Re: [PATCH] ovl: add ioctls to retrieve layer file descriptors

Giuseppe Scrivano <[email protected]> Wed, 08 Jul 2026 17:55:01 +0200
Newsgroups org.kernel.vger.linux-unionfs,org.kernel.vger.linux-api,org.kernel.vger.linux-fsdevel
Message-ID <[email protected]>
Miklos Szeredi <[email protected]> writes:

> On Wed, 8 Jul 2026 at 16:32, Giuseppe Scrivano <[email protected]> wrote:
>
>> Amir suggested to add that functionality when I've asked for some
>> feedback before sending the patch here.  I am fine to drop it if this is
>> the consensus although I see its utility from user space.
>
> How about a completely different interface:
>
> int get_fd_opt(const char *name, unsigned int index, unsigned int flags);
>
> Enumerating layers would be as easy as passing an index stating from
> zero and stopping when -ERANGE is received.
>
> It would work for all filesystems that use files as options.  No more
> fs specific ioctls.

Is a new syscall really justified for such a narrow use case?

On the other hand, it would cover both ioctl's I am working on right
now.

Regards,
Giuseppe