---

yaml
---
r: 214432
b: refs/heads/master
c: bcf50ef
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: abf454398c2ebafc629ebb8b149f5a752c79e919
+refs/heads/master: bcf50ef2ce3c5d8f2fe995259da16677898cb300

trunk/net/rds/connection.c

@@ -62,14 +62,15 @@ static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
 		var |= RDS_INFO_CONNECTION_FLAG_##suffix;	\
 } while (0)
 
+/* rcu read lock must be held or the connection spinlock */
 static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
 					      __be32 laddr, __be32 faddr,
 					      struct rds_transport *trans)
 {
 	struct rds_connection *conn, *ret = NULL;
 	struct hlist_node *pos;
 
-	hlist_for_each_entry(conn, pos, head, c_hash_node) {
+	hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
 		if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
 				conn->c_trans == trans) {
 			ret = conn;
@@ -119,7 +120,8 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&rds_conn_lock, flags);
+
+	rcu_read_lock();
 	conn = rds_conn_lookup(head, laddr, faddr, trans);
 	if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
 	    !is_outgoing) {
@@ -130,7 +132,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 		parent = conn;
 		conn = parent->c_passive;
 	}
-	spin_unlock_irqrestore(&rds_conn_lock, flags);
+	rcu_read_unlock();
 	if (conn)
 		goto out;
 
@@ -227,7 +229,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 			kmem_cache_free(rds_conn_slab, conn);
 			conn = found;
 		} else {
-			hlist_add_head(&conn->c_hash_node, head);
+			hlist_add_head_rcu(&conn->c_hash_node, head);
 			rds_cong_add_conn(conn);
 			rds_conn_count++;
 		}
@@ -306,8 +308,13 @@ void rds_conn_shutdown(struct rds_connection *conn)
 	 * to the conn hash, so we never trigger a reconnect on this
 	 * conn - the reconnect is always triggered by the active peer. */
 	cancel_delayed_work_sync(&conn->c_conn_w);
-	if (!hlist_unhashed(&conn->c_hash_node))
+	rcu_read_lock();
+	if (!hlist_unhashed(&conn->c_hash_node)) {
+		rcu_read_unlock();
 		rds_queue_reconnect(conn);
+	} else {
+		rcu_read_unlock();
+	}
 }
 
 /*
@@ -323,14 +330,12 @@ void rds_conn_destroy(struct rds_connection *conn)
 
 	/* Ensure conn will not be scheduled for reconnect */
 	spin_lock_irq(&rds_conn_lock);
-	hlist_del_init(&conn->c_hash_node);
+	hlist_del_init_rcu(&conn->c_hash_node);
 	spin_unlock_irq(&rds_conn_lock);
 
-	/* wait for the rds thread to shut it down */
-	atomic_set(&conn->c_state, RDS_CONN_ERROR);
-	cancel_delayed_work(&conn->c_conn_w);
-	queue_work(rds_wq, &conn->c_down_w);
-	flush_workqueue(rds_wq);
+	synchronize_rcu();
+
+	rds_conn_shutdown(conn);
 
 	/* tear down queued messages */
 	list_for_each_entry_safe(rm, rtmp,
@@ -369,17 +374,16 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 	struct list_head *list;
 	struct rds_connection *conn;
 	struct rds_message *rm;
-	unsigned long flags;
 	unsigned int total = 0;
 	size_t i;
 
 	len /= sizeof(struct rds_info_message);
 
-	spin_lock_irqsave(&rds_conn_lock, flags);
+	rcu_read_lock();
 
 	for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
 	     i++, head++) {
-		hlist_for_each_entry(conn, pos, head, c_hash_node) {
+		hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
 			if (want_send)
 				list = &conn->c_send_queue;
 			else
@@ -399,8 +403,7 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 			spin_unlock(&conn->c_lock);
 		}
 	}
-
-	spin_unlock_irqrestore(&rds_conn_lock, flags);
+	rcu_read_unlock();
 
 	lens->nr = total;
 	lens->each = sizeof(struct rds_info_message);
@@ -430,19 +433,17 @@ void rds_for_each_conn_info(struct socket *sock, unsigned int len,
 	uint64_t buffer[(item_len + 7) / 8];
 	struct hlist_head *head;
 	struct hlist_node *pos;
-	struct hlist_node *tmp;
 	struct rds_connection *conn;
-	unsigned long flags;
 	size_t i;
 
-	spin_lock_irqsave(&rds_conn_lock, flags);
+	rcu_read_lock();
 
 	lens->nr = 0;
 	lens->each = item_len;
 
 	for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
 	     i++, head++) {
-		hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) {
+		hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
 
 			/* XXX no c_lock usage.. */
 			if (!visitor(conn, buffer))
@@ -458,8 +459,7 @@ void rds_for_each_conn_info(struct socket *sock, unsigned int len,
 			lens->nr++;
 		}
 	}
-
-	spin_unlock_irqrestore(&rds_conn_lock, flags);
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(rds_for_each_conn_info);