types btrfs: inline subvolumes

lib/types/btrfs.nix

@@ -17,7 +17,36 @@
       description = "A list of options to pass to mount.";
     };
     subvolumes = lib.mkOption {
-      type = lib.types.attrsOf diskoLib.types.btrfs_subvol;
+      type = lib.types.attrsOf (lib.types.submodule ({ config, ... }: {
+        options = {
+          name = lib.mkOption {
+            type = lib.types.str;
+            default = config._module.args.name;
+            description = "Name of the BTRFS subvolume.";
+          };
+          type = lib.mkOption {
+            type = lib.types.enum [ "btrfs_subvol" ];
+            default = "btrfs_subvol";
+            internal = true;
+            description = "Type";
+          };
+          extraArgs = lib.mkOption {
+            type = lib.types.listOf lib.types.str;
+            default = [ ];
+            description = "Extra arguments";
+          };
+          mountOptions = lib.mkOption {
+            type = lib.types.listOf lib.types.str;
+            default = [ "defaults" ];
+            description = "Options to pass to mount";
+          };
+          mountpoint = lib.mkOption {
+            type = lib.types.nullOr diskoLib.optionTypes.absolute-pathname;
+            default = null;
+            description = "Location to mount the subvolume to.";
+          };
+        };
+      }));
       default = { };
       description = "Subvolumes to define for BTRFS.";
     };
@@ -30,22 +59,46 @@
       internal = true;
       readOnly = true;
       type = lib.types.functionTo diskoLib.jsonType;
-      default = dev:
+      default = dev: { };
-        diskoLib.deepMergeMap (subvol: subvol._meta dev) (lib.attrValues config.subvolumes);
       description = "Metadata";
     };
     _create = diskoLib.mkCreateOption {
       inherit config options;
       default = { dev }: ''
         mkfs.btrfs ${dev} ${toString config.extraArgs}
-        ${lib.concatMapStrings (subvol: subvol._create { inherit dev; }) (lib.attrValues config.subvolumes)}
+        ${lib.concatMapStrings (subvol: ''
+          MNTPOINT=$(mktemp -d)
+          (
+            mount ${dev} "$MNTPOINT" -o subvol=/
+            trap 'umount $MNTPOINT; rm -rf $MNTPOINT' EXIT
+            btrfs subvolume create "$MNTPOINT"/${subvol.name} ${toString subvol.extraArgs}
+          )
+        '') (lib.attrValues config.subvolumes)}
       '';
     };
     _mount = diskoLib.mkMountOption {
       inherit config options;
       default = { dev }:
         let
-          subvolMounts = diskoLib.deepMergeMap (subvol: subvol._mount { inherit dev; parent = config.mountpoint; }) (lib.attrValues config.subvolumes);
+          subvolMounts = lib.concatMapAttrs
+            (_: subvol:
+              let
+                mountpoint =
+                  if (subvol.mountpoint != null) then subvol.mountpoint
+                  else if (config.mountpoint == null) then subvol.name
+                  else null;
+              in
+              lib.optionalAttrs (mountpoint != null) {
+                fs.${mountpoint} = ''
+                  if ! findmnt ${dev} "${rootMountPoint}${mountpoint}" > /dev/null 2>&1; then
+                    mount ${dev} "${rootMountPoint}${mountpoint}" \
+                    ${lib.concatMapStringsSep " " (opt: "-o ${opt}") (subvol.mountOptions ++ [ "subvol=${subvol.name}" ])} \
+                    -o X-mount.mkdir
+                  fi
+                '';
+              }
+            )
+            config.subvolumes;
         in
         {
           fs = subvolMounts.fs // lib.optionalAttrs (config.mountpoint != null) {
@@ -63,7 +116,23 @@
       internal = true;
       readOnly = true;
       default = dev: [
-        (map (subvol: subvol._config dev config.mountpoint) (lib.attrValues config.subvolumes))
+        (map
+          (subvol:
+            let
+              mountpoint =
+                if (subvol.mountpoint != null) then subvol.mountpoint
+                else if (config.mountpoint == null) then subvol.name
+                else null;
+            in
+            lib.optional (mountpoint != null) {
+              fileSystems.${mountpoint} = {
+                device = dev;
+                fsType = "btrfs";
+                options = subvol.mountOptions ++ [ "subvol=${subvol.name}" ];
+              };
+            }
+          )
+          (lib.attrValues config.subvolumes))
         (lib.optional (config.mountpoint != null) {
           fileSystems.${config.mountpoint} = {
             device = dev;
@@ -79,7 +148,7 @@
       readOnly = true;
       type = lib.types.functionTo (lib.types.listOf lib.types.package);
       default = pkgs:
-        [ pkgs.btrfs-progs ] ++ lib.flatten (map (subvolume: subvolume._pkgs pkgs) (lib.attrValues config.subvolumes));
+        [ pkgs.btrfs-progs pkgs.coreutils ];
       description = "Packages";
     };
   };

lib/types/btrfs_subvol.nix

@@ -1,94 +0,0 @@
-{ config, options, diskoLib, lib, rootMountPoint, ... }:
-{
-  options = {
-    name = lib.mkOption {
-      type = lib.types.str;
-      default = config._module.args.name;
-      description = "Name of the BTRFS subvolume.";
-    };
-    type = lib.mkOption {
-      type = lib.types.enum [ "btrfs_subvol" ];
-      default = "btrfs_subvol";
-      internal = true;
-      description = "Type";
-    };
-    extraArgs = lib.mkOption {
-      type = lib.types.listOf lib.types.str;
-      default = [ ];
-      description = "Extra arguments";
-    };
-    mountOptions = lib.mkOption {
-      type = lib.types.listOf lib.types.str;
-      default = [ "defaults" ];
-      description = "Options to pass to mount";
-    };
-    mountpoint = lib.mkOption {
-      type = lib.types.nullOr diskoLib.optionTypes.absolute-pathname;
-      default = null;
-      description = "Location to mount the subvolume to.";
-    };
-    _meta = lib.mkOption {
-      internal = true;
-      readOnly = true;
-      type = lib.types.functionTo diskoLib.jsonType;
-      default = dev: { };
-      description = "Metadata";
-    };
-    _create = diskoLib.mkCreateOption {
-      inherit config options;
-      default = { dev }: ''
-        MNTPOINT=$(mktemp -d)
-        (
-          mount ${dev} "$MNTPOINT" -o subvol=/
-          trap 'umount $MNTPOINT; rm -rf $MNTPOINT' EXIT
-          btrfs subvolume create "$MNTPOINT"/${config.name} ${toString config.extraArgs}
-        )
-      '';
-    };
-    _mount = diskoLib.mkMountOption {
-      inherit config options;
-      default = { dev, parent }:
-        let
-          mountpoint =
-            if (config.mountpoint != null) then config.mountpoint
-            else if (parent == null) then config.name
-            else null;
-        in
-        lib.optionalAttrs (mountpoint != null) {
-          fs.${mountpoint} = ''
-            if ! findmnt ${dev} "${rootMountPoint}${mountpoint}" > /dev/null 2>&1; then
-              mount ${dev} "${rootMountPoint}${mountpoint}" \
-              ${lib.concatMapStringsSep " " (opt: "-o ${opt}") (config.mountOptions ++ [ "subvol=${config.name}" ])} \
-              -o X-mount.mkdir
-            fi
-          '';
-        };
-    };
-    _config = lib.mkOption {
-      internal = true;
-      readOnly = true;
-      default = dev: parent:
-        let
-          mountpoint =
-            if (config.mountpoint != null) then config.mountpoint
-            else if (parent == null) then config.name
-            else null;
-        in
-        lib.optional (mountpoint != null) {
-          fileSystems.${mountpoint} = {
-            device = dev;
-            fsType = "btrfs";
-            options = config.mountOptions ++ [ "subvol=${config.name}" ];
-          };
-        };
-      description = "NixOS configuration";
-    };
-    _pkgs = lib.mkOption {
-      internal = true;
-      readOnly = true;
-      type = lib.types.functionTo (lib.types.listOf lib.types.package);
-      default = pkgs: [ pkgs.coreutils ];
-      description = "Packages";
-    };
-  };
-}