Re: [PATCH v6 1/4] openat2: new OPENAT2_REGULAR flag support

[Dorjoy Chowdhury]

On Mon, Apr 27, 2026 at 7:28 PM Florian Weimer <fweimer@xxxxxxxxxx> wrote:
>
> * Dorjoy Chowdhury:
>
> > diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
> > index 92e7ae493ee3..bd78e69e0a43 100644
> > --- a/include/uapi/asm-generic/errno.h
> > +++ b/include/uapi/asm-generic/errno.h
> > @@ -122,4 +122,6 @@
> >
> >  #define EHWPOISON    133     /* Memory page has hardware error */
> >
> > +#define EFTYPE               134     /* Wrong file type for the intended operation */
> > +
> >  #endif
>
> This is what POSIX says about EFTYPE, in the Rationale for System
> Interfaces:
>
> “
> [EFTYPE]
>     This error code was proposed in earlier proposals as "Inappropriate
>     operation for file type", meaning that the operation requested is
>     not appropriate for the file specified in the function call. This
>     code was proposed, although the same idea was covered by [ENOTTY],
>     because the connotations of the name would be misleading. It was
>     pointed out that the fcntl() function uses the error code [EINVAL]
>     for this notion, and hence all instances of [EFTYPE] were changed to
>     this code.
> ”
>
> So I'm not sure if reusing this name is a good idea.
>

Thanks for pointing this out. I had started out the patch series with
ENOTREGULAR and it was discussed that EFTYPE was a better and more
generic error code which is also used in BSD systems like FreeBSD[1]
and MacOS[2]. I also agree that EFTYPE makes sense. We can of course
change to something else if everyone agrees.

cc Christian Brauner who originally suggested EFTYPE for input on this.

[1]: https://man.freebsd.org/cgi/man.cgi?errno(2)
[2]: https://developer.apple.com/documentation/foundation/posixerror/eftype

Regards,
Dorjoy