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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 98408d520c32..3f7bd7ae7d7a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1001,7 +1001,14 @@ static u32 tcp_dsack_seen(struct tcp_sock *tp, u32 start_seq,
return 0;
tp->rx_opt.sack_ok |= TCP_DSACK_SEEN;
- tp->rack.dsack_seen = 1;
+ /* We increase the RACK ordering window in rounds where we receive
+ * DSACKs that may have been due to reordering causing RACK to trigger
+ * a spurious fast recovery. Thus RACK ignores DSACKs that happen
+ * without having seen reordering, or that match TLP probes (TLP
+ * is timer-driven, not triggered by RACK).
+ */
+ if (tp->reord_seen && !(state->flag & FLAG_DSACK_TLP))
+ tp->rack.dsack_seen = 1;
state->flag |= FLAG_DSACKING_ACK;
/* A spurious retransmission is delivered */