Add declarative unmount

cli.nix

@@ -23,6 +23,7 @@ let
           destroy = "_cliDestroyNoDeps";
           format = "_cliFormatNoDeps";
           mount = "_cliMountNoDeps";
+          unmount = "_cliUnmountNoDeps";
 
           "format,mount" = "_cliFormatMountNoDeps";
           "destroy,format,mount" = "_cliDestroyFormatMountNoDeps";
@@ -32,6 +33,7 @@ let
           destroy = "destroyNoDeps";
           format = "formatNoDeps";
           mount = "mountNoDeps";
+          unmount = "unmountNoDeps";
 
           "format,mount" = "formatMountNoDeps";
           "destroy,format,mount" = "destroyFormatMountNoDeps";
@@ -47,6 +49,7 @@ let
           destroy = "_cliDestroy";
           format = "_cliFormat";
           mount = "_cliMount";
+          unmount = "_cliUnmount";
 
           "format,mount" = "_cliFormatMount";
           "destroy,format,mount" = "_cliDestroyFormatMount";
@@ -55,7 +58,8 @@ let
         {
           destroy = "destroy";
           format = "format";
-          mount = "munt";
+          mount = "mount";
+          unmount = "unmount";
 
           "format,mount" = "formatMount";
           "destroy,format,mount" = "destroyFormatMount";

default.nix

@@ -31,6 +31,9 @@ in
   _cliMount = cfg: pkgs: ((eval cfg).config.disko.devices._scripts { inherit pkgs checked; }).mount;
   _cliMountNoDeps = cfg: pkgs: ((eval cfg).config.disko.devices._scripts { inherit pkgs checked; }).mountNoDeps;
 
+  _cliUnmount = cfg: pkgs: ((eval cfg).config.disko.devices._scripts { inherit pkgs checked; }).unmount;
+  _cliUnmountNoDeps = cfg: pkgs: ((eval cfg).config.disko.devices._scripts { inherit pkgs checked; }).unmountNoDeps;
+
   _cliFormatMount = cfg: pkgs: ((eval cfg).config.disko.devices._scripts { inherit pkgs checked; }).formatMount;
   _cliFormatMountNoDeps = cfg: pkgs: ((eval cfg).config.disko.devices._scripts { inherit pkgs checked; }).formatMountNoDeps;
 

disko

@@ -26,7 +26,7 @@ or else from the disko module of a NixOS configuration of that name under .nixos
 Options:
 
 * -m, --mode mode
-  set the mode, either distroy, format, mount, format,mount or destroy,format,mount
+  set the mode, either distroy, format, mount, unmount, format,mount or destroy,format,mount
     destroy: unmount filesystems and destroy partition tables of the selected disks
     format: create partition tables, zpools, lvms, raids and filesystems if they don't exist yet
     mount: mount the partitions at the specified root-mountpoint
@@ -136,7 +136,7 @@ nixBuild() {
 
 if ! {
   # Base modes
-  [[ $mode = "destroy" ]] || [[ $mode = "format" ]] || [[ $mode = "mount" ]] ||
+  [[ $mode = "destroy" ]] || [[ $mode = "format" ]] || [[ $mode = "mount" ]] || [[ $mode = "unmount" ]] ||
   # Combined modes
   [[ $mode = "format,mount" ]] ||
   [[ $mode = "destroy,format,mount" ]] || # Replaces --mode disko

lib/default.nix

@@ -242,6 +242,8 @@ let
           postCreateHook = diskoLib.mkHook "shell commands to run after create";
           preMountHook = diskoLib.mkHook "shell commands to run before mount";
           postMountHook = diskoLib.mkHook "shell commands to run after mount";
+          preUnmountHook = diskoLib.mkHook "shell commands to run before unmount";
+          postUnmountHook = diskoLib.mkHook "shell commands to run after unmount";
         };
         config._module.args = {
           inherit diskoLib rootMountPoint;
@@ -284,6 +286,25 @@ let
         description = "Mount script";
       };
 
+    mkUnmountOption = { config, options, default }@attrs:
+      lib.mkOption {
+        internal = true;
+        readOnly = true;
+        type = diskoLib.jsonType;
+        default = lib.mapAttrsRecursive
+          (_name: value:
+            if builtins.isString value then ''
+              (
+                ${diskoLib.indent (diskoLib.defineHookVariables { inherit options; })}
+                ${diskoLib.indent config.preUnmountHook}
+                ${diskoLib.indent value}
+                ${diskoLib.indent config.postUnmountHook}
+              )
+            '' else value)
+          attrs.default;
+        description = "Unmount script";
+      };
+
     /* Writer for optionally checking bash scripts before writing them to the store
 
        writeCheckedBash :: AttrSet -> str -> str -> derivation
@@ -458,6 +479,10 @@ let
                   export PATH=${lib.makeBinPath (cfg.config._packages pkgs)}:$PATH
                   ${cfg.config._mount}
                 '';
+                unmount = (diskoLib.writeCheckedBash { inherit pkgs checked; }) "/bin/disko-unmount" ''
+                  export PATH=${lib.makeBinPath (cfg.config._packages pkgs)}:$PATH
+                  ${cfg.config._unmount}
+                '';
                 formatMount = (diskoLib.writeCheckedBash { inherit pkgs checked; }) "/bin/disko-format-mount" ''
                   export PATH=${lib.makeBinPath ((cfg.config._packages pkgs) ++ [ pkgs.bash ])}:$PATH
                   ${cfg.config._formatMount}
@@ -477,6 +502,9 @@ let
                 mountNoDeps = (diskoLib.writeCheckedBash { inherit pkgs checked; noDeps = true; }) "/bin/disko-mount" ''
                   ${cfg.config._mount}
                 '';
+                unmountNoDeps = (diskoLib.writeCheckedBash { inherit pkgs checked; noDeps = true; }) "/bin/disko-unmount" ''
+                  ${cfg.config._unmount}
+                '';
                 formatMountNoDeps = (diskoLib.writeCheckedBash { inherit pkgs checked; noDeps = true; }) "/bin/disko-format-mount" ''
                   ${cfg.config._formatMount}
                 '';
@@ -622,6 +650,26 @@ let
                 ${concatStrings (attrValues fsMounts)}
               '';
           };
+          _unmount = lib.mkOption {
+            internal = true;
+            type = lib.types.str;
+            description = ''
+              The script to unmount all devices defined by disko.devices
+            '';
+            default =
+              with lib; let
+                fsMounts = diskoLib.deepMergeMap (dev: dev._unmount.fs or { }) (flatten (map attrValues (attrValues devices)));
+                sortedDeviceList = diskoLib.sortDevicesByDependencies (cfg.config._meta.deviceDependencies or { }) devices;
+              in
+              ''
+                set -efux
+                # first unmount the filesystems in reverse alphabetical order
+                ${concatStrings (lib.reverseList (attrValues fsMounts))}
+
+                # Than close the devices
+                ${concatMapStrings (dev: (attrByPath (dev ++ [ "_unmount" ]) {} devices).dev or "") (lib.reverseList sortedDeviceList)}
+              '';
+          };
           _disko = lib.mkOption {
             internal = true;
             type = lib.types.str;

lib/tests.nix

@@ -99,6 +99,7 @@ let
         tsp-generator = pkgs.callPackage ../. { checked = true; };
         tsp-format = (tsp-generator._cliFormat testConfigInstall) pkgs;
         tsp-mount = (tsp-generator._cliMount testConfigInstall) pkgs;
+        tsp-unmount = (tsp-generator._cliUnmount testConfigInstall) pkgs;
         tsp-disko = (tsp-generator._cliDestroyFormatMount testConfigInstall) pkgs;
         tsp-config = tsp-generator.config testConfigBooted;
         num-disks = builtins.length (lib.attrNames testConfigBooted.disko.devices.disk);
@@ -282,6 +283,9 @@ let
             machine.succeed("${lib.getExe tsp-format}")
             machine.succeed("${lib.getExe tsp-mount}")
             machine.succeed("${lib.getExe tsp-mount}") # verify that mount is idempotent
+            machine.succeed("${lib.getExe tsp-unmount}")
+            machine.succeed("${lib.getExe tsp-unmount}") # verify that umount is idempotent
+            machine.succeed("${lib.getExe tsp-mount}") # verify that mount is idempotent
             machine.succeed("${lib.getExe tsp-disko} --yes-wipe-all-disks") # verify that we can destroy and recreate
             machine.succeed("mkdir -p /mnt/home")
             machine.succeed("touch /mnt/home/testfile")

lib/types/btrfs.nix

@@ -199,6 +199,34 @@ in
           };
         };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default =
+        let
+          subvolMounts = lib.concatMapAttrs
+            (_: subvol:
+              lib.optionalAttrs
+              (subvol.mountpoint != null)
+              {
+                ${subvol.mountpoint} = ''
+                  if findmnt "${config.device}" "${rootMountPoint}${subvol.mountpoint}" > /dev/null 2>&1; then
+                    umount "${rootMountPoint}${subvol.mountpoint}"
+                  fi
+                '';
+              }
+            )
+            config.subvolumes;
+        in
+        {
+          fs = subvolMounts // lib.optionalAttrs (config.mountpoint != null) {
+            ${config.mountpoint} = ''
+              if findmnt "${config.device}" "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+                umount "${rootMountPoint}${config.mountpoint}"
+              fi
+            '';
+          };
+        };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/disk.nix

@@ -49,6 +49,10 @@
       inherit config options;
       default = lib.optionalAttrs (config.content != null) config.content._mount;
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = lib.optionalAttrs (config.content != null) config.content._unmount;
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/filesystem.nix

@@ -64,6 +64,16 @@
         '';
       };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = lib.optionalAttrs (config.mountpoint != null) {
+        fs.${config.mountpoint} = ''
+          if findmnt "${config.device}" "${rootMountPoint}${config.mountpoint}" >/dev/null 2>&1; then
+            umount "${rootMountPoint}${config.mountpoint}"
+          fi
+        '';
+      };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/gpt.nix

@@ -45,7 +45,7 @@ in
             defaultText = ''
               if the parent is an mdadm device:
                 /dev/disk/by-id/md-name-any:''${config._parent.name}-part''${toString partition.config._index}
-              
+
               otherwise:
                 /dev/disk/by-partlabel/''${diskoLib.hexEscapeUdevSymlink partition.config.label}
             '';
@@ -249,6 +249,21 @@ in
           fs = partMounts.fs or { };
         };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default =
+        let
+          partMounts = lib.foldr lib.recursiveUpdate { } (map
+            (partition:
+              lib.optionalAttrs (partition.content != null) partition.content._unmount
+            )
+            (lib.attrValues config.partitions));
+        in
+        {
+          dev = partMounts.dev or "";
+          fs = partMounts.fs or { };
+        };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/luks.nix

@@ -170,6 +170,21 @@ in
           fs = lib.optionalAttrs (config.content != null) contentMount.fs or { };
         };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default =
+        let
+          contentUnmount = config.content._unmount;
+        in
+          {
+            dev = ''
+              ${lib.optionalString (config.content != null) contentUnmount.dev or ""}
+              if cryptsetup status "${config.name}" >/dev/null 2>/dev/null; then
+                cryptsetup close "${config.name}"
+              fi
+            '';
+          };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/lvm_pv.nix

@@ -41,6 +41,10 @@
       inherit config options;
       default = { };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = { };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/lvm_vg.nix

@@ -127,6 +127,23 @@ in
           fs = lvMounts.fs or { };
         };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default =
+        let
+          lvMounts = diskoLib.deepMergeMap
+            (lv:
+              lib.optionalAttrs (lv.content != null) lv.content._unmount
+            )
+            (lib.attrValues config.lvs);
+        in {
+          dev = ''
+            ${lib.concatMapStrings (x: x.dev or "") (lib.attrValues lvMounts)}
+            vgchange -a n
+          '';
+          fs = lvMounts.fs or { };
+        };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/mdadm.nix

@@ -58,6 +58,20 @@
         lib.optionalAttrs (config.content != null) config.content._mount;
       # TODO we probably need to assemble the mdadm somehow
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = let
+        content = lib.optionalAttrs (config.content != null) config.content._unmount;
+      in {
+        fs = content.fs;
+        dev = ''
+          ${content.dev or ""}
+          if [ -e "/dev/md/${config.name}" ]; then
+            mdadm --stop "/dev/md/${config.name}"
+          fi
+        '';
+      };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/mdraid.nix

@@ -39,6 +39,10 @@
       inherit config options;
       default = { };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = { };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/nodev.nix

@@ -49,6 +49,16 @@
         '';
       };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = lib.optionalAttrs (config.mountpoint != null) {
+        fs.${config.mountpoint} = ''
+          if findmnt ${config.fsType} "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+            umount "${rootMountPoint}${config.mountpoint}"
+          fi
+        '';
+      };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;

lib/types/swap.nix

@@ -95,6 +95,16 @@
         '';
       };
     };
+    _unmount = diskoLib.mkUnmountOption {
+      inherit config options;
+      default = lib.optionalAttrs (!config.randomEncryption) {
+        fs.${config.device} = ''
+          if swapon --show | grep -q "^$(readlink -f "${config.device}") "; then
+            swapoff "${config.device}"
+          fi
+        '';
+      };
+    };
     _config = lib.mkOption {
       internal = true;
       readOnly = true;