Make bcachefs subvolumes boot-time mount tests pass + more tests

.gitignore

@@ -4,3 +4,6 @@ result-*
 
 # Created by the NixOS interactive test driver
 .nixos-test-history
+
+# Created by `:bl` in `nix repl`
+repl-result-out

example/bcachefs.nix

@@ -23,7 +23,7 @@
               content = {
                 type = "bcachefs";
                 # This refers to a filesystem in the `bcachefs_filesystems` attrset below.
-                filesystem = "unmounted_subvolumes_in_multi";
+                filesystem = "mounted_subvolumes_in_multi";
                 label = "group_a.vdb2";
                 extraFormatArgs = [
                   "--discard"
@@ -44,7 +44,7 @@
               size = "100%";
               content = {
                 type = "bcachefs";
-                filesystem = "unmounted_subvolumes_in_multi";
+                filesystem = "mounted_subvolumes_in_multi";
                 label = "group_a.vdc1";
                 extraFormatArgs = [
                   "--discard"
@@ -65,7 +65,7 @@
               size = "100%";
               content = {
                 type = "bcachefs";
-                filesystem = "unmounted_subvolumes_in_multi";
+                filesystem = "mounted_subvolumes_in_multi";
                 label = "group_b.vdd1";
                 extraFormatArgs = [
                   "--force"
@@ -79,87 +79,6 @@
       vde = {
         device = "/dev/vde";
         type = "disk";
-        content = {
-          type = "gpt";
-          partitions = {
-            vde1 = {
-              size = "100%";
-              content = {
-                type = "bcachefs";
-                filesystem = "mounted_subvolumes_in_multi";
-                label = "group_a.vde1";
-                extraFormatArgs = [
-                  "--discard"
-                ];
-              };
-            };
-          };
-        };
-      };
-
-      vdf = {
-        device = "/dev/vdf";
-        type = "disk";
-        content = {
-          type = "gpt";
-          partitions = {
-            vdf1 = {
-              size = "100%";
-              content = {
-                type = "bcachefs";
-                filesystem = "mounted_subvolumes_in_multi";
-                label = "group_a.vdf1";
-                extraFormatArgs = [
-                  "--discard"
-                ];
-              };
-            };
-          };
-        };
-      };
-
-      vdg = {
-        device = "/dev/vdg";
-        type = "disk";
-        content = {
-          type = "gpt";
-          partitions = {
-            vdd1 = {
-              size = "100%";
-              content = {
-                type = "bcachefs";
-                filesystem = "mounted_subvolumes_in_multi";
-                label = "group_b.vdg1";
-                extraFormatArgs = [
-                  "--force"
-                ];
-              };
-            };
-          };
-        };
-      };
-
-      vdh = {
-        device = "/dev/vdh";
-        type = "disk";
-        content = {
-          type = "gpt";
-          partitions = {
-            vdd1 = {
-              size = "100%";
-              content = {
-                type = "bcachefs";
-                filesystem = "no_reliance_on_external_subvolume";
-                label = "group_a.vdh1";
-              };
-            };
-          };
-        };
-      };
-
-      vdi = {
-        device = "/dev/vdi";
-        type = "disk";
         content = {
           type = "gpt";
           partitions = {
@@ -168,7 +87,7 @@
               content = {
                 type = "bcachefs";
                 filesystem = "relies_on_external_subvolume";
-                label = "group_a.vdi1";
+                label = "group_a.vde1";
               };
             };
           };
@@ -177,72 +96,52 @@
     };
 
     bcachefs_filesystems = {
-      # Example showing unmounted subvolumes in a multi-disk configuration.
+      # Example showing mounted subvolumes in a multi-disk configuration.
-      unmounted_subvolumes_in_multi = {
+      mounted_subvolumes_in_multi = {
         type = "bcachefs_filesystem";
         passwordFile = "/tmp/secret.key";
         extraFormatArgs = [
           "--compression=lz4"
           "--background_compression=lz4"
         ];
+        subvolumes = {
+          # Subvolume name is different from mountpoint.
+          "subvolumes/root" = {
+            mountpoint = "/";
+            mountOptions = [
+              "verbose"
+            ];
+          };
+          # Subvolume name is the same as the mountpoint.
+          "subvolumes/home" = {
+            mountpoint = "/home";
+          };
+          # Nested subvolume doesn't need a mountpoint as its parent is mounted.
+          "subvolumes/home/user" = {
+          };
+          # Parent is not mounted so the mountpoint must be set.
+          "subvolumes/nix" = {
+            mountpoint = "/nix";
+          };
+          # This subvolume will be created but not mounted.
+          "subvolumes/test" = {
+          };
+        };
+      };
+
+      # Example showing a bcachefs filesystem without subvolumes
+      # and which relies on a subvolume in another filesystem being mounted.
+      relies_on_external_subvolume = {
+        type = "bcachefs_filesystem";
+        mountpoint = "/home/Documents";
+        extraFormatArgs = [
+          "--compression=lz4"
+          "--background_compression=lz4"
+        ];
         mountOptions = [
           "verbose"
         ];
-        mountpoint = "/";
-        subvolumes = {
-          "subvolumes/rootfs" = { };
-          "subvolumes/home" = { };
-          "subvolumes/home/user" = { };
-          "subvolumes/nix" = { };
-          "subvolumes/test" = { };
-        };
       };
-
-      # # Example showing mounted subvolumes in a multi-disk configuration (not yet working).
-      # mounted_subvolumes_in_multi = {
-      #   type = "bcachefs_filesystem";
-      #   passwordFile = "/tmp/secret.key";
-      #   extraFormatArgs = [
-      #     "--compression=lz4"
-      #     "--background_compression=lz4"
-      #   ];
-      #   mountOptions = [
-      #     "verbose"
-      #   ];
-      #   subvolumes = {
-      #     # Subvolume name is different from mountpoint
-      #     "foo" = {
-      #       mountpoint = "/bar";
-      #     };
-      #     # Subvolume name is the same as the mountpoint
-      #     "home" = {
-      #       mountpoint = "/home";
-      #     };
-      #     # Sub(sub)volume doesn't need a mountpoint as its parent is mounted
-      #     "home/user" = {
-      #     };
-      #     # Parent is not mounted so the mountpoint must be set
-      #     "nix" = {
-      #       mountpoint = "/nix";
-      #     };
-      #     # This subvolume will be created but not mounted
-      #     "test" = {
-      #     };
-      #   };
-      # };
-
-      # Example showing another bcachefs filesystem.
-      no_reliance_on_external_subvolume = {
-        type = "bcachefs_filesystem";
-        mountpoint = "/sometestdir";
-      };
-
-      # # Example showing another bcachefs filesystem that relies on a subvolume
-      # # in another filesystem being mounted (not yet working).
-      # relies_on_external_subvolume = {
-      #   type = "bcachefs_filesystem";
-      #   mountpoint = "/home/somedir/vdf1";
-      # };
     };
   };
 }

lib/types/bcachefs_filesystem.nix

@@ -113,10 +113,7 @@
               mountpoint = lib.mkOption {
                 type = lib.types.nullOr diskoLib.optionTypes.absolute-pathname;
                 default = null;
-                description = ''
+                description = "Path to mount the subvolume to.";
-                  Path to mount the subvolume to.
-                  DO NOT USE. Currently not working.
-                '';
                 example = "/";
               };
             };
@@ -126,7 +123,19 @@
       default = { };
       description = "List of subvolumes to define.";
       example = {
-        "subvolumes/home" = { };
+        "subvolumes/root" = {
+          mountpoint = "/";
+          extraFormatArgs = [
+            "--compression=lz4"
+            "--background_compression=lz4"
+          ];
+          mountOptions = [
+            "verbose"
+          ];
+        };
+        "subvolumes/home" = {
+          mountpoint = "/home";
+        };
       };
     };
     _parent = lib.mkOption {
@@ -291,7 +300,6 @@
     _config = lib.mkOption {
       internal = true;
       readOnly = true;
-      # @todo Check that this implementation is correct:
       default =
         (lib.optional (config.mountpoint != null) {
           fileSystems.${config.mountpoint} = {

tests/bcachefs.nix

@@ -7,39 +7,120 @@ diskoLib.testLib.makeDiskoTest {
   name = "bcachefs";
   disko-config = ../example/bcachefs.nix;
   enableOCR = true;
+  bootCommands = ''
+    machine.wait_for_text("enter passphrase for /");
+    machine.send_chars("secretsecret\n");
+    machine.wait_for_text("enter passphrase for /home");
+    machine.send_chars("secretsecret\n");
+    machine.wait_for_text("enter passphrase for /nix");
+    machine.send_chars("secretsecret\n");
+  '';
+  extraSystemConfig = {
+    environment.systemPackages = [
+      pkgs.jq
+    ];
+  };
   extraTestScript = ''
-    machine.succeed("mountpoint /");
-    # @todo Verify all devices are part of the filesystem.
-    # @todo Check device labels and group assignments.
-    # Verify mount options were applied.
-    machine.succeed("mount | grep ' / ' | grep -q 'compression=lz4'");
-    machine.succeed("mount | grep ' / ' | grep -q 'background_compression=lz4'");
-    # @todo Verify mountpoint dependency order was respected.
-    # @todo Add tests for subvolumes.
     # Print debug information.
+    machine.succeed("ls -la /subvolumes >&2");
     machine.succeed("lsblk >&2");
     machine.succeed("lsblk -f >&2");
     machine.succeed("mount >&2");
-  '';
+    machine.succeed("bcachefs show-super /dev/vda2 >&2");
-  # extraSystemConfig = { pkgs, ... }: {
+    machine.succeed("bcachefs show-super /dev/vdd1 >&2");
-  #   # @todo Do we need to add any attributes here?
+    machine.succeed("findmnt --json >&2");
-  #   boot = {
+
-  #     supportedFilesystems = [ "bcachefs" ];
+    # Verify subvolume structure.
-  #     initrd = {
+    machine.succeed("test -d /subvolumes/root");
-  #       supportedFilesystems = [ "bcachefs" ];
+    machine.succeed("test -d /subvolumes/home");
-  #       # systemd.enable = false;
+    machine.succeed("test -d /subvolumes/home/user");
-  #     };
+    machine.succeed("test -d /subvolumes/nix");
-  #   };
+    machine.succeed("test -d /subvolumes/test");
-  #   environment.systemPackages = [
+    machine.fail("test -d /subvolumes/non-existent");
-  #     pkgs.bcachefs-tools
+
-  #     pkgs.util-linux
+    # Verify existence of mountpoints.
-  #   ];
+    machine.succeed("mountpoint /");
-  # };
+    machine.succeed("mountpoint /home");
-  # extraInstallerConfig = {
+    machine.succeed("mountpoint /nix");
-  #   # @todo Do we need to add any attributes here?
+    machine.succeed("mountpoint /home/Documents");
-  # };
+    machine.fail("mountpoint /non-existent");
-  bootCommands = ''
+
-    machine.wait_for_text("enter passphrase for");
+    # Verify device membership and labels.
-    machine.send_chars("secretsecret\n");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Devices:' | grep -q '3'");
+    machine.succeed("bcachefs show-super /dev/vdd1 | grep 'Devices:' | grep -q '1'");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'vdb2'");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'vdc1'");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'vdd1'");
+    machine.succeed("bcachefs show-super /dev/vdd1 | grep 'Label:' | grep -q 'vde1'");
+    machine.fail("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'non-existent'");
+
+    # @todo Verify format arguments.
+
+    # Verify mount options from configuration.
+    machine.succeed("""
+      findmnt --json \
+        | jq -e ' \
+          .filesystems[] \
+            | select(.target == "/") \
+            | .options \
+            | split(",") \
+            | contains(["verbose", "compression=lz4", "background_compression=lz4"]) \
+        '
+    """);
+
+    machine.succeed("""
+      findmnt --json \
+        | jq -e ' \
+          .filesystems[] \
+            | .. \
+            | select(.target? == "/home/Documents") \
+            | .options \
+            | split(",") \
+            | contains(["verbose"]) \
+        '
+    """);
+
+    machine.fail("""
+      findmnt --json \
+        | jq -e ' \
+          .filesystems[] \
+            | select(.target == "/") \
+            | .options \
+            | split(",") \
+            | contains(["non-existent"]) \
+        '
+    """);
+
+    # Verify device composition of filesystems.
+    machine.succeed("""
+      findmnt --json \
+        | jq -e ' \
+          .filesystems[] \
+            | select(.target == "/") \
+            | .source | split(":") \
+            | contains(["/dev/vda2", "/dev/vdb1", "/dev/vdc1"]) \
+        '
+    """);
+
+    machine.succeed("""
+      findmnt --json \
+        | jq -e ' \
+          .filesystems[] \
+            | .. \
+            | select(.target? == "/home/Documents") \
+            | .source \
+            | contains("/dev/vdd1") \
+        '
+    """);
+
+    machine.fail("""
+      findmnt --json \
+        | jq -e ' \
+          .filesystems[] \
+            | select(.target == "/") \
+            | .source | split(":") \
+            | contains(["/dev/non-existent"]) \
+        '
+    """);
   '';
 }