patch-2.4.0-test7 linux/net/ipv4/tcp_timer.c

• Lines: 668
• Date: Sat Aug 12 12:09:55 2000
• Orig file: v2.4.0-test6/linux/net/ipv4/tcp_timer.c
• Orig date: Mon Jul 10 16:47:28 2000

diff -u --recursive --new-file v2.4.0-test6/linux/net/ipv4/tcp_timer.c linux/net/ipv4/tcp_timer.c
@@ -5,7 +5,7 @@
  *
  *		Implementation of the Transmission Control Protocol(TCP).
  *
- * Version:	$Id: tcp_timer.c,v 1.77 2000/06/30 10:18:38 davem Exp $
+ * Version:	$Id: tcp_timer.c,v 1.79 2000/08/11 00:13:36 davem Exp $
  *
  * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
@@ -29,13 +29,11 @@
 int sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL;
 int sysctl_tcp_retries1 = TCP_RETR1;
 int sysctl_tcp_retries2 = TCP_RETR2;
-int sysctl_tcp_orphan_retries = TCP_ORPHAN_RETRIES;
+int sysctl_tcp_orphan_retries = 0;
 
-static void tcp_retransmit_timer(unsigned long);
+static void tcp_write_timer(unsigned long);
 static void tcp_delack_timer(unsigned long);
-static void tcp_probe_timer(unsigned long);
 static void tcp_keepalive_timer (unsigned long data);
-static void tcp_twkill(unsigned long);
 
 const char timer_bug_msg[] = KERN_DEBUG "tcpbug: unknown timer value\n";
 
@@ -50,73 +48,35 @@
 	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
 
 	init_timer(&tp->retransmit_timer);
-	tp->retransmit_timer.function=&tcp_retransmit_timer;
+	tp->retransmit_timer.function=&tcp_write_timer;
 	tp->retransmit_timer.data = (unsigned long) sk;
+	tp->pending = 0;
 
 	init_timer(&tp->delack_timer);
 	tp->delack_timer.function=&tcp_delack_timer;
 	tp->delack_timer.data = (unsigned long) sk;
-
-	init_timer(&tp->probe_timer);
-	tp->probe_timer.function=&tcp_probe_timer;
-	tp->probe_timer.data = (unsigned long) sk;
+	tp->ack.pending = 0;
 
 	init_timer(&sk->timer);
 	sk->timer.function=&tcp_keepalive_timer;
 	sk->timer.data = (unsigned long) sk;
 }
 
-/*
- *	Reset the retransmission timer
- */
- 
-void tcp_reset_xmit_timer(struct sock *sk, int what, unsigned long when)
-{
-	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
-
-	switch (what) {
-	case TCP_TIME_RETRANS:
-		/* When seting the transmit timer the probe timer 
-		 * should not be set.
-		 * The delayed ack timer can be set if we are changing the
-		 * retransmit timer when removing acked frames.
-		 */
-		if (timer_pending(&tp->probe_timer) && del_timer(&tp->probe_timer))
-			__sock_put(sk);
-		if (when > TCP_RTO_MAX) {
-			printk(KERN_DEBUG "reset_xmit_timer sk=%p when=0x%lx, caller=%p\n", sk, when, NET_CALLER(sk));
-			when = TCP_RTO_MAX;
-		}
-		if (!mod_timer(&tp->retransmit_timer, jiffies+when))
-			sock_hold(sk);
-		break;
-
-	case TCP_TIME_DACK:
-		if (!mod_timer(&tp->delack_timer, jiffies+when))
-			sock_hold(sk);
-		break;
-
-	case TCP_TIME_PROBE0:
-		if (!mod_timer(&tp->probe_timer, jiffies+when))
-			sock_hold(sk);
-		break;
-
-	default:
-		printk(KERN_DEBUG "bug: unknown timer value\n");
-	};
-}
-
 void tcp_clear_xmit_timers(struct sock *sk)
-{	
+{
 	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
 
-	if(timer_pending(&tp->retransmit_timer) && del_timer(&tp->retransmit_timer))
-		__sock_put(sk);
-	if(timer_pending(&tp->delack_timer) && del_timer(&tp->delack_timer))
+	tp->pending = 0;
+	if (timer_pending(&tp->retransmit_timer) &&
+	    del_timer(&tp->retransmit_timer))
 		__sock_put(sk);
+
+	tp->ack.pending = 0;
 	tp->ack.blocked = 0;
-	if(timer_pending(&tp->probe_timer) && del_timer(&tp->probe_timer))
+	if (timer_pending(&tp->delack_timer) &&
+	    del_timer(&tp->delack_timer))
 		__sock_put(sk);
+
 	if(timer_pending(&sk->timer) && del_timer(&sk->timer))
 		__sock_put(sk);
 }
@@ -127,6 +87,7 @@
 	sk->error_report(sk);
 
 	tcp_done(sk);
+	NET_INC_STATS_BH(TCPAbortOnTimeout);
 }
 
 /* Do not allow orphaned sockets to eat all our resources.
@@ -138,26 +99,60 @@
  * We kill the socket, if:
  * 1. If number of orphaned sockets exceeds an administratively configured
  *    limit.
- * 2. Under pessimistic assumption that all the orphans eat memory not
- *    less than this one, total consumed memory exceeds all
- *    the available memory.
+ * 2. If we have strong memory pressure.
  */
 static int tcp_out_of_resources(struct sock *sk, int do_reset)
 {
+	struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
 	int orphans = atomic_read(&tcp_orphan_count);
 
+	/* If peer does not open window for long time, or did not transmit 
+	 * anything for long time, penalize it. */
+	if ((s32)(tcp_time_stamp - tp->lsndtime) > 2*TCP_RTO_MAX || !do_reset)
+		orphans <<= 1;
+
+	/* If some dubious ICMP arrived, penalize even more. */
+	if (sk->err_soft)
+		orphans <<= 1;
+
 	if (orphans >= sysctl_tcp_max_orphans ||
-	    ((orphans*atomic_read(&sk->wmem_alloc))>>PAGE_SHIFT) >= num_physpages) {
+	    (sk->wmem_queued > SOCK_MIN_SNDBUF &&
+	     atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])) {
 		if (net_ratelimit())
 			printk(KERN_INFO "Out of socket memory\n");
+
+		/* Catch exceptional cases, when connection requires reset.
+		 *      1. Last segment was sent recently. */
+		if ((s32)(tcp_time_stamp - tp->lsndtime) <= TCP_TIMEWAIT_LEN ||
+		    /*  2. Window is closed. */
+		    (!tp->snd_wnd && !tp->packets_out))
+			do_reset = 1;
 		if (do_reset)
 			tcp_send_active_reset(sk, GFP_ATOMIC);
 		tcp_done(sk);
+		NET_INC_STATS_BH(TCPAbortOnMemory);
 		return 1;
 	}
 	return 0;
 }
 
+/* Calculate maximal number or retries on an orphaned socket. */
+static int tcp_orphan_retries(struct sock *sk, int alive)
+{
+	int retries = sysctl_tcp_orphan_retries; /* May be zero. */
+
+	/* We know from an ICMP that something is wrong. */
+	if (sk->err_soft && !alive)
+		retries = 0;
+
+	/* However, if socket sent something recently, select some safe
+	 * number of retries. 8 corresponds to >100 seconds with minimal
+	 * RTO of 200msec. */
+	if (retries == 0 && alive)
+		retries = 8;
+	return retries;
+}
+
 /* A write timeout has occurred. Process the after effects. */
 static int tcp_write_timeout(struct sock *sk)
 {
@@ -195,10 +190,12 @@
 
 		retry_until = sysctl_tcp_retries2;
 		if (sk->dead) {
-			if (tcp_out_of_resources(sk, tp->retransmits < retry_until))
-				return 1;
+			int alive = (tp->rto < TCP_RTO_MAX);
+ 
+			retry_until = tcp_orphan_retries(sk, alive);
 
-			retry_until = sysctl_tcp_orphan_retries;
+			if (tcp_out_of_resources(sk, alive || tp->retransmits < retry_until))
+				return 1;
 		}
 	}
 
@@ -220,14 +217,38 @@
 		/* Try again later. */
 		tp->ack.blocked = 1;
 		NET_INC_STATS_BH(DelayedACKLocked);
-		tcp_reset_xmit_timer(sk, TCP_TIME_DACK, TCP_DELACK_MIN);
+		if (!mod_timer(&tp->delack_timer, jiffies + TCP_DELACK_MIN))
+			sock_hold(sk);
 		goto out_unlock;
 	}
 
-	if (tp->ack.pending) {
+	tcp_mem_reclaim(sk);
+
+	if (sk->state == TCP_CLOSE || !(tp->ack.pending&TCP_ACK_TIMER))
+		goto out;
+
+	if ((long)(tp->ack.timeout - jiffies) > 0) {
+		if (!mod_timer(&tp->delack_timer, tp->ack.timeout))
+			sock_hold(sk);
+		goto out;
+	}
+	tp->ack.pending &= ~TCP_ACK_TIMER;
+
+	if (skb_queue_len(&tp->ucopy.prequeue)) {
+		struct sk_buff *skb;
+
+		net_statistics[smp_processor_id()*2].TCPSchedulerFailed += skb_queue_len(&tp->ucopy.prequeue);
+
+		while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
+			sk->backlog_rcv(sk, skb);
+
+		tp->ucopy.memory = 0;
+	}
+
+	if (tcp_ack_scheduled(tp)) {
 		if (!tp->ack.pingpong) {
 			/* Delayed ACK missed: inflate ATO. */
-			tp->ack.ato = min(tp->ack.ato<<1, TCP_ATO_MAX);
+			tp->ack.ato = min(tp->ack.ato<<1, tp->rto);
 		} else {
 			/* Delayed ACK missed: leave pingpong mode and
 			 * deflate ATO.
@@ -240,30 +261,22 @@
 	}
 	TCP_CHECK_TIMER(sk);
 
+out:
+	if (tcp_memory_pressure)
+		tcp_mem_reclaim(sk);
 out_unlock:
 	bh_unlock_sock(sk);
 	sock_put(sk);
 }
 
-static void tcp_probe_timer(unsigned long data)
+static void tcp_probe_timer(struct sock *sk)
 {
-	struct sock *sk = (struct sock*)data;
 	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
 	int max_probes;
 
-	bh_lock_sock(sk);
-	if (sk->lock.users) {
-		/* Try again later. */
-		tcp_reset_xmit_timer(sk, TCP_TIME_PROBE0, HZ/5);
-		goto out_unlock;
-	}
-
-	if (sk->state == TCP_CLOSE)
-		goto out_unlock;
-
 	if (tp->packets_out || !tp->send_head) {
 		tp->probes_out = 0;
-		goto out_unlock;
+		return;
 	}
 
 	/* *WARNING* RFC 1122 forbids this
@@ -284,10 +297,12 @@
 	max_probes = sysctl_tcp_retries2;
 
 	if (sk->dead) {
-		if (tcp_out_of_resources(sk, tp->probes_out <= max_probes))
-			goto out_unlock;
+		int alive = ((tp->rto<<tp->backoff) < TCP_RTO_MAX);
+ 
+		max_probes = tcp_orphan_retries(sk, alive);
 
-		max_probes = sysctl_tcp_orphan_retries;
+		if (tcp_out_of_resources(sk, alive || tp->probes_out <= max_probes))
+			return;
 	}
 
 	if (tp->probes_out > max_probes) {
@@ -295,284 +310,47 @@
 	} else {
 		/* Only send another probe if we didn't close things up. */
 		tcp_send_probe0(sk);
-		TCP_CHECK_TIMER(sk);
 	}
-out_unlock:
-	bh_unlock_sock(sk);
-	sock_put(sk);
 }
 
-
-/* Kill off TIME_WAIT sockets once their lifetime has expired. */
-static int tcp_tw_death_row_slot = 0;
-int tcp_tw_count = 0;
-
-static struct tcp_tw_bucket *tcp_tw_death_row[TCP_TWKILL_SLOTS];
-static spinlock_t tw_death_lock = SPIN_LOCK_UNLOCKED;
-static struct timer_list tcp_tw_timer = { function: tcp_twkill };
-
-static void SMP_TIMER_NAME(tcp_twkill)(unsigned long dummy)
-{
-	struct tcp_tw_bucket *tw;
-	int killed = 0;
-
-	/* NOTE: compare this to previous version where lock
-	 * was released after detaching chain. It was racy,
-	 * because tw buckets are scheduled in not serialized context
-	 * in 2.3 (with netfilter), and with softnet it is common, because
-	 * soft irqs are not sequenced.
-	 */
-	spin_lock(&tw_death_lock);
-
-	if (tcp_tw_count == 0)
-		goto out;
-
-	while((tw = tcp_tw_death_row[tcp_tw_death_row_slot]) != NULL) {
-		tcp_tw_death_row[tcp_tw_death_row_slot] = tw->next_death;
-		tw->pprev_death = NULL;
-		spin_unlock(&tw_death_lock);
-
-		tcp_timewait_kill(tw);
-		tcp_tw_put(tw);
-
-		killed++;
-
-		spin_lock(&tw_death_lock);
-	}
-	tcp_tw_death_row_slot =
-		((tcp_tw_death_row_slot + 1) & (TCP_TWKILL_SLOTS - 1));
-
-	if ((tcp_tw_count -= killed) != 0)
-		mod_timer(&tcp_tw_timer, jiffies+TCP_TWKILL_PERIOD);
-	net_statistics[smp_processor_id()*2].TimeWaited += killed;
-out:
-	spin_unlock(&tw_death_lock);
-}
-
-SMP_TIMER_DEFINE(tcp_twkill, tcp_twkill_task);
-
-/* These are always called from BH context.  See callers in
- * tcp_input.c to verify this.
- */
-
-/* This is for handling early-kills of TIME_WAIT sockets. */
-void tcp_tw_deschedule(struct tcp_tw_bucket *tw)
-{
-	spin_lock(&tw_death_lock);
-	if (tw->pprev_death) {
-		if(tw->next_death)
-			tw->next_death->pprev_death = tw->pprev_death;
-		*tw->pprev_death = tw->next_death;
-		tw->pprev_death = NULL;
-		tcp_tw_put(tw);
-		if (--tcp_tw_count == 0)
-			del_timer(&tcp_tw_timer);
-	}
-	spin_unlock(&tw_death_lock);
-}
-
-/* Short-time timewait calendar */
-
-static int tcp_twcal_hand = -1;
-static int tcp_twcal_jiffie;
-static void tcp_twcal_tick(unsigned long);
-static struct timer_list tcp_twcal_timer = {function: tcp_twcal_tick};
-static struct tcp_tw_bucket *tcp_twcal_row[TCP_TW_RECYCLE_SLOTS];
-
-void tcp_tw_schedule(struct tcp_tw_bucket *tw, int timeo)
-{
-	struct tcp_tw_bucket **tpp;
-	int slot;
-
-	/* timeout := RTO * 3.5
-	 *
-	 * 3.5 = 1+2+0.5 to wait for two retransmits.
-	 *
-	 * RATIONALE: if FIN arrived and we entered TIME-WAIT state,
-	 * our ACK acking that FIN can be lost. If N subsequent retransmitted
-	 * FINs (or previous seqments) are lost (probability of such event
-	 * is p^(N+1), where p is probability to lose single packet and
-	 * time to detect the loss is about RTO*(2^N - 1) with exponential
-	 * backoff). Normal timewait length is calculated so, that we
-	 * waited at least for one retransmitted FIN (maximal RTO is 120sec).
-	 * [ BTW Linux. following BSD, violates this requirement waiting
-	 *   only for 60sec, we should wait at least for 240 secs.
-	 *   Well, 240 consumes too much of resources 8)
-	 * ]
-	 * This interval is not reduced to catch old duplicate and
-	 * responces to our wandering segments living for two MSLs.
-	 * However, if we use PAWS to detect
-	 * old duplicates, we can reduce the interval to bounds required
-	 * by RTO, rather than MSL. So, if peer understands PAWS, we
-	 * kill tw bucket after 3.5*RTO (it is important that this number
-	 * is greater than TS tick!) and detect old duplicates with help
-	 * of PAWS.
-	 */
-	slot = (timeo + (1<<TCP_TW_RECYCLE_TICK) - 1) >> TCP_TW_RECYCLE_TICK;
-
-	spin_lock(&tw_death_lock);
-
-	/* Unlink it, if it was scheduled */
-	if (tw->pprev_death) {
-		if(tw->next_death)
-			tw->next_death->pprev_death = tw->pprev_death;
-		*tw->pprev_death = tw->next_death;
-		tw->pprev_death = NULL;
-		tcp_tw_count--;
-	} else
-		atomic_inc(&tw->refcnt);
-
-	if (slot >= TCP_TW_RECYCLE_SLOTS) {
-		/* Schedule to slow timer */
-		if (timeo >= TCP_TIMEWAIT_LEN) {
-			slot = TCP_TWKILL_SLOTS-1;
-		} else {
-			slot = (timeo + TCP_TWKILL_PERIOD-1) / TCP_TWKILL_PERIOD;
-			if (slot >= TCP_TWKILL_SLOTS)
-				slot = TCP_TWKILL_SLOTS-1;
-		}
-		tw->ttd = jiffies + timeo;
-		slot = (tcp_tw_death_row_slot + slot) & (TCP_TWKILL_SLOTS - 1);
-		tpp = &tcp_tw_death_row[slot];
-	} else {
-		tw->ttd = jiffies + (slot<<TCP_TW_RECYCLE_TICK);
-
-		if (tcp_twcal_hand < 0) {
-			tcp_twcal_hand = 0;
-			tcp_twcal_jiffie = jiffies;
-			tcp_twcal_timer.expires = tcp_twcal_jiffie + (slot<<TCP_TW_RECYCLE_TICK);
-			add_timer(&tcp_twcal_timer);
-		} else {
-			if ((long)(tcp_twcal_timer.expires - jiffies) > (slot<<TCP_TW_RECYCLE_TICK))
-				mod_timer(&tcp_twcal_timer, jiffies + (slot<<TCP_TW_RECYCLE_TICK));
-			slot = (tcp_twcal_hand + slot)&(TCP_TW_RECYCLE_SLOTS-1);
-		}
-		tpp = &tcp_twcal_row[slot];
-	}
-
-	if((tw->next_death = *tpp) != NULL)
-		(*tpp)->pprev_death = &tw->next_death;
-	*tpp = tw;
-	tw->pprev_death = tpp;
-
-	if (tcp_tw_count++ == 0)
-		mod_timer(&tcp_tw_timer, jiffies+TCP_TWKILL_PERIOD);
-	spin_unlock(&tw_death_lock);
-}
-
-void SMP_TIMER_NAME(tcp_twcal_tick)(unsigned long dummy)
-{
-	int n, slot;
-	unsigned long j;
-	unsigned long now = jiffies;
-	int killed = 0;
-	int adv = 0;
-
-	spin_lock(&tw_death_lock);
-	if (tcp_twcal_hand < 0)
-		goto out;
-
-	slot = tcp_twcal_hand;
-	j = tcp_twcal_jiffie;
-
-	for (n=0; n<TCP_TW_RECYCLE_SLOTS; n++) {
-		if ((long)(j - now) <= 0) {
-			struct tcp_tw_bucket *tw;
-
-			while((tw = tcp_twcal_row[slot]) != NULL) {
-				tcp_twcal_row[slot] = tw->next_death;
-				tw->pprev_death = NULL;
-
-				tcp_timewait_kill(tw);
-				tcp_tw_put(tw);
-				killed++;
-			}
-		} else {
-			if (!adv) {
-				adv = 1;
-				tcp_twcal_jiffie = j;
-				tcp_twcal_hand = slot;
-			}
-
-			if (tcp_twcal_row[slot] != NULL) {
-				mod_timer(&tcp_twcal_timer, j);
-				goto out;
-			}
-		}
-		j += (1<<TCP_TW_RECYCLE_TICK);
-		slot = (slot+1)&(TCP_TW_RECYCLE_SLOTS-1);
-	}
-	tcp_twcal_hand = -1;
-
-out:
-	if ((tcp_tw_count -= killed) == 0)
-		del_timer(&tcp_tw_timer);
-	net_statistics[smp_processor_id()*2].TimeWaitKilled += killed;
-	spin_unlock(&tw_death_lock);
-}
-
-SMP_TIMER_DEFINE(tcp_twcal_tick, tcp_twcal_tasklet);
-
 /*
  *	The TCP retransmit timer.
  */
 
-static void tcp_retransmit_timer(unsigned long data)
+static void tcp_retransmit_timer(struct sock *sk)
 {
-	struct sock *sk = (struct sock*)data;
 	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
 
-	bh_lock_sock(sk);
-	if (sk->lock.users) {
-		/* Try again later */  
-		tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, HZ/20);
-		goto out_unlock;
-	}
-
-	if (sk->state == TCP_CLOSE || tp->packets_out == 0)
-		goto out_unlock;
+	if (tp->packets_out == 0)
+		goto out;
 
 	BUG_TRAP(!skb_queue_empty(&sk->write_queue));
 
 	if (tcp_write_timeout(sk))
-		goto out_unlock;
-
-	/* RFC 2018, clear all 'sacked' flags in retransmission queue,
-	 * the sender may have dropped out of order frames and we must
-	 * send them out should this timer fire on us.
-	 */
-	if(tp->sack_ok) {
-		struct sk_buff *skb = skb_peek(&sk->write_queue);
+		goto out;
 
-		while((skb != NULL) &&
-		      (skb != tp->send_head) &&
-		      (skb != (struct sk_buff *)&sk->write_queue)) {
-			TCP_SKB_CB(skb)->sacked &=
-				~(TCPCB_SACKED_ACKED | TCPCB_SACKED_RETRANS);
-			skb = skb->next;
+	if (tp->retransmits == 0) {
+		if (tp->ca_state == TCP_CA_Disorder || tp->ca_state == TCP_CA_Recovery) {
+			if (tp->sack_ok) {
+				if (tp->ca_state == TCP_CA_Recovery)
+					NET_INC_STATS_BH(TCPSackRecoveryFail);
+				else
+					NET_INC_STATS_BH(TCPSackFailures);
+			} else {
+				if (tp->ca_state == TCP_CA_Recovery)
+					NET_INC_STATS_BH(TCPRenoRecoveryFail);
+				else
+					NET_INC_STATS_BH(TCPRenoFailures);
+			}
+		} else if (tp->ca_state == TCP_CA_Loss) {
+			NET_INC_STATS_BH(TCPLossFailures);
+		} else {
+			NET_INC_STATS_BH(TCPTimeouts);
 		}
 	}
 
-	/* Retransmission. */
-	tp->retrans_head = NULL;
-	tp->rexmt_done = 0;
-	tp->fackets_out = 0;
-	tp->retrans_out = 0;
-	if (tp->retransmits == 0) {
-		/* Remember window where we lost:
-		 * "one half of the current window but at least 2 segments"
-		 *
-		 * Here "current window" means the effective one, which
-		 * means it must be an accurate representation of our current
-		 * sending rate _and_ the snd_wnd.
-		 */
-		tp->snd_ssthresh = tcp_recalc_ssthresh(tp);
-		tp->snd_cwnd_cnt = 0;
-		tp->snd_cwnd = 1;
-	}
+	tcp_enter_loss(sk, 0);
 
-	tp->dup_acks = 0;
-	tp->high_seq = tp->snd_nxt;
 	if (tcp_retransmit_skb(sk, skb_peek(&sk->write_queue)) > 0) {
 		/* Retransmission failed because of local congestion,
 		 * do not backoff.
@@ -581,8 +359,7 @@
 			tp->retransmits=1;
 		tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS,
 				     min(tp->rto, TCP_RESOURCE_PROBE_INTERVAL));
-		TCP_CHECK_TIMER(sk);
-		goto out_unlock;
+		goto out;
 	}
 
 	/* Increase the timeout each time we retransmit.  Note that
@@ -606,8 +383,48 @@
 	tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
 	if (tp->retransmits > sysctl_tcp_retries1)
 		__sk_dst_reset(sk);
+
+out:
+}
+
+static void tcp_write_timer(unsigned long data)
+{
+	struct sock *sk = (struct sock*)data;
+	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
+	int event;
+
+	bh_lock_sock(sk);
+	if (sk->lock.users) {
+		/* Try again later */
+		if (!mod_timer(&tp->retransmit_timer, jiffies + (HZ/20)))
+			sock_hold(sk);
+		goto out_unlock;
+	}
+
+	if (sk->state == TCP_CLOSE || !tp->pending)
+		goto out;
+
+	if ((long)(tp->timeout - jiffies) > 0) {
+		if (!mod_timer(&tp->retransmit_timer, tp->timeout))
+			sock_hold(sk);
+		goto out;
+	}
+
+	event = tp->pending;
+	tp->pending = 0;
+
+	switch (event) {
+	case TCP_TIME_RETRANS:
+		tcp_retransmit_timer(sk);
+		break;
+	case TCP_TIME_PROBE0:
+		tcp_probe_timer(sk);
+		break;
+	}
 	TCP_CHECK_TIMER(sk);
 
+out:
+	tcp_mem_reclaim(sk);
 out_unlock:
 	bh_unlock_sock(sk);
 	sock_put(sk);
@@ -794,6 +611,7 @@
 	}
 
 	TCP_CHECK_TIMER(sk);
+	tcp_mem_reclaim(sk);
 
 resched:
 	tcp_reset_keepalive_timer (sk, elapsed);