Re: [PATCH] fs: efs: Fix compilation bug and use pr_debug()

From: Matthew Wilcox

Date: Fri Jun 05 2026 - 13:14:16 EST


On Thu, Jun 04, 2026 at 10:33:10PM -0500, Maxwell Doose wrote:
> On Thu, Jun 4, 2026 at 10:27 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> >
> > On Thu, Jun 04, 2026 at 10:16:44PM -0500, Maxwell Doose wrote:
> > > ps: I noticed this was listed as an orphan in MAINTAINERS. I'd be
> > > happy to step up and maintain this, I've got a bit of experience
> > > maintaining stuff in iio. Hopefully this isn't too far-fetched!
> >
> > I'd be just as happy to see it deleted. efs was succeeded by XFS in
> > the mid-90s. The last efs filesystem I personally saw was in 1999 (an
> > SGI Freeware CD). If there's any filesystem crying out to be converted
> > to FUSE and removed from the kernel, this is it.
>
> I guess that is a fair point. But given the fact that we quite
> literally just found a compile-time bug I think there may be further
> underlying issues that need to be resolved before conversion to FUSE
> :/

I'd argue that shows the exact opposite. efs just isn't useful any more.
While looking up some information on Wikipedia, I discovered that XFS
filesystems from SGI used v2 of the directory format. Linux no longer
supports anything from before v4 (and even that is now under a CONFIG
option). So we're in the weird situation where SGI filesystems from
1992 are readable in Linux, but SGI filesystems from 1995 are not.