net/sctp: Make wrappers for accessing in/out streams

This patch introduces wrappers for accessing in/out streams indirectly.
This will enable to replace physically contiguous memory arrays
of streams with flexible arrays (or maybe any other appropriate
mechanism) which do memory allocation on a per-page basis.

Signed-off-by: Oleg Babin <obabin@virtuozzo.com>
Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 103 insertions, 81 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ab869e0d8326..6b2b8df8a1d2 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -398,37 +398,35 @@ void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
 
 /* What is the current SSN number for this stream? */
 #define sctp_ssn_peek(stream, type, sid) \
-        ((stream)->type[sid].ssn)
+        (sctp_stream_##type((stream), (sid))->ssn)
 
 /* Return the next SSN number for this stream.  */
 #define sctp_ssn_next(stream, type, sid) \
-        ((stream)->type[sid].ssn++)
+        (sctp_stream_##type((stream), (sid))->ssn++)
 
 /* Skip over this ssn and all below. */
 #define sctp_ssn_skip(stream, type, sid, ssn) \
-        ((stream)->type[sid].ssn = ssn + 1)
+        (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
 
 /* What is the current MID number for this stream? */
 #define sctp_mid_peek(stream, type, sid) \
-        ((stream)->type[sid].mid)
+        (sctp_stream_##type((stream), (sid))->mid)
 
 /* Return the next MID number for this stream.  */
 #define sctp_mid_next(stream, type, sid) \
-        ((stream)->type[sid].mid++)
+        (sctp_stream_##type((stream), (sid))->mid++)
 
 /* Skip over this mid and all below. */
 #define sctp_mid_skip(stream, type, sid, mid) \
-        ((stream)->type[sid].mid = mid + 1)
-
-#define sctp_stream_in(asoc, sid) (&(asoc)->stream.in[sid])
+        (sctp_stream_##type((stream), (sid))->mid = mid + 1)
 
 /* What is the current MID_uo number for this stream? */
 #define sctp_mid_uo_peek(stream, type, sid) \
-        ((stream)->type[sid].mid_uo)
+        (sctp_stream_##type((stream), (sid))->mid_uo)
 
 /* Return the next MID_uo number for this stream.  */
 #define sctp_mid_uo_next(stream, type, sid) \
-        ((stream)->type[sid].mid_uo++)
+        (sctp_stream_##type((stream), (sid))->mid_uo++)
 
 /*
  * Pointers to address related SCTP functions.
@@ -1463,6 +1461,23 @@ struct sctp_stream {
         struct sctp_stream_interleave *si;
 };
 
+static inline struct sctp_stream_out *sctp_stream_out(
+        const struct sctp_stream *stream,
+        __u16 sid)
+{
+        return ((struct sctp_stream_out *)(stream->out)) + sid;
+}
+
+static inline struct sctp_stream_in *sctp_stream_in(
+        const struct sctp_stream *stream,
+        __u16 sid)
+{
+        return ((struct sctp_stream_in *)(stream->in)) + sid;
+}
+
+#define SCTP_SO(s, i) sctp_stream_out((s), (i))
+#define SCTP_SI(s, i) sctp_stream_in((s), (i))
+
 #define SCTP_STREAM_CLOSED              0x00
 #define SCTP_STREAM_OPEN                0x01
 
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index bfb9f812e2ef..ce8087846f05 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -325,7 +325,8 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
         if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
             time_after(jiffies, chunk->msg->expires_at)) {
                 struct sctp_stream_out *streamout =
-                        &chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
+                        SCTP_SO(&chunk->asoc->stream,
+                                chunk->sinfo.sinfo_stream);
 
                 if (chunk->sent_count) {
                         chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
@@ -339,7 +340,8 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
         } else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
                    chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
                 struct sctp_stream_out *streamout =
-                        &chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
+                        SCTP_SO(&chunk->asoc->stream,
+                                chunk->sinfo.sinfo_stream);
 
                 chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
                 streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index d68aa33485a9..d74d00b29942 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -80,7 +80,7 @@ static inline void sctp_outq_head_data(struct sctp_outq *q,
         q->out_qlen += ch->skb->len;
 
         stream = sctp_chunk_stream_no(ch);
-        oute = q->asoc->stream.out[stream].ext;
+        oute = SCTP_SO(&q->asoc->stream, stream)->ext;
         list_add(&ch->stream_list, &oute->outq);
 }
 
@@ -101,7 +101,7 @@ static inline void sctp_outq_tail_data(struct sctp_outq *q,
         q->out_qlen += ch->skb->len;
 
         stream = sctp_chunk_stream_no(ch);
-        oute = q->asoc->stream.out[stream].ext;
+        oute = SCTP_SO(&q->asoc->stream, stream)->ext;
         list_add_tail(&ch->stream_list, &oute->outq);
 }
 
@@ -372,7 +372,7 @@ static int sctp_prsctp_prune_sent(struct sctp_association *asoc,
                 sctp_insert_list(&asoc->outqueue.abandoned,
                                  &chk->transmitted_list);
 
-                streamout = &asoc->stream.out[chk->sinfo.sinfo_stream];
+                streamout = SCTP_SO(&asoc->stream, chk->sinfo.sinfo_stream);
                 asoc->sent_cnt_removable--;
                 asoc->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
                 streamout->ext->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
@@ -416,7 +416,7 @@ static int sctp_prsctp_prune_unsent(struct sctp_association *asoc,
                 asoc->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++;
                 if (chk->sinfo.sinfo_stream < asoc->stream.outcnt) {
                         struct sctp_stream_out *streamout =
-                                &asoc->stream.out[chk->sinfo.sinfo_stream];
+                                SCTP_SO(&asoc->stream, chk->sinfo.sinfo_stream);
 
                         streamout->ext->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++;
                 }
@@ -1082,6 +1082,7 @@ static void sctp_outq_flush_data(struct sctp_flush_ctx *ctx,
         /* Finally, transmit new packets.  */
         while ((chunk = sctp_outq_dequeue_data(ctx->q)) != NULL) {
                 __u32 sid = ntohs(chunk->subh.data_hdr->stream);
+                __u8 stream_state = SCTP_SO(&ctx->asoc->stream, sid)->state;
 
                 /* Has this chunk expired? */
                 if (sctp_chunk_abandoned(chunk)) {
@@ -1091,7 +1092,7 @@ static void sctp_outq_flush_data(struct sctp_flush_ctx *ctx,
                         continue;
                 }
 
-                if (ctx->asoc->stream.out[sid].state == SCTP_STREAM_CLOSED) {
+                if (stream_state == SCTP_STREAM_CLOSED) {
                         sctp_outq_head_data(ctx->q, chunk);
                         break;
                 }
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 502c0d7cb105..e96b15a66aba 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1911,7 +1911,7 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
                 goto err;
         }
 
-        if (unlikely(!asoc->stream.out[sinfo->sinfo_stream].ext)) {
+        if (unlikely(!SCTP_SO(&asoc->stream, sinfo->sinfo_stream)->ext)) {
                 err = sctp_stream_init_ext(&asoc->stream, sinfo->sinfo_stream);
                 if (err)
                         goto err;
@@ -7154,7 +7154,7 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
         if (!asoc || params.sprstat_sid >= asoc->stream.outcnt)
                 goto out;
 
-        streamoute = asoc->stream.out[params.sprstat_sid].ext;
+        streamoute = SCTP_SO(&asoc->stream, params.sprstat_sid)->ext;
         if (!streamoute) {
                 /* Not allocated yet, means all stats are 0 */
                 params.sprstat_abandoned_unsent = 0;
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index f1f1d1b232ba..7ca6fe4e7882 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -162,7 +162,7 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 
         stream->outcnt = outcnt;
         for (i = 0; i < stream->outcnt; i++)
-                stream->out[i].state = SCTP_STREAM_OPEN;
+                SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
 
         sched->init(stream);
 
@@ -193,7 +193,7 @@ int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
         soute = kzalloc(sizeof(*soute), GFP_KERNEL);
         if (!soute)
                 return -ENOMEM;
-        stream->out[sid].ext = soute;
+        SCTP_SO(stream, sid)->ext = soute;
 
         return sctp_sched_init_sid(stream, sid, GFP_KERNEL);
 }
@@ -205,7 +205,7 @@ void sctp_stream_free(struct sctp_stream *stream)
 
         sched->free(stream);
         for (i = 0; i < stream->outcnt; i++)
-                kfree(stream->out[i].ext);
+                kfree(SCTP_SO(stream, i)->ext);
         kfree(stream->out);
         kfree(stream->in);
 }
@@ -215,12 +215,12 @@ void sctp_stream_clear(struct sctp_stream *stream)
         int i;
 
         for (i = 0; i < stream->outcnt; i++) {
-                stream->out[i].mid = 0;
-                stream->out[i].mid_uo = 0;
+                SCTP_SO(stream, i)->mid = 0;
+                SCTP_SO(stream, i)->mid_uo = 0;
         }
 
         for (i = 0; i < stream->incnt; i++)
-                stream->in[i].mid = 0;
+                SCTP_SI(stream, i)->mid = 0;
 }
 
 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
@@ -273,8 +273,8 @@ static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
         for (i = 0; i < str_nums; i++) {
                 __u16 sid = ntohs(str_list[i]);
 
-                if (stream->out[sid].ext &&
-                    !list_empty(&stream->out[sid].ext->outq))
+                if (SCTP_SO(stream, sid)->ext &&
+                    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
                         return false;
         }
 
@@ -361,11 +361,11 @@ int sctp_send_reset_streams(struct sctp_association *asoc,
         if (out) {
                 if (str_nums)
                         for (i = 0; i < str_nums; i++)
-                                stream->out[str_list[i]].state =
+                                SCTP_SO(stream, str_list[i])->state =
                                                        SCTP_STREAM_CLOSED;
                 else
                         for (i = 0; i < stream->outcnt; i++)
-                                stream->out[i].state = SCTP_STREAM_CLOSED;
+                                SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
         }
 
         asoc->strreset_chunk = chunk;
@@ -380,11 +380,11 @@ int sctp_send_reset_streams(struct sctp_association *asoc,
 
                 if (str_nums)
                         for (i = 0; i < str_nums; i++)
-                                stream->out[str_list[i]].state =
+                                SCTP_SO(stream, str_list[i])->state =
                                                        SCTP_STREAM_OPEN;
                 else
                         for (i = 0; i < stream->outcnt; i++)
-                                stream->out[i].state = SCTP_STREAM_OPEN;
+                                SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
 
                 goto out;
         }
@@ -418,7 +418,7 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
 
         /* Block further xmit of data until this request is completed */
         for (i = 0; i < stream->outcnt; i++)
-                stream->out[i].state = SCTP_STREAM_CLOSED;
+                SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
 
         asoc->strreset_chunk = chunk;
         sctp_chunk_hold(asoc->strreset_chunk);
@@ -429,7 +429,7 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
                 asoc->strreset_chunk = NULL;
 
                 for (i = 0; i < stream->outcnt; i++)
-                        stream->out[i].state = SCTP_STREAM_OPEN;
+                        SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
 
                 return retval;
         }
@@ -609,10 +609,10 @@ struct sctp_chunk *sctp_process_strreset_outreq(
                 }
 
                 for (i = 0; i < nums; i++)
-                        stream->in[ntohs(str_p[i])].mid = 0;
+                        SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
         } else {
                 for (i = 0; i < stream->incnt; i++)
-                        stream->in[i].mid = 0;
+                        SCTP_SI(stream, i)->mid = 0;
         }
 
         result = SCTP_STRRESET_PERFORMED;
@@ -683,11 +683,11 @@ struct sctp_chunk *sctp_process_strreset_inreq(
 
         if (nums)
                 for (i = 0; i < nums; i++)
-                        stream->out[ntohs(str_p[i])].state =
+                        SCTP_SO(stream, ntohs(str_p[i]))->state =
                                                SCTP_STREAM_CLOSED;
         else
                 for (i = 0; i < stream->outcnt; i++)
-                        stream->out[i].state = SCTP_STREAM_CLOSED;
+                        SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
 
         asoc->strreset_chunk = chunk;
         asoc->strreset_outstanding = 1;
@@ -786,11 +786,11 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
          *      incoming and outgoing streams.
          */
         for (i = 0; i < stream->outcnt; i++) {
-                stream->out[i].mid = 0;
-                stream->out[i].mid_uo = 0;
+                SCTP_SO(stream, i)->mid = 0;
+                SCTP_SO(stream, i)->mid_uo = 0;
         }
         for (i = 0; i < stream->incnt; i++)
-                stream->in[i].mid = 0;
+                SCTP_SI(stream, i)->mid = 0;
 
         result = SCTP_STRRESET_PERFORMED;
 
@@ -979,15 +979,18 @@ struct sctp_chunk *sctp_process_strreset_resp(
                        sizeof(__u16);
 
                 if (result == SCTP_STRRESET_PERFORMED) {
+                        struct sctp_stream_out *sout;
                         if (nums) {
                                 for (i = 0; i < nums; i++) {
-                                        stream->out[ntohs(str_p[i])].mid = 0;
-                                        stream->out[ntohs(str_p[i])].mid_uo = 0;
+                                        sout = SCTP_SO(stream, ntohs(str_p[i]));
+                                        sout->mid = 0;
+                                        sout->mid_uo = 0;
                                 }
                         } else {
                                 for (i = 0; i < stream->outcnt; i++) {
-                                        stream->out[i].mid = 0;
-                                        stream->out[i].mid_uo = 0;
+                                        sout = SCTP_SO(stream, i);
+                                        sout->mid = 0;
+                                        sout->mid_uo = 0;
                                 }
                         }
 
@@ -995,7 +998,7 @@ struct sctp_chunk *sctp_process_strreset_resp(
                 }
 
                 for (i = 0; i < stream->outcnt; i++)
-                        stream->out[i].state = SCTP_STREAM_OPEN;
+                        SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
 
                 *evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
                         nums, str_p, GFP_ATOMIC);
@@ -1050,15 +1053,15 @@ struct sctp_chunk *sctp_process_strreset_resp(
                         asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
 
                         for (i = 0; i < stream->outcnt; i++) {
-                                stream->out[i].mid = 0;
-                                stream->out[i].mid_uo = 0;
+                                SCTP_SO(stream, i)->mid = 0;
+                                SCTP_SO(stream, i)->mid_uo = 0;
                         }
                         for (i = 0; i < stream->incnt; i++)
-                                stream->in[i].mid = 0;
+                                SCTP_SI(stream, i)->mid = 0;
                 }
 
                 for (i = 0; i < stream->outcnt; i++)
-                        stream->out[i].state = SCTP_STREAM_OPEN;
+                        SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
 
                 *evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
                         stsn, rtsn, GFP_ATOMIC);
@@ -1072,7 +1075,7 @@ struct sctp_chunk *sctp_process_strreset_resp(
 
                 if (result == SCTP_STRRESET_PERFORMED)
                         for (i = number; i < stream->outcnt; i++)
-                                stream->out[i].state = SCTP_STREAM_OPEN;
+                                SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
                 else
                         stream->outcnt = number;
 
diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c
index d3764c181299..0a78cdf86463 100644
--- a/net/sctp/stream_interleave.c
+++ b/net/sctp/stream_interleave.c
@@ -197,7 +197,7 @@ static struct sctp_ulpevent *sctp_intl_retrieve_partial(
         __u32 next_fsn = 0;
         int is_last = 0;
 
-        sin = sctp_stream_in(ulpq->asoc, event->stream);
+        sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
 
         skb_queue_walk(&ulpq->reasm, pos) {
                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
@@ -278,7 +278,7 @@ static struct sctp_ulpevent *sctp_intl_retrieve_reassembled(
         __u32 pd_len = 0;
         __u32 mid = 0;
 
-        sin = sctp_stream_in(ulpq->asoc, event->stream);
+        sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
 
         skb_queue_walk(&ulpq->reasm, pos) {
                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
@@ -368,7 +368,7 @@ static struct sctp_ulpevent *sctp_intl_reasm(struct sctp_ulpq *ulpq,
 
         sctp_intl_store_reasm(ulpq, event);
 
-        sin = sctp_stream_in(ulpq->asoc, event->stream);
+        sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
         if (sin->pd_mode && event->mid == sin->mid &&
             event->fsn == sin->fsn)
                 retval = sctp_intl_retrieve_partial(ulpq, event);
@@ -575,7 +575,7 @@ static struct sctp_ulpevent *sctp_intl_retrieve_partial_uo(
         __u32 next_fsn = 0;
         int is_last = 0;
 
-        sin = sctp_stream_in(ulpq->asoc, event->stream);
+        sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
 
         skb_queue_walk(&ulpq->reasm_uo, pos) {
                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
@@ -659,7 +659,7 @@ static struct sctp_ulpevent *sctp_intl_retrieve_reassembled_uo(
         __u32 pd_len = 0;
         __u32 mid = 0;
 
-        sin = sctp_stream_in(ulpq->asoc, event->stream);
+        sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
 
         skb_queue_walk(&ulpq->reasm_uo, pos) {
                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
@@ -750,7 +750,7 @@ static struct sctp_ulpevent *sctp_intl_reasm_uo(struct sctp_ulpq *ulpq,
 
         sctp_intl_store_reasm_uo(ulpq, event);
 
-        sin = sctp_stream_in(ulpq->asoc, event->stream);
+        sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
         if (sin->pd_mode_uo && event->mid == sin->mid_uo &&
             event->fsn == sin->fsn_uo)
                 retval = sctp_intl_retrieve_partial_uo(ulpq, event);
@@ -774,7 +774,7 @@ static struct sctp_ulpevent *sctp_intl_retrieve_first_uo(struct sctp_ulpq *ulpq)
         skb_queue_walk(&ulpq->reasm_uo, pos) {
                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 
-                csin = sctp_stream_in(ulpq->asoc, cevent->stream);
+                csin = sctp_stream_in(&ulpq->asoc->stream, cevent->stream);
                 if (csin->pd_mode_uo)
                         continue;
 
@@ -875,7 +875,7 @@ static struct sctp_ulpevent *sctp_intl_retrieve_first(struct sctp_ulpq *ulpq)
         skb_queue_walk(&ulpq->reasm, pos) {
                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 
-                csin = sctp_stream_in(ulpq->asoc, cevent->stream);
+                csin = sctp_stream_in(&ulpq->asoc->stream, cevent->stream);
                 if (csin->pd_mode)
                         continue;
 
@@ -1053,7 +1053,7 @@ static void sctp_intl_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
         __u16 sid;
 
         for (sid = 0; sid < stream->incnt; sid++) {
-                struct sctp_stream_in *sin = &stream->in[sid];
+                struct sctp_stream_in *sin = SCTP_SI(stream, sid);
                 __u32 mid;
 
                 if (sin->pd_mode_uo) {
@@ -1247,7 +1247,7 @@ static void sctp_handle_fwdtsn(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk)
 static void sctp_intl_skip(struct sctp_ulpq *ulpq, __u16 sid, __u32 mid,
                            __u8 flags)
 {
-        struct sctp_stream_in *sin = sctp_stream_in(ulpq->asoc, sid);
+        struct sctp_stream_in *sin = sctp_stream_in(&ulpq->asoc->stream, sid);
         struct sctp_stream *stream  = &ulpq->asoc->stream;
 
         if (flags & SCTP_FTSN_U_BIT) {
diff --git a/net/sctp/stream_sched.c b/net/sctp/stream_sched.c
index f5fcd425232a..a6c04a94b08f 100644
--- a/net/sctp/stream_sched.c
+++ b/net/sctp/stream_sched.c
@@ -161,7 +161,7 @@ int sctp_sched_set_sched(struct sctp_association *asoc,
 
                 /* Give the next scheduler a clean slate. */
                 for (i = 0; i < asoc->stream.outcnt; i++) {
-                        void *p = asoc->stream.out[i].ext;
+                        void *p = SCTP_SO(&asoc->stream, i)->ext;
 
                         if (!p)
                                 continue;
@@ -175,7 +175,7 @@ int sctp_sched_set_sched(struct sctp_association *asoc,
         asoc->outqueue.sched = n;
         n->init(&asoc->stream);
         for (i = 0; i < asoc->stream.outcnt; i++) {
-                if (!asoc->stream.out[i].ext)
+                if (!SCTP_SO(&asoc->stream, i)->ext)
                         continue;
 
                 ret = n->init_sid(&asoc->stream, i, GFP_KERNEL);
@@ -217,7 +217,7 @@ int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
         if (sid >= asoc->stream.outcnt)
                 return -EINVAL;
 
-        if (!asoc->stream.out[sid].ext) {
+        if (!SCTP_SO(&asoc->stream, sid)->ext) {
                 int ret;
 
                 ret = sctp_stream_init_ext(&asoc->stream, sid);
@@ -234,7 +234,7 @@ int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
         if (sid >= asoc->stream.outcnt)
                 return -EINVAL;
 
-        if (!asoc->stream.out[sid].ext)
+        if (!SCTP_SO(&asoc->stream, sid)->ext)
                 return 0;
 
         return asoc->outqueue.sched->get(&asoc->stream, sid, value);
@@ -252,7 +252,7 @@ void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch)
                  * priority stream comes in.
                  */
                 sid = sctp_chunk_stream_no(ch);
-                sout = &q->asoc->stream.out[sid];
+                sout = SCTP_SO(&q->asoc->stream, sid);
                 q->asoc->stream.out_curr = sout;
                 return;
         }
@@ -272,8 +272,9 @@ void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch)
 int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
 {
         struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
+        struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;
 
-        INIT_LIST_HEAD(&stream->out[sid].ext->outq);
+        INIT_LIST_HEAD(&ext->outq);
         return sched->init_sid(stream, sid, gfp);
 }
 
diff --git a/net/sctp/stream_sched_prio.c b/net/sctp/stream_sched_prio.c
index 7997d35dd0fd..2245083a98f2 100644
--- a/net/sctp/stream_sched_prio.c
+++ b/net/sctp/stream_sched_prio.c
@@ -75,10 +75,10 @@ static struct sctp_stream_priorities *sctp_sched_prio_get_head(
 
         /* No luck. So we search on all streams now. */
         for (i = 0; i < stream->outcnt; i++) {
-                if (!stream->out[i].ext)
+                if (!SCTP_SO(stream, i)->ext)
                         continue;
 
-                p = stream->out[i].ext->prio_head;
+                p = SCTP_SO(stream, i)->ext->prio_head;
                 if (!p)
                         /* Means all other streams won't be initialized
                          * as well.
@@ -165,7 +165,7 @@ static void sctp_sched_prio_sched(struct sctp_stream *stream,
 static int sctp_sched_prio_set(struct sctp_stream *stream, __u16 sid,
                                __u16 prio, gfp_t gfp)
 {
-        struct sctp_stream_out *sout = &stream->out[sid];
+        struct sctp_stream_out *sout = SCTP_SO(stream, sid);
         struct sctp_stream_out_ext *soute = sout->ext;
         struct sctp_stream_priorities *prio_head, *old;
         bool reschedule = false;
@@ -186,7 +186,7 @@ static int sctp_sched_prio_set(struct sctp_stream *stream, __u16 sid,
                 return 0;
 
         for (i = 0; i < stream->outcnt; i++) {
-                soute = stream->out[i].ext;
+                soute = SCTP_SO(stream, i)->ext;
                 if (soute && soute->prio_head == old)
                         /* It's still in use, nothing else to do here. */
                         return 0;
@@ -201,7 +201,7 @@ static int sctp_sched_prio_set(struct sctp_stream *stream, __u16 sid,
 static int sctp_sched_prio_get(struct sctp_stream *stream, __u16 sid,
                                __u16 *value)
 {
-        *value = stream->out[sid].ext->prio_head->prio;
+        *value = SCTP_SO(stream, sid)->ext->prio_head->prio;
         return 0;
 }
 
@@ -215,7 +215,7 @@ static int sctp_sched_prio_init(struct sctp_stream *stream)
 static int sctp_sched_prio_init_sid(struct sctp_stream *stream, __u16 sid,
                                     gfp_t gfp)
 {
-        INIT_LIST_HEAD(&stream->out[sid].ext->prio_list);
+        INIT_LIST_HEAD(&SCTP_SO(stream, sid)->ext->prio_list);
         return sctp_sched_prio_set(stream, sid, 0, gfp);
 }
 
@@ -233,9 +233,9 @@ static void sctp_sched_prio_free(struct sctp_stream *stream)
          */
         sctp_sched_prio_unsched_all(stream);
         for (i = 0; i < stream->outcnt; i++) {
-                if (!stream->out[i].ext)
+                if (!SCTP_SO(stream, i)->ext)
                         continue;
-                prio = stream->out[i].ext->prio_head;
+                prio = SCTP_SO(stream, i)->ext->prio_head;
                 if (prio && list_empty(&prio->prio_sched))
                         list_add(&prio->prio_sched, &list);
         }
@@ -255,7 +255,7 @@ static void sctp_sched_prio_enqueue(struct sctp_outq *q,
         ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list);
         sid = sctp_chunk_stream_no(ch);
         stream = &q->asoc->stream;
-        sctp_sched_prio_sched(stream, stream->out[sid].ext);
+        sctp_sched_prio_sched(stream, SCTP_SO(stream, sid)->ext);
 }
 
 static struct sctp_chunk *sctp_sched_prio_dequeue(struct sctp_outq *q)
@@ -297,7 +297,7 @@ static void sctp_sched_prio_dequeue_done(struct sctp_outq *q,
          * this priority.
          */
         sid = sctp_chunk_stream_no(ch);
-        soute = q->asoc->stream.out[sid].ext;
+        soute = SCTP_SO(&q->asoc->stream, sid)->ext;
         prio = soute->prio_head;
 
         sctp_sched_prio_next_stream(prio);
@@ -317,7 +317,7 @@ static void sctp_sched_prio_sched_all(struct sctp_stream *stream)
                 __u16 sid;
 
                 sid = sctp_chunk_stream_no(ch);
-                sout = &stream->out[sid];
+                sout = SCTP_SO(stream, sid);
                 if (sout->ext)
                         sctp_sched_prio_sched(stream, sout->ext);
         }
diff --git a/net/sctp/stream_sched_rr.c b/net/sctp/stream_sched_rr.c
index 1155692448f1..52ba743fa7a7 100644
--- a/net/sctp/stream_sched_rr.c
+++ b/net/sctp/stream_sched_rr.c
@@ -100,7 +100,7 @@ static int sctp_sched_rr_init(struct sctp_stream *stream)
 static int sctp_sched_rr_init_sid(struct sctp_stream *stream, __u16 sid,
                                   gfp_t gfp)
 {
-        INIT_LIST_HEAD(&stream->out[sid].ext->rr_list);
+        INIT_LIST_HEAD(&SCTP_SO(stream, sid)->ext->rr_list);
 
         return 0;
 }
@@ -120,7 +120,7 @@ static void sctp_sched_rr_enqueue(struct sctp_outq *q,
         ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list);
         sid = sctp_chunk_stream_no(ch);
         stream = &q->asoc->stream;
-        sctp_sched_rr_sched(stream, stream->out[sid].ext);
+        sctp_sched_rr_sched(stream, SCTP_SO(stream, sid)->ext);
 }
 
 static struct sctp_chunk *sctp_sched_rr_dequeue(struct sctp_outq *q)
@@ -154,7 +154,7 @@ static void sctp_sched_rr_dequeue_done(struct sctp_outq *q,
 
         /* Last chunk on that msg, move to the next stream */
         sid = sctp_chunk_stream_no(ch);
-        soute = q->asoc->stream.out[sid].ext;
+        soute = SCTP_SO(&q->asoc->stream, sid)->ext;
 
         sctp_sched_rr_next_stream(&q->asoc->stream);
 
@@ -173,7 +173,7 @@ static void sctp_sched_rr_sched_all(struct sctp_stream *stream)
                 __u16 sid;
 
                 sid = sctp_chunk_stream_no(ch);
-                soute = stream->out[sid].ext;
+                soute = SCTP_SO(stream, sid)->ext;
                 if (soute)
                         sctp_sched_rr_sched(stream, soute);
         }