[TCP]: Must count fack_count also when skipping

It makes fackets_out to grow too slowly compared with the
real write queue.

This shouldn't cause those BUG_TRAP(packets <= tp->packets_out)
to trigger but how knows how such inconsistent fackets_out
affects here and there around TCP when everything is nowadays
assuming accurate fackets_out. So lets see if this silences
them all.

Reported by Guillaume Chazarain <guichaz@gmail.com>.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 5 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 19c449f62672..7facdb0f6960 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1367,7 +1367,7 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
  * a normal way
  */
 static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
-                                        u32 skip_to_seq)
+                                        u32 skip_to_seq, int *fack_count)
 {
         tcp_for_write_queue_from(skb, sk) {
                 if (skb == tcp_send_head(sk))
@@ -1375,6 +1375,8 @@ static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
 
                 if (!before(TCP_SKB_CB(skb)->end_seq, skip_to_seq))
                         break;
+
+                *fack_count += tcp_skb_pcount(skb);
         }
         return skb;
 }
@@ -1390,7 +1392,7 @@ static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
                 return skb;
 
         if (before(next_dup->start_seq, skip_to_seq)) {
-                skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq);
+                skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq, fack_count);
                 tcp_sacktag_walk(skb, sk, NULL,
                                  next_dup->start_seq, next_dup->end_seq,
                                  1, fack_count, reord, flag);
@@ -1537,7 +1539,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
 
                         /* Head todo? */
                         if (before(start_seq, cache->start_seq)) {
-                                skb = tcp_sacktag_skip(skb, sk, start_seq);
+                                skb = tcp_sacktag_skip(skb, sk, start_seq,
+                                                       &fack_count);
                                 skb = tcp_sacktag_walk(skb, sk, next_dup,
                                                        start_seq,
                                                        cache->start_seq,
@@ -1565,7 +1568,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
                                 goto walk;
                         }
 
-                        skb = tcp_sacktag_skip(skb, sk, cache->end_seq);
+                        skb = tcp_sacktag_skip(skb, sk, cache->end_seq,
+                                               &fack_count);
                         /* Check overlap against next cached too (past this one already) */
                         cache++;
                         continue;
@@ -1577,7 +1581,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
                                 break;
                         fack_count = tp->fackets_out;
                 }
-                skb = tcp_sacktag_skip(skb, sk, start_seq);
+                skb = tcp_sacktag_skip(skb, sk, start_seq, &fack_count);
 
 walk:
                 skb = tcp_sacktag_walk(skb, sk, next_dup, start_seq, end_seq,