[systemd-devel] sys-module-fuse.device: Failed to enqueue SYSTEMD_WANTS= job, ignoring: Unit modprobe at fuse.service is masked

[Mike Gilbert]

On Mon, Feb 8, 2021 at 1:01 PM Reindl Harald <h.reindl at thelounge.net> wrote:
>
>
>
> Am 08.02.21 um 18:27 schrieb Lennart Poettering:
> > On So, 07.02.21 22:43, Reindl Harald (h.reindl at thelounge.net) wrote:
> >
> >> https://bugzilla.redhat.com/show_bug.cgi?id=1909805
> >
> > In response to your actual issue, ignoring all the nasty wording:
> >
> > Masking is a last resort thing, you really want to use that only after
> > having investigated everything. You use it here anyway to mask out a
> > really low-level system thing, hence you might get warnings about
> > this.
> >
> > You can of course mask sys-fs-fuse-connections.mount too
> who needs anything related to fuse at every boot?
> fuse is nothing in common used
> fuse is not used unconditional
>
> directly after boot on a server-vm with no fuse business
>
> [root at testserver:~]$ lsmod | grep fuse
> fuse                  163840  1
>
> my only usecase on 50 machines is every few weeks fuse.sshfs abd what
> makes people nasty is that for months nobody responds to systemd related
> issues in the Fedora bugracker
>
> if something is usiong fuse it happily loads the kernel module on-demand
> for years

Looking into this a bit closer, it looks like systemd installs a symlink:

/usr/lib/systemd/system/sysinit.target.wants/sys-fs-fuse-connections.mount
-> ../sys-fs-fuse-connections.mount

I think removing this symlink would prevent /sys/fs/fuse/connections
from being mounted and the fuse module from being loaded
unconditionally on boot.

As well, udev installs a couple of relevant rules (50-default.rules,
99-systemd.rules):

KERNEL=="fuse", MODE="0666", OPTIONS+="static_node=fuse"

# Asynchronously mount file systems implemented by these modules as
soon as they are loaded.
SUBSYSTEM=="module", KERNEL=="fuse", TAG+="systemd",
ENV{SYSTEMD_WANTS}+="sys-fs-fuse-connections.mount"

I think these rules should take care of providing a static /dev/fuse
node to allow module auto-loading, and should cause
/sys/fs/fuse/connections to be mounted on-demand.