3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> commit 51446780fc33e45cb790c05a7fa2c5bf7e8bc53b upstream. It's currently written as: if (!tchunk->tsn_gap_acked) { [1] tchunk->tsn_gap_acked = 1; ... } if (TSN_lte(tsn, sack_ctsn)) { if (!tchunk->tsn_gap_acked) { /* SFR-CACC processing */ ... } } Which causes the SFR-CACC processing on ack reception to never process, as tchunk->tsn_gap_acked is always true by then. Block [1] was moved to that position by the commit marked below. This patch fixes it by doing SFR-CACC processing earlier, before tsn_gap_acked is set to true. Fixes: 31b02e154940 ("sctp: Failover transmitted list on transport delete") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> Reviewed-by: Xin Long <lucien.xin@xxxxxxxxx> Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- net/sctp/outqueue.c | 48 ++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 25 deletions(-) --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -1346,7 +1346,7 @@ static void sctp_check_transmitted(struc * the outstanding bytes for this chunk, so only * count bytes associated with a transport. */ - if (transport) { + if (transport && !tchunk->tsn_gap_acked) { /* If this chunk is being used for RTT * measurement, calculate the RTT and update * the RTO using this value. @@ -1358,14 +1358,34 @@ static void sctp_check_transmitted(struc * first instance of the packet or a later * instance). */ - if (!tchunk->tsn_gap_acked && - !tchunk->resent && + if (!tchunk->resent && tchunk->rtt_in_progress) { tchunk->rtt_in_progress = 0; rtt = jiffies - tchunk->sent_at; sctp_transport_update_rto(transport, rtt); } + + if (TSN_lte(tsn, sack_ctsn)) { + /* + * SFR-CACC algorithm: + * 2) If the SACK contains gap acks + * and the flag CHANGEOVER_ACTIVE is + * set the receiver of the SACK MUST + * take the following action: + * + * B) For each TSN t being acked that + * has not been acked in any SACK so + * far, set cacc_saw_newack to 1 for + * the destination that the TSN was + * sent to. + */ + if (sack->num_gap_ack_blocks && + q->asoc->peer.primary_path->cacc. + changeover_active) + transport->cacc.cacc_saw_newack + = 1; + } } /* If the chunk hasn't been marked as ACKED, @@ -1397,28 +1417,6 @@ static void sctp_check_transmitted(struc restart_timer = 1; forward_progress = true; - if (!tchunk->tsn_gap_acked) { - /* - * SFR-CACC algorithm: - * 2) If the SACK contains gap acks - * and the flag CHANGEOVER_ACTIVE is - * set the receiver of the SACK MUST - * take the following action: - * - * B) For each TSN t being acked that - * has not been acked in any SACK so - * far, set cacc_saw_newack to 1 for - * the destination that the TSN was - * sent to. - */ - if (transport && - sack->num_gap_ack_blocks && - q->asoc->peer.primary_path->cacc. - changeover_active) - transport->cacc.cacc_saw_newack - = 1; - } - list_add_tail(&tchunk->transmitted_list, &q->sacked); } else {