SERVER-29453 Disallow removing featureCompatibilityVersion document and renaming collection

4 files changed, 15 insertions, 45 deletions

diff --git a/src/mongo/db/commands/rename_collection_cmd.cpp b/src/mongo/db/commands/rename_collection_cmd.cpp
index 569907eaab2..6385dcc5d0f 100644
--- a/src/mongo/db/commands/rename_collection_cmd.cpp
+++ b/src/mongo/db/commands/rename_collection_cmd.cpp
@@ -144,6 +144,13 @@ public:
             return false;
         }
 
+        if (source.isAdminDotSystemDotVersion()) {
+            appendCommandStatus(result,
+                                Status(ErrorCodes::IllegalOperation,
+                                       "renaming admin.system.version is not allowed"));
+            return false;
+        }
+
         RenameCollectionOptions options;
         options.dropTarget = cmdObj["dropTarget"].trueValue();
         options.stayTemp = cmdObj["stayTemp"].trueValue();
diff --git a/src/mongo/db/namespace_string.h b/src/mongo/db/namespace_string.h
index f110489916e..07240fa9f0a 100644
--- a/src/mongo/db/namespace_string.h
+++ b/src/mongo/db/namespace_string.h
@@ -192,6 +192,9 @@ public:
     bool isSystemDotViews() const {
         return coll() == kSystemDotViewsCollectionName;
     }
+    bool isAdminDotSystemDotVersion() const {
+        return ((db() == "admin") && (coll() == "system.version"));
+    }
     bool isConfigDB() const {
         return db() == "config";
     }
diff --git a/src/mongo/db/op_observer_impl.cpp b/src/mongo/db/op_observer_impl.cpp
index 6da9b7f9599..cdc1dbc4756 100644
--- a/src/mongo/db/op_observer_impl.cpp
+++ b/src/mongo/db/op_observer_impl.cpp
@@ -437,8 +437,11 @@ void OpObserverImpl::onDelete(OperationContext* opCtx,
         Scope::storedFuncMod(opCtx);
     } else if (nss.coll() == DurableViewCatalog::viewsCollectionName()) {
         DurableViewCatalog::onExternalChange(opCtx, nss);
-    } else if (nss.ns() == FeatureCompatibilityVersion::kCollection) {
-        FeatureCompatibilityVersion::onDelete(opCtx, deleteState.documentKey);
+    } else if (nss.isAdminDotSystemDotVersion()) {
+        auto _id = deleteState.documentKey["_id"];
+        if (_id.type() == BSONType::String &&
+            _id.String() == FeatureCompatibilityVersion::kParameterName)
+            uasserted(40670, "removing FeatureCompatibilityVersion document is not allowed");
     } else if (nss == NamespaceString::kSessionTransactionsTableNamespace &&
                !opTime.writeOpTime.isNull()) {
         SessionCatalog::get(opCtx)->invalidateSessions(opCtx, deleteState.documentKey);
diff --git a/src/mongo/db/repl/sync_tail_test.cpp b/src/mongo/db/repl/sync_tail_test.cpp
index e1c83e5e89f..6f7537ee68f 100644
--- a/src/mongo/db/repl/sync_tail_test.cpp
+++ b/src/mongo/db/repl/sync_tail_test.cpp
@@ -1664,29 +1664,6 @@ TEST_F(SyncTailTest, FailOnDropFCVCollectionInRecovering) {
     ASSERT_EQUALS(runOpSteadyState(op), ErrorCodes::OplogOperationUnsupported);
 }
 
-TEST_F(SyncTailTest, FailOnDeleteFCVDocumentInRecovering) {
-    auto fcvNS = NamespaceString(FeatureCompatibilityVersion::kCollection);
-    CollectionOptions options;
-    options.uuid = UUID::gen();
-    ::mongo::repl::createCollection(_opCtx.get(), fcvNS, options);
-
-    // Insert the fCV document.
-    ASSERT_OK(
-        ReplicationCoordinator::get(_opCtx.get())->setFollowerMode(MemberState::RS_SECONDARY));
-    auto insertCmd = BSON("_id" << FeatureCompatibilityVersion::kParameterName
-                                << FeatureCompatibilityVersion::kVersionField
-                                << FeatureCompatibilityVersionCommandParser::kVersion36);
-    auto insertOp = makeInsertDocumentOplogEntry(nextOpTime(), fcvNS, insertCmd);
-    ASSERT_OK(runOpSteadyState(insertOp));
-
-    ASSERT_OK(
-        ReplicationCoordinator::get(_opCtx.get())->setFollowerMode(MemberState::RS_RECOVERING));
-
-    auto cmd = BSON("_id" << FeatureCompatibilityVersion::kParameterName);
-    auto op = makeDeleteDocumentOplogEntry(nextOpTime(), fcvNS, cmd);
-    ASSERT_EQUALS(runOpSteadyState(op), ErrorCodes::OplogOperationUnsupported);
-}
-
 TEST_F(SyncTailTest, SuccessOnUpdateFCV34TargetVersionUnsetDocumentInRecovering) {
     auto fcvNS = NamespaceString(FeatureCompatibilityVersion::kCollection);
     ::mongo::repl::createCollection(_opCtx.get(), fcvNS, CollectionOptions());
@@ -1732,26 +1709,6 @@ TEST_F(SyncTailTest, SuccessOnDropFCVCollectionInSecondary) {
     ASSERT_OK(runOpSteadyState(op));
 }
 
-TEST_F(SyncTailTest, SuccessOnDeleteFCVDocumentInSecondary) {
-    auto fcvNS = NamespaceString(FeatureCompatibilityVersion::kCollection);
-    CollectionOptions options;
-    options.uuid = UUID::gen();
-    ::mongo::repl::createCollection(_opCtx.get(), fcvNS, options);
-    ASSERT_OK(
-        ReplicationCoordinator::get(_opCtx.get())->setFollowerMode(MemberState::RS_SECONDARY));
-
-    // Insert the fCV document.
-    auto insertCmd = BSON("_id" << FeatureCompatibilityVersion::kParameterName
-                                << FeatureCompatibilityVersion::kVersionField
-                                << FeatureCompatibilityVersionCommandParser::kVersion36);
-    auto insertOp = makeInsertDocumentOplogEntry(nextOpTime(), fcvNS, insertCmd);
-    ASSERT_OK(runOpSteadyState(insertOp));
-
-    auto cmd = BSON("_id" << FeatureCompatibilityVersion::kParameterName);
-    auto op = makeDeleteDocumentOplogEntry(nextOpTime(), fcvNS, cmd);
-    ASSERT_OK(runOpSteadyState(op));
-}
-
 TEST_F(SyncTailTest, SuccessOnUpdateFCV34TargetVersion34DocumentInSecondary) {
     auto fcvNS = NamespaceString(FeatureCompatibilityVersion::kCollection);
     ::mongo::repl::createCollection(_opCtx.get(), fcvNS, CollectionOptions());