factor

1 files changed, 6 insertions, 2 deletions

diff --git a/fsmgr.hs b/fsmgr.hs
index 00f840b..890064d 100644
--- a/fsmgr.hs
+++ b/fsmgr.hs
@@ -220,6 +220,11 @@ readFileOptional f = IO.doesFileExist f >>= \case
   True -> readFile f
   False -> return ""
 
+copyParentDevices :: FilePath -> FilePath -> Action ()
+copyParentDevices parent out = do
+  devices <- either (const []) lines . readEither <$> liftIO (readFileOptional (parent <.> "devices.txt"))
+  writeFile' (out -<.> "devices.txt") (unlines $ parent:devices)
+
 buildInitialImage :: DiskImageConfig -> FilePath -> FilePath -> Action ()
 buildInitialImage DiskImageConfig{..} mountpoint out = do
   case initialImage of
@@ -241,8 +246,7 @@ buildInitialImage DiskImageConfig{..} mountpoint out = do
       let parent = f -<.> "seed.btrfs"
       need [parent]
 
-      devices <- either (const []) lines . readEither <$> liftIO (readFileOptional (parent <.> "devices.txt"))
-      writeFile' (out -<.> "devices.txt") (unlines $ parent:devices)
+      copyParentDevices parent out
 
       -- allocate new image file
       cmd_ "rm -f" [out]