Merge ~newell-jensen/maas:2.4-lp1799161 into maas:2.4

[Newell Jensen]

Backport of d7581c456287e5dc5149a77d96b7943a926a1aa6

LP: #1799161 -- Do not allow partition formatting if current filesystem is a non-formatted type.

[Newell Jensen (newell-jensen)]

Self-approved backport.

review: Approve

diff --git a/src/maasserver/api/tests/test_blockdevice.py b/src/maasserver/api/tests/test_blockdevice.py
index 9312d9a..1c40285 100644
--- a/src/maasserver/api/tests/test_blockdevice.py
+++ b/src/maasserver/api/tests/test_blockdevice.py
@@ -1,4 +1,4 @@
-# Copyright 2015-2016 Canonical Ltd.  This software is licensed under the
+# Copyright 2015-2018 Canonical Ltd.  This software is licensed under the
 # GNU Affero General Public License version 3 (see the file LICENSE).
 
 """Tests for blockdevice API."""
diff --git a/src/maasserver/forms/__init__.py b/src/maasserver/forms/__init__.py
index d59b282..4e97792 100644
--- a/src/maasserver/forms/__init__.py
+++ b/src/maasserver/forms/__init__.py
@@ -111,6 +111,7 @@ from maasserver.enum import (
     BOOT_RESOURCE_TYPE,
     CACHE_MODE_TYPE_CHOICES,
     FILESYSTEM_FORMAT_TYPE_CHOICES,
+    FILESYSTEM_FORMAT_TYPE_CHOICES_DICT,
     FILESYSTEM_GROUP_RAID_TYPE_CHOICES,
     FILESYSTEM_TYPE,
     INTERFACE_TYPE,
@@ -2577,10 +2578,18 @@ class FormatBlockDeviceForm(Form):
 
         This implementation of `save` does not support the `commit` argument.
         """
-        # Remove the previous format if one already exists.
-        Filesystem.objects.filter(
+        filesystem = Filesystem.objects.filter(
             block_device=self.block_device,
-            acquired=self.node.is_in_allocated_state()).delete()
+            acquired=self.node.is_in_allocated_state()).first()
+        if (filesystem is not None and
+                filesystem.fstype not in FILESYSTEM_FORMAT_TYPE_CHOICES_DICT):
+            raise ValidationError(
+                "Cannot format a block device that has a filesystem "
+                "type of %s." % filesystem.fstype)
+
+        # Remove the previous format if one already exists.
+        if filesystem is not None:
+            filesystem.delete()
 
         # Create the new filesystem
         Filesystem.objects.create(
@@ -2640,10 +2649,18 @@ class FormatPartitionForm(Form):
 
         This implementation of `save` does not support the `commit` argument.
         """
-        # Remove the previous format if one already exists.
-        Filesystem.objects.filter(
+        filesystem = Filesystem.objects.filter(
             partition=self.partition,
-            acquired=self.node.is_in_allocated_state()).delete()
+            acquired=self.node.is_in_allocated_state()).first()
+        if (filesystem is not None and
+                filesystem.fstype not in FILESYSTEM_FORMAT_TYPE_CHOICES_DICT):
+            raise ValidationError(
+                "Cannot format a partition that has a filesystem "
+                "type of %s." % filesystem.fstype)
+
+        # Remove the previous format if one already exists.
+        if filesystem is not None:
+            filesystem.delete()
 
         # Create the new filesystem
         Filesystem.objects.create(
diff --git a/src/maasserver/forms/tests/test_blockdevice.py b/src/maasserver/forms/tests/test_blockdevice.py
index 39e6596..cef2280 100644
--- a/src/maasserver/forms/tests/test_blockdevice.py
+++ b/src/maasserver/forms/tests/test_blockdevice.py
@@ -1,4 +1,4 @@
-# Copyright 2015-2016 Canonical Ltd.  This software is licensed under the
+# Copyright 2015-2018 Canonical Ltd.  This software is licensed under the
 # GNU Affero General Public License version 3 (see the file LICENSE).
 
 """Tests for all forms that are used with `BlockDevice`."""
@@ -8,6 +8,7 @@ __all__ = []
 import random
 import uuid
 
+from django.core.exceptions import ValidationError
 from maasserver.enum import FILESYSTEM_TYPE
 from maasserver.forms import (
     CreatePhysicalBlockDeviceForm,
@@ -109,6 +110,16 @@ class TestFormatBlockDeviceForm(MAASServerTestCase):
             "Should be invalid because of an invalid uuid.")
         self.assertEqual({'uuid': ["Enter a valid value."]}, form._errors)
 
+    def test_is_not_valid_if_non_user_format_fstype(self):
+        block_device = factory.make_PhysicalBlockDevice()
+        factory.make_Filesystem(
+            fstype='bcache-backing', block_device=block_device)
+        data = {
+            'fstype': FILESYSTEM_TYPE.EXT4,
+            }
+        form = FormatBlockDeviceForm(block_device, data=data)
+        self.assertRaises(ValidationError, form.save)
+
     def test_creates_filesystem(self):
         fsuuid = "%s" % uuid.uuid4()
         fstype = factory.pick_filesystem_type()
diff --git a/src/maasserver/forms/tests/test_partition.py b/src/maasserver/forms/tests/test_partition.py
index b3a5d68..c3de82e 100644
--- a/src/maasserver/forms/tests/test_partition.py
+++ b/src/maasserver/forms/tests/test_partition.py
@@ -1,4 +1,4 @@
-# Copyright 2015-2016 Canonical Ltd.  This software is licensed under the
+# Copyright 2015-2018 Canonical Ltd.  This software is licensed under the
 # GNU Affero General Public License version 3 (see the file LICENSE).
 
 """Tests for all forms that are used with `Partition`."""
@@ -7,6 +7,7 @@ __all__ = []
 
 import uuid
 
+from django.core.exceptions import ValidationError
 from maasserver.enum import FILESYSTEM_TYPE
 from maasserver.forms import (
     AddPartitionForm,
@@ -159,6 +160,15 @@ class TestFormatPartitionForm(MAASServerTestCase):
                 ],
             }, form._errors)
 
+    def test_is_not_valid_if_non_user_format_fstype(self):
+        partition = factory.make_Partition()
+        factory.make_Filesystem(fstype='bcache-backing', partition=partition)
+        data = {
+            'fstype': FILESYSTEM_TYPE.EXT4,
+            }
+        form = FormatPartitionForm(partition, data=data)
+        self.assertRaises(ValidationError, form.save)
+
     def test_creates_filesystem(self):
         fsuuid = "%s" % uuid.uuid4()
         fstype = factory.pick_filesystem_type()