Re: bridge/netfilter: regression in 2.6.39.1

From: Alexander Holler
Date: Mon Jun 06 2011 - 07:49:17 EST


Am 06.06.2011 13:15, schrieb Neil Horman:
On Fri, Jun 03, 2011 at 09:21:06PM +0200, Alexander Holler wrote:
Hello,

I'm getting a oops in the bridge code in br_change_mtu() with
2.6.39.1. The patch below seems to fix that.

I'm not sure about the usage of dst_cow_metrics_generic() in
fake_dst_ops, but after having a quick look at it seems to be ok to
use that here.

Regards,

Alexander

How did the flags of the dst entry on which we're callnig dst_entry_write_ptr
wind up getting the READ_ONLY flag set on it? I don't see how we'er falling
into that clause in which we call cow_metrics when we call dst_metric_set. It
seems like that flag is set erroneously. perhaps we should just update
fake_rtable.dst to have the correct flags?
Neil

It is set by that change:

--------
@@ -124,7 +128,7 @@ void br_netfilter_rtable_init(struct net_bridge *br)
atomic_set(&rt->dst.__refcnt, 1);
rt->dst.dev = br->dev;
rt->dst.path = &rt->dst;
- dst_metric_set(&rt->dst, RTAX_MTU, 1500);
+ dst_init_metrics(&rt->dst, br_dst_default_metrics, true);
rt->dst.flags = DST_NOXFRM;
rt->dst.ops = &fake_dst_ops;
}
--------

The true in dst_init_metrics() is responsible for that flag.

Regards,

Alexander
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/