Re: [PATCH v6 0/4] OPENAT2_REGULAR flag support for openat2
From: Dorjoy Chowdhury
Date: Thu May 21 2026 - 12:45:09 EST
On Thu, May 21, 2026 at 4:54 PM Christian Brauner <brauner@xxxxxxxxxx> wrote:
>
> On Thu, Apr 16, 2026 at 03:07:12PM +0200, Christian Brauner wrote:
> > On Sat, 28 Mar 2026 23:22:21 +0600, Dorjoy Chowdhury wrote:
> > > I came upon this "Ability to only open regular files" uapi feature suggestion
> > > from https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files
> > > and thought it would be something I could do as a first patch and get to
> > > know the kernel code a bit better.
> > >
> > > The following filesystems have been tested by building and booting the kernel
> > > x86 bzImage in a Fedora 43 VM in QEMU. I have tested with OPENAT2_REGULAR that
> > > regular files can be successfully opened and non-regular files (directory, fifo etc)
> > > return -EFTYPE.
> > > - btrfs
> > > - NFS (loopback)
> > > - SMB (loopback)
> > >
> > > [...]
> >
> > - I've added an explanation why OPENAT2_REGULAR is only needed for some
> > ->atomic_open() implementers but not others. What I don't like is that
> > we need all that custom handling in there but it's managable.
> >
> > - I dropped the topmost style conversions. They really don't belong
> > there and if we switch to something better we should use (1 << <nr>).
> >
> > - I split the EFTYPE errno introduction into a separate patch.
>
> So I've massaged this series a bit in that I moved OPENAT2_REGULAR into
> the upper 64-bit and internally use a __O_REGULAR bit. After having
> thought about it makes a lot more sense to move the openat2() only
> features into the upper 32-bit for the uapi space. I also ported the
> selftests to the TEST* framework to fit with Aleksa's recent rework.
Thanks for fixing up!
Regards,
Dorjoy