nixos/activation: Avoid remounting non-existing FS

Regression introduced by 79d4636d506094eae3c5c7575a0bef817cba9bda.

The mentioned commit moves /run/keys from stage 2 to
boot.specialFileSystems, the latter being remounted during system
activation.

Unfortunately, the specialMount function in the activation script does
this unconditionally and thus will fail if it can't be remounted because
the mount point simply doesn't exist.

We now check the mount point for existance and only remount if it exists
but mkdir + mount it if it doesn't.

Tested against the "simple" NixOS installer test.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/nixos/modules/system/activation/activation-script.nix b/nixos/modules/system/activation/activation-script.nix
index 4c3d30e346c5..fa0ad747454c 100644
--- a/nixos/modules/system/activation/activation-script.nix
+++ b/nixos/modules/system/activation/activation-script.nix
@@ -167,7 +167,12 @@ in
           local options="$3"
           local fsType="$4"
 
-          ${pkgs.utillinux}/bin/mount -t "$fsType" -o "remount,$options" "$device" "$mountPoint"
+          if ${pkgs.utillinux}/bin/mountpoint -q "$mountPoint"; then
+            local options="remount,$options"
+          else
+            mkdir -m 0755 -p "$mountPoint"
+          fi
+          ${pkgs.utillinux}/bin/mount -t "$fsType" -o "$options" "$device" "$mountPoint"
         }
         source ${config.system.build.earlyMountScript}
       '';