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: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 12 Apr 2013 13:16:57 +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
---
 src/shared/fstab-util.c | 2 ++
 src/shutdown/umount.c   | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/src/shared/fstab-util.c b/src/shared/fstab-util.c
index f683f05981..5a04c2c2a6 100644
--- a/src/shared/fstab-util.c
+++ b/src/shared/fstab-util.c
@@ -40,6 +40,8 @@ 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 e650b82170..5d0d41aa28 100644
--- a/src/shutdown/umount.c
+++ b/src/shutdown/umount.c
@@ -522,6 +522,8 @@ static int delete_md(MountPoint *m) {
 
 static bool nonunmountable_path(const char *path) {
         return path_equal(path, "/")
+                || path_equal(path, "/nix")
+                || path_equal(path, "/nix/store")
 #if ! HAVE_SPLIT_USR
                 || path_equal(path, "/usr")
 #endif