Re: [PATCH v2 10/12] [xen] fix "direction" argument of iov_iter_kvec()

From: John Stoffel
Date: Fri Oct 28 2022 - 08:50:03 EST


On Fri, Oct 28, 2022 at 08:48:22AM -0400, John Stoffel wrote:
> On Fri, Oct 28, 2022 at 03:33:50AM +0100, Al Viro wrote:
> > Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/xen/pvcalls-back.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
> > index d6f945fd4147..21b9c850a382 100644
> > --- a/drivers/xen/pvcalls-back.c
> > +++ b/drivers/xen/pvcalls-back.c
> > @@ -129,13 +129,13 @@ static bool pvcalls_conn_back_read(void *opaque)
> > if (masked_prod < masked_cons) {
> > vec[0].iov_base = data->in + masked_prod;
> > vec[0].iov_len = wanted;
> > - iov_iter_kvec(&msg.msg_iter, WRITE, vec, 1, wanted);
> > + iov_iter_kvec(&msg.msg_iter, READ, vec, 1, wanted);
>
>
> Wouldn't it make more sense to use READER and WRITER here, since the
> current READ/WRITE are 100% non-obvious? This is probably a bigger
> change, but this just looks wrong and will be so easy for people to
> screw up again and again down the line.

And if I had only made it down to patch 12, I would have seen that you
fixed this. Sorry for the noise!