storage: fix coding style

circle/storage/tasks/periodic_tasks.py

@@ -12,6 +12,7 @@ logger = logging.getLogger(__name__)
 @celery.task
 def garbage_collector(timeout=15):
     """ Garbage collector for disk images.
+
     Moves 1 day old deleted images to trash folder.
     If there is not enough free space on datastore (default 10%)
     deletes oldest images from trash.
@@ -40,6 +41,7 @@ def garbage_collector(timeout=15):
 @celery.task
 def list_orphan_disks(timeout=15):
     """List disk image files without Disk object in the database.
+
     Exclude cloud-xxxxxxxx.dump format images.
 
     :param timeout: Seconds before TimeOut exception
@@ -48,10 +50,10 @@ def list_orphan_disks(timeout=15):
     import re
     for ds in DataStore.objects.all():
         queue_name = ds.get_remote_queue_name('storage')
-        file_list = remote_tasks.list_files.apply_async(
-            args=[ds.path], queue=queue_name).get(timeout=timeout)
-        disk_list = [disk.filename for disk in ds.disk_set.all()]
-        for i in set(file_list).difference(disk_list):
+        files = set(remote_tasks.list_files.apply_async(
+            args=[ds.path], queue=queue_name).get(timeout=timeout))
+        disks = set([disk.filename for disk in ds.disk_set.all()])
+        for i in files - disks:
             if not re.match('cloud-[0-9]*\.dump', i):
                 logging.warning("Orphan disk: %s" % i)
 
@@ -65,10 +67,10 @@ def list_missing_disks(timeout=15):
     """
     for ds in DataStore.objects.all():
         queue_name = ds.get_remote_queue_name('storage')
-        file_list = remote_tasks.list_files.apply_async(
-            args=[ds.path], queue=queue_name).get(timeout=timeout)
-        disk_list = [disk.filename for disk in
-                     ds.disk_set.filter(destroyed__isnull=True)]
-        for i in set(disk_list).difference(file_list):
+        files = set(remote_tasks.list_files.apply_async(
+            args=[ds.path], queue=queue_name).get(timeout=timeout))
+        disks = set([disk.filename for disk in
+                     ds.disk_set.filter(destroyed__isnull=True)])
+        for i in disks - files:
             logging.critical("Image: %s is missing from %s datastore."
                              % (i, ds.path))