tipc: improve destination linked list

We often see a need for a linked list of destination identities,
sometimes containing a port number, sometimes a node identity, and
sometimes both. The currently defined struct u32_list is not generic
enough to cover all cases, so we extend it to contain two u32 integers
and rename it to struct tipc_dest_list.

Signed-off-by: Jon Maloy <[email protected]>
Acked-by: Ying Xue <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Jon Maloy

net/tipc/bcast.c

@@ -258,20 +258,20 @@ static int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts,
 static int tipc_rcast_xmit(struct net *net, struct sk_buff_head *pkts,
 			   struct tipc_nlist *dests, u16 *cong_link_cnt)
 {
+	struct tipc_dest *dst, *tmp;
 	struct sk_buff_head _pkts;
-	struct u32_item *n, *tmp;
-	u32 dst, selector;
+	u32 dnode, selector;
 
 	selector = msg_link_selector(buf_msg(skb_peek(pkts)));
 	skb_queue_head_init(&_pkts);
 
-	list_for_each_entry_safe(n, tmp, &dests->list, list) {
-		dst = n->value;
-		if (!tipc_msg_pskb_copy(dst, pkts, &_pkts))
+	list_for_each_entry_safe(dst, tmp, &dests->list, list) {
+		dnode = dst->node;
+		if (!tipc_msg_pskb_copy(dnode, pkts, &_pkts))
 			return -ENOMEM;
 
 		/* Any other return value than -ELINKCONG is ignored */
-		if (tipc_node_xmit(net, &_pkts, dst, selector) == -ELINKCONG)
+		if (tipc_node_xmit(net, &_pkts, dnode, selector) == -ELINKCONG)
 			(*cong_link_cnt)++;
 	}
 	return 0;
@@ -554,21 +554,21 @@ void tipc_nlist_add(struct tipc_nlist *nl, u32 node)
 {
 	if (node == nl->self)
 		nl->local = true;
-	else if (u32_push(&nl->list, node))
+	else if (tipc_dest_push(&nl->list, node, 0))
 		nl->remote++;
 }
 
 void tipc_nlist_del(struct tipc_nlist *nl, u32 node)
 {
 	if (node == nl->self)
 		nl->local = false;
-	else if (u32_del(&nl->list, node))
+	else if (tipc_dest_del(&nl->list, node, 0))
 		nl->remote--;
 }
 
 void tipc_nlist_purge(struct tipc_nlist *nl)
 {
-	u32_list_purge(&nl->list);
+	tipc_dest_list_purge(&nl->list);
 	nl->remote = 0;
 	nl->local = 0;
 }

net/tipc/name_table.c

@@ -634,7 +634,7 @@ int tipc_nametbl_mc_translate(struct net *net, u32 type, u32 lower, u32 upper,
 		info = sseq->info;
 		list_for_each_entry(publ, &info->node_list, node_list) {
 			if (publ->scope <= limit)
-				u32_push(dports, publ->ref);
+				tipc_dest_push(dports, 0, publ->ref);
 		}
 
 		if (info->cluster_list_size != info->node_list_size)
@@ -1057,78 +1057,79 @@ int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
-bool u32_find(struct list_head *l, u32 value)
+struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
 {
-	struct u32_item *item;
+	u64 value = (u64)node << 32 | port;
+	struct tipc_dest *dst;
 
-	list_for_each_entry(item, l, list) {
-		if (item->value == value)
-			return true;
+	list_for_each_entry(dst, l, list) {
+		if (dst->value != value)
+			continue;
+		return dst;
 	}
-	return false;
+	return NULL;
 }
 
-bool u32_push(struct list_head *l, u32 value)
+bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
 {
-	struct u32_item *item;
+	u64 value = (u64)node << 32 | port;
+	struct tipc_dest *dst;
 
-	list_for_each_entry(item, l, list) {
-		if (item->value == value)
-			return false;
-	}
-	item = kmalloc(sizeof(*item), GFP_ATOMIC);
-	if (unlikely(!item))
+	if (tipc_dest_find(l, node, port))
 		return false;
 
-	item->value = value;
-	list_add(&item->list, l);
+	dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
+	if (unlikely(!dst))
+		return false;
+	dst->value = value;
+	list_add(&dst->list, l);
 	return true;
 }
 
-u32 u32_pop(struct list_head *l)
+bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
 {
-	struct u32_item *item;
-	u32 value = 0;
+	struct tipc_dest *dst;
 
 	if (list_empty(l))
-		return 0;
-	item = list_first_entry(l, typeof(*item), list);
-	value = item->value;
-	list_del(&item->list);
-	kfree(item);
-	return value;
+		return false;
+	dst = list_first_entry(l, typeof(*dst), list);
+	if (port)
+		*port = dst->port;
+	if (node)
+		*node = dst->node;
+	list_del(&dst->list);
+	kfree(dst);
+	return true;
 }
 
-bool u32_del(struct list_head *l, u32 value)
+bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
 {
-	struct u32_item *item, *tmp;
+	struct tipc_dest *dst;
 
-	list_for_each_entry_safe(item, tmp, l, list) {
-		if (item->value != value)
-			continue;
-		list_del(&item->list);
-		kfree(item);
-		return true;
-	}
-	return false;
+	dst = tipc_dest_find(l, node, port);
+	if (!dst)
+		return false;
+	list_del(&dst->list);
+	kfree(dst);
+	return true;
 }
 
-void u32_list_purge(struct list_head *l)
+void tipc_dest_list_purge(struct list_head *l)
 {
-	struct u32_item *item, *tmp;
+	struct tipc_dest *dst, *tmp;
 
-	list_for_each_entry_safe(item, tmp, l, list) {
-		list_del(&item->list);
-		kfree(item);
+	list_for_each_entry_safe(dst, tmp, l, list) {
+		list_del(&dst->list);
+		kfree(dst);
 	}
 }
 
-int u32_list_len(struct list_head *l)
+int tipc_dest_list_len(struct list_head *l)
 {
-	struct u32_item *item;
+	struct tipc_dest *dst;
 	int i = 0;
 
-	list_for_each_entry(item, l, list) {
+	list_for_each_entry(dst, l, list) {
 		i++;
 	}
 	return i;

net/tipc/name_table.h

@@ -120,16 +120,22 @@ void tipc_nametbl_unsubscribe(struct tipc_subscription *s);
 int tipc_nametbl_init(struct net *net);
 void tipc_nametbl_stop(struct net *net);
 
-struct u32_item {
+struct tipc_dest {
 	struct list_head list;
-	u32 value;
+	union {
+		struct {
+			u32 port;
+			u32 node;
+		};
+		u64 value;
+	};
 };
 
-bool u32_push(struct list_head *l, u32 value);
-u32 u32_pop(struct list_head *l);
-bool u32_find(struct list_head *l, u32 value);
-bool u32_del(struct list_head *l, u32 value);
-void u32_list_purge(struct list_head *l);
-int u32_list_len(struct list_head *l);
+struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port);
+bool tipc_dest_push(struct list_head *l, u32 node, u32 port);
+bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port);
+bool tipc_dest_del(struct list_head *l, u32 node, u32 port);
+void tipc_dest_list_purge(struct list_head *l);
+int tipc_dest_list_len(struct list_head *l);
 
 #endif

net/tipc/socket.c

@@ -565,7 +565,7 @@ static int tipc_release(struct socket *sock)
 
 	/* Reject any messages that accumulated in backlog queue */
 	release_sock(sk);
-	u32_list_purge(&tsk->cong_links);
+	tipc_dest_list_purge(&tsk->cong_links);
 	tsk->cong_link_cnt = 0;
 	call_rcu(&tsk->rcu, tipc_sk_callback);
 	sock->sk = NULL;
@@ -826,8 +826,7 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
 		tipc_nametbl_mc_translate(net,
 					  msg_nametype(msg), msg_namelower(msg),
 					  msg_nameupper(msg), scope, &dports);
-		portid = u32_pop(&dports);
-		for (; portid; portid = u32_pop(&dports)) {
+		while (tipc_dest_pop(&dports, NULL, &portid)) {
 			_skb = __pskb_copy(skb, hsz, GFP_ATOMIC);
 			if (_skb) {
 				msg_set_destport(buf_msg(_skb), portid);
@@ -1000,7 +999,8 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 	}
 
 	/* Block or return if destination link is congested */
-	rc = tipc_wait_for_cond(sock, &timeout, !u32_find(clinks, dnode));
+	rc = tipc_wait_for_cond(sock, &timeout,
+				!tipc_dest_find(clinks, dnode, 0));
 	if (unlikely(rc))
 		return rc;
 
@@ -1012,7 +1012,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 
 	rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
 	if (unlikely(rc == -ELINKCONG)) {
-		u32_push(clinks, dnode);
+		tipc_dest_push(clinks, dnode, 0);
 		tsk->cong_link_cnt++;
 		rc = 0;
 	}
@@ -1549,7 +1549,7 @@ static void tipc_sk_proto_rcv(struct sock *sk,
 		tipc_sk_conn_proto_rcv(tsk, skb, xmitq);
 		return;
 	case SOCK_WAKEUP:
-		u32_del(&tsk->cong_links, msg_orignode(hdr));
+		tipc_dest_del(&tsk->cong_links, msg_orignode(hdr), 0);
 		tsk->cong_link_cnt--;
 		sk->sk_write_space(sk);
 		break;