2 files changed, 12 insertions, 4 deletions

diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c
index 71f373c421b..c47a511f203 100644
--- a/net/rds/ib_send.c
+++ b/net/rds/ib_send.c
@@ -551,7 +551,10 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
         if (conn->c_loopback
             && rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
                 rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
-                return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES;
+                scat = &rm->data.op_sg[sg];
+                ret = sizeof(struct rds_header) + RDS_CONG_MAP_BYTES;
+                ret = min_t(int, ret, scat->length - conn->c_xmit_data_off);
+                return ret;
         }
 
         /* FIXME we may overallocate here */
diff --git a/net/rds/loop.c b/net/rds/loop.c
index aeec1d483b1..bca6761a3ca 100644
--- a/net/rds/loop.c
+++ b/net/rds/loop.c
@@ -61,10 +61,15 @@ static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
                          unsigned int hdr_off, unsigned int sg,
                          unsigned int off)
 {
+        struct scatterlist *sgp = &rm->data.op_sg[sg];
+        int ret = sizeof(struct rds_header) +
+                        be32_to_cpu(rm->m_inc.i_hdr.h_len);
+
         /* Do not send cong updates to loopback */
         if (rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
                 rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
-                return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES;
+                ret = min_t(int, ret, sgp->length - conn->c_xmit_data_off);
+                goto out;
         }
 
         BUG_ON(hdr_off || sg || off);
@@ -80,8 +85,8 @@ static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
                             NULL);
 
         rds_inc_put(&rm->m_inc);
-
-        return sizeof(struct rds_header) + be32_to_cpu(rm->m_inc.i_hdr.h_len);
+out:
+        return ret;
 }
 
 /*