[openib-general] [PATCHv2] SDP: use linux/list.h for listen conns

[Tom Duffy]

This patch changes sdp to use Linux native lists for the listen conn
list.  The first version had a bug where if the listen list was empty,
the lookup would return a bogus conn.

Signed-off-by: Tom Duffy <tduffy at sun.com>

Index: linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_conn.c
===================================================================
--- linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_conn.c	(revision 2763)
+++ linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_conn.c	(working copy)
@@ -291,21 +291,11 @@ int sdp_inet_listen_start(struct sdp_soc
 	conn->state  = SDP_CONN_ST_LISTEN;
 	conn->accept_next = conn;
 	conn->accept_prev = conn;
-	/*
-	 * table lock
-	 */
-	spin_lock_irqsave(&dev_root_s.listen_lock, flags);
-	/*
-	 * insert into listening list.
-	 */
-	conn->lstn_next = dev_root_s.listen_list;
-	dev_root_s.listen_list = conn;
-	conn->lstn_p_next = &dev_root_s.listen_list;
-
-	if (conn->lstn_next)
-		conn->lstn_next->lstn_p_next = &conn->lstn_next;
 
+	spin_lock_irqsave(&dev_root_s.listen_lock, flags);
+	list_add(&conn->lstn_next, &dev_root_s.listen_list);
 	spin_unlock_irqrestore(&dev_root_s.listen_lock, flags);
+
 	return 0;
 }
 
@@ -323,22 +313,11 @@ int sdp_inet_listen_stop(struct sdp_sock
 	}
 
 	listen_conn->state  = SDP_CONN_ST_CLOSED;
-	/*
-	 * table lock
-	 */
-	spin_lock_irqsave(&dev_root_s.listen_lock, flags);
-	/*
-	 * remove from listening list.
-	 */
-	if (listen_conn->lstn_next)
-		listen_conn->lstn_next->lstn_p_next = listen_conn->lstn_p_next;
-
-	*(listen_conn->lstn_p_next) = listen_conn->lstn_next;
-
-	listen_conn->lstn_p_next = NULL;
-	listen_conn->lstn_next = NULL;
 
+	spin_lock_irqsave(&dev_root_s.listen_lock, flags);
+	list_del(&listen_conn->lstn_next);
 	spin_unlock_irqrestore(&dev_root_s.listen_lock, flags);
+
 	/*
 	 * reject and delete all pending connections
 	 */
@@ -367,7 +346,7 @@ int sdp_inet_listen_stop(struct sdp_sock
  */
 struct sdp_sock *sdp_inet_listen_lookup(u32 addr, u16 port)
 {
-	struct sdp_sock *conn;
+	struct sdp_sock *conn, *ret = NULL;
 	unsigned long flags;
 	/*
 	 * table lock
@@ -376,15 +355,16 @@ struct sdp_sock *sdp_inet_listen_lookup(
 	/*
 	 * first find a listening connection
 	 */
-	for (conn = dev_root_s.listen_list; conn; conn = conn->lstn_next)
+	list_for_each_entry(conn, &dev_root_s.listen_list, lstn_next)
 		if (port == conn->src_port &&
 		    (INADDR_ANY == conn->src_addr || addr == conn->src_addr)) {
 			sdp_conn_hold(conn);
+			ret = conn;
 			break;
 		}
 
 	spin_unlock_irqrestore(&dev_root_s.listen_lock, flags);
-	return conn;
+	return ret;
 }
 
 /*
@@ -1936,7 +1916,7 @@ int sdp_conn_table_init(int proto_family
 	/*
 	 * list
 	 */
-	dev_root_s.listen_list = NULL;
+	INIT_LIST_HEAD(&dev_root_s.listen_list);
 	dev_root_s.bind_list = NULL;
 
 	spin_lock_init(&dev_root_s.sock_lock);
Index: linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_conn.h
===================================================================
--- linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_conn.h	(revision 2763)
+++ linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_conn.h	(working copy)
@@ -36,6 +36,8 @@
 #ifndef _SDP_CONN_H
 #define _SDP_CONN_H
 
+#include <linux/list.h>
+
 #include "sdp_advt.h"
 #include "sdp_iocb.h"
 #include "sdp_dev.h"
@@ -336,8 +338,7 @@ struct sdp_sock {
 	/*
 	 * table managment
 	 */
-	struct sdp_sock *lstn_next;    /* next conn in the chain */
-	struct sdp_sock **lstn_p_next; /* previous next conn in the chain */
+	struct list_head lstn_next;
 
 	struct sdp_sock *bind_next;    /* next conn in the chain */
 	struct sdp_sock **bind_p_next; /* previous next conn in the chain */
Index: linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_dev.h
===================================================================
--- linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_dev.h	(revision 2763)
+++ linux-2.6.12-openib/drivers/infiniband/ulp/sdp/sdp_dev.h	(working copy)
@@ -43,6 +43,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/proc_fs.h>
+#include <linux/list.h>
 #include <net/sock.h>
 /*
  * sdp types
@@ -186,7 +187,7 @@ struct sdev_root {
 	/*
 	 * connection managment
 	 */
-	struct sdp_sock *listen_list;	/* list of listening connections */
+	struct list_head listen_list;
 	struct sdp_sock *bind_list;	/* connections bound to a port. */
 	/*
 	 * list locks