sctp: define the member stream as an object instead of pointer in asoc

As Marcelo's suggestion, stream is a fixed size member of asoc and would
not grow with more streams. To avoid an allocation for it, this patch is
to define it as an object instead of pointer and update the places using
it, also create sctp_stream_update() called in sctp_assoc_update() to
migrate the stream info from one stream to another.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 35 deletions

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index dda53a293986..af6b49850344 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -37,30 +37,23 @@
 
 int sctp_stream_new(struct sctp_association *asoc, gfp_t gfp)
 {
-        struct sctp_stream *stream;
+        struct sctp_stream *stream = &asoc->stream;
         int i;
 
-        stream = kzalloc(sizeof(*stream), gfp);
-        if (!stream)
-                return -ENOMEM;
-
         stream->outcnt = asoc->c.sinit_num_ostreams;
         stream->out = kcalloc(stream->outcnt, sizeof(*stream->out), gfp);
-        if (!stream->out) {
-                kfree(stream);
+        if (!stream->out)
                 return -ENOMEM;
-        }
+
         for (i = 0; i < stream->outcnt; i++)
                 stream->out[i].state = SCTP_STREAM_OPEN;
 
-        asoc->stream = stream;
-
         return 0;
 }
 
 int sctp_stream_init(struct sctp_association *asoc, gfp_t gfp)
 {
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         int i;
 
         /* Initial stream->out size may be very big, so free it and alloc
@@ -70,7 +63,7 @@ int sctp_stream_init(struct sctp_association *asoc, gfp_t gfp)
         stream->outcnt = asoc->c.sinit_num_ostreams;
         stream->out = kcalloc(stream->outcnt, sizeof(*stream->out), gfp);
         if (!stream->out)
-                goto nomem;
+                return -ENOMEM;
 
         for (i = 0; i < stream->outcnt; i++)
                 stream->out[i].state = SCTP_STREAM_OPEN;
@@ -79,26 +72,17 @@ int sctp_stream_init(struct sctp_association *asoc, gfp_t gfp)
         stream->in = kcalloc(stream->incnt, sizeof(*stream->in), gfp);
         if (!stream->in) {
                 kfree(stream->out);
-                goto nomem;
+                stream->out = NULL;
+                return -ENOMEM;
         }
 
         return 0;
-
-nomem:
-        asoc->stream = NULL;
-        kfree(stream);
-
-        return -ENOMEM;
 }
 
 void sctp_stream_free(struct sctp_stream *stream)
 {
-        if (unlikely(!stream))
-                return;
-
         kfree(stream->out);
         kfree(stream->in);
-        kfree(stream);
 }
 
 void sctp_stream_clear(struct sctp_stream *stream)
@@ -112,6 +96,19 @@ void sctp_stream_clear(struct sctp_stream *stream)
                 stream->in[i].ssn = 0;
 }
 
+void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
+{
+        sctp_stream_free(stream);
+
+        stream->out = new->out;
+        stream->in  = new->in;
+        stream->outcnt = new->outcnt;
+        stream->incnt  = new->incnt;
+
+        new->out = NULL;
+        new->in  = NULL;
+}
+
 static int sctp_send_reconf(struct sctp_association *asoc,
                             struct sctp_chunk *chunk)
 {
@@ -128,7 +125,7 @@ static int sctp_send_reconf(struct sctp_association *asoc,
 int sctp_send_reset_streams(struct sctp_association *asoc,
                             struct sctp_reset_streams *params)
 {
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         __u16 i, str_nums, *str_list;
         struct sctp_chunk *chunk;
         int retval = -EINVAL;
@@ -214,6 +211,7 @@ out:
 
 int sctp_send_reset_assoc(struct sctp_association *asoc)
 {
+        struct sctp_stream *stream = &asoc->stream;
         struct sctp_chunk *chunk = NULL;
         int retval;
         __u16 i;
@@ -230,8 +228,8 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
                 return -ENOMEM;
 
         /* Block further xmit of data until this request is completed */
-        for (i = 0; i < asoc->stream->outcnt; i++)
-                asoc->stream->out[i].state = SCTP_STREAM_CLOSED;
+        for (i = 0; i < stream->outcnt; i++)
+                stream->out[i].state = SCTP_STREAM_CLOSED;
 
         asoc->strreset_chunk = chunk;
         sctp_chunk_hold(asoc->strreset_chunk);
@@ -241,8 +239,8 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
                 sctp_chunk_put(asoc->strreset_chunk);
                 asoc->strreset_chunk = NULL;
 
-                for (i = 0; i < asoc->stream->outcnt; i++)
-                        asoc->stream->out[i].state = SCTP_STREAM_OPEN;
+                for (i = 0; i < stream->outcnt; i++)
+                        stream->out[i].state = SCTP_STREAM_OPEN;
 
                 return retval;
         }
@@ -255,7 +253,7 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
 int sctp_send_add_streams(struct sctp_association *asoc,
                           struct sctp_add_streams *params)
 {
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         struct sctp_chunk *chunk = NULL;
         int retval = -ENOMEM;
         __u32 outcnt, incnt;
@@ -357,7 +355,7 @@ struct sctp_chunk *sctp_process_strreset_outreq(
                                 struct sctp_ulpevent **evp)
 {
         struct sctp_strreset_outreq *outreq = param.v;
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         __u16 i, nums, flags = 0, *str_p = NULL;
         __u32 result = SCTP_STRRESET_DENIED;
         __u32 request_seq;
@@ -449,7 +447,7 @@ struct sctp_chunk *sctp_process_strreset_inreq(
                                 struct sctp_ulpevent **evp)
 {
         struct sctp_strreset_inreq *inreq = param.v;
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         __u32 result = SCTP_STRRESET_DENIED;
         struct sctp_chunk *chunk = NULL;
         __u16 i, nums, *str_p;
@@ -523,7 +521,7 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
 {
         __u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
         struct sctp_strreset_tsnreq *tsnreq = param.v;
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         __u32 result = SCTP_STRRESET_DENIED;
         __u32 request_seq;
         __u16 i;
@@ -612,7 +610,7 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
                                 struct sctp_ulpevent **evp)
 {
         struct sctp_strreset_addstrm *addstrm = param.v;
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         __u32 result = SCTP_STRRESET_DENIED;
         struct sctp_stream_in *streamin;
         __u32 request_seq, incnt;
@@ -687,7 +685,7 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
                                 struct sctp_ulpevent **evp)
 {
         struct sctp_strreset_addstrm *addstrm = param.v;
-        struct sctp_stream *stream = asoc->stream;
+        struct sctp_stream *stream = &asoc->stream;
         __u32 result = SCTP_STRRESET_DENIED;
         struct sctp_stream_out *streamout;
         struct sctp_chunk *chunk = NULL;
@@ -758,8 +756,8 @@ struct sctp_chunk *sctp_process_strreset_resp(
                                 union sctp_params param,
                                 struct sctp_ulpevent **evp)
 {
+        struct sctp_stream *stream = &asoc->stream;
         struct sctp_strreset_resp *resp = param.v;
-        struct sctp_stream *stream = asoc->stream;
         struct sctp_transport *t;
         __u16 i, nums, flags = 0;
         sctp_paramhdr_t *req;