any reason for CONFIG_FUSE_FS=y

[Dimitri John Ledkov]

Hi,

On Tue, 9 Aug 2022 at 14:22, Bernd Schubert <bs_lists at aakef.fastmail.fm> wrote:
>
> Hello,
>
> I would like to ask if there is a good reason Ubuntu builds fuse as
> statically into the kernel instead of using a module?
>
> Reason I'm asking is that we are currently working on a couple of fuse
> improvements and
>
> a) A static module makes development a bit harder, I cannot take any
> quickly installed ubuntu system and just load an updated module, but
> always need to install a non custom kernel package.
>
> b) Makes it impossible to provide the updated module as preview to our
> customers, without extra work like renaming all exported symbols and
> adding another /dev/something char device to replace /dev/fuse
>
> c) Makes it hard for us to support customer issues if a fuse issue
> should come up (rare case).
>

Historically this is due to many bugs with dynamically loaded fuse. It
is an autoloadable module, thus userspace requesting fuse would
autoload it. then later one has to mount /sys/fs/fuse/connections
which is all racy. And in practice fuse is often always in use as
well..... on my system it is common to mount things in nautilus with
fuse; lxd/lxc uses fuse; and keybase as well. Also my windows
partition is mounted with fuse (not sure why it's not using kernel's
module here).

you can change ACL methods to not make /dev/fuse accesible; or change
udev rules not not even create it; then make your loaded module
provide /dev/fuse possibly under a different character device number.
You can use linux-backports infrastructure to create a
non-symbol-clashing fuse module (see how we build and vendor
backports-iwlwifi module). Or something similar.

But furthermore.... If you have an improved fuse module, can we not
make it available as part of stock Ubuntu or Ubuntu Pro? If it is
useful, and your customers are on Ubuntu, let's make it the best out
of the box experience.

-- 
okurrr,

Dimitri