On 10/15/2013 02:13 PM, Chang Xiangzhong wrote:
Signed-off-by: Xiangzhong Chang <changxiangzh...@gmail.com>
Your proposed solution is very nice, but it does 2 things in one
patch.
1) It fixes the bug
2) It refactors the code to improve the flow.
While (2) is very nice, it needs a much more careful review.
Can you please split this into 2 patches? First patch can
make the code look like this:
if (sctp_acked(sack, tsn)) {
...
if (!tchunk->tsn_gap_acked) {
tchunk->tsn_gap_acked = 1;
*highest_new_tsn_in_sack = tsn;
bytes_acked += sctp_data_size(tchunk);
if (!tchunk->transport)
migrate_bytes += sctp_data_size(tchunk);
forward_progress = true;
/*
* 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:
...
}
}
Then you can file a second patch to improve the flow/refactor the
function. You have to be very careful here though and be sure to
run through all the regression tests since you would be modifying
a very critcal part of the code.
Thanks
-vlad
---
net/sctp/outqueue.c | 76 ++++++++++++++++++++++++---------------------------
1 file changed, 35 insertions(+), 41 deletions(-)
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 94df758..84ef3b8 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -1357,13 +1357,13 @@ static void sctp_check_transmitted(struct sctp_outq *q,
tsn = ntohl(tchunk->subh.data_hdr->tsn);
if (sctp_acked(sack, tsn)) {
- /* If this queue is the retransmit queue, the
- * retransmit timer has already reclaimed
- * the outstanding bytes for this chunk, so only
- * count bytes associated with a transport.
- */
- if (transport) {
- /* If this chunk is being used for RTT
+ if (!tchunk->tsn_gap_acked) {
+ /* If this queue is the retransmit queue, the
+ * retransmit timer has already reclaimed
+ * the outstanding bytes for this chunk, so only
+ * count bytes associated with a transport.
+ *
+ * If this chunk is being used for RTT
* measurement, calculate the RTT and update
* the RTO using this value.
*
@@ -1374,28 +1374,44 @@ static void sctp_check_transmitted(struct sctp_outq *q,
* first instance of the packet or a later
* instance).
*/
- if (!tchunk->tsn_gap_acked &&
- tchunk->rtt_in_progress) {
+ if (transport && tchunk->rtt_in_progress) {
tchunk->rtt_in_progress = 0;
rtt = jiffies - tchunk->sent_at;
sctp_transport_update_rto(transport,
- rtt);
+ rtt);
}
- }
- /* If the chunk hasn't been marked as ACKED,
- * mark it and account bytes_acked if the
- * chunk had a valid transport (it will not
- * have a transport if ASCONF had deleted it
- * while DATA was outstanding).
- */
- if (!tchunk->tsn_gap_acked) {
+ /* If the chunk hasn't been marked as ACKED,
+ * mark it and account bytes_acked if the
+ * chunk had a valid transport (it will not
+ * have a transport if ASCONF had deleted it
+ * while DATA was outstanding).
+ */
tchunk->tsn_gap_acked = 1;
*highest_new_tsn_in_sack = tsn;
bytes_acked += sctp_data_size(tchunk);
if (!tchunk->transport)
migrate_bytes += sctp_data_size(tchunk);
forward_progress = true;
+
+ /* 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;
}
if (TSN_lte(tsn, sack_ctsn)) {
@@ -1411,30 +1427,8 @@ static void sctp_check_transmitted(struct sctp_outq *q,
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);
+ &q->sacked);
} else {
/* RFC2960 7.2.4, sctpimpguide-05 2.8.2
* M2) Each time a SACK arrives reporting
--
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