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Diffstat (limited to 'net/ipv4/ip_output.c')
-rw-r--r--net/ipv4/ip_output.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index d2a8f8bb78a6..8ebe86dd72af 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -430,7 +430,7 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
* single device frame, and queue such a frame for sending.
*/
-int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
+int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
{
struct iphdr *iph;
int raw = 0;
@@ -720,7 +720,7 @@ static inline int ip_ufo_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 hh_len, int fragheaderlen,
- int transhdrlen, int mtu,unsigned int flags)
+ int transhdrlen, int mtu, unsigned int flags)
{
struct sk_buff *skb;
int err;
@@ -741,7 +741,7 @@ static inline int ip_ufo_append_data(struct sock *sk,
skb_reserve(skb, hh_len);
/* create space for UDP/IP header */
- skb_put(skb,fragheaderlen + transhdrlen);
+ skb_put(skb, fragheaderlen + transhdrlen);
/* initialize network header pointer */
skb_reset_network_header(skb);
@@ -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);
@@ -1279,7 +1284,12 @@ int ip_push_pending_frames(struct sock *sk)
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
- skb->dst = dst_clone(&rt->u.dst);
+ /*
+ * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec
+ * on dst refcount
+ */
+ inet->cork.dst = NULL;
+ skb->dst = &rt->u.dst;
if (iph->protocol == IPPROTO_ICMP)
icmp_out_count(net, ((struct icmphdr *)
@@ -1391,7 +1401,7 @@ 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) +