nixpkgs/pkgs/os-specific/linux/systemd/0002-Don-t-try-to-unmount-nix-or-nix-store.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Raito Bezarius <masterancpp@gmail.com>
Date: Mon, 19 Jun 2023 02:11:35 +0200
Subject: [PATCH] Don't try to unmount /nix or /nix/store

They'll still be remounted read-only.

https://github.com/NixOS/nixos/issues/126

Original-Author: Eelco Dolstra <eelco.dolstra@logicblox.com>
---
 src/shared/fstab-util.c | 2 ++
 src/shutdown/umount.c   | 6 ++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/shared/fstab-util.c b/src/shared/fstab-util.c
index 55e76b6e16..015a608035 100644
--- a/src/shared/fstab-util.c
+++ b/src/shared/fstab-util.c
@@ -66,6 +66,8 @@ bool fstab_is_extrinsic(const char *mount, const char *opts) {
         /* Don't bother with the OS data itself */
         if (PATH_IN_SET(mount,
                         "/",
+                        "/nix",
+                        "/nix/store",
                         "/usr",
                         "/etc"))
                 return true;
diff --git a/src/shutdown/umount.c b/src/shutdown/umount.c
index 1a9b99d761..04ef9af1ea 100644
--- a/src/shutdown/umount.c
+++ b/src/shutdown/umount.c
@@ -170,8 +170,10 @@ int mount_points_list_get(const char *mountinfo, MountPoint **head) {
 static bool nonunmountable_path(const char *path) {
         assert(path);
 
-        return PATH_IN_SET(path, "/", "/usr") ||
-                path_startswith(path, "/run/initramfs");
+        return PATH_IN_SET(path, "/", "/usr")
+                || path_equal(path, "/nix")
+                || path_equal(path, "/nix/store")
+                || path_startswith(path, "/run/initramfs");
 }
 
 static void log_umount_blockers(const char *mnt) {