From: Frank Blaschka <blaschka@linux.vnet.ibm.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: arnd@arndb.de, davem@davemloft.net, netdev@vger.kernel.org,
linux-s390@vger.kernel.org
Subject: Re: [PATCH] net: skb_set_dev do not unconditionally drop ref to dst
Date: Mon, 30 Apr 2012 08:53:22 +0200 [thread overview]
Message-ID: <20120430065322.GA28320@tuxmaker.boeblingen.de.ibm.com> (raw)
In-Reply-To: <1335765093.2296.4.camel@edumazet-glaptop>
On Mon, Apr 30, 2012 at 07:51:33AM +0200, Eric Dumazet wrote:
> On Mon, 2012-04-30 at 07:38 +0200, Frank Blaschka wrote:
> > From: Frank Blaschka <frank.blaschka@de.ibm.com>
> >
> > commit 8a83a00b0735190384a348156837918271034144 unconditionally
> > drops dst reference when skb->dev is set. This causes a regression
> > with VLAN and the qeth_l3 network driver. qeth_l3 can not get gw
> > information from the skb coming from the vlan driver. It is only
> > valid to drop the dst in case of different name spaces.
> >
> > Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
> > ---
> > net/core/dev.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -1881,8 +1881,8 @@ EXPORT_SYMBOL(netif_device_attach);
> > #ifdef CONFIG_NET_NS
> > void skb_set_dev(struct sk_buff *skb, struct net_device *dev)
> > {
> > - skb_dst_drop(skb);
> > if (skb->dev && !net_eq(dev_net(skb->dev), dev_net(dev))) {
> > + skb_dst_drop(skb);
> > secpath_reset(skb);
> > nf_reset(skb);
> > skb_init_secmark(skb);
> >
>
> You forgot CC Arnd Bergmann <arnd@arndb.de> ?
>
> But we do want to do the skb_dst_drop() in dev_forward_skb()
>
> Your patch breaks dev_forward_skb() then.
>
> But apparently this forward path was alredy broken in Arnd patch...
>
Hi Eric,
do you have and suggestions how to fix this regression?
The qeth_l3 driver needs the gw information to address the frame.
The way to look at dst works well for the non vlan case and was
also working for vlan prior Arnds changes.
>
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
next prev parent reply other threads:[~2012-04-30 6:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-30 5:38 [PATCH] net: skb_set_dev do not unconditionally drop ref to dst Frank Blaschka
2012-04-30 5:51 ` Eric Dumazet
2012-04-30 6:53 ` Frank Blaschka [this message]
2012-05-02 5:50 ` Frank Blaschka
2012-05-02 6:59 ` Eric Dumazet
2012-05-03 6:28 ` David Miller
2012-05-03 12:32 ` Arnd Bergmann
2012-05-09 10:48 ` Frank Blaschka
2012-05-11 3:06 ` David Miller
2012-05-09 15:16 ` Stephen Hemminger
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120430065322.GA28320@tuxmaker.boeblingen.de.ibm.com \
--to=blaschka@linux.vnet.ibm.com \
--cc=arnd@arndb.de \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=linux-s390@vger.kernel.org \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).