tests: check canmount ZFS flag is respected

example/non-root-zfs.nix

@@ -59,6 +59,22 @@
           };
         };
       };
+      a = {
+        type = "disk";
+        device = "/dev/sda";
+        content = {
+          type = "gpt";
+          partitions = {
+            zfs = {
+              size = "100%";
+              content = {
+                type = "zfs";
+                pool = "storage2";
+              };
+            };
+          };
+        };
+      };
     };
     zpool = {
       storage = {
@@ -73,6 +89,20 @@
           };
         };
       };
+      storage2 = {
+        type = "zpool";
+        mountpoint = "/storage2";
+        rootFsOptions = {
+          canmount = "off";
+        };
+
+        datasets = {
+          dataset = {
+            type = "zfs_fs";
+            mountpoint = "/storage2/dataset";
+          };
+        };
+      };
     };
   };
 }

tests/non-root-zfs.nix

@@ -14,13 +14,35 @@ diskoLib.testLib.makeDiskoTest {
     filesystem = machine.execute("stat --file-system --format=%T /mnt/storage")[1].rstrip()
     print(f"/mnt/storage {filesystem=}")
     assert filesystem == "zfs", "/mnt/storage is not ZFS"
+
+    machine.fail("mountpoint /mnt/storage2")
+    machine.succeed("mountpoint /mnt/storage2/dataset")
+
+    filesystem = machine.execute("stat --file-system --format=%T /mnt/storage2")[1].rstrip()
+    print(f"/mnt/storage2 {filesystem=}")
+    assert filesystem != "zfs", "/mnt/storage should not be ZFS"
+
+    filesystem = machine.execute("stat --file-system --format=%T /mnt/storage2/dataset")[1].rstrip()
+    print(f"/mnt/storage2/dataset {filesystem=}")
+    assert filesystem == "zfs", "/mnt/storage/dataset is not ZFS"
   '';
   extraTestScript = ''
     machine.succeed("mountpoint /storage")
     machine.succeed("mountpoint /storage/dataset")
 
     filesystem = machine.execute("stat --file-system --format=%T /storage")[1].rstrip()
-    print(f"/mnt/storage {filesystem=}")
+    print(f"/storage {filesystem=}")
     assert filesystem == "zfs", "/storage is not ZFS"
+
+    machine.fail("mountpoint /storage2")
+    machine.succeed("mountpoint /storage2/dataset")
+
+    filesystem = machine.execute("stat --file-system --format=%T /storage2")[1].rstrip()
+    print(f"/storage2 {filesystem=}")
+    assert filesystem != "zfs", "/storage should not be ZFS"
+
+    filesystem = machine.execute("stat --file-system --format=%T /storage2/dataset")[1].rstrip()
+    print(f"/storage2/dataset {filesystem=}")
+    assert filesystem == "zfs", "/storage/dataset is not ZFS"
   '';
 }