GPFS stub calls to truncate and dd in unit tests

gpfs unit tests had calls to truncate, and allowed
driver call to dd and df.  Modify tests to stub these
out.

Also remove references to image_path.  This was a temp file
created using truncate that is no longer used.

Change-Id: I437b56505ba025b256b051dfaf43d8124005f854
Fixes: bug #1203075

cinder/tests/test_gpfs.py

@@ -72,8 +72,6 @@ def setUp(self):
         if not os.path.exists(self.images_dir):
             os.mkdir(self.images_dir)
         self.image_id = '70a599e0-31e7-49b7-b260-868f441e862b'
-        self.image_path = self.images_dir + "/" + self.image_id
-        utils.execute('truncate', '-s', 1024, self.image_path)
 
         self.driver = GPFSDriver(configuration=conf.Configuration(None))
         self.driver.set_execute(self._execute_wrapper)
@@ -92,18 +90,22 @@ def setUp(self):
                        self._fake_is_gpfs_parent)
         self.stubs.Set(GPFSDriver, '_delete_gpfs_file',
                        self._fake_delete_gpfs_file)
+        self.stubs.Set(GPFSDriver, '_create_sparse_file',
+                       self._fake_create_sparse_file)
+        self.stubs.Set(GPFSDriver, '_create_regular_file',
+                       self._fake_create_regular_file)
+        self.stubs.Set(GPFSDriver, '_get_available_capacity',
+                       self._fake_get_available_capacity)
         self.stubs.Set(image_utils, 'qemu_img_info',
                        self._fake_qemu_qcow2_image_info)
         self.stubs.Set(image_utils, 'convert_image',
                        self._fake_convert_image)
 
         self.context = context.get_admin_context()
-
         CONF.gpfs_images_dir = self.images_dir
 
     def tearDown(self):
         try:
-            os.remove(self.image_path)
             os.rmdir(self.images_dir)
             os.rmdir(self.volumes_path)
         except OSError:
@@ -135,11 +137,9 @@ def test_create_delete_volume_full_backing_file(self):
         self.assertTrue(os.path.exists(self.volumes_path))
         self.volume.create_volume(self.context, volume_id)
         path = self.volumes_path + '/' + vol['name']
-        self.assertTrue(os.path.exists(self.volumes_path))
         self.assertTrue(os.path.exists(path))
         self.volume.delete_volume(self.context, volume_id)
         self.assertFalse(os.path.exists(path))
-        self.assertTrue(os.path.exists(self.volumes_path))
 
     def test_create_delete_volume_sparse_backing_file(self):
         """create and delete vol with default sparse creation method"""
@@ -149,11 +149,9 @@ def test_create_delete_volume_sparse_backing_file(self):
         self.assertTrue(os.path.exists(self.volumes_path))
         self.volume.create_volume(self.context, volume_id)
         path = self.volumes_path + '/' + vol['name']
-        self.assertTrue(os.path.exists(self.volumes_path))
         self.assertTrue(os.path.exists(path))
         self.volume.delete_volume(self.context, volume_id)
         self.assertFalse(os.path.exists(path))
-        self.assertTrue(os.path.exists(self.volumes_path))
 
     def _create_snapshot(self, volume_id, size='0'):
         """Create a snapshot object."""
@@ -362,22 +360,35 @@ def test_check_for_setup_error_not_gpfs_path(self):
         self.assertRaises(exception.VolumeBackendAPIException,
                           self.driver.check_for_setup_error)
 
+    def _fake_create_file(self, path, modebits='666'):
+        open(path, 'w').close()
+        utils.execute('chmod', modebits, path)
+
     def _fake_gpfs_snap(self, src, dest=None, modebits='644'):
         if dest is None:
             dest = src
-        utils.execute('truncate', '-s', 0, dest)
-        utils.execute('chmod', '644', dest)
+        self._fake_create_file(dest, '644')
 
     def _fake_gpfs_copy(self, src, dest):
-        utils.execute('truncate', '-s', 0, dest)
-        utils.execute('chmod', '666', dest)
+        self._fake_create_file(dest)
+
+    def _fake_create_sparse_file(self, path, size):
+        self._fake_create_file(path)
+
+    def _fake_create_regular_file(self, path, size):
+        self._fake_create_file(path)
 
     def _fake_gpfs_redirect(self, src):
         return True
 
     def _fake_is_gpfs_parent(self, gpfs_file):
         return False
 
+    def _fake_get_available_capacity(self, path):
+        fake_avail = 80 * 1024 * 1024 * 1024
+        fake_size = 2 * fake_avail
+        return fake_avail, fake_size
+
     def _fake_gpfs_get_state_active(self):
         active_txt = ('mmgetstate::HEADER:version:reserved:reserved:'
                       'nodeName:nodeNumber:state:quorum:nodesUp:totalNodes:'