Re: [PATCH] Re: skb_segment() questions

[Jarek Poplawski <jarkao2@gmail.com>]

On Wed, Apr 01, 2009 at 05:24:57PM +0800, Herbert Xu wrote:
> On Wed, Apr 01, 2009 at 09:18:01AM +0000, Jarek Poplawski wrote:
> >
> > gso: Fix support for linear packets 2
> > 
> > The previous fix removed a check, which should be useful, only a bit
> > later, by skipping at least two similar checks and three useless
> > assignments in case a header is (still) copied.
> > 
> > Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
> > ---
> > 
> >  net/core/skbuff.c |    2 ++
> >  1 files changed, 2 insertions(+), 0 deletions(-)
> > 
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index ce6356c..2123a92 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> > @@ -2594,6 +2594,8 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
> >  
> >  		skb_copy_from_linear_data_offset(skb, offset,
> >  						 skb_put(nskb, hsize), hsize);
> > +		if (pos >= offset + len)
> > +			continue;
> >  
> >  		while (pos < offset + len && i < nfrags) {
> >  			*frag = skb_shinfo(skb)->frags[i];
> 
> The common case (non-linear skb) is going to fail that check so 
> I'm no sure if it's warranted.

I guess you mean non-linear skb with a header smaller than mtu? Well,
if it's the most common case now, I agree.

Thanks,
Jarek P.