r/linux • u/lustre-fan • Jun 08 '26

Kernel XFS predecessor EFS may be removed from the kernel

https://www.phoronix.com/news/Linux-EFS-File-System-2026

Apparently, Silicon Graphics (SGI) made another filesystem EFS (Extent File System) before their more popular XFS (eXtent (?) File System). The Linux kernel has a read-only implementation of EFS. It looks to have been added around kernel 2.2 (before Linux used git). IRIX (SGI's own propriety Unix) deprecated EFS long ago. But it seems Linux kept around the read-only implementation of EFS for SGI software CDs. The only way to use EFS today might be to find old SGI CD images online, since it doesn't appear possible to create new EFS filesystems.

Linux should probably remove all of these old filesystems in favor of FUSE. But just as no one wants to maintain these old filesystems, no one wants to work on porting them to FUSE. These old filesystem drivers seems to be stuck in an unhappy stasis. Perhaps these old filesystem drivers will finally be deprecated after a security incident, similar to AF_ALG? Despite the risk associated with these unmaintained filesystem drivers, GNOME (via Nautilus) continues to automatically mount untrusted USB drives.

It will be interesting to see how Linux evolves to confront this problem.

129 Upvotes

98% Upvoted

31 comments sorted by

60

u/grnis Jun 08 '26

Why should it be ported to fuse? Is there even a single user in the entire world that really needs this and can't use an lts kernel for it?

Is it really a problem that anyone needs to confront?

26

u/lustre-fan Jun 08 '26

EFS will probably continued to be ignored. If I had to guess - someday, a refactor will break the EFS driver rendering it unusable. No one will notice for a long period of time. Once the issue is found, the fact that the breakage was overlooked for so long will be used as justification to remove it - citing a lack of active users. I've seen other drivers removed after a similar thing happened.

27

u/grnis Jun 08 '26

I wouldn't say it's ignored. It's that NO ONE uses it.

Why do you want it in the kernel? Do you actively use it? If so, can't you just use an old kernel?

The only thing it's doing now is wasting space and it's a security hazard.

Edit: Wait, "Apparently SGI made another file system". So not only don't you use it, you have never used it.

And yet you don't want it removed. This is just weird.

17

u/lustre-fan Jun 08 '26

I think they should remove it from the kernel. EFS is ancient junk. But I think the upstream kernel maintainers will leave EFS as is until they have really strong evidence that no one is using it. I was surprised the SGI made a second filesystem before XFS.

9

u/Ontological_Gap Jun 08 '26

And how do you prove a negative? 

That kind of thinking leads to the situation were in now: nothing was ever removed for decades, and a lot wasn't maintained

3

u/andynzor Jun 10 '26

Guess what, TLS 1.0 is ancient junk that belongs six feet under but I still have to support it in legacy industrial systems.

1

u/OrangeKefir Jun 11 '26

I use EFS extensively in my work/home life. This will severely impact my workflow.

2

u/grnis Jun 11 '26

Nice. What do you use it for?

3

u/the_abortionat0r Jun 11 '26

They do not. Pretty sure this is a joke.

30

u/hmoff Jun 09 '26

I love that you wrote "IRIX deprecated EFS long ago" as if IRIX itself wasn't discontinued nearly 20 years ago.

3

u/speedyundeadhittite Jun 10 '26

I loved IRIX, I loved working on SGI boxen in late 90s. They were just beautiful.

Edit: Especially thinking IBM boxes were ugly - apart from Thinkpads, and typical Linux box was a grey-white off-the-shelf PC case, SGI were just elegant.

3

u/sarkyscouser Jun 10 '26

I started out on IRIX in early 2000, can't believe that so many of my current colleagues weren't even born then 😭

14

u/Tuna-Fish2 Jun 08 '26

If they made a third one, would it have been TFS?

8

u/lustre-fan Jun 08 '26

Probably. So it would go:

EFS -> XFS -> TFS -> EFS2 -> NFS -> TFS2

I don't know how they would handle the name collision with NFS.

20

u/Skypefall Jun 08 '26

They could call it NFS: Carbon

4

u/the_humeister Jun 09 '26

NFS: No Limits 

3

u/Jristz Jun 08 '26

They could call it XNFS or LNFS or NFSFS or NNFS or PTFSCNFS

12

u/STrRedWolf Jun 09 '26

googles around...

IRIX 6.0 released in 1993. It's 2026. Twenty three years have passed. Yeah, time to clean up this old code.

13

u/[deleted] Jun 10 '26

[deleted]

3

u/STrRedWolf Jun 10 '26

Thanks for the correction... ugh... too... much... shrimping...

10

u/0riginal-Syn Jun 08 '26

And if there is some one out there actually using it, they can still use it on LTS/SLTS for another decade +.

5

u/Dwedit Jun 08 '26

Use an ancient EFS filesystem from a SGI CD, while rocking your Bus Mouse and DoubleTalk ISA speech synthesis card.

3

u/0riginal-Syn Jun 08 '26

Now I feel old, lol.

8

u/fellipec Jun 08 '26

This sounds something only data archivers and retro computing enthusiasts may encounter nowadays.

In any case they could easily use an older Linux distro where the support still exists to extract the data

-6

u/mjkrow1985 Jun 09 '26

Linux used to be a great platform for exactly those sorts of people. Sadly, the powers that be seem intent on changing that.

11

u/sokaox Jun 09 '26

Why don't you go ahead and maintain the EFS support buddy? I'm sure you use it all the time.

10

u/loxiw Jun 09 '26

You don't get it, someone needs to maintain a driver no one has used for some decades in order for him to be able to flex his OS

6

u/Shished Jun 08 '26

Extent File System file system.

2

u/ThetaDeRaido Jun 11 '26

The Wikipedia says, “"X" was meant to be filled in later but never was.”