Re: skbuff: skb_under_panic warning in 3.10rc7+
From: Hannes Frederic Sowa <hidden>
Date: 2013-07-01 08:24:41
On Mon, Jul 01, 2013 at 01:23:08AM +0200, Hannes Frederic Sowa wrote:
I'll look at it again tomorrow.
[Cc Gao feng because of commit 0c1833797a5a6ec23ea9261d979aa18078720b74
("ipv6: fix incorrect ipsec fragment")]
Just a small update:
The following diff fixes the UDP_CORK case for me. I just traced the various
len variables and brought ip6_append_data_mtu in line with the initial
initialization when the first call to ip6_append_data happens.
I'll have to do more research on this and check if this correlates
somehow with Dave's report.
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c@@ -1097,7 +1097,9 @@ static void ip6_append_data_mtu(int *mtu, int *maxfraglen, unsigned int fragheaderlen, struct sk_buff *skb, - struct rt6_info *rt) + struct rt6_info *rt, + __u32 frag_size, + bool pmtudisc) { if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { if (skb == NULL) {
@@ -1109,7 +1111,9 @@ static void ip6_append_data_mtu(int *mtu, * this fragment is not first, the headers * space is regarded as data space. */ - *mtu = dst_mtu(rt->dst.path); + *mtu = pmtudisc ? rt->dst.dev->mtu : dst_mtu(rt->dst.path); + if (frag_size && frag_size < *mtu) + *mtu = frag_size; } *maxfraglen = ((*mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
@@ -1287,7 +1291,8 @@ alloc_new_skb: /* update mtu and maxfraglen if necessary */ if (skb == NULL || skb_prev == NULL) ip6_append_data_mtu(&mtu, &maxfraglen, - fragheaderlen, skb, rt); + fragheaderlen, skb, rt, np->frag_size, + np->pmtudisc == IPV6_PMTUDISC_PROBE); skb_prev = skb;