[PATCH AUTOSEL for 4.14 037/100] sctp: only update outstanding_bytes for transmitted queue when doing prsctp_prune

Sasha Levin
2018-01-28T23:11:07Z

From: Xin Long <lucien.xin@gmail.com>

[ Upstream commit d30fc5126efb0c33b7adf5966d3051db2c3d7721 ]

Now outstanding_bytes is only increased when appending chunks into one
packet and sending it at 1st time, while decreased when it is about to
move into retransmit queue. It means outstanding_bytes value is already
decreased for all chunks in retransmit queue.

However sctp_prsctp_prune_sent is a common function to check the chunks
in both transmitted and retransmit queue, it decrease outstanding_bytes
when moving a chunk into abandoned queue from either of them.

It could cause outstanding_bytes underflow, as it also decreases it's
value for the chunks in retransmit queue.

This patch fixes it by only updating outstanding_bytes for transmitted
queue when pruning queues for prsctp prio policy, the same fix is also
needed in sctp_check_transmitted.

Fixes: 8dbdf1f5b09c ("sctp: implement prsctp PRIO policy")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
net/sctp/outqueue.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 2966ff400755..39ac91060bc2 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -368,7 +368,8 @@ static int sctp_prsctp_prune_sent(struct sctp_association *asoc,
asoc->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
streamout->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;

- if (!chk->tsn_gap_acked) {
+ if (queue != &asoc->outqueue.retransmit &&
+ !chk->tsn_gap_acked) {
if (chk->transport)
chk->transport->flight_size -=
sctp_data_size(chk);
@@ -1429,7 +1430,8 @@ static void sctp_check_transmitted(struct sctp_outq *q,
/* If this chunk has not been acked, stop
* considering it as 'outstanding'.
*/
- if (!tchunk->tsn_gap_acked) {
+ if (transmitted_queue != &q->retransmit &&
+ !tchunk->tsn_gap_acked) {
if (tchunk->transport)
tchunk->transport->flight_size -=
sctp_data_size(tchunk);
--
2.11.0