From 0f786baf5db22e7eaa0e356b9ad595d9ee000eeb Mon Sep 17 00:00:00 2001
From: r-vdp <ramses@well-founded.dev>
Date: Thu, 5 Sep 2024 15:28:00 +0200
Subject: [PATCH] etc: remove unneeded temporary directions after putting in
 place the new etc

---
 nixos/modules/system/etc/etc.nix | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/nixos/modules/system/etc/etc.nix b/nixos/modules/system/etc/etc.nix
index 7547f4304709..e8eeae03a360 100644
--- a/nixos/modules/system/etc/etc.nix
+++ b/nixos/modules/system/etc/etc.nix
@@ -276,6 +276,22 @@ in
 
         # Unmount the top /etc mount to atomically reveal the new mount.
         umount --lazy --recursive /etc
+
+        # Unmount the temporary mount
+        umount --lazy "$tmpEtcMount"
+        rmdir "$tmpEtcMount"
+
+        # Unmount old metadata mounts
+        # For some reason, `findmnt /tmp --submounts` does not show the nested
+        # mounts. So we'll just find all mounts of type erofs and filter on the
+        # name of the mountpoint.
+        findmnt --type erofs --list --kernel --output TARGET | while read -r mountPoint; do
+          if [[ "$mountPoint" =~ ^/tmp/nixos-etc-metadata\..{10}$ &&
+                "$mountPoint" != "$tmpMetadataMount" ]]; then
+            umount --lazy $mountPoint
+            rmdir "$mountPoint"
+          fi
+        done
       fi
     '' else ''
       # Set up the statically computed bits of /etc.