3 files changed, 9 insertions, 4 deletions

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 56aebe444ad3..7e4e9dfdbc0b 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -147,6 +147,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
         conn->c_next_tx_seq = 1;
 
         spin_lock_init(&conn->c_send_lock);
+        atomic_set(&conn->c_send_generation, 1);
         INIT_LIST_HEAD(&conn->c_send_queue);
         INIT_LIST_HEAD(&conn->c_retrans);
 
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 2f19d49fac9c..b57cb50c1f22 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -92,6 +92,7 @@ struct rds_connection {
         struct rds_cong_map     *c_fcong;
 
         spinlock_t              c_send_lock;    /* protect send ring */
+        atomic_t                c_send_generation;
         struct rds_message      *c_xmit_rm;
         unsigned long           c_xmit_sg;
         unsigned int            c_xmit_hdr_off;
diff --git a/net/rds/send.c b/net/rds/send.c
index de5693cdcefb..663fd60b40cf 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -112,6 +112,7 @@ int rds_send_xmit(struct rds_connection *conn)
         unsigned int tmp;
         struct scatterlist *sg;
         int ret = 0;
+        int gen = 0;
         LIST_HEAD(to_be_dropped);
 
 restart:
@@ -134,6 +135,8 @@ restart:
         if (conn->c_trans->xmit_prepare)
                 conn->c_trans->xmit_prepare(conn);
 
+        gen = atomic_inc_return(&conn->c_send_generation);
+
         /*
          * spin trying to push headers and data down the connection until
          * the connection doesn't make forward progress.
@@ -359,13 +362,13 @@ restart:
         if (ret == 0) {
                 /* A simple bit test would be way faster than taking the
                  * spin lock */
-                spin_lock_irqsave(&conn->c_lock, flags);
+                smp_mb();
                 if (!list_empty(&conn->c_send_queue)) {
                         rds_stats_inc(s_send_lock_queue_raced);
-                        spin_unlock_irqrestore(&conn->c_lock, flags);
-                        goto restart;
+                        if (gen == atomic_read(&conn->c_send_generation)) {
+                                goto restart;
+                        }
                 }
-                spin_unlock_irqrestore(&conn->c_lock, flags);
         }
 out:
         return ret;