Merge pull request #8519 from jazkarta/check-ccx-enabled

WIP: Limit application of CCX overrides to enabled courses and providers

lms/djangoapps/ccx/overrides.py

@@ -47,6 +47,14 @@ class CustomCoursesForEdxOverrideProvider(FieldOverrideProvider):
             return get_override_for_ccx(ccx, block, name, default)
         return default
 
+    @classmethod
+    def enabled_for(cls, course):
+        """CCX field overrides are enabled per-course
+
+        protect against missing attributes
+        """
+        return getattr(course, 'enable_ccx', False)
+
 
 def get_current_ccx(course_key):
     """

lms/djangoapps/ccx/tests/test_field_override_performance.py

@@ -7,6 +7,7 @@ import itertools
 import mock
 
 from courseware.views import progress  # pylint: disable=import-error
+from courseware.field_overrides import OverrideFieldData
 from datetime import datetime
 from django.conf import settings
 from django.core.cache import get_cache
@@ -56,7 +57,7 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
 
         MakoMiddleware().process_request(self.request)
 
-    def setup_course(self, size):
+    def setup_course(self, size, enable_ccx):
         """
         Build a gradable course where each node has `size` children.
         """
@@ -98,7 +99,8 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
         self.course = CourseFactory.create(
             graded=True,
             start=datetime.now(UTC),
-            grading_policy=grading_policy
+            grading_policy=grading_policy,
+            enable_ccx=enable_ccx,
         )
         self.populate_course(size)
 
@@ -117,11 +119,11 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
             student_id=self.student.id
         )
 
-    def instrument_course_progress_render(self, dataset_index, queries, reads, xblocks):
+    def instrument_course_progress_render(self, course_width, enable_ccx, queries, reads, xblocks):
         """
         Renders the progress page, instrumenting Mongo reads and SQL queries.
         """
-        self.setup_course(dataset_index + 1)
+        self.setup_course(course_width, enable_ccx)
 
         # Switch to published-only mode to simulate the LMS
         with self.settings(MODULESTORE_BRANCH='published-only'):
@@ -135,17 +137,21 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
             # We clear the request cache to simulate a new request in the LMS.
             RequestCache.clear_request_cache()
 
+            # Reset the list of provider classes, so that our django settings changes
+            # can actually take affect.
+            OverrideFieldData.provider_classes = None
+
             with self.assertNumQueries(queries):
                 with check_mongo_calls(reads):
                     with check_sum_of_calls(XBlock, ['__init__'], xblocks):
                         self.grade_course(self.course)
 
-    @ddt.data(*itertools.product(('no_overrides', 'ccx'), range(3)))
+    @ddt.data(*itertools.product(('no_overrides', 'ccx'), range(1, 4), (True, False)))
     @ddt.unpack
     @override_settings(
         FIELD_OVERRIDE_PROVIDERS=(),
     )
-    def test_field_overrides(self, overrides, dataset_index):
+    def test_field_overrides(self, overrides, course_width, enable_ccx):
         """
         Test without any field overrides.
         """
@@ -154,8 +160,8 @@ class FieldOverridePerformanceTestCase(ProceduralCourseTestMixin,
             'ccx': ('ccx.overrides.CustomCoursesForEdxOverrideProvider',)
         }
         with self.settings(FIELD_OVERRIDE_PROVIDERS=providers[overrides]):
-            queries, reads, xblocks = self.TEST_DATA[overrides][dataset_index]
-            self.instrument_course_progress_render(dataset_index, queries, reads, xblocks)
+            queries, reads, xblocks = self.TEST_DATA[(overrides, course_width, enable_ccx)]
+            self.instrument_course_progress_render(course_width, enable_ccx, queries, reads, xblocks)
 
 
 class TestFieldOverrideMongoPerformance(FieldOverridePerformanceTestCase):
@@ -166,12 +172,19 @@ class TestFieldOverrideMongoPerformance(FieldOverridePerformanceTestCase):
     __test__ = True
 
     TEST_DATA = {
-        'no_overrides': [
-            (27, 7, 19), (135, 7, 131), (595, 7, 537)
-        ],
-        'ccx': [
-            (27, 7, 47), (135, 7, 455), (595, 7, 2037)
-        ],
+        # (providers, course_width, enable_ccx): # of sql queries, # of mongo queries, # of xblocks
+        ('no_overrides', 1, True): (27, 7, 19),
+        ('no_overrides', 2, True): (135, 7, 131),
+        ('no_overrides', 3, True): (595, 7, 537),
+        ('ccx', 1, True): (27, 7, 47),
+        ('ccx', 2, True): (135, 7, 455),
+        ('ccx', 3, True): (595, 7, 2037),
+        ('no_overrides', 1, False): (27, 7, 19),
+        ('no_overrides', 2, False): (135, 7, 131),
+        ('no_overrides', 3, False): (595, 7, 537),
+        ('ccx', 1, False): (27, 7, 19),
+        ('ccx', 2, False): (135, 7, 131),
+        ('ccx', 3, False): (595, 7, 537),
     }
 
 
@@ -183,10 +196,16 @@ class TestFieldOverrideSplitPerformance(FieldOverridePerformanceTestCase):
     __test__ = True
 
     TEST_DATA = {
-        'no_overrides': [
-            (27, 4, 9), (135, 19, 54), (595, 84, 215)
-        ],
-        'ccx': [
-            (27, 4, 9), (135, 19, 54), (595, 84, 215)
-        ]
+        ('no_overrides', 1, True): (27, 4, 9),
+        ('no_overrides', 2, True): (135, 19, 54),
+        ('no_overrides', 3, True): (595, 84, 215),
+        ('ccx', 1, True): (27, 4, 9),
+        ('ccx', 2, True): (135, 19, 54),
+        ('ccx', 3, True): (595, 84, 215),
+        ('no_overrides', 1, False): (27, 4, 9),
+        ('no_overrides', 2, False): (135, 19, 54),
+        ('no_overrides', 3, False): (595, 84, 215),
+        ('ccx', 1, False): (27, 4, 9),
+        ('ccx', 2, False): (135, 19, 54),
+        ('ccx', 3, False): (595, 84, 215),
     }

lms/djangoapps/ccx/tests/test_overrides.py

@@ -36,6 +36,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         """
         super(TestFieldOverrides, self).setUp()
         self.course = course = CourseFactory.create()
+        self.course.enable_ccx = True
 
         # Create a course outline
         self.mooc_start = start = datetime.datetime(
@@ -71,7 +72,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         OverrideFieldData.provider_classes = None
         for block in iter_blocks(ccx.course):
             block._field_data = OverrideFieldData.wrap(   # pylint: disable=protected-access
-                AdminFactory.create(), block._field_data)   # pylint: disable=protected-access
+                AdminFactory.create(), course, block._field_data)   # pylint: disable=protected-access
 
         def cleanup_provider_classes():
             """

lms/djangoapps/ccx/tests/test_views.py

@@ -466,7 +466,11 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
         Set up tests
         """
         super(TestCCXGrades, self).setUp()
-        course = CourseFactory.create()
+        self.course = course = CourseFactory.create(enable_ccx=True)
+
+        # Create instructor account
+        self.coach = coach = AdminFactory.create()
+        self.client.login(username=coach.username, password="test")
 
         # Create a course outline
         self.mooc_start = start = datetime.datetime(
@@ -491,9 +495,6 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
             ] for section in sections
         ]
 
-        # Create instructor account
-        self.coach = coach = AdminFactory.create()
-
         # Create CCX
         role = CourseCcxCoachRole(course.id)
         role.add_users(coach)
@@ -505,7 +506,7 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
         OverrideFieldData.provider_classes = None
         # pylint: disable=protected-access
         for block in iter_blocks(course):
-            block._field_data = OverrideFieldData.wrap(coach, block._field_data)
+            block._field_data = OverrideFieldData.wrap(coach, course, block._field_data)
             new_cache = {'tabs': [], 'discussion_topics': []}
             if 'grading_policy' in block._field_data_cache:
                 new_cache['grading_policy'] = block._field_data_cache['grading_policy']
@@ -559,6 +560,7 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
 
     @patch('ccx.views.render_to_response', intercept_renderer)
     def test_gradebook(self):
+        self.course.enable_ccx = True
         url = reverse(
             'ccx_gradebook',
             kwargs={'course_id': self.ccx_key}
@@ -574,6 +576,7 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
             len(student_info['grade_summary']['section_breakdown']), 4)
 
     def test_grades_csv(self):
+        self.course.enable_ccx = True
         url = reverse(
             'ccx_grades_csv',
             kwargs={'course_id': self.ccx_key}
@@ -593,6 +596,7 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
 
     @patch('courseware.views.render_to_response', intercept_renderer)
     def test_student_progress(self):
+        self.course.enable_ccx = True
         patch_context = patch('courseware.views.get_course_with_access')
         get_course = patch_context.start()
         get_course.return_value = self.course

lms/djangoapps/ccx/views.py

@@ -477,7 +477,8 @@ def prep_course_for_grading(course, request):
     field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
         course.id, request.user, course, depth=2)
     course = get_module_for_descriptor(
-        request.user, request, course, field_data_cache, course.id)
+        request.user, request, course, field_data_cache, course.id, course=course
+    )
 
     course._field_data_cache = {}  # pylint: disable=protected-access
     course.set_grading_policy(course.grading_policy)

lms/djangoapps/course_structure_api/v0/views.py

@@ -555,7 +555,8 @@ class CourseBlocksAndNavigation(ListAPIView):
             request_info.request,
             block_info.block,
             request_info.field_data_cache,
-            request_info.course.id
+            request_info.course.id,
+            course=request_info.course
         )
 
         # verify the user has access to this block

lms/djangoapps/courseware/courses.py

@@ -203,7 +203,8 @@ def get_course_about_section(course, section_key):
                 field_data_cache,
                 log_if_not_found=False,
                 wrap_xmodule_display=False,
-                static_asset_path=course.static_asset_path
+                static_asset_path=course.static_asset_path,
+                course=course
             )
 
             html = ''
@@ -256,7 +257,8 @@ def get_course_info_section_module(request, course, section_key):
         field_data_cache,
         log_if_not_found=False,
         wrap_xmodule_display=False,
-        static_asset_path=course.static_asset_path
+        static_asset_path=course.static_asset_path,
+        course=course
     )
 
 

lms/djangoapps/courseware/entrance_exams.py

@@ -144,7 +144,8 @@ def get_entrance_exam_score(request, course):
             request,
             descriptor,
             field_data_cache,
-            course.id
+            course.id,
+            course=course
         )
 
     exam_module_generators = yield_dynamic_descriptor_descendants(

lms/djangoapps/courseware/field_overrides.py

@@ -19,11 +19,12 @@ import threading
 from abc import ABCMeta, abstractmethod
 from contextlib import contextmanager
 from django.conf import settings
+from request_cache.middleware import RequestCache
 from xblock.field_data import FieldData
 from xmodule.modulestore.inheritance import InheritanceMixin
 
-
 NOTSET = object()
+ENABLED_OVERRIDE_PROVIDERS_KEY = "courseware.field_overrides.enabled_providers"
 
 
 def resolve_dotted(name):
@@ -61,7 +62,7 @@ class OverrideFieldData(FieldData):
     provider_classes = None
 
     @classmethod
-    def wrap(cls, user, wrapped):
+    def wrap(cls, user, course, wrapped):
         """
         Will return a :class:`OverrideFieldData` which wraps the field data
         given in `wrapped` for the given `user`, if override providers are
@@ -75,14 +76,42 @@ class OverrideFieldData(FieldData):
                 (resolve_dotted(name) for name in
                  settings.FIELD_OVERRIDE_PROVIDERS))
 
-        if cls.provider_classes:
-            return cls(user, wrapped)
+        enabled_providers = cls._providers_for_course(course)
+
+        if enabled_providers:
+            # TODO: we might not actually want to return here.  Might be better
+            # to check for instance.providers after the instance is built. This
+            # would allow for the case where we have registered providers but
+            # none are enabled for the provided course
+            return cls(user, wrapped, enabled_providers)
 
         return wrapped
 
-    def __init__(self, user, fallback):
+    @classmethod
+    def _providers_for_course(cls, course):
+        """
+        Return a filtered list of enabled providers based
+        on the course passed in. Cache this result per request to avoid
+        needing to call the provider filter api hundreds of times.
+
+        Arguments:
+            course: The course XBlock
+        """
+        request_cache = RequestCache.get_request_cache()
+        enabled_providers = request_cache.data.get(
+            ENABLED_OVERRIDE_PROVIDERS_KEY, NOTSET
+        )
+        if enabled_providers == NOTSET:
+            enabled_providers = tuple(
+                (provider_class for provider_class in cls.provider_classes if provider_class.enabled_for(course))
+            )
+            request_cache.data[ENABLED_OVERRIDE_PROVIDERS_KEY] = enabled_providers
+
+        return enabled_providers
+
+    def __init__(self, user, fallback, providers):
         self.fallback = fallback
-        self.providers = tuple((cls(user) for cls in self.provider_classes))
+        self.providers = tuple(provider(user) for provider in providers)
 
     def get_override(self, block, name):
         """
@@ -109,6 +138,9 @@ class OverrideFieldData(FieldData):
         self.fallback.delete(block, name)
 
     def has(self, block, name):
+        if not self.providers:
+            return self.fallback.has(block, name)
+
         has = self.get_override(block, name)
         if has is NOTSET:
             # If this is an inheritable field and an override is set above,
@@ -128,7 +160,7 @@ class OverrideFieldData(FieldData):
     def default(self, block, name):
         # The `default` method is overloaded by the field storage system to
         # also handle inheritance.
-        if not overrides_disabled():
+        if self.providers and not overrides_disabled():
             inheritable = InheritanceMixin.fields.keys()
             if name in inheritable:
                 for ancestor in _lineage(block):
@@ -192,6 +224,17 @@ class FieldOverrideProvider(object):
         """
         raise NotImplementedError
 
+    @abstractmethod
+    def enabled_for(self, course):  # pragma no cover
+        """
+        Return True if this provider should be enabled for a given course
+
+        Return False otherwise
+
+        Concrete implementations are responsible for implementing this method
+        """
+        return False
+
 
 def _lineage(block):
     """

lms/djangoapps/courseware/grades.py

@@ -207,7 +207,9 @@ def _grade(student, request, course, keep_raw_scores):
                     # would be simpler
                     with manual_transaction():
                         field_data_cache = FieldDataCache([descriptor], course.id, student)
-                    return get_module_for_descriptor(student, request, descriptor, field_data_cache, course.id)
+                    return get_module_for_descriptor(
+                        student, request, descriptor, field_data_cache, course.id, course=course
+                    )
 
                 for module_descriptor in yield_dynamic_descriptor_descendants(
                         section_descriptor, student.id, create_module
@@ -337,7 +339,9 @@ def _progress_summary(student, request, course):
         )
         # TODO: We need the request to pass into here. If we could
         # forego that, our arguments would be simpler
-        course_module = get_module_for_descriptor(student, request, course, field_data_cache, course.id)
+        course_module = get_module_for_descriptor(
+            student, request, course, field_data_cache, course.id, course=course
+        )
         if not course_module:
             # This student must not have access to the course.
             return None

lms/djangoapps/courseware/module_render.py

@@ -138,7 +138,9 @@ def toc_for_course(request, course, active_chapter, active_section, field_data_c
     '''
 
     with modulestore().bulk_operations(course.id):
-        course_module = get_module_for_descriptor(request.user, request, course, field_data_cache, course.id)
+        course_module = get_module_for_descriptor(
+            request.user, request, course, field_data_cache, course.id, course=course
+        )
         if course_module is None:
             return None
 
@@ -190,7 +192,7 @@ def toc_for_course(request, course, active_chapter, active_section, field_data_c
 def get_module(user, request, usage_key, field_data_cache,
                position=None, log_if_not_found=True, wrap_xmodule_display=True,
                grade_bucket_type=None, depth=0,
-               static_asset_path=''):
+               static_asset_path='', course=None):
     """
     Get an instance of the xmodule class identified by location,
     setting the state based on an existing StudentModule, or creating one if none
@@ -224,7 +226,8 @@ def get_module(user, request, usage_key, field_data_cache,
                                          position=position,
                                          wrap_xmodule_display=wrap_xmodule_display,
                                          grade_bucket_type=grade_bucket_type,
-                                         static_asset_path=static_asset_path)
+                                         static_asset_path=static_asset_path,
+                                         course=course)
     except ItemNotFoundError:
         if log_if_not_found:
             log.debug("Error in get_module: ItemNotFoundError")
@@ -253,7 +256,8 @@ def get_xqueue_callback_url_prefix(request):
 
 def get_module_for_descriptor(user, request, descriptor, field_data_cache, course_key,
                               position=None, wrap_xmodule_display=True, grade_bucket_type=None,
-                              static_asset_path='', disable_staff_debug_info=False):
+                              static_asset_path='', disable_staff_debug_info=False,
+                              course=None):
     """
     Implements get_module, extracting out the request-specific functionality.
 
@@ -280,6 +284,7 @@ def get_module_for_descriptor(user, request, descriptor, field_data_cache, cours
         user_location=user_location,
         request_token=xblock_request_token(request),
         disable_staff_debug_info=disable_staff_debug_info,
+        course=course
     )
 
 
@@ -287,7 +292,8 @@ def get_module_system_for_user(user, field_data_cache,  # TODO  # pylint: disabl
                                # Arguments preceding this comment have user binding, those following don't
                                descriptor, course_id, track_function, xqueue_callback_url_prefix,
                                request_token, position=None, wrap_xmodule_display=True, grade_bucket_type=None,
-                               static_asset_path='', user_location=None, disable_staff_debug_info=False):
+                               static_asset_path='', user_location=None, disable_staff_debug_info=False,
+                               course=None):
     """
     Helper function that returns a module system and student_data bound to a user and a descriptor.
 
@@ -382,6 +388,7 @@ def get_module_system_for_user(user, field_data_cache,  # TODO  # pylint: disabl
             static_asset_path=static_asset_path,
             user_location=user_location,
             request_token=request_token,
+            course=course
         )
 
     def _fulfill_content_milestones(user, course_key, content_key):
@@ -508,14 +515,15 @@ def get_module_system_for_user(user, field_data_cache,  # TODO  # pylint: disabl
             grade_bucket_type=grade_bucket_type,
             static_asset_path=static_asset_path,
             user_location=user_location,
-            request_token=request_token
+            request_token=request_token,
+            course=course
         )
 
         module.descriptor.bind_for_student(
             inner_system,
             real_user.id,
             [
-                partial(OverrideFieldData.wrap, real_user),
+                partial(OverrideFieldData.wrap, real_user, course),
                 partial(LmsFieldData, student_data=inner_student_data),
             ],
         )
@@ -681,10 +689,13 @@ def get_module_system_for_user(user, field_data_cache,  # TODO  # pylint: disabl
     return system, field_data
 
 
+# TODO: Find all the places that this method is called and figure out how to
+# get a loaded course passed into it
 def get_module_for_descriptor_internal(user, descriptor, field_data_cache, course_id,  # pylint: disable=invalid-name
                                        track_function, xqueue_callback_url_prefix, request_token,
                                        position=None, wrap_xmodule_display=True, grade_bucket_type=None,
-                                       static_asset_path='', user_location=None, disable_staff_debug_info=False):
+                                       static_asset_path='', user_location=None, disable_staff_debug_info=False,
+                                       course=None):
     """
     Actually implement get_module, without requiring a request.
 
@@ -708,13 +719,14 @@ def get_module_for_descriptor_internal(user, descriptor, field_data_cache, cours
         user_location=user_location,
         request_token=request_token,
         disable_staff_debug_info=disable_staff_debug_info,
+        course=course
     )
 
     descriptor.bind_for_student(
         system,
         user.id,
         [
-            partial(OverrideFieldData.wrap, user),
+            partial(OverrideFieldData.wrap, user, course),
             partial(LmsFieldData, student_data=student_data),
         ],
     )
@@ -732,7 +744,7 @@ def get_module_for_descriptor_internal(user, descriptor, field_data_cache, cours
     return descriptor
 
 
-def load_single_xblock(request, user_id, course_id, usage_key_string):
+def load_single_xblock(request, user_id, course_id, usage_key_string, course=None):
     """
     Load a single XBlock identified by usage_key_string.
     """
@@ -746,7 +758,7 @@ def load_single_xblock(request, user_id, course_id, usage_key_string):
         modulestore().get_item(usage_key),
         depth=0,
     )
-    instance = get_module(user, request, usage_key, field_data_cache, grade_bucket_type='xqueue')
+    instance = get_module(user, request, usage_key, field_data_cache, grade_bucket_type='xqueue', course=course)
     if instance is None:
         msg = "No module {0} for user {1}--access denied?".format(usage_key_string, user)
         log.debug(msg)
@@ -772,24 +784,29 @@ def xqueue_callback(request, course_id, userid, mod_id, dispatch):
     if not isinstance(header, dict) or 'lms_key' not in header:
         raise Http404
 
-    instance = load_single_xblock(request, userid, course_id, mod_id)
+    course_key = CourseKey.from_string(course_id)
+
+    with modulestore().bulk_operations(course_key):
+        course = modulestore().get_course(course_key, depth=0)
 
-    # Transfer 'queuekey' from xqueue response header to the data.
-    # This is required to use the interface defined by 'handle_ajax'
-    data.update({'queuekey': header['lms_key']})
+        instance = load_single_xblock(request, userid, course_id, mod_id, course=course)
 
-    # We go through the "AJAX" path
-    # So far, the only dispatch from xqueue will be 'score_update'
-    try:
-        # Can ignore the return value--not used for xqueue_callback
-        instance.handle_ajax(dispatch, data)
-        # Save any state that has changed to the underlying KeyValueStore
-        instance.save()
-    except:
-        log.exception("error processing ajax call")
-        raise
+        # Transfer 'queuekey' from xqueue response header to the data.
+        # This is required to use the interface defined by 'handle_ajax'
+        data.update({'queuekey': header['lms_key']})
+
+        # We go through the "AJAX" path
+        # So far, the only dispatch from xqueue will be 'score_update'
+        try:
+            # Can ignore the return value--not used for xqueue_callback
+            instance.handle_ajax(dispatch, data)
+            # Save any state that has changed to the underlying KeyValueStore
+            instance.save()
+        except:
+            log.exception("error processing ajax call")
+            raise
 
-    return HttpResponse("")
+        return HttpResponse("")
 
 
 @csrf_exempt
@@ -799,7 +816,10 @@ def handle_xblock_callback_noauth(request, course_id, usage_id, handler, suffix=
     """
     request.user.known = False
 
-    return _invoke_xblock_handler(request, course_id, usage_id, handler, suffix)
+    course_key = CourseKey.from_string(course_id)
+    with modulestore().bulk_operations(course_key):
+        course = modulestore().get_course(course_key, depth=0)
+        return _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, course=course)
 
 
 def handle_xblock_callback(request, course_id, usage_id, handler, suffix=None):
@@ -820,7 +840,18 @@ def handle_xblock_callback(request, course_id, usage_id, handler, suffix=None):
     if not request.user.is_authenticated():
         return HttpResponse('Unauthenticated', status=403)
 
-    return _invoke_xblock_handler(request, course_id, usage_id, handler, suffix)
+    try:
+        course_key = CourseKey.from_string(course_id)
+    except InvalidKeyError:
+        raise Http404("Invalid location")
+
+    with modulestore().bulk_operations(course_key):
+        try:
+            course = modulestore().get_course(course_key)
+        except ItemNotFoundError:
+            raise Http404("invalid location")
+
+        return _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, course=course)
 
 
 def xblock_resource(request, block_type, uri):  # pylint: disable=unused-argument
@@ -840,7 +871,7 @@ def xblock_resource(request, block_type, uri):  # pylint: disable=unused-argumen
     return HttpResponse(content, mimetype=mimetype)
 
 
-def get_module_by_usage_id(request, course_id, usage_id, disable_staff_debug_info=False):
+def get_module_by_usage_id(request, course_id, usage_id, disable_staff_debug_info=False, course=None):
     """
     Gets a module instance based on its `usage_id` in a course, for a given request/user
 
@@ -890,7 +921,8 @@ def get_module_by_usage_id(request, course_id, usage_id, disable_staff_debug_inf
         descriptor,
         field_data_cache,
         usage_key.course_key,
-        disable_staff_debug_info=disable_staff_debug_info
+        disable_staff_debug_info=disable_staff_debug_info,
+        course=course
     )
     if instance is None:
         # Either permissions just changed, or someone is trying to be clever
@@ -901,7 +933,7 @@ def get_module_by_usage_id(request, course_id, usage_id, disable_staff_debug_inf
     return (instance, tracking_context)
 
 
-def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix):
+def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, course=None):
     """
     Invoke an XBlock handler, either authenticated or not.
 
@@ -926,7 +958,7 @@ def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix):
         raise Http404
 
     with modulestore().bulk_operations(course_key):
-        instance, tracking_context = get_module_by_usage_id(request, course_id, usage_id)
+        instance, tracking_context = get_module_by_usage_id(request, course_id, usage_id, course=course)
 
         # Name the transaction so that we can view XBlock handlers separately in
         # New Relic. The suffix is necessary for XModule handlers because the
@@ -991,23 +1023,30 @@ def xblock_view(request, course_id, usage_id, view_name):
     if not request.user.is_authenticated():
         raise PermissionDenied
 
-    instance, _ = get_module_by_usage_id(request, course_id, usage_id)
-
     try:
-        fragment = instance.render(view_name, context=request.GET)
-    except NoSuchViewError:
-        log.exception("Attempt to render missing view on %s: %s", instance, view_name)
-        raise Http404
+        course_key = SlashSeparatedCourseKey.from_deprecated_string(course_id)
+    except InvalidKeyError:
+        raise Http404("Invalid location")
+
+    with modulestore().bulk_operations(course_key):
+        course = modulestore().get_course(course_key)
+        instance, _ = get_module_by_usage_id(request, course_id, usage_id, course=course)
+
+        try:
+            fragment = instance.render(view_name, context=request.GET)
+        except NoSuchViewError:
+            log.exception("Attempt to render missing view on %s: %s", instance, view_name)
+            raise Http404
 
-    hashed_resources = OrderedDict()
-    for resource in fragment.resources:
-        hashed_resources[hash_resource(resource)] = resource
+        hashed_resources = OrderedDict()
+        for resource in fragment.resources:
+            hashed_resources[hash_resource(resource)] = resource
 
-    return JsonResponse({
-        'html': fragment.content,
-        'resources': hashed_resources.items(),
-        'csrf_token': unicode(csrf(request)['csrf_token']),
-    })
+        return JsonResponse({
+            'html': fragment.content,
+            'resources': hashed_resources.items(),
+            'csrf_token': unicode(csrf(request)['csrf_token']),
+        })
 
 
 def get_score_bucket(grade, max_grade):

lms/djangoapps/courseware/student_field_overrides.py

@@ -17,6 +17,11 @@ class IndividualStudentOverrideProvider(FieldOverrideProvider):
     def get(self, block, name, default):
         return get_override_for_user(self.user, block, name, default)
 
+    @classmethod
+    def enabled_for(cls, course):
+        """This simple override provider is always enabled"""
+        return True
+
 
 def get_override_for_user(user, block, name, default=None):
     """

lms/djangoapps/courseware/tests/test_courses.py

@@ -262,7 +262,8 @@ class CourseInstantiationTests(ModuleStoreTestCase):
                 fake_request,
                 course,
                 field_data_cache,
-                course.id
+                course.id,
+                course=course
             )
             for chapter in course_module.get_children():
                 for section in chapter.get_children():

lms/djangoapps/courseware/tests/test_field_overrides.py

@@ -4,9 +4,12 @@ Tests for `field_overrides` module.
 import unittest
 from nose.plugins.attrib import attr
 
-from django.test import TestCase
 from django.test.utils import override_settings
 from xblock.field_data import DictFieldData
+from xmodule.modulestore.tests.factories import CourseFactory
+from xmodule.modulestore.tests.django_utils import (
+    ModuleStoreTestCase,
+)
 
 from ..field_overrides import (
     disable_overrides,
@@ -22,13 +25,14 @@ TESTUSER = "testuser"
 @attr('shard_1')
 @override_settings(FIELD_OVERRIDE_PROVIDERS=(
     'courseware.tests.test_field_overrides.TestOverrideProvider',))
-class OverrideFieldDataTests(TestCase):
+class OverrideFieldDataTests(ModuleStoreTestCase):
     """
     Tests for `OverrideFieldData`.
     """
 
     def setUp(self):
         super(OverrideFieldDataTests, self).setUp()
+        self.course = CourseFactory.create(enable_ccx=True)
         OverrideFieldData.provider_classes = None
 
     def tearDown(self):
@@ -39,7 +43,7 @@ class OverrideFieldDataTests(TestCase):
         """
         Factory method.
         """
-        return OverrideFieldData.wrap(TESTUSER, DictFieldData({
+        return OverrideFieldData.wrap(TESTUSER, self.course, DictFieldData({
             'foo': 'bar',
             'bees': 'knees',
         }))
@@ -124,3 +128,7 @@ class TestOverrideProvider(FieldOverrideProvider):
         if name == 'oh':
             return 'man'
         return default
+
+    @classmethod
+    def enabled_for(cls, course):
+        return True

lms/djangoapps/courseware/tests/test_module_render.py

@@ -184,7 +184,13 @@ class ModuleRenderTestCase(ModuleStoreTestCase, LoginEnrollmentTestCase):
         with patch('courseware.module_render.load_single_xblock', return_value=self.mock_module):
             # call xqueue_callback with our mocked information
             request = self.request_factory.post(self.callback_url, data)
-            render.xqueue_callback(request, self.course_key, self.mock_user.id, self.mock_module.id, self.dispatch)
+            render.xqueue_callback(
+                request,
+                unicode(self.course_key),
+                self.mock_user.id,
+                self.mock_module.id,
+                self.dispatch
+            )
 
         # Verify that handle ajax is called with the correct data
         request.POST['queuekey'] = fake_key
@@ -200,12 +206,24 @@ class ModuleRenderTestCase(ModuleStoreTestCase, LoginEnrollmentTestCase):
             # Test with missing xqueue data
             with self.assertRaises(Http404):
                 request = self.request_factory.post(self.callback_url, {})
-                render.xqueue_callback(request, self.course_key, self.mock_user.id, self.mock_module.id, self.dispatch)
+                render.xqueue_callback(
+                    request,
+                    unicode(self.course_key),
+                    self.mock_user.id,
+                    self.mock_module.id,
+                    self.dispatch
+                )
 
             # Test with missing xqueue_header
             with self.assertRaises(Http404):
                 request = self.request_factory.post(self.callback_url, data)
-                render.xqueue_callback(request, self.course_key, self.mock_user.id, self.mock_module.id, self.dispatch)
+                render.xqueue_callback(
+                    request,
+                    unicode(self.course_key),
+                    self.mock_user.id,
+                    self.mock_module.id,
+                    self.dispatch
+                )
 
     def test_get_score_bucket(self):
         self.assertEquals(render.get_score_bucket(0, 10), 'incorrect')
@@ -275,11 +293,28 @@ class ModuleRenderTestCase(ModuleStoreTestCase, LoginEnrollmentTestCase):
         course = CourseFactory()
         descriptor = ItemFactory(category=block_type, parent=course)
         field_data_cache = FieldDataCache([self.toy_course, descriptor], self.toy_course.id, self.mock_user)
-        render.get_module_for_descriptor(self.mock_user, request, descriptor, field_data_cache, self.toy_course.id)
-        render.get_module_for_descriptor(self.mock_user, request, descriptor, field_data_cache, self.toy_course.id)
+        # This is verifying that caching doesn't cause an error during get_module_for_descriptor, which
+        # is why it calls the method twice identically.
+        render.get_module_for_descriptor(
+            self.mock_user,
+            request,
+            descriptor,
+            field_data_cache,
+            self.toy_course.id,
+            course=self.toy_course
+        )
+        render.get_module_for_descriptor(
+            self.mock_user,
+            request,
+            descriptor,
+            field_data_cache,
+            self.toy_course.id,
+            course=self.toy_course
+        )
 
     @override_settings(FIELD_OVERRIDE_PROVIDERS=(
-        'ccx.overrides.CustomCoursesForEdxOverrideProvider',))
+        'ccx.overrides.CustomCoursesForEdxOverrideProvider',
+    ))
     def test_rebind_different_users_ccx(self):
         """
         This tests the rebinding a descriptor to a student does not result
@@ -287,18 +322,18 @@ class ModuleRenderTestCase(ModuleStoreTestCase, LoginEnrollmentTestCase):
         """
         request = self.request_factory.get('')
         request.user = self.mock_user
-        course = CourseFactory()
+        course = CourseFactory.create(enable_ccx=True)
 
         descriptor = ItemFactory(category='html', parent=course)
         field_data_cache = FieldDataCache(
-            [self.toy_course, descriptor], self.toy_course.id, self.mock_user
+            [course, descriptor], course.id, self.mock_user
         )
 
         # grab what _field_data was originally set to
         original_field_data = descriptor._field_data  # pylint: disable=protected-access, no-member
 
         render.get_module_for_descriptor(
-            self.mock_user, request, descriptor, field_data_cache, self.toy_course.id
+            self.mock_user, request, descriptor, field_data_cache, course.id, course=course
         )
 
         # check that _unwrapped_field_data is the same as the original
@@ -314,7 +349,8 @@ class ModuleRenderTestCase(ModuleStoreTestCase, LoginEnrollmentTestCase):
                 request,
                 descriptor,
                 field_data_cache,
-                self.toy_course.id
+                course.id,
+                course=course
             )
 
         # _field_data should now be wrapped by LmsFieldData
@@ -832,6 +868,7 @@ class JsonInitDataTest(ModuleStoreTestCase):
             descriptor,
             field_data_cache,
             course.id,                          # pylint: disable=no-member
+            course=course
         )
         html = module.render(STUDENT_VIEW).content
         self.assertIn(json_output, html)
@@ -1098,6 +1135,8 @@ class TestAnonymousStudentId(ModuleStoreTestCase, LoginEnrollmentTestCase):
     def setUp(self):
         super(TestAnonymousStudentId, self).setUp(create_user=False)
         self.user = UserFactory()
+        self.course_key = self.create_toy_course()
+        self.course = modulestore().get_course(self.course_key)
 
     @patch('courseware.module_render.has_access', Mock(return_value=True))
     def _get_anonymous_id(self, course_id, xblock_class):
@@ -1135,6 +1174,7 @@ class TestAnonymousStudentId(ModuleStoreTestCase, LoginEnrollmentTestCase):
             track_function=Mock(name='track_function'),  # Track Function
             xqueue_callback_url_prefix=Mock(name='xqueue_callback_url_prefix'),  # XQueue Callback Url Prefix
             request_token='request_token',
+            course=self.course,
         ).xmodule_runtime.anonymous_student_id
 
     @ddt.data(*PER_STUDENT_ANONYMIZED_DESCRIPTORS)
@@ -1444,7 +1484,8 @@ class LMSXBlockServiceBindingTest(ModuleStoreTestCase):
             self.course.id,
             self.track_function,
             self.xqueue_callback_url_prefix,
-            self.request_token
+            self.request_token,
+            course=self.course
         )
         service = runtime.service(descriptor, expected_service)
         self.assertIsNotNone(service)
@@ -1462,7 +1503,8 @@ class LMSXBlockServiceBindingTest(ModuleStoreTestCase):
             self.course.id,
             self.track_function,
             self.xqueue_callback_url_prefix,
-            self.request_token
+            self.request_token,
+            course=self.course
         )
 
         self.assertFalse(getattr(runtime, u'user_is_beta_tester'))
@@ -1607,6 +1649,7 @@ class TestFilteredChildren(ModuleStoreTestCase):
             block,
             field_data_cache,
             course_id,
+            course=self.course
         )
 
     def _has_access(self, user, action, obj, course_key=None):

lms/djangoapps/courseware/tests/test_split_module.py

@@ -310,7 +310,8 @@ class SplitTestPosition(ModuleStoreTestCase):
             MagicMock(name='request'),
             self.course,
             mock_field_data_cache,
-            self.course.id
+            self.course.id,
+            course=self.course
         )
 
         # Now that we have the course, change the position and save, nothing should explode!

lms/djangoapps/courseware/views.py

@@ -253,7 +253,7 @@ def save_child_position(seq_module, child_name):
     seq_module.save()
 
 
-def save_positions_recursively_up(user, request, field_data_cache, xmodule):
+def save_positions_recursively_up(user, request, field_data_cache, xmodule, course=None):
     """
     Recurses up the course tree starting from a leaf
     Saving the position property based on the previous node as it goes
@@ -265,7 +265,14 @@ def save_positions_recursively_up(user, request, field_data_cache, xmodule):
         parent = None
         if parent_location:
             parent_descriptor = modulestore().get_item(parent_location)
-            parent = get_module_for_descriptor(user, request, parent_descriptor, field_data_cache, current_module.location.course_key)
+            parent = get_module_for_descriptor(
+                user,
+                request,
+                parent_descriptor,
+                field_data_cache,
+                current_module.location.course_key,
+                course=course
+            )
 
         if parent and hasattr(parent, 'position'):
             save_child_position(parent, current_module.location.name)
@@ -412,7 +419,9 @@ def _index_bulk_op(request, course_key, chapter, section, position):
         field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
             course_key, user, course, depth=2)
 
-        course_module = get_module_for_descriptor(user, request, course, field_data_cache, course_key)
+        course_module = get_module_for_descriptor(
+            user, request, course, field_data_cache, course_key, course=course
+        )
         if course_module is None:
             log.warning(u'If you see this, something went wrong: if we got this'
                         u' far, should have gotten a course module for this user')
@@ -532,7 +541,8 @@ def _index_bulk_op(request, course_key, chapter, section, position):
                 section_descriptor,
                 field_data_cache,
                 course_key,
-                position
+                position,
+                course=course
             )
 
             if section_module is None:
@@ -1180,7 +1190,7 @@ def get_static_tab_contents(request, course, tab):
         course.id, request.user, modulestore().get_item(loc), depth=0
     )
     tab_module = get_module(
-        request.user, request, loc, field_data_cache, static_asset_path=course.static_asset_path
+        request.user, request, loc, field_data_cache, static_asset_path=course.static_asset_path, course=course
     )
 
     logging.debug('course_module = {0}'.format(tab_module))
@@ -1238,7 +1248,8 @@ def get_course_lti_endpoints(request, course_id):
                 anonymous_user,
                 descriptor
             ),
-            course_key
+            course_key,
+            course=course
         )
         for descriptor in lti_descriptors
     ]
@@ -1411,7 +1422,7 @@ def render_xblock(request, usage_key_string, check_if_enrolled=True):
 
         # get the block, which verifies whether the user has access to the block.
         block, _ = get_module_by_usage_id(
-            request, unicode(course_key), unicode(usage_key), disable_staff_debug_info=True
+            request, unicode(course_key), unicode(usage_key), disable_staff_debug_info=True, course=course
         )
 
         context = {

lms/djangoapps/edxnotes/tests.py

@@ -831,7 +831,9 @@ class EdxNotesViewsTest(ModuleStoreTestCase):
         Returns the course module.
         """
         field_data_cache = FieldDataCache([self.course], self.course.id, self.user)
-        return get_module_for_descriptor(self.user, MagicMock(), self.course, field_data_cache, self.course.id)
+        return get_module_for_descriptor(
+            self.user, MagicMock(), self.course, field_data_cache, self.course.id, course=self.course
+        )
 
     def test_edxnotes_tab(self):
         """

lms/djangoapps/edxnotes/views.py

@@ -53,7 +53,9 @@ def edxnotes(request, course_id):
         field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
             course.id, request.user, course, depth=2
         )
-        course_module = get_module_for_descriptor(request.user, request, course, field_data_cache, course_key)
+        course_module = get_module_for_descriptor(
+            request.user, request, course, field_data_cache, course_key, course=course
+        )
         position = get_course_position(course_module)
         if position:
             context.update({
@@ -103,7 +105,9 @@ def edxnotes_visibility(request, course_id):
     course_key = CourseKey.from_string(course_id)
     course = get_course_with_access(request.user, "load", course_key)
     field_data_cache = FieldDataCache([course], course_key, request.user)
-    course_module = get_module_for_descriptor(request.user, request, course, field_data_cache, course_key)
+    course_module = get_module_for_descriptor(
+        request.user, request, course, field_data_cache, course_key, course=course
+    )
 
     if not is_feature_enabled(course):
         raise Http404

lms/djangoapps/instructor/hint_manager.py

@@ -31,7 +31,7 @@ def hint_manager(request, course_id):
     """
     course_key = SlashSeparatedCourseKey.from_deprecated_string(course_id)
     try:
-        get_course_with_access(request.user, 'staff', course_key, depth=None)
+        course = get_course_with_access(request.user, 'staff', course_key, depth=None)
     except Http404:
         out = 'Sorry, but students are not allowed to access the hint manager!'
         return HttpResponse(out)
@@ -57,13 +57,13 @@ def hint_manager(request, course_id):
     error_text = switch_dict[request.POST['op']](request, course_key, field)
     if error_text is None:
         error_text = ''
-    render_dict = get_hints(request, course_key, field)
+    render_dict = get_hints(request, course_key, field, course=course)
     render_dict.update({'error': error_text})
     rendered_html = render_to_string('instructor/hint_manager_inner.html', render_dict)
     return HttpResponse(json.dumps({'success': True, 'contents': rendered_html}))
 
 
-def get_hints(request, course_id, field):
+def get_hints(request, course_id, field, course=None):  # pylint: disable=unused-argument
     """
     Load all of the hints submitted to the course.
 
@@ -148,7 +148,7 @@ def location_to_problem_name(course_id, loc):
         return None
 
 
-def delete_hints(request, course_id, field):
+def delete_hints(request, course_id, field, course=None):  # pylint: disable=unused-argument
     """
     Deletes the hints specified.
 
@@ -176,7 +176,7 @@ def delete_hints(request, course_id, field):
         this_problem.save()
 
 
-def change_votes(request, course_id, field):
+def change_votes(request, course_id, field, course=None):  # pylint: disable=unused-argument
     """
     Updates the number of votes.
 
@@ -203,7 +203,7 @@ def change_votes(request, course_id, field):
         this_problem.save()
 
 
-def add_hint(request, course_id, field):
+def add_hint(request, course_id, field, course=None):
     """
     Add a new hint.  `request.POST`:
     op
@@ -226,7 +226,14 @@ def add_hint(request, course_id, field):
     except ItemNotFoundError:
         descriptors = []
     field_data_cache = model_data.FieldDataCache(descriptors, course_id, request.user)
-    hinter_module = module_render.get_module(request.user, request, problem_key, field_data_cache, course_id)
+    hinter_module = module_render.get_module(
+        request.user,
+        request,
+        problem_key,
+        field_data_cache,
+        course_id,
+        course=course
+    )
     if not hinter_module.validate_answer(answer):
         # Invalid answer.  Don't add it to the database, or else the
         # hinter will crash when we encounter it.
@@ -247,7 +254,7 @@ def add_hint(request, course_id, field):
     this_problem.save()
 
 
-def approve(request, course_id, field):
+def approve(request, course_id, field, course=None):  # pylint: disable=unused-argument
     """
     Approve a list of hints, moving them from the mod_queue to the real
     hint list.  POST:

lms/djangoapps/instructor/management/commands/openended_post.py

@@ -77,7 +77,7 @@ def post_submission_for_student(student, course, location, task_number, dry_run=
     request.host = hostname
 
     try:
-        module = get_module_for_student(student, location, request=request)
+        module = get_module_for_student(student, location, request=request, course=course)
         if module is None:
             print "  WARNING: No state found."
             return False

lms/djangoapps/instructor/management/commands/openended_stats.py

@@ -89,7 +89,7 @@ def calculate_task_statistics(students, course, location, task_number, write_to_
         student = student_module.student
         print "{0}:{1}".format(student.id, student.username)
 
-        module = get_module_for_student(student, location)
+        module = get_module_for_student(student, location, course=course)
         if module is None:
             print "  WARNING: No state found"
             students_with_no_state.append(student)

lms/djangoapps/instructor/tests/test_tools.py

@@ -227,7 +227,7 @@ class TestSetDueDateExtension(ModuleStoreTestCase):
         # just inject the override field storage in this brute force manner.
         for block in (course, week1, week2, week3, homework, assignment):
             block._field_data = OverrideFieldData.wrap(  # pylint: disable=protected-access
-                user, block._field_data)  # pylint: disable=protected-access
+                user, course, block._field_data)  # pylint: disable=protected-access
 
     def tearDown(self):
         super(TestSetDueDateExtension, self).tearDown()

lms/djangoapps/instructor/utils.py

@@ -27,7 +27,7 @@ class DummyRequest(object):
         return False
 
 
-def get_module_for_student(student, usage_key, request=None):
+def get_module_for_student(student, usage_key, request=None, course=None):
     """Return the module for the (student, location) using a DummyRequest."""
     if request is None:
         request = DummyRequest()
@@ -35,4 +35,4 @@ def get_module_for_student(student, usage_key, request=None):
 
     descriptor = modulestore().get_item(usage_key, depth=0)
     field_data_cache = FieldDataCache([descriptor], usage_key.course_key, student)
-    return get_module(student, request, usage_key, field_data_cache)
+    return get_module(student, request, usage_key, field_data_cache, course=course)

lms/djangoapps/instructor_task/tasks_helper.py

@@ -406,7 +406,7 @@ def _get_track_function_for_task(student, xmodule_instance_args=None, source_pag
 
 
 def _get_module_instance_for_task(course_id, student, module_descriptor, xmodule_instance_args=None,
-                                  grade_bucket_type=None):
+                                  grade_bucket_type=None, course=None):
     """
     Fetches a StudentModule instance for a given `course_id`, `student` object, and `module_descriptor`.
 
@@ -445,6 +445,8 @@ def _get_module_instance_for_task(course_id, student, module_descriptor, xmodule
         grade_bucket_type=grade_bucket_type,
         # This module isn't being used for front-end rendering
         request_token=None,
+        # pass in a loaded course for override enabling
+        course=course
     )
 
 
@@ -465,37 +467,76 @@ def rescore_problem_module_state(xmodule_instance_args, module_descriptor, stude
     course_id = student_module.course_id
     student = student_module.student
     usage_key = student_module.module_state_key
-    instance = _get_module_instance_for_task(course_id, student, module_descriptor, xmodule_instance_args, grade_bucket_type='rescore')
-
-    if instance is None:
-        # Either permissions just changed, or someone is trying to be clever
-        # and load something they shouldn't have access to.
-        msg = "No module {loc} for student {student}--access denied?".format(loc=usage_key,
-                                                                             student=student)
-        TASK_LOG.debug(msg)
-        raise UpdateProblemModuleStateError(msg)
-
-    if not hasattr(instance, 'rescore_problem'):
-        # This should also not happen, since it should be already checked in the caller,
-        # but check here to be sure.
-        msg = "Specified problem does not support rescoring."
-        raise UpdateProblemModuleStateError(msg)
-
-    result = instance.rescore_problem()
-    instance.save()
-    if 'success' not in result:
-        # don't consider these fatal, but false means that the individual call didn't complete:
-        TASK_LOG.warning(u"error processing rescore call for course {course}, problem {loc} and student {student}: "
-                         u"unexpected response {msg}".format(msg=result, course=course_id, loc=usage_key, student=student))
-        return UPDATE_STATUS_FAILED
-    elif result['success'] not in ['correct', 'incorrect']:
-        TASK_LOG.warning(u"error processing rescore call for course {course}, problem {loc} and student {student}: "
-                         u"{msg}".format(msg=result['success'], course=course_id, loc=usage_key, student=student))
-        return UPDATE_STATUS_FAILED
-    else:
-        TASK_LOG.debug(u"successfully processed rescore call for course {course}, problem {loc} and student {student}: "
-                       u"{msg}".format(msg=result['success'], course=course_id, loc=usage_key, student=student))
-        return UPDATE_STATUS_SUCCEEDED
+
+    with modulestore().bulk_operations(course_id):
+        course = get_course_by_id(course_id)
+        # TODO: Here is a call site where we could pass in a loaded course.  I
+        # think we certainly need it since grading is happening here, and field
+        # overrides would be important in handling that correctly
+        instance = _get_module_instance_for_task(
+            course_id,
+            student,
+            module_descriptor,
+            xmodule_instance_args,
+            grade_bucket_type='rescore',
+            course=course
+        )
+
+        if instance is None:
+            # Either permissions just changed, or someone is trying to be clever
+            # and load something they shouldn't have access to.
+            msg = "No module {loc} for student {student}--access denied?".format(
+                loc=usage_key,
+                student=student
+            )
+            TASK_LOG.debug(msg)
+            raise UpdateProblemModuleStateError(msg)
+
+        if not hasattr(instance, 'rescore_problem'):
+            # This should also not happen, since it should be already checked in the caller,
+            # but check here to be sure.
+            msg = "Specified problem does not support rescoring."
+            raise UpdateProblemModuleStateError(msg)
+
+        result = instance.rescore_problem()
+        instance.save()
+        if 'success' not in result:
+            # don't consider these fatal, but false means that the individual call didn't complete:
+            TASK_LOG.warning(
+                u"error processing rescore call for course %(course)s, problem %(loc)s "
+                u"and student %(student)s: unexpected response %(msg)s",
+                dict(
+                    msg=result,
+                    course=course_id,
+                    loc=usage_key,
+                    student=student
+                )
+            )
+            return UPDATE_STATUS_FAILED
+        elif result['success'] not in ['correct', 'incorrect']:
+            TASK_LOG.warning(
+                u"error processing rescore call for course %(course)s, problem %(loc)s "
+                u"and student %(student)s: %(msg)s",
+                dict(
+                    msg=result['success'],
+                    course=course_id,
+                    loc=usage_key,
+                    student=student
+                )
+            )
+            return UPDATE_STATUS_FAILED
+        else:
+            TASK_LOG.debug(
+                u"successfully processed rescore call for course %(course)s, problem %(loc)s "
+                u"and student %(student)s: %(msg)s",
+                dict(
+                    msg=result['success'],
+                    course=course_id,
+                    loc=usage_key,
+                    student=student
+                )
+            )
+            return UPDATE_STATUS_SUCCEEDED
 
 
 @transaction.autocommit

lms/djangoapps/mobile_api/users/views.py

@@ -106,7 +106,9 @@ class UserCourseStatus(views.APIView):
         field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
             course.id, request.user, course, depth=2)
 
-        course_module = get_module_for_descriptor(request.user, request, course, field_data_cache, course.id)
+        course_module = get_module_for_descriptor(
+            request.user, request, course, field_data_cache, course.id, course=course
+        )
 
         path = [course_module]
         chapter = get_current_child(course_module, min_depth=2)
@@ -140,7 +142,9 @@ class UserCourseStatus(views.APIView):
             module_descriptor = modulestore().get_item(module_key)
         except ItemNotFoundError:
             return Response(errors.ERROR_INVALID_MODULE_ID, status=400)
-        module = get_module_for_descriptor(request.user, request, module_descriptor, field_data_cache, course.id)
+        module = get_module_for_descriptor(
+            request.user, request, module_descriptor, field_data_cache, course.id, course=course
+        )
 
         if modification_date:
             key = KeyValueStore.Key(
@@ -154,7 +158,7 @@ class UserCourseStatus(views.APIView):
                 # old modification date so skip update
                 return self._get_course_info(request, course)
 
-        save_positions_recursively_up(request.user, request, field_data_cache, module)
+        save_positions_recursively_up(request.user, request, field_data_cache, module, course=course)
         return self._get_course_info(request, course)
 
     @mobile_course_access(depth=2)

lms/djangoapps/mobile_api/video_outlines/serializers.py

@@ -4,7 +4,9 @@ Serializer for video outline
 from rest_framework.reverse import reverse
 
 from xmodule.modulestore.mongo.base import BLOCK_TYPES_WITH_CHILDREN
+from xmodule.modulestore.django import modulestore
 from courseware.access import has_access
+from courseware.courses import get_course_by_id
 from courseware.model_data import FieldDataCache
 from courseware.module_render import get_module_for_descriptor
 from util.module_utils import get_dynamic_descriptor_children
@@ -49,50 +51,52 @@ class BlockOutline(object):
             field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
                 self.course_id, self.request.user, descriptor, depth=0,
             )
+            course = get_course_by_id(self.course_id)
             return get_module_for_descriptor(
-                self.request.user, self.request, descriptor, field_data_cache, self.course_id
+                self.request.user, self.request, descriptor, field_data_cache, self.course_id, course=course
             )
 
-        child_to_parent = {}
-        stack = [self.start_block]
-        while stack:
-            curr_block = stack.pop()
-
-            if curr_block.hide_from_toc:
-                # For now, if the 'hide_from_toc' setting is set on the block, do not traverse down
-                # the hierarchy.  The reason being is that these blocks may not have human-readable names
-                # to display on the mobile clients.
-                # Eventually, we'll need to figure out how we want these blocks to be displayed on the
-                # mobile clients.  As they are still accessible in the browser, just not navigatable
-                # from the table-of-contents.
-                continue
-
-            if curr_block.location.block_type in self.block_types:
-                if not has_access(self.request.user, 'load', curr_block, course_key=self.course_id):
+        with modulestore().bulk_operations(self.course_id):
+            child_to_parent = {}
+            stack = [self.start_block]
+            while stack:
+                curr_block = stack.pop()
+
+                if curr_block.hide_from_toc:
+                    # For now, if the 'hide_from_toc' setting is set on the block, do not traverse down
+                    # the hierarchy.  The reason being is that these blocks may not have human-readable names
+                    # to display on the mobile clients.
+                    # Eventually, we'll need to figure out how we want these blocks to be displayed on the
+                    # mobile clients.  As they are still accessible in the browser, just not navigatable
+                    # from the table-of-contents.
                     continue
 
-                summary_fn = self.block_types[curr_block.category]
-                block_path = list(path(curr_block, child_to_parent, self.start_block))
-                unit_url, section_url = find_urls(self.course_id, curr_block, child_to_parent, self.request)
-
-                yield {
-                    "path": block_path,
-                    "named_path": [b["name"] for b in block_path],
-                    "unit_url": unit_url,
-                    "section_url": section_url,
-                    "summary": summary_fn(self.course_id, curr_block, self.request, self.local_cache)
-                }
-
-            if curr_block.has_children:
-                children = get_dynamic_descriptor_children(
-                    curr_block,
-                    self.request.user.id,
-                    create_module,
-                    usage_key_filter=parent_or_requested_block_type
-                )
-                for block in reversed(children):
-                    stack.append(block)
-                    child_to_parent[block] = curr_block
+                if curr_block.location.block_type in self.block_types:
+                    if not has_access(self.request.user, 'load', curr_block, course_key=self.course_id):
+                        continue
+
+                    summary_fn = self.block_types[curr_block.category]
+                    block_path = list(path(curr_block, child_to_parent, self.start_block))
+                    unit_url, section_url = find_urls(self.course_id, curr_block, child_to_parent, self.request)
+
+                    yield {
+                        "path": block_path,
+                        "named_path": [b["name"] for b in block_path],
+                        "unit_url": unit_url,
+                        "section_url": section_url,
+                        "summary": summary_fn(self.course_id, curr_block, self.request, self.local_cache)
+                    }
+
+                if curr_block.has_children:
+                    children = get_dynamic_descriptor_children(
+                        curr_block,
+                        self.request.user.id,
+                        create_module,
+                        usage_key_filter=parent_or_requested_block_type
+                    )
+                    for block in reversed(children):
+                        stack.append(block)
+                        child_to_parent[block] = curr_block
 
 
 def path(block, child_to_parent, start_block):