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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2005-08-04 19:52:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-08-04 21:43:14 -0700 |
| commit | b68e9f857271189bd7a59b74c99890de9195b0e1 (patch) | |
| tree | 92ef0899ca9ff07f64458febcb7ab8095e891042 /net | |
| parent | 846998ae87a80b0fd45b4cf5cf001a159d746f27 (diff) | |
| download | linux-3.10-b68e9f857271189bd7a59b74c99890de9195b0e1.tar.gz linux-3.10-b68e9f857271189bd7a59b74c99890de9195b0e1.tar.bz2 linux-3.10-b68e9f857271189bd7a59b74c99890de9195b0e1.zip | |
[PATCH] tcp: fix TSO cwnd caching bug
tcp_write_xmit caches the cwnd value indirectly in cwnd_quota. When
tcp_transmit_skb reduces the cwnd because of tcp_enter_cwr, the cached
value becomes invalid.
This patch ensures that the cwnd value is always reread after each
tcp_transmit_skb call.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_output.c | 34 |
1 files changed, 9 insertions, 25 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e118b4b5b32..7d076f0db10 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -972,19 +972,18 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) if (unlikely(sk->sk_state == TCP_CLOSE)) return 0; - skb = sk->sk_send_head; - if (unlikely(!skb)) - return 0; - - tso_segs = tcp_init_tso_segs(sk, skb, mss_now); - cwnd_quota = tcp_cwnd_test(tp, skb); - if (unlikely(!cwnd_quota)) - goto out; - sent_pkts = 0; - while (likely(tcp_snd_wnd_test(tp, skb, mss_now))) { + while ((skb = sk->sk_send_head)) { + tso_segs = tcp_init_tso_segs(sk, skb, mss_now); BUG_ON(!tso_segs); + cwnd_quota = tcp_cwnd_test(tp, skb); + if (!cwnd_quota) + break; + + if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now))) + break; + if (tso_segs == 1) { if (unlikely(!tcp_nagle_test(tp, skb, mss_now, (tcp_skb_is_last(sk, skb) ? @@ -1026,27 +1025,12 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) tcp_minshall_update(tp, mss_now, skb); sent_pkts++; - - /* Do not optimize this to use tso_segs. If we chopped up - * the packet above, tso_segs will no longer be valid. - */ - cwnd_quota -= tcp_skb_pcount(skb); - - BUG_ON(cwnd_quota < 0); - if (!cwnd_quota) - break; - - skb = sk->sk_send_head; - if (!skb) - break; - tso_segs = tcp_init_tso_segs(sk, skb, mss_now); } if (likely(sent_pkts)) { tcp_cwnd_validate(sk, tp); return 0; } -out: return !tp->packets_out && sk->sk_send_head; } |