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>

2 files changed, 10 insertions, 12 deletions

diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 29b32206e494..b7acb9ebc4f5 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -113,7 +113,6 @@ static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
 }
 
 struct request_sock *inet6_csk_search_req(const struct sock *sk,
-                                          struct request_sock ***prevp,
                                           const __be16 rport,
                                           const struct in6_addr *raddr,
                                           const struct in6_addr *laddr,
@@ -121,13 +120,13 @@ struct request_sock *inet6_csk_search_req(const struct sock *sk,
 {
         const struct inet_connection_sock *icsk = inet_csk(sk);
         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
-        struct request_sock *req, **prev;
+        struct request_sock *req;
 
-        for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
+        for (req = lopt->syn_table[inet6_synq_hash(raddr, rport,
                                                      lopt->hash_rnd,
                                                      lopt->nr_table_entries)];
-             (req = *prev) != NULL;
-             prev = &req->dl_next) {
+             req != NULL;
+             req = req->dl_next) {
                 const struct inet_request_sock *ireq = inet_rsk(req);
 
                 if (ireq->ir_rmt_port == rport &&
@@ -136,7 +135,6 @@ struct request_sock *inet6_csk_search_req(const struct sock *sk,
                     ipv6_addr_equal(&ireq->ir_v6_loc_addr, laddr) &&
                     (!ireq->ir_iif || ireq->ir_iif == iif)) {
                         WARN_ON(req->sk != NULL);
-                        *prevp = prev;
                         return req;
                 }
         }
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 720676d073d9..146f123b52c9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -403,13 +403,13 @@ static void tcp_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 TCP_LISTEN:
                 if (sock_owned_by_user(sk))
                         goto out;
 
                 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
-                req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
+                req = inet6_csk_search_req(sk, th->dest, &hdr->daddr,
                                            &hdr->saddr, inet6_iif(skb));
                 if (!req)
                         goto out;
@@ -424,7 +424,7 @@ static void tcp_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);
                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
                 goto out;
 
@@ -980,16 +980,16 @@ static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 
 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 {
-        struct request_sock *req, **prev;
         const struct tcphdr *th = tcp_hdr(skb);
+        struct request_sock *req;
         struct sock *nsk;
 
         /* Find possible connection requests. */
-        req = inet6_csk_search_req(sk, &prev, th->source,
+        req = inet6_csk_search_req(sk, th->source,
                                    &ipv6_hdr(skb)->saddr,
                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
         if (req)
-                return tcp_check_req(sk, skb, req, prev, false);
+                return tcp_check_req(sk, skb, req, false);
 
         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
                                          &ipv6_hdr(skb)->saddr, th->source,