tests: cover btrfs mountOptions consistency guardrails

Author: sedlund

tests/btrfs-mountoptions-consistency-guardrail.nix

@@ -0,0 +1,23 @@
+{
+  pkgs ? import <nixpkgs> { },
+  diskoLib ? pkgs.callPackage ../lib { },
+}:
+let
+  name = "btrfs-mountoptions-consistency-guardrail";
+  disko = pkgs.callPackage ../. {
+    checked = true;
+    inherit diskoLib;
+  };
+  disko-config = pkgs.lib.recursiveUpdate (import ../example/btrfs-subvolumes.nix) {
+    # Intentionally conflicting filesystem-wide mount options across mounted subvolumes.
+    disko.devices.disk.main.content.partitions.root.content.subvolumes = {
+      "/rootfs".mountOptions = [ "compress=zstd" ];
+      "/home".mountOptions = [ "compress=no" ];
+    };
+  };
+
+  # The guardrail throws during evaluation; this test validates that behavior directly.
+  evalResult = builtins.tryEval (builtins.deepSeq (disko._cliMount disko-config pkgs) true);
+in
+assert (!evalResult.success);
+pkgs.writeText name "ok\n"

tests/btrfs-mountoptions-per-mount-allowed.nix

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+{
+  pkgs ? import <nixpkgs> { },
+  diskoLib ? pkgs.callPackage ../lib { },
+}:
+diskoLib.testLib.makeDiskoTest {
+  inherit pkgs;
+  name = "btrfs-mountoptions-per-mount-allowed";
+  disko-config = pkgs.lib.recursiveUpdate (import ../example/btrfs-subvolumes.nix) {
+    disko.devices.disk.main.content.partitions.root.content.subvolumes = {
+      "/home".mountOptions = [ "noexec" ];
+      "/nosuid" = {
+        mountpoint = "/nosuid";
+        mountOptions = [ "nosuid" ];
+      };
+      "/nodev" = {
+        mountpoint = "/nodev";
+        mountOptions = [ "nodev" ];
+      };
+      "/noatime" = {
+        mountpoint = "/noatime";
+        mountOptions = [ "noatime" ];
+      };
+    };
+  };
+  extraTestScript = ''
+    machine.succeed("mountpoint /");
+    machine.succeed("mountpoint /home");
+    machine.succeed("mountpoint /nosuid");
+    machine.succeed("mountpoint /nodev");
+    machine.succeed("mountpoint /noatime");
+    machine.succeed("findmnt -no OPTIONS /home | tr ',' '\n' | grep -qx noexec");
+    machine.succeed("findmnt -no OPTIONS /nosuid | tr ',' '\n' | grep -qx nosuid");
+    machine.succeed("findmnt -no OPTIONS /nodev | tr ',' '\n' | grep -qx nodev");
+    machine.succeed("findmnt -no OPTIONS /noatime | tr ',' '\n' | grep -qx noatime");
+    machine.fail("findmnt -no OPTIONS / | tr ',' '\n' | grep -qx noexec");
+    machine.fail("findmnt -no OPTIONS / | tr ',' '\n' | grep -qx nosuid");
+    machine.fail("findmnt -no OPTIONS / | tr ',' '\n' | grep -qx nodev");
+    machine.fail("findmnt -no OPTIONS / | tr ',' '\n' | grep -qx noatime");
+  '';
+}