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;
 }