ZFS legacy mounting not working after recent version update (zfs: 2.0.0 -> 2.0.1)

[Philipp-M]

Describe the bug

When booting with ZFS legacy mountpoints like this:

{
  fileSystems."/tank/media" = {
    device = "tank/media";
    fsType = "zfs";
  };
  boot.supportedFilesystems = [ "zfs" ];
  boot.zfs.enableUnstable = true; # this doesn't seem to matter
}

the boot fails as described in this post:
https://discourse.nixos.org/t/since-updating-zfs-recently-one-of-my-volumes-fails-to-mount-at-boot/11054

To Reproduce
I guess this is difficult if not anyone is having this issue with legacy mountpoints, but it seems that in the linked discourse post, I'm not the only one with this issue.

But I've tested it just on this commit: e44a4ab
where it fails, and on this (just one commit before): c92a996
And there everything works.

Expected behavior

Mounting of legacy ZFS mountpoints succeeds while booting.

Notify maintainers
@hmenke @jcumming @jonringer @wizeman @fpletz @globin @Mic92

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/since-updating-zfs-recently-one-of-my-volumes-fails-to-mount-at-boot/11054/9

[Mic92]

Can you check if this is fixed by openzfs/zfs@03f036c ?

[edmundmiller]

@Mic92 I tried with this overlay:

self: super: {
  zfs = super.zfs.overrideAttrs (old: {
    extraPatches = (old.extraPatches or [ ]) ++ [
      (super.fetchpatch {
        url =
          "https://github.com/openzfs/zfs/commit/03f036cbccdd8699f5fe8540ef317595a35bceb8.patch";
        sha256 = "07sx98d422589gxr8wflfpkdd0k44kbagxl3b51i56ky2wfix7rc";
      })
    ];
  });
}

Not sure if that's the way to do it, but it didn't work.

[jonringer]

it should probably be

self: super: {
  zfs = super.zfs.overrideAttrs (old: {
    patches = (old.patches or [ ]) ++ [
      (super.fetchpatch {
        url =
          "https://github.com/openzfs/zfs/commit/03f036cbccdd8699f5fe8540ef317595a35bceb8.patch";
        sha256 = "07sx98d422589gxr8wflfpkdd0k44kbagxl3b51i56ky2wfix7rc";
      })
    ];
  });
}

[edmundmiller]

Thanks I tried that, and it didn't work. Not sure how to confirm the patch got applied properly though.

[jonringer]

if you have the log output, you will have something like:

patchPhase
applying patches to ....

[bryanasdev000]

Guys, just to report, I'm in the latest zen with ZFS 2.0.1-1 with encryption, unstable channel and I'm not having any problems.

[Philipp-M]

I've just found time to test this, thanks for the research.

The patch did indeed fix the issue for me!
(I've checked the log output for the application of the patch).

For the sake of completeness the overlay I've applied (needed a slightly different sha256 sum for me):

{
  nixpkgs.overlays = [
    (self: super: {
      zfs = super.zfs.overrideAttrs (old: {
        patches = (old.patches or [ ]) ++ [
          (super.fetchpatch {
            url =
              "https://github.com/openzfs/zfs/commit/03f036cbccdd8699f5fe8540ef317595a35bceb8.patch";
            sha256 = "0b2p8ylhm5dgscjmr650gx1f3lnsvkz4hb9nlx2hllm8v50z3fl2";
          })
        ];
      });
    })
  ];
}

[Mic92]

I've just found time to test this, thanks for the research.

The patch did indeed fix the issue for me!
(I've checked the log output for the application of the patch).

For the sake of completeness the overlay I've applied (needed a slightly different sha256 sum for me):

{
  nixpkgs.overlays = [
    (self: super: {
      zfs = super.zfs.overrideAttrs (old: {
        patches = (old.patches or [ ]) ++ [
          (super.fetchpatch {
            url =
              "https://github.com/openzfs/zfs/commit/03f036cbccdd8699f5fe8540ef317595a35bceb8.patch";
            sha256 = "0b2p8ylhm5dgscjmr650gx1f3lnsvkz4hb9nlx2hllm8v50z3fl2";
          })
        ];
      });
    })
  ];
}

Could you make a PR adding the patch to zfs?