--- contrib/python/parso/py3/parso/cache.py	(index)
+++ contrib/python/parso/py3/parso/cache.py	(working tree)
@@ -135,6 +135,8 @@ def load_module(hashed_grammar, file_io, cache_path=None):
 def _load_from_file_system(hashed_grammar, path, p_time, cache_path=None):
     cache_path = _get_hashed_path(hashed_grammar, path, cache_path=cache_path)
     try:
+        # SUBBOTNIK-2721 - Для безопасности отключаем загрузку с диска
+        raise FileNotFoundError
         if p_time > os.path.getmtime(cache_path):
             # Cache is outdated
             return None
--- contrib/python/parso/py3/parso/file_io.py	(index)
+++ contrib/python/parso/py3/parso/file_io.py	(working tree)
@@ -2,6 +2,8 @@ import os
 from pathlib import Path
 from typing import Union
 
+import __res as res
+
 
 class FileIO:
     def __init__(self, path: Union[os.PathLike, str]):
@@ -13,6 +15,9 @@ class FileIO:
         # We would like to read unicode here, but we cannot, because we are not
         # sure if it is a valid unicode file. Therefore just read whatever is
         # here.
+        data = res.resfs_read(self.path)
+        if data:
+            return data
         with open(self.path, 'rb') as f:
             return f.read()
 
--- contrib/python/parso/py3/parso/grammar.py	(index)
+++ contrib/python/parso/py3/parso/grammar.py	(working tree)
@@ -1,5 +1,6 @@
 import hashlib
 import os
+import pkgutil
 from typing import Generic, TypeVar, Union, Dict, Optional, Any
 from pathlib import Path
 
@@ -252,12 +253,13 @@ def load_grammar(*, version: str = None, path: str = None):
         return _loaded_grammars[path]
     except KeyError:
         try:
-            with open(path) as f:
-                bnf_text = f.read()
+            bnf_text = pkgutil.get_data("parso", file).decode("utf-8")
+            if bnf_text is None:
+                raise FileNotFoundError
 
             grammar = PythonGrammar(version_info, bnf_text)
             return _loaded_grammars.setdefault(path, grammar)
-        except FileNotFoundError:
+        except (FileNotFoundError, IOError):
             message = "Python version %s.%s is currently not supported." % (
                 version_info.major, version_info.minor
             )
--- contrib/python/parso/py3/tests/conftest.py	(index)
+++ contrib/python/parso/py3/tests/conftest.py	(working tree)
@@ -6,6 +6,7 @@ import os
 from pathlib import Path
 
 import pytest
+import yatest.common
 
 import parso
 from parso import cache
@@ -42,7 +43,7 @@ def pytest_addoption(parser):
 
 def pytest_generate_tests(metafunc):
     if 'normalizer_issue_case' in metafunc.fixturenames:
-        base_dir = os.path.join(os.path.dirname(__file__), 'test', 'normalizer_issue_files')
+        base_dir = os.path.join(yatest.common.test_source_path(), 'normalizer_issue_files')
 
         cases = list(colllect_normalizer_tests(base_dir))
         metafunc.parametrize(
--- contrib/python/parso/py3/tests/test_cache.py	(index)
+++ contrib/python/parso/py3/tests/test_cache.py	(working tree)
@@ -34,6 +34,7 @@ def isolated_parso_cache(monkeypatch, tmpdir):
     return cache_path
 
 
+@pytest.mark.skip("SUBBOTNIK-2721 Disable load cache from disk")
 def test_modulepickling_change_cache_dir(tmpdir):
     """
     ParserPickling should not save old cache when cache_directory is changed.
@@ -99,6 +100,7 @@ def test_modulepickling_simulate_deleted_cache(tmpdir):
     assert cached2 is None
 
 
+@pytest.mark.skip
 def test_cache_limit():
     def cache_size():
         return sum(len(v) for v in parser_cache.values())
@@ -129,6 +131,7 @@ class _FixedTimeFileIO(file_io.KnownContentFileIO):
         return self._last_modified
 
 
+@pytest.mark.skip
 @pytest.mark.parametrize('diff_cache', [False, True])
 @pytest.mark.parametrize('use_file_io', [False, True])
 def test_cache_last_used_update(diff_cache, use_file_io):
@@ -175,6 +178,7 @@ def test_inactive_cache(tmpdir, isolated_parso_cache):
     assert not old_paths.intersection(os.listdir(raw_cache_path))
 
 
+@pytest.mark.skip
 @skip_pypy
 def test_permission_error(monkeypatch):
     def save(*args, **kwargs):