在 2016年01月20日 17:56, zhuyj 写道:
On 01/20/2016 05:47 PM, Wengang Wang wrote:
在 2016年01月20日 15:54, zhuyj 写道:
On 01/20/2016 03:38 PM, Wengang Wang wrote:
在 2016年01月20日 14:24, zhuyj 写道:
On 01/20/2016 01:32 PM, Wengang Wang wrote:
In a bonding setting, we determines fragment size according to
MTU and
PMTU associated to the bonding master. If the slave finds the
fragment
size is too big, it drops the fragment and calls
ip_rt_update_pmtu(),
passing _skb_ and _pmtu_, trying to update the path MTU.
Problem is that the target device that function ip_rt_update_pmtu
actually
tries to update is the slave (skb->dev), not the master. Thus
since no
PMTU change happens on master, the fragment size for later
packets doesn't
change so all later fragments/packets are dropped too.
The fix is letting build_skb_flow_key() take care of the
transition of
device index from bonding slave to the master. That makes the
master become
the target device that ip_rt_update_pmtu tries to update PMTU to.
Signed-off-by: Wengang Wang <[email protected]>
---
net/ipv4/route.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 85f184e..c59fb0d 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -523,10 +523,21 @@ static void build_skb_flow_key(struct
flowi4 *fl4, const struct sk_buff *skb,
const struct sock *sk)
{
const struct iphdr *iph = ip_hdr(skb);
- int oif = skb->dev->ifindex;
+ struct net_device *master = NULL;
u8 tos = RT_TOS(iph->tos);
u8 prot = iph->protocol;
u32 mark = skb->mark;
+ int oif;
+
+ if (skb->dev->flags & IFF_SLAVE) {
+ rtnl_lock();
+ master = netdev_master_upper_dev_get(skb->dev);
+ rtnl_unlock();
update_pmtu is called very frequently. Is it appropriate to use
rtnl_lock here?
By "very frequently", how frequently it is expected? And what
situation can cause that?
For my case, the update_pmtu is called only once.
ip_tunnel_xmit
Can you please explain with more details?
dev_queue_xmit->ipip_tunnel_xmit->ip_tunnel_xmit->tnl_update_pmtu->
skb_dst(skb)->ops->update_pmtu
For ipip, yes seems update_pmtu is called in line for each call of
queue_xmit. Do you know if it's a good configuration for ipip + bonding?
Other's comment and suggestion?
thanks,
wengang
