do not blow up on a format action that has an unknown fstype

we do not know what we might see on an exsiting system

subiquity/controllers/filesystem.py

@@ -161,7 +161,7 @@ class FilesystemController(BaseController):
         raise Exception("could not resolve {}".format(id))
 
     def _action_clean_fstype(self, fstype):
-        return self.model.fs_by_name[fstype]
+        return self.model.get_fs_by_name(fstype)
 
     def _action_clean_devices_raid(self, devices):
         return {
@@ -306,7 +306,7 @@ class FilesystemController(BaseController):
                 disk,
                 dict(
                     size=part_size,
-                    fstype=self.model.fs_by_name['fat32'],
+                    fstype=self.model.get_fs_by_name('fat32'),
                     mount='/boot/efi'),
                 flag="boot")
         elif self.is_prep():

subiquity/models/filesystem.py

@@ -807,7 +807,7 @@ class Filesystem:
     def _available(self):
         # False if mounted or if fs does not require a mount, True otherwise.
         if self._mount is None:
-            fs_obj = FilesystemModel.fs_by_name[self.fstype]
+            fs_obj = FilesystemModel.get_fs_by_name(self.fstype)
             return fs_obj.is_mounted
         else:
             return False
@@ -850,22 +850,25 @@ class FilesystemModel(object):
         ('ext4', True, FS('ext4', True)),
         ('xfs', True, FS('xfs', True)),
         ('btrfs', True, FS('btrfs', True)),
-        ('---', False),
+        ('---', False, None),
         ('swap', True, FS('swap', False)),
-        ('---', False),
+        ('---', False, None),
         ('leave unformatted', True, FS(None, False)),
     ]
 
-    fs_by_name = {}
-    longest_fs_name = 0
+    _fs_by_name = {}
     for t in supported_filesystems:
-        if len(t) > 2:
-            fs = t[2]
-            if fs.label is not None:
-                if len(fs.label) > longest_fs_name:
-                    longest_fs_name = len(fs.label)
-            fs_by_name[fs.label] = fs
-    fs_by_name['fat32'] = FS('fat32', True)
+        fs = t[2]
+        if fs is not None:
+            _fs_by_name[fs.label] = fs
+
+    @classmethod
+    def get_fs_by_name(cls, fstype):
+        if fstype in cls._fs_by_name:
+            return cls._fs_by_name[fstype]
+        else:
+            fs = cls._fs_by_name[fstype] = FS(fstype, True)
+            return fs
 
     def __init__(self):
         self._disk_info = []

subiquity/ui/views/filesystem/guided.py

@@ -145,10 +145,11 @@ class GuidedDiskSelectionView(BaseView):
     def choose_disk(self, btn, disk_path):
         self.model.reset()
         disk = self.model.disk_by_path(disk_path)
+        ext4 = self.model.get_fs_by_name("ext4")
         if self.method == "direct":
             result = {
                 "size": disk.free_for_partitions,
-                "fstype": self.model.fs_by_name["ext4"],
+                "fstype": ext4,
                 "mount": "/",
                 }
             self.controller.partition_disk_handler(disk, None, result)
@@ -158,7 +159,7 @@ class GuidedDiskSelectionView(BaseView):
             self.controller.create_partition(
                 device=disk, spec=dict(
                     size=dehumanize_size('1G'),
-                    fstype=self.model.fs_by_name['ext4'],
+                    fstype=ext4,
                     mount='/boot'
                     ))
             part = self.controller.create_partition(
@@ -175,7 +176,7 @@ class GuidedDiskSelectionView(BaseView):
                 vg=vg, spec=dict(
                     size=dehumanize_size("4G"),
                     name="ubuntu-lv",
-                    fstype=self.model.fs_by_name['ext4'],
+                    fstype=ext4,
                     mount="/",
                     ))
         else:

subiquity/ui/views/filesystem/partition.py

@@ -245,7 +245,7 @@ class PartitionStretchy(Stretchy):
             fs = self.partition.fs()
             if fs is not None:
                 if partition.flag != "boot":
-                    initial['fstype'] = self.model.fs_by_name[fs.fstype]
+                    initial['fstype'] = self.model.get_fs_by_name(fs.fstype)
                 mount = fs.mount()
                 if mount is not None:
                     initial['mount'] = mount.path
@@ -253,7 +253,7 @@ class PartitionStretchy(Stretchy):
                 else:
                     initial['mount'] = None
             else:
-                initial['fstype'] = self.model.fs_by_name[None]
+                initial['fstype'] = self.model.get_fs_by_name(None)
             if isinstance(disk, LVM_VolGroup):
                 initial['name'] = partition.name
                 lvm_names.remove(partition.name)
@@ -281,7 +281,9 @@ class PartitionStretchy(Stretchy):
         if partition is not None:
             if partition.flag == "boot":
                 opts = [
-                    Option(("fat32", True, self.model.fs_by_name["fat32"])),
+                    Option(
+                        ("fat32", True, self.model.get_fs_by_name("fat32")),
+                    ),
                 ]
                 self.form.fstype.widget.options = opts
                 self.form.fstype.widget.index = 0
@@ -344,7 +346,8 @@ class PartitionStretchy(Stretchy):
         log.debug("Add Partition Result: {}".format(form.as_data()))
         data = form.as_data()
         if self.partition is not None and self.partition.flag == "boot":
-            data['fstype'] = self.model.fs_by_name[self.partition.fs().fstype]
+            data['fstype'] = self.model.get_fs_by_name(
+                self.partition.fs().fstype)
             data['mount'] = self.partition.fs().mount().path
         if isinstance(self.disk, LVM_VolGroup):
             handler = self.controller.logical_volume_handler
@@ -369,13 +372,13 @@ class FormatEntireStretchy(Stretchy):
         initial = {}
         fs = device.fs()
         if fs is not None:
-            initial['fstype'] = self.model.fs_by_name[fs.fstype]
+            initial['fstype'] = self.model.get_fs_by_name(fs.fstype)
             mount = fs.mount()
             if mount is not None:
                 initial['mount'] = mount.path
                 del mountpoints[mount.path]
         else:
-            initial['fstype'] = self.model.fs_by_name[None]
+            initial['fstype'] = self.model.get_fs_by_name(None)
         self.form = PartitionForm(mountpoints, 0, initial, False, {})
         self.form.remove_field('size')
         self.form.remove_field('name')

subiquity/ui/views/filesystem/tests/test_partition.py

@@ -54,7 +54,7 @@ class PartitionViewTests(unittest.TestCase):
     def test_create_partition(self):
         valid_data = {
             'size': "1M",
-            'fstype': FilesystemModel.fs_by_name["ext4"],
+            'fstype': FilesystemModel.get_fs_by_name("ext4"),
             }
         model, disk = make_model_and_disk()
         view, stretchy = make_view(model, disk)
@@ -68,7 +68,7 @@ class PartitionViewTests(unittest.TestCase):
     def test_edit_partition(self):
         form_data = {
             'size': "256M",
-            'fstype': FilesystemModel.fs_by_name['xfs'],
+            'fstype': FilesystemModel.get_fs_by_name("xfs"),
             }
         model, disk = make_model_and_disk()
         partition = model.add_partition(disk, 512*(2**20))
@@ -79,7 +79,7 @@ class PartitionViewTests(unittest.TestCase):
         view_helpers.click(stretchy.form.done_btn.base_widget)
         expected_data = {
             'size': dehumanize_size(form_data['size']),
-            'fstype': FilesystemModel.fs_by_name['xfs'],
+            'fstype': FilesystemModel.get_fs_by_name('xfs'),
             'mount': None,
             }
         view.controller.partition_disk_handler.assert_called_once_with(
@@ -98,7 +98,7 @@ class PartitionViewTests(unittest.TestCase):
         view_helpers.click(stretchy.form.done_btn.base_widget)
         expected_data = {
             'size': dehumanize_size(form_data['size']),
-            'fstype': FilesystemModel.fs_by_name["fat32"],
+            'fstype': FilesystemModel.get_fs_by_name("fat32"),
             'mount': '/boot/efi',
             }
         view.controller.partition_disk_handler.assert_called_once_with(