storage: fixed garbage_collector to check child_disks before delete

circle/storage/models.py

@@ -10,6 +10,7 @@ from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
 from model_utils.models import TimeStampedModel
 from sizefield.models import FileSizeField
+from datetime import timedelta
 
 from acl.models import AclBase
 from .tasks import local_tasks, remote_tasks
@@ -45,6 +46,11 @@ class DataStore(Model):
         else:
             raise WorkerNotFound()
 
+    def get_deletable_disks(self):
+        return [disk.filename for disk in
+                self.disk_set.filter(
+                    destroyed__isnull=False) if disk.is_deletable()]
+
 
 class Disk(AclBase, TimeStampedModel):
 
@@ -126,6 +132,23 @@ class Disk(AclBase, TimeStampedModel):
             'raw-rw': 'vd',
         }[self.type]
 
+    def is_deletable(self):
+        """Returns True if no child and disk is destroyed."""
+        time_before = timezone.now() - timedelta(days=1)
+        if self.destroyed > time_before or self.has_active_child():
+            return False
+        else:
+            return True
+
+    def has_active_child(self):
+        """Returns True if disk have iactive childs."""
+        time_before = timezone.now() - timedelta(days=1)
+        for child in self.derivatives.all():
+            if child.destroyed > time_before or None:
+                return True
+        else:
+            return False
+
     def is_in_use(self):
         """Returns True if disc is attached to an active VM else False"""
         return any([i.state != 'STOPPED' for i in self.instance_set.all()])

circle/storage/tasks/periodic_tasks.py

 from storage.models import DataStore
 import os
-from django.utils import timezone
-from datetime import timedelta
 from manager.mancelery import celery
 import logging
 from storage.tasks import remote_tasks
@@ -20,10 +18,8 @@ def garbage_collector(timeout=15):
     :type timeoit: int
     """
     for ds in DataStore.objects.all():
-        time_before = timezone.now() - timedelta(days=1)
         file_list = os.listdir(ds.path)
-        disk_list = [disk.filename for disk in
-                     ds.disk_set.filter(destroyed__lt=time_before)]
+        disk_list = ds.get_deletable_disks()
         queue_name = ds.get_remote_queue_name('storage')
         for i in set(file_list).intersection(disk_list):
             logger.info("Image: %s at Datastore: %s moved to trash folder." %