sctp: shrink sctp_tsnmap some more by removing gabs array

The gabs array in the sctp_tsnmap structure is only used
in one place, sctp_make_sack().  As such, carrying the
array around in the sctp_tsnmap and thus directly in
the sctp_association is rather pointless since most
of the time it's just taking up space.  Now, let
sctp_make_sack create and populate it and then throw
it away when it's done.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 12 insertions, 9 deletions

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 6dd9b3ef33d0..fd8acb48c3f2 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -702,12 +702,14 @@ struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
         __u32 ctsn;
         __u16 num_gabs, num_dup_tsns;
         struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
+        struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
 
+        memset(gabs, 0, sizeof(gabs));
         ctsn = sctp_tsnmap_get_ctsn(map);
         SCTP_DEBUG_PRINTK("sackCTSNAck sent:  0x%x.\n", ctsn);
 
         /* How much room is needed in the chunk? */
-        num_gabs = sctp_tsnmap_num_gabs(map);
+        num_gabs = sctp_tsnmap_num_gabs(map, gabs);
         num_dup_tsns = sctp_tsnmap_num_dups(map);
 
         /* Initialize the SACK header.  */
@@ -763,7 +765,7 @@ struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
         /* Add the gap ack block information.   */
         if (num_gabs)
                 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
-                                 sctp_tsnmap_get_gabs(map));
+                                 gabs);
 
         /* Add the duplicate TSN information.  */
         if (num_dup_tsns)
diff --git a/net/sctp/tsnmap.c b/net/sctp/tsnmap.c
index 142ed7ca424d..35c73e82553a 100644
--- a/net/sctp/tsnmap.c
+++ b/net/sctp/tsnmap.c
@@ -335,10 +335,11 @@ void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
 }
 
 /* How many gap ack blocks do we have recorded? */
-__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map)
+__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
+                           struct sctp_gap_ack_block *gabs)
 {
         struct sctp_tsnmap_iter iter;
-        int gabs = 0;
+        int ngaps = 0;
 
         /* Refresh the gap ack information. */
         if (sctp_tsnmap_has_gap(map)) {
@@ -348,14 +349,14 @@ __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map)
                                                 &start,
                                                 &end)) {
 
-                        map->gabs[gabs].start = htons(start);
-                        map->gabs[gabs].end = htons(end);
-                        gabs++;
-                        if (gabs >= SCTP_MAX_GABS)
+                        gabs[ngaps].start = htons(start);
+                        gabs[ngaps].end = htons(end);
+                        ngaps++;
+                        if (ngaps >= SCTP_MAX_GABS)
                                 break;
                 }
         }
-        return gabs;
+        return ngaps;
 }
 
 static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap)