sctp: remove prsctp_param from sctp_chunk

Now sctp uses chunk->prsctp_param to save the prsctp param for all the
prsctp polices, we didn't need to introduce prsctp_param to sctp_chunk.
We can just use chunk->sinfo.sinfo_timetolive for RTX and BUF polices,
and reuse msg->expires_at for TTL policy, as the prsctp polices and old
expires policy are mutual exclusive.

This patch is to remove prsctp_param from sctp_chunk, and reuse msg's
expires_at for TTL and chunk's sinfo.sinfo_timetolive for RTX and BUF
polices.

Note that sctp can't use chunk's sinfo.sinfo_timetolive for TTL policy,
as it needs a u64 variables to save the expires_at time.

This one also fixes the "netperf-Throughput_Mbps -37.2% regression"
issue.

Fixes: a6c2f792873a ("sctp: implement prsctp TTL policy")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/structs.h

@@ -606,13 +606,6 @@ struct sctp_chunk {
 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
 	struct sctp_sndrcvinfo sinfo;
 
-	/* We use this field to record param for prsctp policies,
-	 * for TTL policy, it is the time_to_drop of this chunk,
-	 * for RTX policy, it is the max_sent_count of this chunk,
-	 * for PRIO policy, it is the priority of this chunk.
-	 */
-	unsigned long prsctp_param;
-
 	/* Which association does this belong to?  */
 	struct sctp_association *asoc;
 

net/sctp/chunk.c

@@ -179,6 +179,11 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 			 msg, msg->expires_at, jiffies);
 	}
 
+	if (asoc->prsctp_enable &&
+	    SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags))
+		msg->expires_at =
+			jiffies + msecs_to_jiffies(sinfo->sinfo_timetolive);
+
 	/* This is the biggest possible DATA chunk that can fit into
 	 * the packet
 	 */
@@ -349,14 +354,14 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
 	}
 
 	if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
-	    time_after(jiffies, chunk->prsctp_param)) {
+	    time_after(jiffies, chunk->msg->expires_at)) {
 		if (chunk->sent_count)
 			chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
 		else
 			chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
 		return 1;
 	} else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
-		   chunk->sent_count > chunk->prsctp_param) {
+		   chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
 		chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
 		return 1;
 	}

net/sctp/outqueue.c

@@ -383,7 +383,7 @@ static int sctp_prsctp_prune_sent(struct sctp_association *asoc,
 
 	list_for_each_entry_safe(chk, temp, queue, transmitted_list) {
 		if (!SCTP_PR_PRIO_ENABLED(chk->sinfo.sinfo_flags) ||
-		    chk->prsctp_param <= sinfo->sinfo_timetolive)
+		    chk->sinfo.sinfo_timetolive <= sinfo->sinfo_timetolive)
 			continue;
 
 		list_del_init(&chk->transmitted_list);
@@ -418,7 +418,7 @@ static int sctp_prsctp_prune_unsent(struct sctp_association *asoc,
 
 	list_for_each_entry_safe(chk, temp, queue, list) {
 		if (!SCTP_PR_PRIO_ENABLED(chk->sinfo.sinfo_flags) ||
-		    chk->prsctp_param <= sinfo->sinfo_timetolive)
+		    chk->sinfo.sinfo_timetolive <= sinfo->sinfo_timetolive)
 			continue;
 
 		list_del_init(&chk->list);

net/sctp/sm_make_chunk.c

@@ -706,20 +706,6 @@ nodata:
 	return retval;
 }
 
-static void sctp_set_prsctp_policy(struct sctp_chunk *chunk,
-				   const struct sctp_sndrcvinfo *sinfo)
-{
-	if (!chunk->asoc->prsctp_enable)
-		return;
-
-	if (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags))
-		chunk->prsctp_param =
-			jiffies + msecs_to_jiffies(sinfo->sinfo_timetolive);
-	else if (SCTP_PR_RTX_ENABLED(sinfo->sinfo_flags) ||
-		 SCTP_PR_PRIO_ENABLED(sinfo->sinfo_flags))
-		chunk->prsctp_param = sinfo->sinfo_timetolive;
-}
-
 /* Make a DATA chunk for the given association from the provided
  * parameters.  However, do not populate the data payload.
  */
@@ -753,7 +739,6 @@ struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
 
 	retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
 	memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
-	sctp_set_prsctp_policy(retval, sinfo);
 
 nodata:
 	return retval;