Re: [PATCH net-next 3/4] kcm: Support MSG_SPLICE_PAGES

[David Howells]

Jakub Kicinski <kuba@xxxxxxxxxx> wrote:

> On Wed, 24 May 2023 15:49:22 +0100 David Howells wrote:
> > +			err = skb_splice_from_iter(skb, &msg->msg_iter, copy,
> > +						   sk->sk_allocation);
> > +			if (err < 0) {
> > +				if (err == -EMSGSIZE)
> > +					goto wait_for_memory;
> > +				goto out_error;
> > +			}
> >  
> 
> should there be a:
> 
> 		copy = err;
> or:
> 		copy -= msg_data_left(msg);
> 
> or some such here? Can we safely assume that skb_splice_from_iter() will
> copy all or nothing? 

Yeah.  Good point.  I didn't add one because the normal operation code doesn't
do that - but I guess that's all-or-nothing.

David