storage: always accept to resize a partition that is being wiped

If we are wiping a partition, don't bother checking if the filesystem that was
on it supports resizing. The filesystem is going to be erased anyway. The new
filesystem (if any) will be created using mkfs.* so there is no need for resize
support.

LP: #2096799

Signed-off-by: Olivier Gayot <[email protected]>

subiquity/common/filesystem/manipulator.py

@@ -276,9 +276,13 @@ def reformat(self, disk, ptable=None, wipe=None):
             self.delete_partition(p, True)
         self.clear(disk, wipe)
 
-    def can_resize_partition(self, partition):
+    def can_resize_partition(self, partition, *, wipe=None):
+        # For a new partition.
         if not partition.preserve:
             return True
+        # For an existing partition that is being wiped.
+        if wipe is not None:
+            return True
         if partition.format not in get_resize_fstypes():
             return False
         return True
@@ -297,7 +301,7 @@ def partition_disk_handler(
                 size_change = new_size - partition.size
                 if size_change > gap_size:
                     raise Exception("partition size too large")
-                if not self.can_resize_partition(partition):
+                if not self.can_resize_partition(partition, wipe=spec.get("wipe")):
                     raise Exception("partition cannot support resize")
                 partition.size = new_size
                 partition.resize = True

subiquity/common/filesystem/tests/test_manipulator.py

@@ -21,7 +21,10 @@
 
 from subiquity.common.filesystem import boot, gaps, sizes
 from subiquity.common.filesystem.actions import DeviceAction
-from subiquity.common.filesystem.manipulator import FilesystemManipulator
+from subiquity.common.filesystem.manipulator import (
+    FilesystemManipulator,
+    get_resize_fstypes,
+)
 from subiquity.models.filesystem import Bootloader, MiB, Partition
 from subiquity.models.tests.test_filesystem import (
     make_disk,
@@ -743,6 +746,22 @@ def test_resize_unpreserved(self):
         part = make_partition(self.manipulator.model, disk, preserve=False)
         self.assertTrue(self.manipulator.can_resize_partition(part))
 
+    def test_resize_non_resizable(self):
+        disk = make_disk(self.manipulator.model, ptable=None)
+        part = make_partition(self.manipulator.model, disk, preserve=True)
+        # If XFS becomes resizable, replace with something else.
+        self.assertNotIn("xfs", get_resize_fstypes())
+        make_filesystem(self.manipulator.model, partition=part, fstype="xfs")
+        self.assertFalse(self.manipulator.can_resize_partition(part))
+
+    def test_resize_non_resizable_but_wipe(self):
+        disk = make_disk(self.manipulator.model, ptable=None)
+        part = make_partition(self.manipulator.model, disk, preserve=True)
+        # If XFS becomes resizable, replace with something else.
+        self.assertNotIn("xfs", get_resize_fstypes())
+        make_filesystem(self.manipulator.model, partition=part, fstype="xfs")
+        self.assertTrue(self.manipulator.can_resize_partition(part, wipe="superblock"))
+
     def test_resize_ext4(self):
         disk = make_disk(self.manipulator.model, ptable=None)
         part = make_partition(self.manipulator.model, disk, preserve=True)