LWN: Comments on "FUSE - implementing filesystems in user space"

FUSE - implementing filesystems in user space

mcatkins — 2004-02-06T04:59:59+00:00

Ron Minnich had a good go at it, but I don't think it was really
completed - pitty, because as you say, it would "let you implement
almost anything you like..."

Some stuff is on his homepage at:
http://public.lanl.gov/rminnich/
and there is an inactive sourceforge site at:
http://v9fs.sourceforge.net/

There was also work on private namespaces for Linux and BSD, which is
the other key technology to getting this all to work properly!

FUSE - implementing filesystems in user space

xoddam — 2004-02-06T03:47:55+00:00

Has anyone ever written a 9P (aka 9fs) client for Linux? I know there are a couple of servers but I can't see anything obvious on Google.

a kernel-space 9P client would let you implement almost anything you like in terms of filesystems as userspace servers.

Userspace NFS

kamil — 2004-01-31T21:19:34+00:00

That has always been my recollection, as well. NFS server in user space, using Linux-specific calls like setfsuid(2), client in the kernel.

FUSE - implementing filesystems in user space

mszeredi — 2004-01-29T14:17:43+00:00

OK, so making homepages is not my strong point :). This is not the first time somebody complains, and it's now being worked on by a brave volunteer (SF job recruitment is cool).

Anyway here's a link to a list of filesystems (that I know of) that are using FUSE:

http://www.inf.bme.hu/~mszeredi/fuse/Filesystems

FUSE - implementing filesystems in user space

mszeredi — 2004-01-29T14:00:40+00:00

Security is one of the main design principles of FUSE. The only operation that requires root access is the mounting, and that can be done fairly securely by a non-root user with the help of a suid program (fusermount).

SieFS

hensema — 2004-01-29T10:55:25+00:00

SieFS is an example of a filesystem implemented with FUSE. SieFS can mount the filesystems of recent Siemens mobile phones (such as the S55) on Linux. Site: http://mirror01.iptelecom.net.ua/~dmitry_z/siefs/

FUSE - implementing filesystems in user space

mjr — 2004-01-29T10:03:17+00:00

There's also LUFS (which incidentally supports gnome-vfs modules like fuse supports kioslaves - can't have one doing both, it seems ;). I'd really like to see one of these make it to the default kernel...

Anyway, anyone know if the fuse kernel interface is secure nowadays, in a sense that one can safely allow users to freely use even their own filesystem code to mount things? I asked basically the same on the lufs list a good while back, and there were, in effect, no answers, and the lufs daemons seem to run as root which is a kind of telltale sign that one doesn't want arbitrary user code there...

Userspace NFS

Ross — 2004-01-29T09:18:19+00:00

I thought only the NFS server was in userspace but the client was always
in the kernel. Or am I just not remembering correctly?

FUSE - implementing filesystems in user space

stuart2048 — 2004-01-29T08:38:30+00:00

One of the cool features of userland isolation is that it's much easier to watch behaviour and resource consumption. Curious about how much memory or CPU your protocol stack is consuming? Easy...

--Stuart

FUSE - implementing filesystems in user space

aleXXX — 2004-01-29T06:56:09+00:00

KIO fuse "gateway":

http://kde.ground.cz/tiki-index.php?page=KIO+Fuse+Gateway

And it works :-)
Only the file mode flags (for opening) are still ignored, mainly I need more
users/testers now :-)

Bye
Alex
<neundorf at kde dot org >

FUSE - implementing filesystems in user space

mcatkins — 2004-01-29T05:45:16+00:00

Unfortunately, this seems to be something of a graveyard of projects, I also know of (at least):

Podfuk: http://atrey.karlin.mff.cuni.cz/~pavel/podfuk/podfuk.html
userfs: http://www.penguin.cz/~jim/userfs/
uvfs: http://www.sciencething.org/geekthings/index.html
virtualfs: http://www.solucorp.qc.ca/virtualfs/

(although the last subverts libc, rather than using a kernel module)

as well as my own effort (not yet released!) allowing filesystems to be written in Python (as does fuse), but without requiring a non-standard kernel module.

FUSE - implementing filesystems in user space

iabervon — 2004-01-29T03:54:46+00:00

I think it's a good idea to support microkernel-like behavior, so that
users can trade off performance for isolation. I'd certainly prefer that
drivers be in userspace when performance isn't an issue; if my PDA sync
takes twice as many context switches, I probably won't even notice the
difference, but I will be glad if it doesn't take the system down if it
is buggy. On the other hand, I don't think that Linux will get
particularly micro; just because you can have filesystems and drivers in
userspace doesn't mean that having your root filesystem or video drivers
in userspace is going to be a good idea.

FUSE - implementing filesystems in user space

marduk — 2004-01-29T02:50:25+00:00

It certainly does seem like Linux is becoming more and more microkernel-like every day. One wonders what Linus says about this.

FUSE - implementing filesystems in user space

pynm0001 — 2004-01-29T02:41:01+00:00

Actually, there is a project to implement the KIO protocol using FUSE.
This would enable GTK/GNOME applications to use the KIO slaves, for
example.

I don't know the link offhand, but I think http://dot.kde.org/ has news
about it.

FUSE - implementing filesystems in user space

flewellyn — 2004-01-29T02:17:57+00:00

Interesting. So, how long before Linux becomes a microkernel, then? :-)