From 3a69ec5f156ead261e57a377fb03e105e9a6fe0c Mon Sep 17 00:00:00 2001
From: qubitnano <146656568+qubitnano@users.noreply.github.com>
Date: Sat, 21 Jun 2025 15:05:39 -0400
Subject: [PATCH] nixos/bcachefs: include poly1305 and chacha20 kernel modules
 for kernel < 6.15

Kernel 6.16-rc1 removed the poly1305 algorithm in
ceef731b0e22df80a13d67773ae9afd55a971f9e

bcachefs switched to the kernel libraries for poly1305 and chacha20 in
6.15 in 4bf4b5046de0ef7f9dc50f3a9ef8a6dcda178a6d

(cherry picked from commit f9bd91aa07c30359540aeec8613a29f0b742f540)
---
 nixos/modules/tasks/filesystems/bcachefs.nix | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/nixos/modules/tasks/filesystems/bcachefs.nix b/nixos/modules/tasks/filesystems/bcachefs.nix
index a3d0e9463832..1570cf1a6860 100644
--- a/nixos/modules/tasks/filesystems/bcachefs.nix
+++ b/nixos/modules/tasks/filesystems/bcachefs.nix
@@ -179,13 +179,18 @@ in
 
       (lib.mkIf ((config.boot.initrd.supportedFilesystems.bcachefs or false) || (bootFs != { })) {
         inherit assertions;
-        # chacha20 and poly1305 are required only for decryption attempts
-        boot.initrd.availableKernelModules = [
-          "bcachefs"
-          "sha256"
-          "chacha20"
-          "poly1305"
-        ];
+        boot.initrd.availableKernelModules =
+          [
+            "bcachefs"
+            "sha256"
+          ]
+          ++ lib.optionals (config.boot.kernelPackages.kernel.kernelOlder "6.15") [
+            # chacha20 and poly1305 are required only for decryption attempts
+            # kernel 6.15 uses kernel api libraries for poly1305/chacha20: 4bf4b5046de0ef7f9dc50f3a9ef8a6dcda178a6d
+            # kernel 6.16 removes poly1305: ceef731b0e22df80a13d67773ae9afd55a971f9e
+            "poly1305"
+            "chacha20"
+          ];
         boot.initrd.systemd.extraBin = {
           # do we need this? boot/systemd.nix:566 & boot/systemd/initrd.nix:357
           "bcachefs" = "${pkgs.bcachefs-tools}/bin/bcachefs";