bcachefs-tools: 1.31.0 -> 1.31.3, nixos/bcachefs: Use out-of-tree module. (#444428)

nixos/doc/manual/release-notes/rl-2511.section.md

@@ -264,6 +264,8 @@
 
 - Due to [deprecation of gnome-session X11 support](https://blogs.gnome.org/alatiera/2025/06/08/the-x11-session-removal/), `services.desktopManager.pantheon` now defaults to pantheon-wayland session. The X11 session has been removed, see [this issue](https://github.com/elementary/session-settings/issues/91) for details.
 
+- `bcachefs` file systems will now use the out-of-tree module for supported kernels. The in-tree module is unmaintained and users are strongly recommended to switch to kernels that support the out-of-tree module.
+
 - `services.gitea` supports sending notifications with sendmail again. To do this, activate the parameter `services.gitea.mailerUseSendmail` and configure SMTP server.
 
 - `networking.wireless.networks.<name>` now has an option to specify SSID, hence allowing duplicated SSID setup. The BSSID option is added along side with this.

nixos/modules/tasks/filesystems/bcachefs.nix

@@ -175,25 +175,6 @@ let
             '';
       };
     };
-
-  assertions = [
-    {
-      assertion =
-        let
-          kernel = config.boot.kernelPackages.kernel;
-        in
-        (
-          kernel.kernelAtLeast "6.7"
-          || (lib.elem (kernel.structuredExtraConfig.BCACHEFS_FS or null) [
-            lib.kernel.module
-            lib.kernel.yes
-            (lib.kernel.option lib.kernel.yes)
-          ])
-        );
-
-      message = "Linux 6.7-rc1 at minimum or a custom linux kernel with bcachefs support is required";
-    }
-  ];
 in
 
 {
@@ -230,7 +211,32 @@ in
   config = lib.mkIf (config.boot.supportedFilesystems.bcachefs or false) (
     lib.mkMerge [
       {
-        inherit assertions;
+        assertions = [
+          {
+            assertion =
+              let
+                kernel = config.boot.kernelPackages.kernel;
+              in
+              (
+                kernel.kernelAtLeast "6.7"
+                || (lib.elem (kernel.structuredExtraConfig.BCACHEFS_FS or null) [
+                  lib.kernel.module
+                  lib.kernel.yes
+                  (lib.kernel.option lib.kernel.yes)
+                ])
+              );
+
+            message = "Linux 6.7-rc1 at minimum or a custom linux kernel with bcachefs support is required";
+          }
+        ];
+
+        warnings = lib.mkIf config.boot.kernelPackages.bcachefs.meta.broken [
+          ''
+            Using unmaintained in-tree bcachefs kernel module. This
+            will be removed in 26.05. Please use a kernel supported
+            by the out-of-tree module package.
+          ''
+        ];
 
         # Bcachefs upstream recommends using the latest kernel
         boot.kernelPackages = lib.mkDefault pkgs.linuxPackages_latest;
@@ -239,6 +245,10 @@ in
         system.fsPackages = [ cfg.package ];
         services.udev.packages = [ cfg.package ];
 
+        boot.extraModulePackages = lib.optionals (!config.boot.kernelPackages.bcachefs.meta.broken) [
+          config.boot.kernelPackages.bcachefs
+        ];
+
         systemd = {
           packages = [ cfg.package ];
           services = lib.mapAttrs' (mkUnits "") (
@@ -248,7 +258,6 @@ in
       }
 
       (lib.mkIf ((config.boot.initrd.supportedFilesystems.bcachefs or false) || (bootFs != { })) {
-        inherit assertions;
         boot.initrd.availableKernelModules = [
           "bcachefs"
           "sha256"

pkgs/by-name/bc/bcachefs-tools/package.nix

@@ -29,13 +29,13 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "bcachefs-tools";
-  version = "1.31.0";
+  version = "1.31.3";
 
   src = fetchFromGitHub {
     owner = "koverstreet";
     repo = "bcachefs-tools";
     tag = "v${finalAttrs.version}";
-    hash = "sha256-wYlfU4PTcVSPSHbIIDbl8pBOJsBAAl44XBapwFZ528U=";
+    hash = "sha256-sXv6YFM91T08WF5dPU7iQNqWbB/QiL2kMaXm6ZtIDqI=";
   };
 
   nativeBuildInputs = [
@@ -66,19 +66,29 @@ stdenv.mkDerivation (finalAttrs: {
 
   cargoDeps = rustPlatform.fetchCargoVendor {
     src = finalAttrs.src;
-    hash = "sha256-ZCzw3cDpQ8fb2jLYdIWrmlNTPStikIs09jx6jzzC2vM=";
+    hash = "sha256-04YrgYfhZ5NfA2BcF2H6Np1SXRiH6CJpkgc9hzlbMAo=";
   };
 
+  outputs = [
+    "out"
+    "dkms"
+  ];
+
   makeFlags = [
     "PREFIX=${placeholder "out"}"
     "VERSION=${finalAttrs.version}"
     "INITRAMFS_DIR=${placeholder "out"}/etc/initramfs-tools"
+    "DKMSDIR=${placeholder "dkms"}"
 
     # Tries to install to the 'systemd-minimal' and 'udev' nix installation paths
     "PKGCONFIG_SERVICEDIR=$(out)/lib/systemd/system"
     "PKGCONFIG_UDEVDIR=$(out)/lib/udev"
   ]
   ++ lib.optional fuseSupport "BCACHEFS_FUSE=1";
+  installFlags = [
+    "install"
+    "install_dkms"
+  ];
 
   env = {
     CARGO_BUILD_TARGET = stdenv.hostPlatform.rust.rustcTargetSpec;
@@ -100,11 +110,7 @@ stdenv.mkDerivation (finalAttrs: {
   '';
   checkFlags = [ "BCACHEFS_TEST_USE_VALGRIND=no" ];
 
-  postInstall = ''
-    substituteInPlace $out/libexec/bcachefsck_all \
-      --replace-fail "/usr/bin/python3" "${python3.interpreter}"
-  ''
-  + lib.optionalString (stdenv.buildPlatform.canExecute stdenv.hostPlatform) ''
+  postInstall = lib.optionalString (stdenv.buildPlatform.canExecute stdenv.hostPlatform) ''
     installShellCompletion --cmd bcachefs \
       --bash <($out/sbin/bcachefs completions bash) \
       --zsh  <($out/sbin/bcachefs completions zsh) \

pkgs/os-specific/linux/bcachefs-kernel-module/default.nix

@@ -0,0 +1,48 @@
+{
+  lib,
+  stdenv,
+  bcachefs-tools,
+  kernelModuleMakeFlags,
+  kernel,
+}:
+
+stdenv.mkDerivation {
+  pname = "bcachefs";
+  version = "${kernel.version}-${bcachefs-tools.version}";
+
+  __structuredAttrs = true;
+
+  src = bcachefs-tools.dkms;
+
+  nativeBuildInputs = kernel.moduleBuildDependencies;
+
+  enableParallelBuilding = true;
+
+  makeFlags = kernelModuleMakeFlags ++ [
+    "KDIR=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
+    "INSTALL_MOD_PATH=${placeholder "out"}"
+  ];
+
+  installPhase = ''
+    runHook preInstall
+    make -C ${kernel.dev}/lib/modules/${kernel.modDirVersion}/build M=$(pwd) modules_install "''${makeFlags[@]}" "''${installFlags[@]}"
+    runHook postInstall
+  '';
+
+  passthru = {
+    inherit (bcachefs-tools.passthru) tests;
+  };
+
+  meta = {
+    description = "out-of-tree bcachefs kernel module";
+
+    inherit (bcachefs-tools.meta)
+      homepage
+      license
+      maintainers
+      platforms
+      ;
+
+    broken = !(lib.versionAtLeast kernel.version "6.16" && lib.versionOlder kernel.version "6.18");
+  };
+}

pkgs/top-level/linux-kernels.nix

@@ -375,6 +375,8 @@ in
 
         bbswitch = callPackage ../os-specific/linux/bbswitch { };
 
+        bcachefs = callPackage ../os-specific/linux/bcachefs-kernel-module { };
+
         ch9344 = callPackage ../os-specific/linux/ch9344 { };
 
         chipsec = callPackage ../tools/security/chipsec {