inet: drop prev pointer handling in request sock

When request sock are put in ehash table, the whole notion
of having a previous request to update dl_next is pointless.

Also, following patch will get rid of big purge timer,
so we want to delete a request sock without holding listener lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 18 insertions, 25 deletions

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 3b1d64d6e093..2396f50c5b04 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -280,8 +280,7 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
 				       struct request_sock *req,
 				       struct dst_entry *dst);
 struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
-			    struct request_sock *req,
-			    struct request_sock **prev);
+			    struct request_sock *req);
 
 int dccp_child_process(struct sock *parent, struct sock *child,
 		       struct sk_buff *skb);
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index e7ad291cd96b..5bffbbaf1fac 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -288,11 +288,11 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
 	}
 
 	switch (sk->sk_state) {
-		struct request_sock *req , **prev;
+		struct request_sock *req;
 	case DCCP_LISTEN:
 		if (sock_owned_by_user(sk))
 			goto out;
-		req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
+		req = inet_csk_search_req(sk, dh->dccph_dport,
 					  iph->daddr, iph->saddr);
 		if (!req)
 			goto out;
@@ -314,7 +314,7 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
 		 * created socket, and POSIX does not want network
 		 * errors returned from accept().
 		 */
-		inet_csk_reqsk_queue_drop(sk, req, prev);
+		inet_csk_reqsk_queue_drop(sk, req);
 		goto out;
 
 	case DCCP_REQUESTING:
@@ -448,13 +448,11 @@ static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
 	const struct dccp_hdr *dh = dccp_hdr(skb);
 	const struct iphdr *iph = ip_hdr(skb);
 	struct sock *nsk;
-	struct request_sock **prev;
 	/* Find possible connection requests. */
-	struct request_sock *req = inet_csk_search_req(sk, &prev,
-						       dh->dccph_sport,
+	struct request_sock *req = inet_csk_search_req(sk, dh->dccph_sport,
 						       iph->saddr, iph->daddr);
-	if (req != NULL)
-		return dccp_check_req(sk, skb, req, prev);
+	if (req)
+		return dccp_check_req(sk, skb, req);
 
 	nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
 				      iph->saddr, dh->dccph_sport,
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index c655de5f67c9..ae2184039fe3 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -149,12 +149,12 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 	/* Might be for an request_sock */
 	switch (sk->sk_state) {
-		struct request_sock *req, **prev;
+		struct request_sock *req;
 	case DCCP_LISTEN:
 		if (sock_owned_by_user(sk))
 			goto out;
 
-		req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
+		req = inet6_csk_search_req(sk, dh->dccph_dport,
 					   &hdr->daddr, &hdr->saddr,
 					   inet6_iif(skb));
 		if (req == NULL)
@@ -172,7 +172,7 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 			goto out;
 		}
 
-		inet_csk_reqsk_queue_drop(sk, req, prev);
+		inet_csk_reqsk_queue_drop(sk, req);
 		goto out;
 
 	case DCCP_REQUESTING:
@@ -317,16 +317,13 @@ static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
 {
 	const struct dccp_hdr *dh = dccp_hdr(skb);
 	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct request_sock *req;
 	struct sock *nsk;
-	struct request_sock **prev;
-	/* Find possible connection requests. */
-	struct request_sock *req = inet6_csk_search_req(sk, &prev,
-							dh->dccph_sport,
-							&iph->saddr,
-							&iph->daddr,
-							inet6_iif(skb));
+
+	req = inet6_csk_search_req(sk, dh->dccph_sport, &iph->saddr,
+				   &iph->daddr, inet6_iif(skb));
 	if (req != NULL)
-		return dccp_check_req(sk, skb, req, prev);
+		return dccp_check_req(sk, skb, req);
 
 	nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
 					 &iph->saddr, dh->dccph_sport,
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index b50dc436db1f..332f7d6d9942 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -152,8 +152,7 @@ EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
  * as an request_sock.
  */
 struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
-			    struct request_sock *req,
-			    struct request_sock **prev)
+			    struct request_sock *req)
 {
 	struct sock *child = NULL;
 	struct dccp_request_sock *dreq = dccp_rsk(req);
@@ -200,7 +199,7 @@ struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 	if (child == NULL)
 		goto listen_overflow;
 
-	inet_csk_reqsk_queue_unlink(sk, req, prev);
+	inet_csk_reqsk_queue_unlink(sk, req);
 	inet_csk_reqsk_queue_removed(sk, req);
 	inet_csk_reqsk_queue_add(sk, req, child);
 out:
@@ -212,7 +211,7 @@ drop:
 	if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
 		req->rsk_ops->send_reset(sk, skb);
 
-	inet_csk_reqsk_queue_drop(sk, req, prev);
+	inet_csk_reqsk_queue_drop(sk, req);
 	goto out;
 }