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| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-10-07 23:43:10 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-10-07 23:43:10 -0700 |
| commit | 48611c47d09023d9356e78550d1cadb8d61da9c8 (patch) | |
| tree | 1e118a43db7143f8091b5b0a95e6d6f85dc5b2f9 | |
| parent | 3eb215de26e6e94bf5fed9cb77230c383b30e53b (diff) | |
| download | linux-3.10-48611c47d09023d9356e78550d1cadb8d61da9c8.tar.gz linux-3.10-48611c47d09023d9356e78550d1cadb8d61da9c8.tar.bz2 linux-3.10-48611c47d09023d9356e78550d1cadb8d61da9c8.zip | |
[TCP]: Fix fastpath_cnt_hint when GSO skb is partially ACKed
When only GSO skb was partially ACKed, no hints are reset,
therefore fastpath_cnt_hint must be tweaked too or else it can
corrupt fackets_out. The corruption to occur, one must have
non-trivial ACK/SACK sequence, so this bug is not very often
that harmful. There's a fackets_out state reset in TCP because
fackets_out is known to be inaccurate and that fixes the issue
eventually anyway.
In case there was also at least one skb that got fully ACKed,
the fastpath_skb_hint is set to NULL which causes a recount for
fastpath_cnt_hint (the old value won't be accessed anymore),
thus it can safely be decremented without additional checking.
Reported by Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/tcp_input.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bbad2cdb74b..f893e90061e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2420,6 +2420,9 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb, __u32 dval = min(tp->fackets_out, packets_acked); tp->fackets_out -= dval; } + /* hint's skb might be NULL but we don't need to care */ + tp->fastpath_cnt_hint -= min_t(u32, packets_acked, + tp->fastpath_cnt_hint); tp->packets_out -= packets_acked; BUG_ON(tcp_skb_pcount(skb) == 0); |