rds: remove unused rds_send_acked_before()

rds_send_acked_before() wasn't blocking interrupts when acquiring c_lock from
user context but nothing calls it.  Rather than fix its use of c_lock we just
remove the function.
Signed-off-by: NZach Brown <zach.brown@oracle.com>

net/rds/rds.h

@@ -724,7 +724,6 @@ 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);
-int rds_send_acked_before(struct rds_connection *conn, u64 seq);
 void rds_send_remove_from_sock(struct list_head *messages, int status);
 int rds_send_pong(struct rds_connection *conn, __be16 dport);
 struct rds_message *rds_send_get_message(struct rds_connection *,

net/rds/send.c

@@ -404,35 +404,6 @@ static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
 	return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
 }
 
-/*
- * Returns true if there are no messages on the send and retransmit queues
- * which have a sequence number greater than or equal to the given sequence
- * number.
- */
-int rds_send_acked_before(struct rds_connection *conn, u64 seq)
-{
-	struct rds_message *rm, *tmp;
-	int ret = 1;
-
-	spin_lock(&conn->c_lock);
-
-	list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
-		if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
-			ret = 0;
-		break;
-	}
-
-	list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
-		if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
-			ret = 0;
-		break;
-	}
-
-	spin_unlock(&conn->c_lock);
-
-	return ret;
-}
-
 /*
  * This is pretty similar to what happens below in the ACK
  * handling code - except that we call here as soon as we get