Turn fileSystems into an attribute set

So now you can write

  fileSystems =
    [ { mountPoint = "/";
        device = "/dev/sda1";
      }
    ];

as

  fileSystems."/".device = "/dev/sda1";

doc/manual/installation.xml

@@ -230,11 +230,7 @@ $ reboot</screen>
 {
   boot.loader.grub.device = "/dev/sda";
 
-  fileSystems =
+  fileSystems."/".device = "/dev/disk/by-label/nixos";
-    [ { mountPoint = "/";
-        device = "/dev/disk/by-label/nixos";
-      }
-    ];
 
   swapDevices =
     [ { device = "/dev/disk/by-label/swap"; } ];

modules/installer/cd-dvd/iso-image.nix

@@ -184,17 +184,13 @@ in
   # Note that /dev/root is a symlink to the actual root device
   # specified on the kernel command line, created in the stage 1 init
   # script.
-  fileSystems =
+  fileSystems."/".device = "/dev/root";
-    [ { mountPoint = "/";
+
-        device = "/dev/root";
+  fileSystems."/nix/store" =
-      }
+    { fsType = "squashfs";
-      { mountPoint = "/nix/store";
-        fsType = "squashfs";
       device = "/nix-store.squashfs";
       options = "loop";
-        neededForBoot = true;
+    };
-      }
-    ];
 
   # We need squashfs in the initrd to mount the compressed Nix store,
   # and aufs to make the root filesystem appear writable.

modules/installer/tools/nixos-option.sh

@@ -239,17 +239,14 @@ if $generate; then
   # Add filesystem entries for each partition that you want to see
   # mounted at boot time.  This should include at least the root
   # filesystem.
-  fileSystems =
-    [ # { mountPoint = "/";
-      #   device = "/dev/disk/by-label/nixos";
-      # }
 
-      # { mountPoint = "/data"; # where you want to mount the device
+  # fileSystems."/".device = "/dev/disk/by-label/nixos";
-      #   device = "/dev/sdb";  # the device
+
+  # fileSystems."/data" =     # where you want to mount the device
+  #   { device = "/dev/sdb";  # the device
   #     fsType = "ext3";      # the type of the partition
   #     options = "data=journal";
-      # }
+  #   };
-    ];
 
   # List swap partitions activated at boot time.
   swapDevices =

modules/system/boot/stage-1.nix

@@ -99,9 +99,12 @@ let
       options.neededForBoot = mkOption {
         default = false;
         type = types.bool;
-        description = "
+        description = ''
-          Mount this file system to boot on NixOS.
+          If set, this file system will be mounted in the initial
-        ";
+          ramdisk.  By default, this applies to the root file system
+          and to the file system containing
+          <filename>/nix/store</filename>.
+        '';
       };
     };
 
@@ -236,8 +239,8 @@ let
   # booting (such as the FS containing /nix/store, or an FS needed for
   # mounting /, like / on a loopback).
   fileSystems = filter
-    (fs: fs.mountPoint == "/" || fs.neededForBoot)
+    (fs: fs.mountPoint == "/" || fs.mountPoint == "/nix" || fs.mountPoint == "/nix/store" || fs.neededForBoot)
-    config.fileSystems;
+    (attrValues config.fileSystems);
 
 
   udevRules = pkgs.stdenv.mkDerivation {

modules/tasks/filesystems.nix

@@ -5,12 +5,14 @@ with utils;
 
 let
 
+  fileSystems = attrValues config.fileSystems;
+
   fstab = pkgs.writeText "fstab"
     ''
       # This is a generated file.  Do not edit!
 
       # Filesystems.
-      ${flip concatMapStrings config.fileSystems (fs:
+      ${flip concatMapStrings fileSystems (fs:
           (if fs.device != null then fs.device else "/dev/disk/by-label/${fs.label}")
           + " " + fs.mountPoint
           + " " + fs.fsType
@@ -27,47 +29,7 @@ let
       )}
     '';
 
-in
+  fileSystemOpts = { name, ... }: {
-
-{
-
-  ###### interface
-
-  options = {
-
-    fileSystems = mkOption {
-      example = [
-        { mountPoint = "/";
-          device = "/dev/hda1";
-        }
-        { mountPoint = "/data";
-          device = "/dev/hda2";
-          fsType = "ext3";
-          options = "data=journal";
-        }
-        { mountPoint = "/bigdisk";
-          label = "bigdisk";
-        }
-      ];
-
-      description = ''
-        The file systems to be mounted.  It must include an entry for
-        the root directory (<literal>mountPoint = \"/\"</literal>).  Each
-        entry in the list is an attribute set with the following fields:
-        <literal>mountPoint</literal>, <literal>device</literal>,
-        <literal>fsType</literal> (a file system type recognised by
-        <command>mount</command>; defaults to
-        <literal>\"auto\"</literal>), and <literal>options</literal>
-        (the mount options passed to <command>mount</command> using the
-        <option>-o</option> flag; defaults to <literal>\"defaults\"</literal>).
-
-        Instead of specifying <literal>device</literal>, you can also
-        specify a volume label (<literal>label</literal>) for file
-        systems that support it, such as ext2/ext3 (see <command>mke2fs
-        -L</command>).
-      '';
-
-      type = types.list types.optionSet;
 
     options = {
 
@@ -122,7 +84,51 @@ in
         type = types.bool;
         description = "Disable running fsck on this filesystem.";
       };
+
     };
+
+    config = {
+      mountPoint = mkDefault name;
+    };
+
+  };
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    fileSystems = mkOption {
+      example = {
+        "/".device = "/dev/hda1";
+        "/data" = {
+          device = "/dev/hda2";
+          fsType = "ext3";
+          options = "data=journal";
+        };
+        "/bigdisk".label = "bigdisk";
+      };
+      type = types.loaOf types.optionSet;
+      options = [ fileSystemOpts ];
+      description = ''
+        The file systems to be mounted.  It must include an entry for
+        the root directory (<literal>mountPoint = \"/\"</literal>).  Each
+        entry in the list is an attribute set with the following fields:
+        <literal>mountPoint</literal>, <literal>device</literal>,
+        <literal>fsType</literal> (a file system type recognised by
+        <command>mount</command>; defaults to
+        <literal>\"auto\"</literal>), and <literal>options</literal>
+        (the mount options passed to <command>mount</command> using the
+        <option>-o</option> flag; defaults to <literal>\"defaults\"</literal>).
+
+        Instead of specifying <literal>device</literal>, you can also
+        specify a volume label (<literal>label</literal>) for file
+        systems that support it, such as ext2/ext3 (see <command>mke2fs
+        -L</command>).
+      '';
     };
 
     system.fsPackages = mkOption {
@@ -152,12 +158,11 @@ in
 
   config = {
 
-    boot.supportedFilesystems =
+    boot.supportedFilesystems = map (fs: fs.fsType) fileSystems;
-      map (fs: fs.fsType) config.fileSystems;
 
     boot.initrd.supportedFilesystems =
       map (fs: fs.fsType)
-        (filter (fs: fs.mountPoint == "/" || fs.neededForBoot) config.fileSystems);
+        (filter (fs: fs.mountPoint == "/" || fs.neededForBoot) fileSystems);
 
     # Add the mount helpers to the system path so that `mount' can find them.
     system.fsPackages = [ pkgs.dosfstools ];
@@ -207,7 +212,7 @@ in
             serviceConfig.Type = "oneshot";
           };
 
-      in listToAttrs (map formatDevice (filter (fs: fs.autoFormat) config.fileSystems));
+      in listToAttrs (map formatDevice (filter (fs: fs.autoFormat) fileSystems));
 
   };
 

modules/virtualisation/amazon-image.nix

@@ -62,11 +62,7 @@ with pkgs.lib;
         ''
     );
 
-  fileSystems =
+  fileSystems."/".device = "/dev/disk/by-label/nixos";
-    [ { mountPoint = "/";
-        device = "/dev/disk/by-label/nixos";
-      }
-    ];
 
   boot.initrd.kernelModules = [ "xen-blkfront" "aufs" ];
   boot.kernelModules = [ "xen-netfront" ];

modules/virtualisation/nova-image.nix

@@ -68,11 +68,7 @@ with pkgs.lib;
         ''
     );
 
-  fileSystems =
+  fileSystems."/".device = "/dev/disk/by-label/nixos";
-    [ { mountPoint = "/";
-        device = "/dev/disk/by-label/nixos";
-      }
-    ];
 
   boot.kernelParams = [ "console=ttyS0" ];
 

modules/virtualisation/qemu-vm.nix

@@ -320,35 +320,33 @@ in
   # where the regular value for the `fileSystems' attribute should be
   # disregarded for the purpose of building a VM test image (since
   # those filesystems don't exist in the VM).
-  fileSystems = mkOverride 50 (
+  fileSystems =
-    [ { mountPoint = "/";
+    { "/".device = "/dev/vda";
-        device = "/dev/vda";
+      "/nix/store" =
-      }
+        { device = "//10.0.2.4/store";
-      { mountPoint = "/nix/store";
+          fsType = "cifs";
-        device = "//10.0.2.4/store";
+          options = "guest,sec=none,noperm,noacl";
+        };
+      "/tmp/xchg" =
+        { device = "//10.0.2.4/xchg";
           fsType = "cifs";
           options = "guest,sec=none,noperm,noacl";
           neededForBoot = true;
-      }
+        };
-      { mountPoint = "/tmp/xchg";
+      "/tmp/shared" =
-        device = "//10.0.2.4/xchg";
+        { device = "//10.0.2.4/shared";
           fsType = "cifs";
           options = "guest,sec=none,noperm,noacl";
           neededForBoot = true;
-      }
+        };
-      { mountPoint = "/tmp/shared";
+    } // optionalAttrs cfg.useBootLoader
-        device = "//10.0.2.4/shared";
+    { "/boot" =
-        fsType = "cifs";
+        { device = "/dev/disk/by-label/boot";
-        options = "guest,sec=none,noperm,noacl";
-        neededForBoot = true;
-      }
-    ] ++ optional cfg.useBootLoader
-      { mountPoint = "/boot";
-        device = "/dev/disk/by-label/boot";
           fsType = "ext4";
           options = "ro";
           noCheck = true; # fsck fails on a r/o filesystem
-      });
+        };
+    };
 
   swapDevices = mkOverride 50 [ ];
 

modules/virtualisation/virtualbox-image.nix

@@ -71,11 +71,7 @@ with pkgs.lib;
         ''
     );
 
-  fileSystems =
+  fileSystems."/".device = "/dev/disk/by-label/nixos";
-    [ { mountPoint = "/";
-        device = "/dev/disk/by-label/nixos";
-      }
-    ];
 
   boot.loader.grub.version = 2;
   boot.loader.grub.device = "/dev/sda";