{ config, lib, pkgs, utils, ... }:
with lib;
with utils;
let
fileSystems' = toposort fsBefore (attrValues config.fileSystems);
fileSystems = if fileSystems' ? "result"
then # use topologically sorted fileSystems everywhere
fileSystems'.result
else # the assertion below will catch this,
# but we fall back to the original order
# anyway so that other modules could check
# their assertions too
(attrValues config.fileSystems);
prioOption = prio: optionalString (prio != null) " pri=${toString prio}";
fileSystemOpts = { name, config, ... }: {
options = {
mountPoint = mkOption {
example = "/mnt/usb";
type = types.str;
description = "Location of the mounted the file system.";
};
device = mkOption {
default = null;
example = "/dev/sda";
type = types.nullOr types.str;
description = "Location of the device.";
};
label = mkOption {
default = null;
example = "root-partition";
type = types.nullOr types.str;
description = "Label of the device (if any).";
};
fsType = mkOption {
default = "auto";
example = "ext3";
type = types.str;
description = "Type of the file system.";
};
options = mkOption {
default = [ "defaults" ];
example = [ "data=journal" ];
description = "Options used to mount the file system.";
} // (if versionAtLeast lib.nixpkgsVersion "16.09" then {
type = types.listOf types.str;
} else {
type = types.either types.commas (types.listOf types.str);
apply = x: if isList x then x else lib.strings.splitString "," (builtins.trace "warning: passing a comma-separated string for filesystem options is deprecated; use a list of strings instead. This will become a hard error in 16.09." x);
});
autoFormat = mkOption {
default = false;
type = types.bool;
description = ''
If the device does not currently contain a filesystem (as
determined by <command>blkid</command>, then automatically
format it with the filesystem type specified in
<option>fsType</option>. Use with caution.
'';
};
formatOptions = mkOption {
default = "";
type = types.str;
description = ''
If <option>autoFormat</option> option is set specifies
extra options passed to mkfs.
'';
};
autoResize = mkOption {
default = false;
type = types.bool;
description = ''
If set, the filesystem is grown to its maximum size before
being mounted. (This is typically the size of the containing
partition.) This is currently only supported for ext2/3/4
filesystems that are mounted during early boot.
'';
};
noCheck = mkOption {
default = false;
type = types.bool;
description = "Disable running fsck on this filesystem.";
};
};
config = {
mountPoint = mkDefault name;
device = mkIf (config.fsType == "tmpfs") (mkDefault config.fsType);
options = mkIf config.autoResize [ "x-nixos.autoresize" ];
# -F needed to allow bare block device without partitions
formatOptions = mkIf ((builtins.substring 0 3 config.fsType) == "ext") (mkDefault "-F");
};
};
in
{
###### interface
options = {
fileSystems = mkOption {
default = {};
example = literalExample ''
{
"/".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 {
internal = true;
default = [ ];
description = "Packages supplying file system mounters and checkers.";
};
boot.supportedFilesystems = mkOption {
default = [ ];
example = [ "btrfs" ];
type = types.listOf types.str;
description = "Names of supported filesystem types.";
};
};
###### implementation
config = {
assertions = let
ls = sep: concatMapStringsSep sep (x: x.mountPoint);
in [
{ assertion = ! (fileSystems' ? "cycle");
message = "The ‘fileSystems’ option can't be topologically sorted: mountpoint dependency path ${ls " -> " fileSystems'.cycle} loops to ${ls ", " fileSystems'.loops}";
}
];
# Export for use in other modules
system.build.fileSystems = fileSystems;
boot.supportedFilesystems = map (fs: fs.fsType) fileSystems;
# Add the mount helpers to the system path so that `mount' can find them.
system.fsPackages = [ pkgs.dosfstools ];
environment.systemPackages = [ pkgs.fuse ] ++ config.system.fsPackages;
environment.etc.fstab.text =
let
fsToSkipCheck = [ "none" "btrfs" "zfs" "tmpfs" "nfs" "vboxsf" ];
skipCheck = fs: fs.noCheck || fs.device == "none" || builtins.elem fs.fsType fsToSkipCheck;
in ''
# This is a generated file. Do not edit!
#
# To make changes, edit the fileSystems and swapDevices NixOS options
# in your /etc/nixos/configuration.nix file.
# Filesystems.
${concatMapStrings (fs:
(if fs.device != null then fs.device
else if fs.label != null then "/dev/disk/by-label/${fs.label}"
else throw "No device specified for mount point ‘${fs.mountPoint}’.")
+ " " + fs.mountPoint
+ " " + fs.fsType
+ " " + builtins.concatStringsSep "," fs.options
+ " 0"
+ " " + (if skipCheck fs then "0" else
if fs.mountPoint == "/" then "1" else "2")
+ "\n"
) fileSystems}
# Swap devices.
${flip concatMapStrings config.swapDevices (sw:
"${sw.realDevice} none swap${prioOption sw.priority}\n"
)}
'';
# Provide a target that pulls in all filesystems.
systemd.targets.fs =
{ description = "All File Systems";
wants = [ "local-fs.target" "remote-fs.target" ];
};
# Emit systemd services to format requested filesystems.
systemd.services =
let
formatDevice = fs:
let
mountPoint' = "${escapeSystemdPath fs.mountPoint}.mount";
device' = escapeSystemdPath fs.device;
device'' = "${device}.device";
in nameValuePair "mkfs-${device'}"
{ description = "Initialisation of Filesystem ${fs.device}";
wantedBy = [ mountPoint' ];
before = [ mountPoint' "systemd-fsck@${device'}.service" ];
requires = [ device'' ];
after = [ device'' ];
path = [ pkgs.utillinux ] ++ config.system.fsPackages;
script =
''
if ! [ -e "${fs.device}" ]; then exit 1; fi
# FIXME: this is scary. The test could be more robust.
type=$(blkid -p -s TYPE -o value "${fs.device}" || true)
if [ -z "$type" ]; then
echo "creating ${fs.fsType} filesystem on ${fs.device}..."
mkfs.${fs.fsType} ${fs.formatOptions} "${fs.device}"
fi
'';
unitConfig.RequiresMountsFor = [ "${dirOf fs.device}" ];
unitConfig.DefaultDependencies = false; # needed to prevent a cycle
serviceConfig.Type = "oneshot";
};
in listToAttrs (map formatDevice (filter (fs: fs.autoFormat) fileSystems));
};
}