Re: Mounting ntfs-3g file systems at Guix System boot time

["Théo Tyburn" <theo.tyburn@gmail.com>]

Thank you for the swift and kind reply Tobias,

> Welcome!

Thanks!

> > This might also be linked to another problem : notice I add the
> > field
> > (check? #f).
> > Without it I got the error :
> > "ntfsfix : no such file or directory"
>
> Oops, that's a bug.  I have a static ntfsfix in my local tree but
> it needs to be cleaned up before I can push it.  I'll try to do so
> this weekend but it's a busy one.  Until then, (check? #f) for
> NTFS is perfectly fine.  Maybe it should even become the default.

Oh I see. Happy I could find one. Anyway there is no hurry.

> > I guess ntfsfix also comes bundled with ntfs-3g
> > so it would make sense that these two bugs have the same origin.
>
> Kind of, in the abstract, but also not really.  For ntfsfix we can
> simply add it to the existing per-file-system logic in (gnu system
> initrd).
>
> For actually mounting ntfs-3g file systems, things aren't so
> simple, because we call the mount syscall directly.  This works
> fine for ‘real’ file systems supported by the kernel, but it cuts
> out the ‘mount helper’ workflow that things like ntfs-3g and FUSE
> in general like to use.
>
> We'd have to add a quick hack for ntfs-3g or a general interface
> for calling mount helper binaries, which will take a bit more
> thought and time…

I see. I was thinking about something like that, but was not sure it
was possible.
I'll have a look at initrd source to try to follow along when this
interface gets put together. If this is not too advanced I could also
give a hand depending on my progress.

> > So the question is : how do I make make guix use the ntfs-3g
> > package
> > in my operating system definition ?
>
> So for ‘use == mounting at boot time’, I don't think this is
> currently possible.
>
> > I looked a bit at the source but couldn't figure out how the
> > command
> > (mount.ntfs or mount.ntfs-3g)
> > is selected depending on the fs type.
>
> So, nowhere.  We never call the mount binary and it's not
> available in the initrd.
>
> > The decisive steps seem to happen in the "mount-file-system"
> > define*
> > at the end of gnu/build/file-system.scm.
> > What I don't understand there is what "(mount source target type
> > flags
> > options)" does,
> > because I don't find where (mount) is defined.
>
> Check out (guix build syscalls) :-)

I'll study that!

> Aside: the coming ntfs3 (no relation despite the similar name)
> driver promises to replace the old & slow ntfs-3g entirely, and
> wouldn't suffer from this trouble.

That sounds promissing !

> Of course a general plan to
> mount other FUSE file systems at Guix boot would still be nice.

Yes that would still be really good to have. It was also difficult on
Debian to do this.

Kind regards,

TT