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authorEric Dumazet <eric.dumazet@gmail.com>2010-05-11 23:19:48 +0000
committerDavid S. Miller <davem@davemloft.net>2010-05-17 17:18:50 -0700
commit7fee226ad2397b635e2fd565a59ca3ae08a164cd (patch)
tree0bcd26150ad74ec1a237109de87a3d214a07fc22 /net/ipv4/icmp.c
parentebda37c27d0c768947e9b058332d7ea798210cf8 (diff)
net: add a noref bit on skb dst
Use low order bit of skb->_skb_dst to tell dst is not refcounted. Change _skb_dst to _skb_refdst to make sure all uses are catched. skb_dst() returns the dst, regardless of noref bit set or not, but with a lockdep check to make sure a noref dst is not given if current user is not rcu protected. New skb_dst_set_noref() helper to set an notrefcounted dst on a skb. (with lockdep check) skb_dst_drop() drops a reference only if skb dst was refcounted. skb_dst_force() helper is used to force a refcount on dst, when skb is queued and not anymore RCU protected. Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if !IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in sock_queue_rcv_skb(), in __nf_queue(). Use skb_dst_force() in dev_requeue_skb(). Note: dst_use_noref() still dirties dst, we might transform it later to do one dirtying per jiffies. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/icmp.c')
-rw-r--r--net/ipv4/icmp.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index f3d339f728b..d65e9215bcd 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -587,20 +587,20 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
err = __ip_route_output_key(net, &rt2, &fl);
else {
struct flowi fl2 = {};
- struct dst_entry *odst;
+ unsigned long orefdst;
fl2.fl4_dst = fl.fl4_src;
if (ip_route_output_key(net, &rt2, &fl2))
goto relookup_failed;
/* Ugh! */
- odst = skb_dst(skb_in);
+ orefdst = skb_in->_skb_refdst; /* save old refdst */
err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src,
RT_TOS(tos), rt2->u.dst.dev);
dst_release(&rt2->u.dst);
rt2 = skb_rtable(skb_in);
- skb_dst_set(skb_in, odst);
+ skb_in->_skb_refdst = orefdst; /* restore old refdst */
}
if (err)