From f5d50a2ddeafa87b6e43311efa2d5372c2faf13b Mon Sep 17 00:00:00 2001
From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Tue, 14 Feb 2023 22:13:43 +0100
Subject: [PATCH] centos: Mount root partition rw by default on CentOS Stream 8

---
 mkosi/__init__.py               |  2 ++
 mkosi/distributions/__init__.py |  4 ++++
 mkosi/distributions/centos.py   | 12 ++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/mkosi/__init__.py b/mkosi/__init__.py
index e988edf6b..a396b120c 100644
--- a/mkosi/__init__.py
+++ b/mkosi/__init__.py
@@ -776,6 +776,8 @@ def install_unified_kernel(state: MkosiState, roothash: Optional[str]) -> None:
             else:
                 cmdline = []
 
+            cmdline += state.installer.kernel_command_line(state)
+
             if roothash:
                 cmdline += [roothash]
 
diff --git a/mkosi/distributions/__init__.py b/mkosi/distributions/__init__.py
index af42b4e0d..226d93471 100644
--- a/mkosi/distributions/__init__.py
+++ b/mkosi/distributions/__init__.py
@@ -33,3 +33,7 @@ class DistributionInstaller:
     @classmethod
     def filesystem(cls) -> str:
         raise NotImplementedError
+
+    @staticmethod
+    def kernel_command_line(state: "MkosiState") -> list[str]:
+        return []
diff --git a/mkosi/distributions/centos.py b/mkosi/distributions/centos.py
index d8fb01adc..7384ad5f1 100644
--- a/mkosi/distributions/centos.py
+++ b/mkosi/distributions/centos.py
@@ -37,6 +37,18 @@ class CentosInstaller(DistributionInstaller):
         # https://marc.info/?l=linux-xfs&m=167450838316386&w=2.
         return "ext4"
 
+    @staticmethod
+    def kernel_command_line(state: MkosiState) -> list[str]:
+        kcl = []
+
+        # systemd-gpt-auto-generator only started applying the GPT partition read-only flag to gpt-auto
+        # mounts from v240 onwards, while CentOS Stream 8 ships systemd v239, so we have to nudge gpt-auto to
+        # mount the root partition rw by default.
+        if state.config.bootable and int(state.config.release) <= 8:
+            kcl += ["rw"]
+
+        return kcl + DistributionInstaller.kernel_command_line(state)
+
     @classmethod
     @complete_step("Installing CentOS…")
     def install(cls, state: "MkosiState") -> None:
-- 
2.47.2