net: avoid a pair of dst_hold()/dst_release() in ip_append_data()

[net-next-2.6.git] / net / ipv4 / ip_output.c

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 46d7be233eac9132e6e023c492b36b535e9bb1df..5516825a0751e7e9b6e0ede5ff3b19f809a8ff2e 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -778,7 +778,7 @@ int ip_append_data(struct sock *sk,
                   int getfrag(void *from, char *to, int offset, int len,
                               int odd, struct sk_buff *skb),
                   void *from, int length, int transhdrlen,
-                  struct ipcm_cookie *ipc, struct rtable *rt,
+                  struct ipcm_cookie *ipc, struct rtable **rtp,
                   unsigned int flags)
 {
        struct inet_sock *inet = inet_sk(sk);
@@ -793,6 +793,7 @@ int ip_append_data(struct sock *sk,
        int offset = 0;
        unsigned int maxfraglen, fragheaderlen;
        int csummode = CHECKSUM_NONE;
+       struct rtable *rt;
 
        if (flags&MSG_PROBE)
                return 0;
@@ -812,7 +813,11 @@ int ip_append_data(struct sock *sk,
                        inet->cork.flags |= IPCORK_OPT;
                        inet->cork.addr = ipc->addr;
                }
-               dst_hold(&rt->u.dst);
+               rt = *rtp;
+               /*
+                * We steal reference to this route, caller should not release it
+                */
+               *rtp = NULL;
                inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ?
                                            rt->u.dst.dev->mtu :
                                            dst_mtu(rt->u.dst.path);
@@ -1391,7 +1396,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
        sk->sk_protocol = ip_hdr(skb)->protocol;
        sk->sk_bound_dev_if = arg->bound_dev_if;
        ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0,
-                      &ipc, rt, MSG_DONTWAIT);
+                      &ipc, &rt, MSG_DONTWAIT);
        if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
                if (arg->csumoffset >= 0)
                        *((__sum16 *)skb_transport_header(skb) +