Fix KVStore reopening of BucketManager's DBInstances.

pkg/storage/database/openablekvstore.go

@@ -38,6 +38,9 @@ func (s *openableKVStore) instance() kvstore.KVStore {
 	parent := s.topParent()
 
 	if parent.dbInstance.isClosed.Load() {
+		parent.dbInstance.Lock()
+		defer parent.dbInstance.Unlock()
+
 		parent.dbInstance.Open()
 	}
 

pkg/storage/prunable/bucket_manager.go

@@ -70,6 +70,40 @@ func (b *BucketManager) Get(epoch iotago.EpochIndex, realm kvstore.Realm) (kvsto
 	return lo.PanicOnErr(kv.WithExtendedRealm(realm)), nil
 }
 
+func (b *BucketManager) Lock() {
+	// Lock b.mutex so that a new DBInstance is not created
+	b.mutex.Lock()
+	// Lock b.openDBsCacheMutex so that DBInstance is not retrieved from cache
+	b.openDBsCacheMutex.Lock()
+
+	// Lock all KVStores so that they can't be reopened by components that store references to them (e.g., StateDiff)
+	b.openDBs.ForEach(func(epoch iotago.EpochIndex, db *database.DBInstance) bool {
+		db.Lock()
+
+		return true
+	})
+}
+
+func (b *BucketManager) Unlock() {
+	b.mutex.Unlock()
+	b.openDBsCacheMutex.Unlock()
+
+	b.openDBs.ForEach(func(epoch iotago.EpochIndex, db *database.DBInstance) bool {
+		db.Unlock()
+
+		return true
+	})
+}
+
+func (b *BucketManager) CloseWithoutLocking() {
+	b.openDBs.ForEach(func(epoch iotago.EpochIndex, db *database.DBInstance) bool {
+		db.CloseWithoutLocking()
+		b.openDBsCache.Remove(epoch)
+
+		return true
+	})
+}
+
 func (b *BucketManager) Shutdown() {
 	b.openDBsCacheMutex.Lock()
 	defer b.openDBsCacheMutex.Unlock()

pkg/storage/prunable/prunable.go

@@ -53,12 +53,12 @@ func Clone(source *Prunable, dbConfig database.Config, apiProvider iotago.APIPro
 	source.semiPermanentDB.Lock()
 	defer source.semiPermanentDB.Unlock()
 
-	source.prunableSlotStore.mutex.Lock()
-	defer source.prunableSlotStore.mutex.Unlock()
+	source.prunableSlotStore.Lock()
+	defer source.prunableSlotStore.Unlock()
 
 	// Close forked prunable storage before copying its contents.
 	source.semiPermanentDB.CloseWithoutLocking()
-	source.prunableSlotStore.Shutdown()
+	source.prunableSlotStore.CloseWithoutLocking()
 
 	// Copy the storage on disk to new location.
 	if err := copydir.Copy(source.prunableSlotStore.dbConfig.Directory, dbConfig.Directory); err != nil {