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|
{ config, lib, pkgs, utils, ... }:
let
bootFs = lib.filterAttrs (n: fs: (fs.fsType == "bcachefs") && (utils.fsNeededForBoot fs)) config.fileSystems;
commonFunctions = ''
prompt() {
local name="$1"
printf "enter passphrase for $name: "
}
tryUnlock() {
local name="$1"
local path="$2"
local success=false
local target
local uuid=$(echo -n $path | sed -e 's,UUID=\(.*\),\1,g')
printf "waiting for device to appear $path"
for try in $(seq 10); do
if [ -e $path ]; then
target=$(readlink -f $path)
success=true
break
else
target=$(blkid --uuid $uuid)
if [ $? == 0 ]; then
success=true
break
fi
fi
echo -n "."
sleep 1
done
printf "\n"
if [ $success == true ]; then
path=$target
fi
if bcachefs unlock -c $path > /dev/null 2> /dev/null; then # test for encryption
prompt $name
until bcachefs unlock $path 2> /dev/null; do # repeat until successfully unlocked
printf "unlocking failed!\n"
prompt $name
done
printf "unlocking successful.\n"
else
echo "Cannot unlock device $uuid with path $path" >&2
fi
}
'';
# we need only unlock one device manually, and cannot pass multiple at once
# remove this adaptation when bcachefs implements mounting by filesystem uuid
# also, implement automatic waiting for the constituent devices when that happens
# bcachefs does not support mounting devices with colons in the path, ergo we don't (see #49671)
firstDevice = fs: lib.head (lib.splitString ":" fs.device);
useClevis = fs: config.boot.initrd.clevis.enable && (lib.hasAttr (firstDevice fs) config.boot.initrd.clevis.devices);
openCommand = name: fs: if useClevis fs then ''
if clevis decrypt < /etc/clevis/${firstDevice fs}.jwe | bcachefs unlock ${firstDevice fs}
then
printf "unlocked ${name} using clevis\n"
else
printf "falling back to interactive unlocking...\n"
tryUnlock ${name} ${firstDevice fs}
fi
'' else ''
tryUnlock ${name} ${firstDevice fs}
'';
mkUnits = prefix: name: fs: let
mountUnit = "${utils.escapeSystemdPath (prefix + (lib.removeSuffix "/" fs.mountPoint))}.mount";
device = firstDevice fs;
deviceUnit = "${utils.escapeSystemdPath device}.device";
in {
name = "unlock-bcachefs-${utils.escapeSystemdPath fs.mountPoint}";
value = {
description = "Unlock bcachefs for ${fs.mountPoint}";
requiredBy = [ mountUnit ];
after = [ deviceUnit ];
before = [ mountUnit "shutdown.target" ];
bindsTo = [ deviceUnit ];
conflicts = [ "shutdown.target" ];
unitConfig.DefaultDependencies = false;
serviceConfig = {
Type = "oneshot";
ExecCondition = "${pkgs.bcachefs-tools}/bin/bcachefs unlock -c \"${device}\"";
Restart = "on-failure";
RestartMode = "direct";
# Ideally, this service would lock the key on stop.
# As is, RemainAfterExit doesn't accomplish anything.
RemainAfterExit = true;
};
script = let
unlock = ''${pkgs.bcachefs-tools}/bin/bcachefs unlock "${device}"'';
unlockInteractively = ''${config.boot.initrd.systemd.package}/bin/systemd-ask-password --timeout=0 "enter passphrase for ${name}" | exec ${unlock}'';
in if useClevis fs then ''
if ${config.boot.initrd.clevis.package}/bin/clevis decrypt < "/etc/clevis/${device}.jwe" | ${unlock}
then
printf "unlocked ${name} using clevis\n"
else
printf "falling back to interactive unlocking...\n"
${unlockInteractively}
fi
'' else ''
${unlockInteractively}
'';
};
};
assertions = [
{
assertion = let
kernel = config.boot.kernelPackages.kernel;
in (
kernel.kernelAtLeast "6.7" || (
lib.elem (kernel.structuredExtraConfig.BCACHEFS_FS or null) [
lib.kernel.module
lib.kernel.yes
(lib.kernel.option lib.kernel.yes)
]
)
);
message = "Linux 6.7-rc1 at minimum or a custom linux kernel with bcachefs support is required";
}
];
in
{
config = lib.mkIf (config.boot.supportedFilesystems.bcachefs or false) (lib.mkMerge [
{
inherit assertions;
# needed for systemd-remount-fs
system.fsPackages = [ pkgs.bcachefs-tools ];
# FIXME: Remove this line when the LTS (default) kernel is at least version 6.7
boot.kernelPackages = lib.mkDefault pkgs.linuxPackages_latest;
services.udev.packages = [ pkgs.bcachefs-tools ];
systemd = {
packages = [ pkgs.bcachefs-tools ];
services = lib.mapAttrs' (mkUnits "") (lib.filterAttrs (n: fs: (fs.fsType == "bcachefs") && (!utils.fsNeededForBoot fs)) config.fileSystems);
};
}
(lib.mkIf ((config.boot.initrd.supportedFilesystems.bcachefs or false) || (bootFs != {})) {
inherit assertions;
# chacha20 and poly1305 are required only for decryption attempts
boot.initrd.availableKernelModules = [ "bcachefs" "sha256" "chacha20" "poly1305" ];
boot.initrd.systemd.extraBin = {
# do we need this? boot/systemd.nix:566 & boot/systemd/initrd.nix:357
"bcachefs" = "${pkgs.bcachefs-tools}/bin/bcachefs";
"mount.bcachefs" = "${pkgs.bcachefs-tools}/bin/mount.bcachefs";
};
boot.initrd.extraUtilsCommands = lib.mkIf (!config.boot.initrd.systemd.enable) ''
copy_bin_and_libs ${pkgs.bcachefs-tools}/bin/bcachefs
copy_bin_and_libs ${pkgs.bcachefs-tools}/bin/mount.bcachefs
'';
boot.initrd.extraUtilsCommandsTest = lib.mkIf (!config.boot.initrd.systemd.enable) ''
$out/bin/bcachefs version
'';
boot.initrd.postDeviceCommands = lib.mkIf (!config.boot.initrd.systemd.enable) (commonFunctions + lib.concatStrings (lib.mapAttrsToList openCommand bootFs));
boot.initrd.systemd.services = lib.mapAttrs' (mkUnits "/sysroot") bootFs;
})
]);
}
|