inet: inet_twsk_deschedule factorization

inet_twsk_deschedule() calls are followed by inet_twsk_put().

Only particular case is in inet_twsk_purge() but there is no point
to defer the inet_twsk_put() after re-enabling BH.

Lets rename inet_twsk_deschedule() to inet_twsk_deschedule_put()
and move the inet_twsk_put() inside.

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

include/net/inet_timewait_sock.h

@@ -111,7 +111,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 			   struct inet_hashinfo *hashinfo);
 
 void inet_twsk_schedule(struct inet_timewait_sock *tw, const int timeo);
-void inet_twsk_deschedule(struct inet_timewait_sock *tw);
+void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);
 
 void inet_twsk_purge(struct inet_hashinfo *hashinfo,
 		     struct inet_timewait_death_row *twdr, int family);

net/ipv4/inet_hashtables.c

@@ -380,8 +380,7 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row,
 		*twp = tw;
 	} else if (tw) {
 		/* Silly. Should hash-dance instead... */
-		inet_twsk_deschedule(tw);
-		inet_twsk_put(tw);
+		inet_twsk_deschedule_put(tw);
 	}
 	return 0;
 
@@ -558,10 +557,8 @@ ok:
 			inet_twsk_bind_unhash(tw, hinfo);
 		spin_unlock(&head->lock);
 
-		if (tw) {
-			inet_twsk_deschedule(tw);
-			inet_twsk_put(tw);
-		}
+		if (tw)
+			inet_twsk_deschedule_put(tw);
 
 		ret = 0;
 		goto out;

net/ipv4/inet_timewait_sock.c

@@ -205,13 +205,17 @@ EXPORT_SYMBOL_GPL(inet_twsk_alloc);
  * tcp_input.c to verify this.
  */
 
-/* This is for handling early-kills of TIME_WAIT sockets. */
-void inet_twsk_deschedule(struct inet_timewait_sock *tw)
+/* This is for handling early-kills of TIME_WAIT sockets.
+ * Warning : consume reference.
+ * Caller should not access tw anymore.
+ */
+void inet_twsk_deschedule_put(struct inet_timewait_sock *tw)
 {
 	if (del_timer_sync(&tw->tw_timer))
 		inet_twsk_kill(tw);
+	inet_twsk_put(tw);
 }
-EXPORT_SYMBOL(inet_twsk_deschedule);
+EXPORT_SYMBOL(inet_twsk_deschedule_put);
 
 void inet_twsk_schedule(struct inet_timewait_sock *tw, const int timeo)
 {
@@ -281,9 +285,8 @@ restart:
 
 			rcu_read_unlock();
 			local_bh_disable();
-			inet_twsk_deschedule(tw);
+			inet_twsk_deschedule_put(tw);
 			local_bh_enable();
-			inet_twsk_put(tw);
 			goto restart_rcu;
 		}
 		/* If the nulls value we got at the end of this lookup is

net/ipv4/tcp_ipv4.c

@@ -1683,8 +1683,7 @@ do_time_wait:
 							iph->daddr, th->dest,
 							inet_iif(skb));
 		if (sk2) {
-			inet_twsk_deschedule(inet_twsk(sk));
-			inet_twsk_put(inet_twsk(sk));
+			inet_twsk_deschedule_put(inet_twsk(sk));
 			sk = sk2;
 			goto process;
 		}

net/ipv4/tcp_minisocks.c

@@ -147,8 +147,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
 		if (!th->fin ||
 		    TCP_SKB_CB(skb)->end_seq != tcptw->tw_rcv_nxt + 1) {
 kill_with_rst:
-			inet_twsk_deschedule(tw);
-			inet_twsk_put(tw);
+			inet_twsk_deschedule_put(tw);
 			return TCP_TW_RST;
 		}
 
@@ -198,8 +197,7 @@ kill_with_rst:
 			 */
 			if (sysctl_tcp_rfc1337 == 0) {
 kill:
-				inet_twsk_deschedule(tw);
-				inet_twsk_put(tw);
+				inet_twsk_deschedule_put(tw);
 				return TCP_TW_SUCCESS;
 			}
 		}

net/ipv6/inet6_hashtables.c

@@ -243,8 +243,7 @@ static int __inet6_check_established(struct inet_timewait_death_row *death_row,
 		*twp = tw;
 	} else if (tw) {
 		/* Silly. Should hash-dance instead... */
-		inet_twsk_deschedule(tw);
-		inet_twsk_put(tw);
+		inet_twsk_deschedule_put(tw);
 	}
 	return 0;
 

net/ipv6/tcp_ipv6.c

@@ -1481,8 +1481,7 @@ do_time_wait:
 					    ntohs(th->dest), tcp_v6_iif(skb));
 		if (sk2) {
 			struct inet_timewait_sock *tw = inet_twsk(sk);
-			inet_twsk_deschedule(tw);
-			inet_twsk_put(tw);
+			inet_twsk_deschedule_put(tw);
 			sk = sk2;
 			tcp_v6_restore_cb(skb);
 			goto process;

net/netfilter/xt_TPROXY.c

@@ -272,8 +272,7 @@ tproxy_handle_time_wait4(struct sk_buff *skb, __be32 laddr, __be16 lport,
 					    hp->source, lport ? lport : hp->dest,
 					    skb->dev, NFT_LOOKUP_LISTENER);
 		if (sk2) {
-			inet_twsk_deschedule(inet_twsk(sk));
-			inet_twsk_put(inet_twsk(sk));
+			inet_twsk_deschedule_put(inet_twsk(sk));
 			sk = sk2;
 		}
 	}
@@ -437,8 +436,7 @@ tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
 					    tgi->lport ? tgi->lport : hp->dest,
 					    skb->dev, NFT_LOOKUP_LISTENER);
 		if (sk2) {
-			inet_twsk_deschedule(inet_twsk(sk));
-			inet_twsk_put(inet_twsk(sk));
+			inet_twsk_deschedule_put(inet_twsk(sk));
 			sk = sk2;
 		}
 	}