Re: [PATCH v4 1/6] fs: add write-stream management ioctls

On Wed, 19 Aug 2026 at 09:06, Christoph Hellwig <[email protected]> wrote:
>
> On Thu, Jul 30, 2026 at 10:22:11AM -0700, Darrick J. Wong wrote:

> > passing through to another layer (e.g. fuse) assume that the third
> > argument is a pointer and that it can copy sizeof(data_type) bytes at
> > that address in and out of the kernel as part of marshalling.
>
> That is not a good assumption and things will break.

Right.  Fuse server should send a whitelist of ioctl numbers it can handle.

But ioctl's are a bad interface anyway.  Why not add proper syscalls instead?

Thanks,
Miklos