCollType);
-                    _doc.setTargetUUID(getCollectionUUID(
-                        opCtx, toNss, optTargetCollType, /*throwNotFound*/ false));
+                    const bool targetExists = [&]() {
+                        if (targetIsSharded) {
+                            return true;
+                        }
+                        auto collectionCatalog = CollectionCatalog::get(opCtx);
+                        auto targetColl =
+                            collectionCatalog->lookupCollectionByNamespace(opCtx, toNss);
+                        return (bool)targetColl;  // true if exists and is unsharded
+                    }();
+
+                    if (targetExists) {
+                        // Release the critical section because the target collection
+                        // already exists, hence no risk of concurrent `createCollection`
+                        criticalSection->releaseRecoverableCriticalSection(
+                            opCtx,
+                            toNss,
+                            criticalSectionReason,
+                            ShardingCatalogClient::kLocalWriteConcern);
+                    }
 
                     sharding_ddl_util::checkRenamePreconditions(
                         opCtx, sourceIsSharded, toNss, _doc.getDropTarget());
 
                 } catch (const DBException&) {
+                    auto criticalSection = RecoverableCriticalSectionService::get(opCtx);
+                    criticalSection->releaseRecoverableCriticalSection(
+                        opCtx,
+                        toNss,
+                        criticalSectionReason,
+                        ShardingCatalogClient::kLocalWriteConcern);
                     _completeOnError = true;
                     throw;
                 }
diff --git a/src/mongo/db/s/rename_collection_participant_service.cpp b/src/mongo/db/s/rename_collection_participant_service.cpp
index 51256975393..15d7d11bd3c 100644
--- a/src/mongo/db/s/rename_collection_participant_service.cpp
+++ b/src/mongo/db/s/rename_collection_participant_service.cpp
@@ -43,6 +43,7 @@
 #include "mongo/db/s/recoverable_critical_section_service.h"
 #include "mongo/db/s/rename_collection_participant_service.h"
 #include "mongo/db/s/shard_metadata_util.h"
+#include "mongo/db/s/sharding_ddl_util.h"
 #include "mongo/logv2/log.h"
 #include "mongo/s/catalog/sharding_catalog_client.h"
 #include "mongo/s/grid.h"
@@ -307,9 +308,7 @@ SemiFuture<void> RenameParticipantInstance::_runImpl(
 
                 // Acquire source/target critical sections
                 const auto reason =
-                    BSON("command"
-                         << "rename"
-                         << "from" << fromNss().toString() << "to" << toNss().toString());
+                    sharding_ddl_util::getCriticalSectionReasonForRename(fromNss(), toNss());
                 auto service = RecoverableCriticalSectionService::get(opCtx);
                 service->acquireRecoverableCriticalSectionBlockWrites(
                     opCtx, fromNss(), reason, ShardingCatalogClient::kLocalWriteConcern);
diff --git a/src/mongo/db/s/sharding_ddl_util.cpp b/src/mongo/db/s/sharding_ddl_util.cpp
index fd4a9af6c2c..ec0af295d45 100644
--- a/src/mongo/db/s/sharding_ddl_util.cpp
+++ b/src/mongo/db/s/sharding_ddl_util.cpp
@@ -487,5 +487,11 @@ void sendDropCollectionParticipantCommandToShards(OperationContext* opCtx,
     }
 }
 
+BSONObj getCriticalSectionReasonForRename(const NamespaceString& from, const NamespaceString& to) {
+    return BSON("command"
+                << "rename"
+                << "from" << from.toString() << "to" << to.toString());
+}
+
 }  // namespace sharding_ddl_util
 }  // namespace mongo
diff --git a/src/mongo/db/s/sharding_ddl_util.h b/src/mongo/db/s/sharding_ddl_util.h
index da78ce04a8b..99816c6fa02 100644
--- a/src/mongo/db/s/sharding_ddl_util.h
+++ b/src/mongo/db/s/sharding_ddl_util.h
@@ -173,5 +173,7 @@ void sendDropCollectionParticipantCommandToShards(OperationContext* opCtx,
                                                   std::shared_ptr<executor::TaskExecutor> executor,
                                                   const OperationSessionInfo& osi);
 
+BSONObj getCriticalSectionReasonForRename(const NamespaceString& from, const NamespaceString& to);
+
 }  // namespace sharding_ddl_util
 }  // namespace mongo