Unverified Commit 4d59ace1 authored by WilliButz's avatar WilliButz
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nixos/systemd-repart: add assertion for partition label length 

The maximum length for a GPT label supported by systemd is 36
characters. When a repart definition contains a label that is longer
than the supported maximum length, it is ignored by systemd-repart and
a log message is produced.

The new assertion makes this obvious to the user at evaluation time,
allowing them to either drop the property entirely or choose a supported
label within the length limit instead.
parent 661d1bec

nixos/modules/system/boot/systemd/repart.nix

+15 −1
Original line number Diff line number Diff line
@@ -10,6 +10,20 @@ let 
    "repart.d"

    format

    (lib.mapAttrs (_n: v: { Partition = v; }) cfg.partitions);



  partitionAssertions = lib.mapAttrsToList (fileName: definition:

    let

      maxLabelLength = 36; # GPT_LABEL_MAX defined in systemd's gpt.h

      labelLength = builtins.stringLength definition.Label;

    in

    {

      assertion = definition ? Label -> maxLabelLength >= labelLength;

      message = ''

        The partition label '${definition.Label}' defined for '${fileName}' is ${toString labelLength}

        characters long, but the maximum label length supported by systemd is ${toString maxLabelLength}.

      '';

    }

  ) cfg.partitions;

in

{

  options = {
@@ -81,7 +95,7 @@ in 
          'boot.initrd.systemd.repart.enable' requires 'boot.initrd.systemd.enable' to be enabled.

        '';

      }

    ];

    ] ++ partitionAssertions;



    # systemd-repart uses loopback devices for partition creation

    boot.initrd.availableKernelModules = lib.optional initrdCfg.enable "loop";