Merge pull request #1346 from dbungert/fix-guided-resize-gap

guided resize: improve post-resize gap handling

subiquity/common/filesystem/gaps.py

@@ -241,3 +241,12 @@ def within(device, gap):
             if pg.offset >= gap.offset and pg_end <= gap_end:
                 return pg
     return None
+
+
+def after(device, offset):
+    """Find the first gap that is after this offset."""
+    for pg in parts_and_gaps(device):
+        if isinstance(pg, Gap):
+            if pg.offset > offset:
+                return pg
+    return None

subiquity/common/filesystem/tests/test_gaps.py

@@ -135,6 +135,35 @@ class TestWithin(unittest.TestCase):
         self.assertEqual(g2, gaps.within(d, orig_g2))
 
 
+class TestAfter(unittest.TestCase):
+    def test_basic(self):
+        d = make_disk()
+        [gap] = gaps.parts_and_gaps(d)
+        self.assertEqual(gap, gaps.after(d, 0))
+
+    def test_no_equals(self):
+        d = make_disk()
+        [gap] = gaps.parts_and_gaps(d)
+        self.assertIsNone(gaps.after(d, gap.offset))
+
+    def test_partition_resize_full_part(self):
+        m, d = make_model_and_disk()
+        [g1] = gaps.parts_and_gaps(d)
+        p1 = make_partition(m, d, size=g1.size)
+        p1.size //= 2
+        gap = gaps.after(d, p1.offset)
+        self.assertIsNotNone(gap)
+
+    def test_partition_resize_half_part(self):
+        m, d = make_model_and_disk()
+        make_partition(m, d)
+        [p1, g1] = gaps.parts_and_gaps(d)
+        p1.size //= 2
+        gap = gaps.after(d, p1.offset)
+        self.assertNotEqual(gap, g1)
+        self.assertTrue(gap.offset < g1.offset)
+
+
 class TestDiskGaps(unittest.TestCase):
 
     def test_no_partition_gpt(self):

subiquity/server/controllers/filesystem.py

@@ -223,11 +223,16 @@ class FilesystemController(SubiquityController, FilesystemManipulator):
             new_size = align_up(choice.target.new_size, part_align)
             if new_size > partition.size:
                 raise Exception(f'Aligned requested size {new_size} too large')
-            gap_offset = partition.offset + new_size
             partition.size = new_size
             partition.resize = True
             mode = 'use_gap'
-            target = gaps.at_offset(disk, gap_offset)
+            # Calculating where that gap will be can be tricky due to alignment
+            # needs and the possibility that we may be splitting a logical
+            # partition, which needs an extra 1MiB spacer.
+            target = gaps.after(disk, partition.offset)
+            if target is None:
+                pgs = gaps.parts_and_gaps(disk)
+                raise Exception(f'gap not found after resize, pgs={pgs}')
         else:
             raise Exception(f'Unknown guided target {choice.target}')
 

subiquity/server/controllers/tests/test_filesystem.py

@@ -184,8 +184,6 @@ class TestGuidedV2(IsolatedAsyncioTestCase):
 
         use_gap = resp.possible.pop(0)
         self.assertEqual(self.disk.id, use_gap.disk_id)
-        if gap_offset != use_gap.gap.offset:
-            breakpoint()
         self.assertEqual(gap_offset, use_gap.gap.offset)
 
         resize = resp.possible.pop(0)

subiquity/tests/api/test_api.py

@@ -479,6 +479,20 @@ class TestGuided(TestAPI):
             }
             self.assertDictSubset(expected_p5, p5)
 
+    @timeout()
+    async def test_guided_v2_resize_logical(self):
+        cfg = 'examples/threebuntu-on-msdos.json'
+        extra = ['--storage-version', '2']
+        async with start_server(cfg, extra_args=extra) as inst:
+            resp = await inst.get('/storage/v2/guided')
+            [resize] = match(
+                    resp['possible'], _type='GuidedStorageTargetResize',
+                    partition_number=6)
+            data = {'target': resize}
+            resp = await inst.post('/storage/v2/guided', data)
+            self.assertEqual(resize, resp['configured']['target'])
+            # should not throw a Gap Not Found exception
+
 
 class TestAdd(TestAPI):
     @timeout()