Make sure the root directory is a regular directory if Overlay= is enabled

overlayfs combined with a btrfs subvolume as the upperdir results in
EXDEV when trying to access files from a lowerdir, so let's make sure
we use a regular directory when Overlay= is enabled.

Fixes #1904

diff --git a/mkosi/state.py b/mkosi/state.py
index 19b4896327704f6aa4bb2852e7365089e6d66dc3..3b3b6d200522e7f15f6631aeba5e3eb2f794d5cc 100644 (file)
--- a/mkosi/state.py
+++ b/mkosi/state.py
@@ -16,7 +16,13 @@ class MkosiState:
         self.workspace = workspace
 
         with umask(~0o755):
-            make_tree(self.config, self.root)
+            # Using a btrfs subvolume as the upperdir in an overlayfs results in EXDEV so make sure we create
+            # the root directory as a regular directory if the Overlay= option is enabled.
+            if config.overlay:
+                self.root.mkdir()
+            else:
+                make_tree(self.config, self.root)
+
         self.staging.mkdir()
         self.pkgmngr.mkdir()
         self.install_dir.mkdir(exist_ok=True)