RDS: Add rds_send_path_drop_acked()

rds_send_path_drop_acked() is the path-specific version of
rds_send_drop_acked() to be invoked by MP capable callers.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds/rds.h

@@ -786,6 +786,8 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest);
 typedef int (*is_acked_func)(struct rds_message *rm, uint64_t ack);
 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
 			 is_acked_func is_acked);
+void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
+			      is_acked_func is_acked);
 int rds_send_pong(struct rds_connection *conn, __be16 dport);
 struct rds_message *rds_send_get_message(struct rds_connection *,
 					 struct rm_rdma_op *);

net/rds/send.c

@@ -691,16 +691,16 @@ static void rds_send_remove_from_sock(struct list_head *messages, int status)
  * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
  * checks the RDS_MSG_HAS_ACK_SEQ bit.
  */
-void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
+void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
 			      is_acked_func is_acked)
 {
 	struct rds_message *rm, *tmp;
 	unsigned long flags;
 	LIST_HEAD(list);
 
-	spin_lock_irqsave(&conn->c_lock, flags);
+	spin_lock_irqsave(&cp->cp_lock, flags);
 
-	list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
+	list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
 		if (!rds_send_is_acked(rm, ack, is_acked))
 			break;
 
@@ -712,11 +712,19 @@ void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
 	if (!list_empty(&list))
 		smp_mb__after_atomic();
 
-	spin_unlock_irqrestore(&conn->c_lock, flags);
+	spin_unlock_irqrestore(&cp->cp_lock, flags);
 
 	/* now remove the messages from the sock list as needed */
 	rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
 }
+EXPORT_SYMBOL_GPL(rds_send_path_drop_acked);
+
+void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
+			 is_acked_func is_acked)
+{
+	WARN_ON(conn->c_trans->t_mp_capable);
+	rds_send_path_drop_acked(&conn->c_path[0], ack, is_acked);
+}
 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
 
 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)