NetApp: Refresh directory before waiting

After image cloning the NFS client cache needs to be refreshed.
This can be accomplished by touching the directory hosting the
cached image file.

See also: https://bugs.launchpad.net/nova/+bug/1617299
Co-Authored-By: Sebastian Schee <sebastian.schee@sap.com>
Co-Authored-By: Goutham Pacha Ravi <gouthampravi@gmail.com>

Closes-bug: #1679716
Change-Id: If392f41f65978721668b53cfab94393f074d24e9
(cherry picked from commit ff6acd62ec)
(cherry picked from commit cd3c1c2c37)

cinder/tests/unit/volume/drivers/netapp/dataontap/test_nfs_cmode.py

@@ -16,6 +16,9 @@
 Mock unit tests for the NetApp cmode nfs storage driver
 """
 
+import hashlib
+import uuid
+
 import ddt
 import mock
 from os_brick.remotefs import remotefs as remotefs_brick
@@ -809,23 +812,35 @@ class NetAppCmodeNfsDriverTestCase(test.TestCase):
     def test__copy_from_img_service_qcow2_copyoffload_workflow_success(
             self, mock_exists, mock_qemu_img_info, mock_cvrt_image):
         drv = self.driver
+        cinder_mount_point_base = '/opt/stack/data/cinder/mnt/'
+        # To get the cinder mount point directory, we use:
+        mount_dir = hashlib.md5(
+            '203.0.113.122:/cinder-flexvol1'.encode('utf-8')).hexdigest()
+        cinder_mount_point = cinder_mount_point_base + mount_dir
+        destination_copied_file = (
+            '/cinder-flexvol1/a155308c-0290-497b-b278-4cdd01de0253'
+        )
         volume = {'id': 'vol_id', 'name': 'name', 'size': 1}
         image_id = 'image_id'
         context = object()
         image_service = mock.Mock()
-        image_service.get_location.return_value = ('nfs://ip1/openstack/img',
+        image_service.get_location.return_value = (
-                                                   None)
+            'nfs://203.0.113.122/glance-flexvol1', None)
         image_service.show.return_value = {'size': 1,
                                            'disk_format': 'qcow2'}
-        drv._check_get_nfs_path_segs =\
+        drv._check_get_nfs_path_segs = (
-            mock.Mock(return_value=('ip1', '/openstack'))
+            mock.Mock(return_value=('203.0.113.122', '/openstack'))
+        )
 
-        drv._get_ip_verify_on_cluster = mock.Mock(return_value='ip1')
+        drv._get_ip_verify_on_cluster = mock.Mock(return_value='203.0.113.122')
-        drv._get_host_ip = mock.Mock(return_value='ip2')
+        drv._get_host_ip = mock.Mock(return_value='203.0.113.122')
-        drv._get_export_path = mock.Mock(return_value='/exp_path')
+        drv._get_export_path = mock.Mock(
+            return_value='/cinder-flexvol1')
         drv._get_provider_location = mock.Mock(return_value='share')
         drv._execute = mock.Mock()
-        drv._get_mount_point_for_share = mock.Mock(return_value='mnt_point')
+        drv._execute_as_root = False
+        drv._get_mount_point_for_share = mock.Mock(
+            return_value=cinder_mount_point)
         img_inf = mock.Mock()
         img_inf.file_format = 'raw'
         mock_qemu_img_info.return_value = img_inf
@@ -835,17 +850,33 @@ class NetAppCmodeNfsDriverTestCase(test.TestCase):
         drv._delete_file_at_path = mock.Mock()
         drv._clone_file_dst_exists = mock.Mock()
         drv._post_clone_image = mock.Mock()
+        self.mock_object(uuid, 'uuid4', mock.Mock(
+            return_value='a155308c-0290-497b-b278-4cdd01de0253'))
 
         retval = drv._copy_from_img_service(
             context, volume, image_service, image_id)
 
         self.assertIsNone(retval)
-        drv._get_ip_verify_on_cluster.assert_any_call('ip1')
+        drv._get_ip_verify_on_cluster.assert_any_call('203.0.113.122')
         drv._get_export_path.assert_called_with('vol_id')
         drv._check_share_can_hold_size.assert_called_with('share', 1)
         drv._post_clone_image.assert_called_with(volume)
         self.assertEqual(1, mock_cvrt_image.call_count)
-        self.assertEqual(1, drv._execute.call_count)
+
+        # _execute must be called once for copy-offload and again to touch
+        # the top directory to refresh cache
+        drv._execute.assert_has_calls(
+            [
+                mock.call(
+                    'copyoffload_tool_path', '203.0.113.122',
+                    '203.0.113.122', '/openstack/glance-flexvol1',
+                    destination_copied_file, run_as_root=False,
+                    check_exit_code=0
+                ),
+                mock.call('touch', cinder_mount_point, run_as_root=False)
+            ]
+        )
+        self.assertEqual(2, drv._execute.call_count)
         self.assertEqual(2, drv._delete_file_at_path.call_count)
         self.assertEqual(1, drv._clone_file_dst_exists.call_count)
 

cinder/volume/drivers/netapp/dataontap/nfs_base.py

@@ -645,6 +645,15 @@ class NetAppNfsDriver(driver.ManageableVD,
         else:
             return False
 
+    @utils.trace_method
+    def _touch_path_to_refresh(self, path):
+        try:
+            # Touching parent directory forces NFS client to flush its cache.
+            self._execute('touch', path, run_as_root=self._execute_as_root)
+        except processutils.ProcessExecutionError:
+            LOG.exception(_LE("Failed to touch path %s."), path)
+
+    @utils.trace_method
     def _discover_file_till_timeout(self, path, timeout=75):
         """Checks if file size at path is equal to size."""
         # Sometimes nfs takes time to discover file
@@ -656,6 +665,9 @@ class NetAppNfsDriver(driver.ManageableVD,
         # retries to ensure that this cache has refreshed.
         retry_seconds = timeout
         sleep_interval = 2
+        base_path = os.path.dirname(path)
+        self._touch_path_to_refresh(base_path)
+
         while True:
             if os.path.exists(path):
                 return True
@@ -666,6 +678,7 @@ class NetAppNfsDriver(driver.ManageableVD,
                 else:
                     time.sleep(sleep_interval)
                     retry_seconds -= sleep_interval
+                    self._touch_path_to_refresh(base_path)
 
     def _is_cloneable_share(self, image_location):
         """Finds if the image at location is cloneable."""

etc/cinder/rootwrap.d/volume.filters

@@ -119,8 +119,9 @@ rm: CommandFilter, rm, root
 # cinder/volume/drivers/remotefs.py
 mkdir: CommandFilter, mkdir, root
 
-# cinder/volume/drivers/netapp/nfs.py:
+# cinder/volume/drivers/netapp/dataontap/nfs_base.py:
 netapp_nfs_find: RegExpFilter, find, root, find, ^[/]*([^/\0]+(/+)?)*$, -maxdepth, \d+, -name, img-cache.*, -amin, \+\d+
+netapp_nfs_touch: CommandFilter, touch, root
 
 # cinder/volume/drivers/glusterfs.py
 chgrp: CommandFilter, chgrp, root