RDS: Pass rds_conn_path to rds_send_xmit()

Pass a struct rds_conn_path to rds_send_xmit so that MP capable
transports can transmit packets on something other than c_path[0].
The eventual goal for MP capable transports is to hash the rds
socket to a path based on the bound local address/port, and use
this path as the argument to rds_send_xmit()
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds/ib_cm.c

@@ -274,7 +274,7 @@ static void rds_ib_tasklet_fn_send(unsigned long data)
 	if (rds_conn_up(conn) &&
 	    (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
 	    test_bit(0, &conn->c_map_queued)))
-		rds_send_xmit(ic->conn);
+		rds_send_xmit(&ic->conn->c_path[0]);
 }
 
 static void poll_rcq(struct rds_ib_connection *ic, struct ib_cq *cq,

net/rds/rds.h

@@ -457,7 +457,9 @@ struct rds_transport {
 	int (*conn_connect)(struct rds_connection *conn);
 	void (*conn_shutdown)(struct rds_connection *conn);
 	void (*xmit_prepare)(struct rds_connection *conn);
+	void (*xmit_path_prepare)(struct rds_conn_path *cp);
 	void (*xmit_complete)(struct rds_connection *conn);
+	void (*xmit_path_complete)(struct rds_conn_path *cp);
 	int (*xmit)(struct rds_connection *conn, struct rds_message *rm,
 		    unsigned int hdr_off, unsigned int sg, unsigned int off);
 	int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
@@ -780,7 +782,7 @@ void rds_inc_info_copy(struct rds_incoming *inc,
 /* send.c */
 int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len);
 void rds_send_reset(struct rds_connection *conn);
-int rds_send_xmit(struct rds_connection *conn);
+int rds_send_xmit(struct rds_conn_path *cp);
 struct sockaddr_in;
 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);

net/rds/threads.c

@@ -177,7 +177,7 @@ void rds_send_worker(struct work_struct *work)
 
 	if (rds_conn_path_state(cp) == RDS_CONN_UP) {
 		clear_bit(RDS_LL_SEND_FULL, &cp->cp_flags);
-		ret = rds_send_xmit(cp->cp_conn);
+		ret = rds_send_xmit(cp);
 		cond_resched();
 		rdsdebug("conn %p ret %d\n", cp->cp_conn, ret);
 		switch (ret) {