From 2aba050e74dc5df483da022dcf436b101c7a4301 Mon Sep 17 00:00:00 2001
From: Vojtech Trefny <vtrefny@redhat.com>
Date: Wed, 11 Jan 2023 14:59:24 +0100
Subject: [PATCH] Default to encryption sector size 512 for LUKS devices

We are currently letting cryptsetup decide the optimal encryption
sector size for LUKS. The problem is that for disks with physical
sector size 4096 cryptsetup will default to 4096 encryption sector
size even if the drive logical sector size is 512 which means
these disks cannot be combined with other 512 logical sector size
disks in LVM. This requires a more sophisticated solution in the
future, but for now just default to 512 if not specified by the
user otherwise.

Resolves: rhbz#2103800
---
 blivet/formats/luks.py                      | 10 +++++++---
 tests/unit_tests/formats_tests/luks_test.py |  2 +-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/blivet/formats/luks.py b/blivet/formats/luks.py
index 8de4911f..2637e0c5 100644
--- a/blivet/formats/luks.py
+++ b/blivet/formats/luks.py
@@ -166,9 +166,13 @@ class LUKS(DeviceFormat):
             if self.pbkdf_args.type == "pbkdf2" and self.pbkdf_args.max_memory_kb:
                 log.warning("Memory limit is not used for pbkdf2 and it will be ignored.")
 
-        self.luks_sector_size = kwargs.get("luks_sector_size") or 0
-        if self.luks_sector_size and self.luks_version != "luks2":
-            raise ValueError("Sector size argument is valid only for LUKS version 2.")
+        self.luks_sector_size = kwargs.get("luks_sector_size")
+        if self.luks_version == "luks2":
+            if self.luks_sector_size is None:
+                self.luks_sector_size = 512  # XXX we don't want cryptsetup choose automatically here so fallback to 512
+        else:
+            if self.luks_sector_size:
+                raise ValueError("Sector size argument is valid only for LUKS version 2.")
 
     def __repr__(self):
         s = DeviceFormat.__repr__(self)
diff --git a/tests/unit_tests/formats_tests/luks_test.py b/tests/unit_tests/formats_tests/luks_test.py
index 5ae6acfe..ec7b7592 100644
--- a/tests/unit_tests/formats_tests/luks_test.py
+++ b/tests/unit_tests/formats_tests/luks_test.py
@@ -53,7 +53,7 @@ class LUKSNodevTestCase(unittest.TestCase):
 
     def test_sector_size(self):
         fmt = LUKS()
-        self.assertEqual(fmt.luks_sector_size, 0)
+        self.assertEqual(fmt.luks_sector_size, 512)
 
         with self.assertRaises(ValueError):
             fmt = LUKS(luks_version="luks1", luks_sector_size=4096)
-- 
2.39.0