nixos: f2fs filesystem module support (close #2085)

nixos/modules/tasks/filesystems/f2fs.nix

@@ -0,0 +1,21 @@
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+let
+  inInitrd = any (fs: fs == "f2fs") config.boot.initrd.supportedFilesystems;
+in
+{
+  config = mkIf (any (fs: fs == "f2fs") config.boot.supportedFilesystems) {
+
+    system.fsPackages = [ pkgs.f2fs-tools ];
+
+    boot.initrd.availableKernelModules = mkIf inInitrd [ "f2fs" ];
+
+    boot.initrd.extraUtilsCommands = mkIf inInitrd ''
+      mkdir -p $out/bin $out/lib
+      cp -v   ${pkgs.f2fs-tools}/sbin/fsck.f2fs $out/bin
+      cp -pdv ${pkgs.f2fs-tools}/lib/lib*.so.* $out/lib
+    '';
+  };
+}