Merge pull request #95751 from srhb/forceImportAll

nixos/zfs: Fix boot.zfs.forceImportAll

nixos/doc/manual/release-notes/rl-2103.xml

@@ -151,6 +151,15 @@
       <literal>vim</literal> switched to Python 3, dropping all Python 2 support.
     </para>
    </listitem>
+   <listitem>
+     <para>
+      <link linkend="opt-boot.zfs.forceImportAll">boot.zfs.forceImportAll</link>
+      previously did nothing, but has been fixed. However its default has been
+      changed to <literal>false</literal> to preserve the existing default
+      behaviour. If you have this explicitly set to <literal>true</literal>,
+      please note that your non-root pools will now be forcibly imported.
+    </para>
+   </listitem>
   </itemizedlist>
  </section>
 

nixos/modules/tasks/filesystems/zfs.nix

@@ -175,14 +175,10 @@ in
 
       forceImportAll = mkOption {
         type = types.bool;
-        default = true;
+        default = false;
         description = ''
           Forcibly import all ZFS pool(s).
 
-          This is enabled by default for backwards compatibility purposes, but it is highly
-          recommended to disable this option, as it bypasses some of the safeguards ZFS uses
-          to protect your ZFS pools.
-
           If you set this option to <literal>false</literal> and NixOS subsequently fails to
           import your non-root ZFS pool(s), you should manually import each pool with
           "zpool import -f &lt;pool-name&gt;", and then reboot. You should only need to do
@@ -507,6 +503,7 @@ in
               Type = "oneshot";
               RemainAfterExit = true;
             };
+            environment.ZFS_FORCE = optionalString cfgZfs.forceImportAll "-f";
             script = (importLib {
               # See comments at importLib definition.
               zpoolCmd="${packages.zfsUser}/sbin/zpool";

nixos/tests/zfs.nix

@@ -18,7 +18,7 @@ let
         maintainers = [ adisbladis ];
       };
 
-      machine = { pkgs, ... }: {
+      machine = { pkgs, lib, ... }: {
         virtualisation.emptyDiskImages = [ 4096 ];
         networking.hostId = "deadbeef";
         boot.kernelPackages = kernelPackage;
@@ -26,6 +26,24 @@ let
         boot.zfs.enableUnstable = enableUnstable;
 
         environment.systemPackages = [ pkgs.parted ];
+
+        # Setup regular fileSystems machinery to ensure forceImportAll can be
+        # tested via the regular service units.
+        fileSystems = lib.mkVMOverride {
+          "/forcepool" = {
+            device = "forcepool";
+            fsType = "zfs";
+            options = [ "noauto" ];
+          };
+        };
+
+        # forcepool doesn't exist at first boot, and we need to manually test
+        # the import after tweaking the hostId.
+        systemd.services.zfs-import-forcepool.wantedBy = lib.mkVMOverride [];
+        systemd.targets.zfs.wantedBy = lib.mkVMOverride [];
+        boot.zfs.forceImportAll = true;
+        # /dev/disk/by-id doesn't get populated in the NixOS test framework
+        boot.zfs.devNodes = "/dev/disk/by-uuid";
       };
 
       testScript = ''
@@ -57,6 +75,21 @@ let
             "zpool destroy rpool",
             "udevadm settle",
         )
+
+        with subtest("boot.zfs.forceImportAll works"):
+            machine.succeed(
+                "rm /etc/hostid",
+                "zgenhostid deadcafe",
+                "zpool create forcepool /dev/vdb1 -O mountpoint=legacy",
+            )
+            machine.shutdown()
+            machine.start()
+            machine.succeed("udevadm settle")
+            machine.fail("zpool import forcepool")
+            machine.succeed(
+                "systemctl start zfs-import-forcepool.service",
+                "mount -t zfs forcepool /tmp/mnt",
+            )
       '' + extraTest;
 
     };