sctp: Tag messages that can be Nagle delayed at creation.

When we create the sctp_datamsg and fragment the user data,
we know exactly if we are sending full segments or not and
how they might be bundled.  During this time, we can mark
messages a Nagle capable or not.  This makes the check at
transmit time much simpler.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

3 files changed, 6 insertions, 8 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index d463296d9f79..9d44aef365da 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -643,17 +643,15 @@ struct sctp_pf {
 struct sctp_datamsg {
         /* Chunks waiting to be submitted to lower layer. */
         struct list_head chunks;
-        /* Chunks that have been transmitted. */
-        size_t msg_size;
         /* Reference counting. */
         atomic_t refcnt;
         /* When is this message no longer interesting to the peer? */
         unsigned long expires_at;
         /* Did the messenge fail to send? */
         int send_error;
-        char send_failed;
-        /* Control whether chunks from this message can be abandoned. */
-        char can_abandon;
+        u8 send_failed:1,
+           can_abandon:1,   /* can chunks from this message can be abandoned. */
+           can_delay;       /* should this message be Nagle delayed */
 };
 
 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index 3eab6db59a37..476caaf100ed 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -58,9 +58,9 @@ static void sctp_datamsg_init(struct sctp_datamsg *msg)
         msg->send_failed = 0;
         msg->send_error = 0;
         msg->can_abandon = 0;
+        msg->can_delay = 1;
         msg->expires_at = 0;
         INIT_LIST_HEAD(&msg->chunks);
-        msg->msg_size = 0;
 }
 
 /* Allocate and initialize datamsg. */
@@ -157,7 +157,6 @@ static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chu
 {
         sctp_datamsg_hold(msg);
         chunk->msg = msg;
-        msg->msg_size += chunk->skb->len;
 }
 
 
@@ -247,6 +246,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
         if (msg_len >= first_len) {
                 msg_len -= first_len;
                 whole = 1;
+                msg->can_delay = 0;
         }
 
         /* How many full sized?  How many bytes leftover? */
diff --git a/net/sctp/output.c b/net/sctp/output.c
index 35e49b9df4e0..a646681f5acd 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -674,7 +674,7 @@ static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet,
                  * Don't delay large message writes that may have been
                  * fragmeneted into small peices.
                  */
-                if ((len < max) && (chunk->msg->msg_size < max)) {
+                if ((len < max) && chunk->msg->can_delay) {
                         retval = SCTP_XMIT_NAGLE_DELAY;
                         goto finish;
                 }