Re: [PATCH v5 1/9] iov_iter: add copy_struct_from_iter()

Omar Sandoval
2020-08-24T21:09:16Z

On Mon, Aug 24, 2020 at 02:52:24PM -0400, Josef Bacik wrote:
> On 8/21/20 3:38 AM, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> >
> > This is essentially copy_struct_from_user() but for an iov_iter.
> >
> > Suggested-by: Aleksa Sarai <cyphar@cyphar.com>
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
>
> This took me a lot longer to grok than I'm proud of, but the idea is you'll
> have a single segment that represents the incoming encoded data, and then
> subsequent segments will be the read/write buffer, correct? The code looks
> fine to me,
>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
>
> Thanks,
>
> Josef

Yes, that's the idea for RWF_ENCODED. This patch is the generic way to
shove an extra metadata struct at the beginning of an iov_iter in a way
that is backwards/forwards compatible.

Thanks!