core/rawdb: open meta file in read only mode

core/rawdb/freezer_table.go

@@ -148,20 +148,12 @@ func newTable(path string, name string, readMeter metrics.Meter, writeMeter metr
 		meta  *os.File
 	)
 	if readonly {
-		// Will fail if table doesn't exist
+		// Will fail if table index file or meta file is not existent
 		index, err = openFreezerFileForReadOnly(filepath.Join(path, idxName))
 		if err != nil {
 			return nil, err
 		}
-		// TODO(rjl493456442) change it to read-only mode. Open the metadata file
-		// in rw mode. It's a temporary solution for now and should be changed
-		// whenever the tail deletion is actually used. The reason for this hack is
-		// the additional meta file for each freezer table is added in order to support
-		// tail deletion, but for most legacy nodes this file is missing. This check
-		// will suddenly break lots of database relevant commands. So the metadata file
-		// is always opened for mutation and nothing else will be written except
-		// the initialization.
-		meta, err = openFreezerFileForAppend(filepath.Join(path, fmt.Sprintf("%s.meta", name)))
+		meta, err = openFreezerFileForReadOnly(filepath.Join(path, fmt.Sprintf("%s.meta", name)))
 		if err != nil {
 			return nil, err
 		}