In https://issues.guix.gnu.org/45692#5Danny brings up that the `kernel-module-loader-shepherd-service` might not need to depend on `file-systems`. So: * `kernel-module-loader-shepherd-service` uses the `/proc` filesystem. * However, this filesystem is mounted in `initrd` before handing over to the real root (in `gnu/build/linux-boot.scm`'s `mount-essential-file-systems`, which is called in `boot-system` very early. * Before handing over to the real root, the mounts are moved in `move-essential-file-systems`, which is called by the `switch-root` procedure that is called by `boot-system` after mounting the root filesystem.* The `/proc/sys/kernel/modprobe` file contains a reference to a `/gnu/store` path to a `modprobe` binary. * Shepherd starts with the root file system already mounted (by the `initrd` `boot-system` procedure), so the full `/gnu/store` should be accessible as soon as Shepherd starts. I've tested this as follows: * Created a QEMU VM image that pointlessly loads "btrfs" (which is not loaded by default) by `(simple-service 'load-btrfs kernel-module-loader-service-type '("btrfs"))` and confirmed it boots to desktop and `lsmod` lists `btrfs`.* Ran tests "loadable-kernel-modules-0", "loadable-kernel-modules-1", and "loadable-kernel-module-2" and confirmed they pass. In theory this could break a system, if an existing kernel module reads from some file (which Linux kernel modules are discouraged from doing) at loadtime *and* the system administrator put that file in a non-root filesystem (which if it's a "proper" module it should be in either `/etc` or `/var`, the former of which is, on Guix System, created by Guix on the root filesystem, and the latter of which should generally be on the root filesystem as well). So I think the risk of this breaking *some* system is fairly low. Please review.
From d028dac0efaf6ab3d8edafc2e68c0d2ef692bab7 Mon Sep 17 00:00:00 2001From: raid5atemyhomework <firstname.lastname@example.org>Date: Fri, 8 Jan 2021 09:41:25 +0800Subject: [PATCH] gnu: kernel-module-loader does not require file-systems * gnu/services/linux.scm (kernel-module-loader-shepherd-service):Remove requirement of file-systems.--- gnu/services/linux.scm | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)