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

[Dorjoy Chowdhury]

On Thu, Apr 16, 2026 at 7:52 PM Jori Koolstra <jkoolstra@xxxxxxxxx> wrote:
>
> On Sat, Mar 28, 2026 at 11:22:22PM +0600, Dorjoy Chowdhury wrote:
> > diff --git a/arch/alpha/include/uapi/asm/fcntl.h b/arch/alpha/include/uapi/asm/fcntl.h
> > index 50bdc8e8a271..fe488bf7c18e 100644
> > --- a/arch/alpha/include/uapi/asm/fcntl.h
> > +++ b/arch/alpha/include/uapi/asm/fcntl.h
> > @@ -34,6 +34,7 @@
> >
> >  #define O_PATH               040000000
> >  #define __O_TMPFILE  0100000000
> > +#define OPENAT2_REGULAR      0200000000
> >
>
> I don't quite understand why we are adding OPENAT2_REGULAR inside the
> O_* flag range. Wasn't this supposed to be only supported for openat2()?
> If so, I don't see the need to waste an O_* flag bit. But maybe I am
> missing something.
>

Yes, OPENAT2_REGULAR is only supported for openat2. I am not sure if I
got a specific review to not add OPENAT2_REGULAR in the O_* flag 32
bit range. But as far as I understand, for the old open system calls
we can't easily add new O_* flags as the older codepaths don't strip
off unknown bits which openat2 does. It's not easy to add new O_*
flags for the old open system calls since that could break userspace
programs. So I guess it's okay to add OPENAT2_REGULAR in the 32 bits
range anyway? (Also lots of code paths take 32bit flags param right
now and those would need changing to take uint64_t instead but this is
of course not a reason to not add the new flag outside of the 32
bits).

Regards,
Dorjoy