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