RDS: Stop supporting old cong map sending method

We now ask the transport to give us a rm for the congestion
map, and then we handle it normally. Previously, the
transport defined a function that we would call to send
a congestion map.

Convert TCP and loop transports to new cong map method.
Signed-off-by: Andy Grover <andy.grover@oracle.com>

net/rds/ib.c

@@ -265,7 +265,6 @@ struct rds_transport rds_ib_transport = {
 	.laddr_check		= rds_ib_laddr_check,
 	.xmit_complete		= rds_ib_xmit_complete,
 	.xmit			= rds_ib_xmit,
-	.xmit_cong_map		= NULL,
 	.xmit_rdma		= rds_ib_xmit_rdma,
 	.xmit_atomic		= rds_ib_xmit_atomic,
 	.recv			= rds_ib_recv,

net/rds/iw.c

@@ -264,7 +264,6 @@ struct rds_transport rds_iw_transport = {
 	.laddr_check		= rds_iw_laddr_check,
 	.xmit_complete		= rds_iw_xmit_complete,
 	.xmit			= rds_iw_xmit,
-	.xmit_cong_map		= NULL,
 	.xmit_rdma		= rds_iw_xmit_rdma,
 	.recv			= rds_iw_recv,
 	.conn_alloc		= rds_iw_conn_alloc,

net/rds/loop.c

@@ -61,6 +61,12 @@ static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
 			 unsigned int hdr_off, unsigned int sg,
 			 unsigned int off)
 {
+	/* 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;
+	}
+
 	BUG_ON(hdr_off || sg || off);
 
 	rds_inc_init(&rm->m_inc, conn, conn->c_laddr);
@@ -88,18 +94,6 @@ static void rds_loop_inc_free(struct rds_incoming *inc)
         rds_message_put(rm);
 }
 
-static int rds_loop_xmit_cong_map(struct rds_connection *conn,
-				  struct rds_cong_map *map,
-				  unsigned long offset)
-{
-	BUG_ON(offset);
-	BUG_ON(map != conn->c_lcong);
-
-	rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
-
-	return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES;
-}
-
 /* we need to at least give the thread something to succeed */
 static int rds_loop_recv(struct rds_connection *conn)
 {
@@ -180,7 +174,6 @@ void rds_loop_exit(void)
  */
 struct rds_transport rds_loop_transport = {
 	.xmit			= rds_loop_xmit,
-	.xmit_cong_map		= rds_loop_xmit_cong_map,
 	.recv			= rds_loop_recv,
 	.conn_alloc		= rds_loop_conn_alloc,
 	.conn_free		= rds_loop_conn_free,

net/rds/rds.h

@@ -393,10 +393,6 @@ struct rds_notifier {
  *                 transport is responsible for other serialization, including
  *                 rds_recv_incoming().  This is called in process context but
  *                 should try hard not to block.
- *
- * @xmit_cong_map: This asks the transport to send the local bitmap down the
- * 		   given connection.  XXX get a better story about the bitmap
- * 		   flag and header.
  */
 
 #define RDS_TRANS_IB	0
@@ -420,8 +416,6 @@ struct rds_transport {
 	void (*xmit_complete)(struct rds_connection *conn);
 	int (*xmit)(struct rds_connection *conn, struct rds_message *rm,
 		    unsigned int hdr_off, unsigned int sg, unsigned int off);
-	int (*xmit_cong_map)(struct rds_connection *conn,
-			     struct rds_cong_map *map, unsigned long offset);
 	int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
 	int (*xmit_atomic)(struct rds_connection *conn, struct rm_atomic_op *op);
 	int (*recv)(struct rds_connection *conn);

net/rds/send.c

@@ -147,32 +147,8 @@ int rds_send_xmit(struct rds_connection *conn)
 		/*
 		 * If between sending messages, we can send a pending congestion
 		 * map update.
-		 *
-		 * Transports either define a special xmit_cong_map function,
-		 * or we allocate a cong_map message and treat it just like any
-		 * other send.
 		 */
 		if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
-			if (conn->c_trans->xmit_cong_map) {
-				unsigned long map_offset = 0;
-				unsigned long map_bytes = sizeof(struct rds_header) +
-					RDS_CONG_MAP_BYTES;
-
-				while (map_bytes) {
-					ret = conn->c_trans->xmit_cong_map(conn, conn->c_lcong,
-									   map_offset);
-					if (ret <= 0) {
-						/* too far down the rabbithole! */
-						mutex_unlock(&conn->c_send_lock);
-						rds_conn_error(conn, "Cong map xmit failed\n");
-						goto out;
-					}
-
-					map_offset += ret;
-					map_bytes -= ret;
-				}
-			} else {
-				/* send cong update like a normal rm */
 			rm = rds_cong_update_alloc(conn);
 			if (IS_ERR(rm)) {
 				ret = PTR_ERR(rm);
@@ -182,7 +158,6 @@ int rds_send_xmit(struct rds_connection *conn)
 
 			conn->c_xmit_rm = rm;
 		}
-		}
 
 		/*
 		 * If not already working on one, grab the next message.

net/rds/tcp.c

@@ -258,7 +258,6 @@ struct rds_transport rds_tcp_transport = {
 	.laddr_check		= rds_tcp_laddr_check,
 	.xmit_prepare		= rds_tcp_xmit_prepare,
 	.xmit_complete		= rds_tcp_xmit_complete,
-	.xmit_cong_map		= rds_tcp_xmit_cong_map,
 	.xmit			= rds_tcp_xmit,
 	.recv			= rds_tcp_recv,
 	.conn_alloc		= rds_tcp_conn_alloc,

net/rds/tcp.h

@@ -80,8 +80,6 @@ void rds_tcp_xmit_complete(struct rds_connection *conn);
 int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
 	         unsigned int hdr_off, unsigned int sg, unsigned int off);
 void rds_tcp_write_space(struct sock *sk);
-int rds_tcp_xmit_cong_map(struct rds_connection *conn,
-			  struct rds_cong_map *map, unsigned long offset);
 
 /* tcp_stats.c */
 DECLARE_PER_CPU(struct rds_tcp_statistics, rds_tcp_stats);

net/rds/tcp_send.c

@@ -76,56 +76,6 @@ int rds_tcp_sendmsg(struct socket *sock, void *data, unsigned int len)
 	return kernel_sendmsg(sock, &msg, &vec, 1, vec.iov_len);
 }
 
-/* the core send_sem serializes this with other xmit and shutdown */
-int rds_tcp_xmit_cong_map(struct rds_connection *conn,
-			  struct rds_cong_map *map, unsigned long offset)
-{
-	static struct rds_header rds_tcp_map_header = {
-		.h_flags = RDS_FLAG_CONG_BITMAP,
-	};
-	struct rds_tcp_connection *tc = conn->c_transport_data;
-	unsigned long i;
-	int ret;
-	int copied = 0;
-
-	/* Some problem claims cpu_to_be32(constant) isn't a constant. */
-	rds_tcp_map_header.h_len = cpu_to_be32(RDS_CONG_MAP_BYTES);
-
-	if (offset < sizeof(struct rds_header)) {
-		ret = rds_tcp_sendmsg(tc->t_sock,
-				      (void *)&rds_tcp_map_header + offset,
-				      sizeof(struct rds_header) - offset);
-		if (ret <= 0)
-			return ret;
-		offset += ret;
-		copied = ret;
-		if (offset < sizeof(struct rds_header))
-			return ret;
-	}
-
-	offset -= sizeof(struct rds_header);
-	i = offset / PAGE_SIZE;
-	offset = offset % PAGE_SIZE;
-	BUG_ON(i >= RDS_CONG_MAP_PAGES);
-
-	do {
-		ret = tc->t_sock->ops->sendpage(tc->t_sock,
-					virt_to_page(map->m_page_addrs[i]),
-					offset, PAGE_SIZE - offset,
-					MSG_DONTWAIT);
-		if (ret <= 0)
-			break;
-		copied += ret;
-		offset += ret;
-		if (offset == PAGE_SIZE) {
-			offset = 0;
-			i++;
-		}
-	} while (i < RDS_CONG_MAP_PAGES);
-
-        return copied ? copied : ret;
-}
-
 /* the core send_sem serializes this with other xmit and shutdown */
 int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
 	         unsigned int hdr_off, unsigned int sg, unsigned int off)