Shura: re-add filesystems module, but in a way that works

hosts/Dimaga/hardware-configuration.nix

@@ -7,7 +7,8 @@
 }:
 
 let
-  luksUUID = "9fdc521b-a037-4070-af47-f54da03675e4";
+  luksUUID = "9fdc521b-a037-4070-af47-f54da03675e4"; # The UUID of the locked LUKS partition.
+  rootUUID = "dfb4fc8f-e82b-43a1-91c1-a77acb6337cb"; # The UUID of the unlocked filesystem partition.
 in
 {
   imports = [ (modulesPath + "/installer/scan/not-detected.nix") ];
@@ -35,7 +36,7 @@ in
     enable = true;
     devices = {
       boot = "/dev/disk/by-uuid/FC20-D155";
-      btrfs = "/dev/disk/by-uuid/${luksUUID}";
+      btrfs = "/dev/disk/by-uuid/${rootUUID}";
     };
     swapFile = {
       enable = true;

hosts/Shura/hardware-configuration.nix

@@ -6,6 +6,10 @@
   modulesPath,
   ...
 }:
+let
+  luksUUID = "bcf67e34-339e-40b9-8ffd-bec8f7f55248"; # The UUID of the locked LUKS partition.
+  rootUUID = "b801fbea-4cb5-4255-bea9-a2ce77d1a1b7"; # The UUID of the unlocked filesystem partition.
+in
 {
   imports = [ (modulesPath + "/installer/scan/not-detected.nix") ];
 
@@ -24,8 +28,8 @@
         "sd_mod"
         "rtsx_pci_sdmmc"
       ];
-      luks.devices."luks-bcf67e34-339e-40b9-8ffd-bec8f7f55248" = {
+      luks.devices."luks-${luksUUID}" = {
-        device = "/dev/disk/by-uuid/bcf67e34-339e-40b9-8ffd-bec8f7f55248";
+        device = "/dev/disk/by-uuid/${luksUUID}";
         crypttabExtraOpts = [ "tpm2-device=auto" ]; # Enable TPM auto-unlocking
       };
     };
@@ -33,25 +37,16 @@
     kernelModules = [ "kvm-amd" ];
   };
 
-  fileSystems = {
+  # Configure the main filesystem.
-    "/" = {
+  aux.system.filesystem.btrfs = {
-      device = "/dev/disk/by-uuid/b801fbea-4cb5-4255-bea9-a2ce77d1a1b7";
+    enable = true;
-      fsType = "btrfs";
+    devices = {
-      options = [ "subvol=@,compress=zstd,discard" ];
+      boot = "/dev/disk/by-uuid/FC20-D155";
+      btrfs = "/dev/disk/by-uuid/${rootUUID}";
     };
-    "/home" = {
+    swapFile = {
-      device = "/dev/disk/by-uuid/b801fbea-4cb5-4255-bea9-a2ce77d1a1b7";
+      enable = true;
-      fsType = "btrfs";
+      size = 16384;
-      options = [ "subvol=@home,compress=zstd,discard" ];
-    };
-    "/swap" = {
-      device = "/dev/disk/by-uuid/b801fbea-4cb5-4255-bea9-a2ce77d1a1b7";
-      fsType = "btrfs";
-      options = [ "subvol=@swap" ];
-    };
-    "/boot" = {
-      device = "/dev/disk/by-uuid/AFCB-D880";
-      fsType = "vfat";
     };
   };
 

modules/system/filesystem.nix

@@ -2,11 +2,7 @@
 let
   cfg = config.aux.system.filesystem.btrfs;
 
-  standardMountOpts = [
+  standardMountOpts = [ "compress=zstd" ];
-    "compress=zstd"
-    "discard=async"
-    "noatime"
-  ];
 in
 {
   options = {
@@ -24,6 +20,16 @@ in
           default = "";
         };
       };
+      subvolumes = lib.mkOption {
+        type = lib.types.listOf lib.types.str;
+        description = "Which subvolumes to mount. Leave as the default to create all standard subvolumes.";
+        default = [
+          "/"
+          "/home"
+          "/nix"
+          "/var/log"
+        ];
+      };
       swapFile = {
         enable = lib.mkEnableOption (lib.mdDoc "Enables the creation of a swap file.");
         size = lib.mkOption {
@@ -50,36 +56,52 @@ in
     ];
     fileSystems =
       {
-        "/" = {
+        "/" = lib.mkIf (builtins.elem "/" cfg.subvolumes) {
           device = cfg.devices.btrfs;
           fsType = "btrfs";
-          options = [ "subvol=@" ] ++ standardMountOpts;
+          options = [
+            "subvol=@"
+            "compress=zstd"
+          ];
         };
         "/boot" = {
           device = cfg.devices.boot;
           fsType = "vfat";
         };
-        "/home" = {
+        "/home" = lib.mkIf (builtins.elem "/home" cfg.subvolumes) {
           device = cfg.devices.btrfs;
           fsType = "btrfs";
-          options = [ "subvol=@home" ] ++ standardMountOpts;
+          options = [
+            "subvol=@home"
+            "compress=zstd"
+          ];
         };
-        "/var/log" = {
+        "/var/log" = lib.mkIf (builtins.elem "/var/log" cfg.subvolumes) {
           device = cfg.devices.btrfs;
           fsType = "btrfs";
-          options = [ "subvol=@log" ] ++ standardMountOpts;
+          options = [
+            "subvol=@log"
+            "compress=zstd"
+          ];
         };
-        "/nix" = {
+        "/nix" = lib.mkIf (builtins.elem "/nix" cfg.subvolumes) {
           device = cfg.devices.btrfs;
           fsType = "btrfs";
-          options = [ "subvol=@nix" ] ++ standardMountOpts;
+          options = [
+            "subvol=@nix"
+            "compress=zstd"
+            "noatime"
+          ];
         };
       }
       // lib.optionalAttrs cfg.swapFile.enable {
         "/swap" = {
           device = cfg.devices.btrfs;
           fsType = "btrfs";
-          options = [ "subvol=@swap" ];
+          options = [
+            "subvol=@swap"
+            "noatime"
+          ];
         };
       };