tipc: use generic SKB list APIs to manage link transmission queue

Use standard SKB list APIs associated with struct sk_buff_head to
manage link transmission queue, having relevant code more clean.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/bcast.c

@@ -217,12 +217,13 @@ struct tipc_node *tipc_bclink_retransmit_to(void)
  */
 static void bclink_retransmit_pkt(u32 after, u32 to)
 {
-	struct sk_buff *buf;
+	struct sk_buff *skb;
 
-	buf = bcl->first_out;
-	while (buf && less_eq(buf_seqno(buf), after))
-		buf = buf->next;
-	tipc_link_retransmit(bcl, buf, mod(to - after));
+	skb_queue_walk(&bcl->outqueue, skb) {
+		if (more(buf_seqno(skb), after))
+			break;
+	}
+	tipc_link_retransmit(bcl, skb, mod(to - after));
 }
 
 /**
@@ -245,14 +246,14 @@ void tipc_bclink_wakeup_users(void)
  */
 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
 {
-	struct sk_buff *crs;
+	struct sk_buff *skb, *tmp;
 	struct sk_buff *next;
 	unsigned int released = 0;
 
 	tipc_bclink_lock();
 	/* Bail out if tx queue is empty (no clean up is required) */
-	crs = bcl->first_out;
-	if (!crs)
+	skb = skb_peek(&bcl->outqueue);
+	if (!skb)
 		goto exit;
 
 	/* Determine which messages need to be acknowledged */
@@ -271,41 +272,41 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
 		 * Bail out if specified sequence number does not correspond
 		 * to a message that has been sent and not yet acknowledged
 		 */
-		if (less(acked, buf_seqno(crs)) ||
+		if (less(acked, buf_seqno(skb)) ||
 		    less(bcl->fsm_msg_cnt, acked) ||
 		    less_eq(acked, n_ptr->bclink.acked))
 			goto exit;
 	}
 
 	/* Skip over packets that node has previously acknowledged */
-	while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked))
-		crs = crs->next;
+	skb_queue_walk(&bcl->outqueue, skb) {
+		if (more(buf_seqno(skb), n_ptr->bclink.acked))
+			break;
+	}
 
 	/* Update packets that node is now acknowledging */
+	skb_queue_walk_from_safe(&bcl->outqueue, skb, tmp) {
+		if (more(buf_seqno(skb), acked))
+			break;
 
-	while (crs && less_eq(buf_seqno(crs), acked)) {
-		next = crs->next;
-
-		if (crs != bcl->next_out)
-			bcbuf_decr_acks(crs);
-		else {
-			bcbuf_set_acks(crs, 0);
+		next = tipc_skb_queue_next(&bcl->outqueue, skb);
+		if (skb != bcl->next_out) {
+			bcbuf_decr_acks(skb);
+		} else {
+			bcbuf_set_acks(skb, 0);
 			bcl->next_out = next;
 			bclink_set_last_sent();
 		}
 
-		if (bcbuf_acks(crs) == 0) {
-			bcl->first_out = next;
-			bcl->out_queue_size--;
-			kfree_skb(crs);
+		if (bcbuf_acks(skb) == 0) {
+			__skb_unlink(skb, &bcl->outqueue);
+			kfree_skb(skb);
 			released = 1;
 		}
-		crs = next;
 	}
 	n_ptr->bclink.acked = acked;
 
 	/* Try resolving broadcast link congestion, if necessary */
-
 	if (unlikely(bcl->next_out)) {
 		tipc_link_push_packets(bcl);
 		bclink_set_last_sent();
@@ -327,19 +328,16 @@ void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 	struct sk_buff *buf;
 
 	/* Ignore "stale" link state info */
-
 	if (less_eq(last_sent, n_ptr->bclink.last_in))
 		return;
 
 	/* Update link synchronization state; quit if in sync */
-
 	bclink_update_last_sent(n_ptr, last_sent);
 
 	if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
 		return;
 
 	/* Update out-of-sync state; quit if loss is still unconfirmed */
-
 	if ((++n_ptr->bclink.oos_state) == 1) {
 		if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
 			return;
@@ -347,12 +345,10 @@ void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 	}
 
 	/* Don't NACK if one has been recently sent (or seen) */
-
 	if (n_ptr->bclink.oos_state & 0x1)
 		return;
 
 	/* Send NACK */
-
 	buf = tipc_buf_acquire(INT_H_SIZE);
 	if (buf) {
 		struct tipc_msg *msg = buf_msg(buf);
@@ -425,9 +421,11 @@ int tipc_bclink_xmit(struct sk_buff *buf)
 		if (likely(bclink->bcast_nodes.count)) {
 			rc = __tipc_link_xmit(bcl, buf);
 			if (likely(!rc)) {
+				u32 len = skb_queue_len(&bcl->outqueue);
+
 				bclink_set_last_sent();
 				bcl->stats.queue_sz_counts++;
-				bcl->stats.accu_queue_sz += bcl->out_queue_size;
+				bcl->stats.accu_queue_sz += len;
 			}
 			bc = 1;
 		}
@@ -462,7 +460,6 @@ static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
 	 * Unicast an ACK periodically, ensuring that
 	 * all nodes in the cluster don't ACK at the same time
 	 */
-
 	if (((seqno - tipc_own_addr) % TIPC_MIN_LINK_WIN) == 0) {
 		tipc_link_proto_xmit(node->active_links[node->addr & 1],
 				     STATE_MSG, 0, 0, 0, 0, 0);
@@ -484,7 +481,6 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 	int deferred = 0;
 
 	/* Screen out unwanted broadcast messages */
-
 	if (msg_mc_netid(msg) != tipc_net_id)
 		goto exit;
 
@@ -497,7 +493,6 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 		goto unlock;
 
 	/* Handle broadcast protocol message */
-
 	if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
 		if (msg_type(msg) != STATE_MSG)
 			goto unlock;
@@ -518,14 +513,12 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 	}
 
 	/* Handle in-sequence broadcast message */
-
 	seqno = msg_seqno(msg);
 	next_in = mod(node->bclink.last_in + 1);
 
 	if (likely(seqno == next_in)) {
 receive:
 		/* Deliver message to destination */
-
 		if (likely(msg_isdata(msg))) {
 			tipc_bclink_lock();
 			bclink_accept_pkt(node, seqno);
@@ -574,7 +567,6 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 		buf = NULL;
 
 		/* Determine new synchronization state */
-
 		tipc_node_lock(node);
 		if (unlikely(!tipc_node_is_up(node)))
 			goto unlock;
@@ -594,7 +586,6 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 			goto unlock;
 
 		/* Take in-sequence message from deferred queue & deliver it */
-
 		buf = node->bclink.deferred_head;
 		node->bclink.deferred_head = buf->next;
 		buf->next = NULL;
@@ -603,7 +594,6 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 	}
 
 	/* Handle out-of-sequence broadcast message */
-
 	if (less(next_in, seqno)) {
 		deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
 					       &node->bclink.deferred_tail,
@@ -963,6 +953,7 @@ int tipc_bclink_init(void)
 	sprintf(bcbearer->media.name, "tipc-broadcast");
 
 	spin_lock_init(&bclink->lock);
+	__skb_queue_head_init(&bcl->outqueue);
 	__skb_queue_head_init(&bcl->waiting_sks);
 	bcl->next_out_no = 1;
 	spin_lock_init(&bclink->node.lock);

net/tipc/link.h

@@ -119,9 +119,7 @@ struct tipc_stats {
  * @max_pkt: current maximum packet size for this link
  * @max_pkt_target: desired maximum packet size for this link
  * @max_pkt_probes: # of probes based on current (max_pkt, max_pkt_target)
- * @out_queue_size: # of messages in outbound message queue
- * @first_out: ptr to first outbound message in queue
- * @last_out: ptr to last outbound message in queue
+ * @outqueue: outbound message queue
  * @next_out_no: next sequence number to use for outbound messages
  * @last_retransmitted: sequence number of most recently retransmitted message
  * @stale_count: # of identical retransmit requests made by peer
@@ -173,9 +171,7 @@ struct tipc_link {
 	u32 max_pkt_probes;
 
 	/* Sending */
-	u32 out_queue_size;
-	struct sk_buff *first_out;
-	struct sk_buff *last_out;
+	struct sk_buff_head outqueue;
 	u32 next_out_no;
 	u32 last_retransmitted;
 	u32 stale_count;
@@ -233,6 +229,8 @@ u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
 void tipc_link_retransmit(struct tipc_link *l_ptr,
 			  struct sk_buff *start, u32 retransmits);
+struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
+				    const struct sk_buff *skb);
 
 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
@@ -258,6 +256,11 @@ static inline int less_eq(u32 left, u32 right)
 	return mod(right - left) < 32768u;
 }
 
+static inline int more(u32 left, u32 right)
+{
+	return !less_eq(left, right);
+}
+
 static inline int less(u32 left, u32 right)
 {
 	return less_eq(left, right) && (mod(right) != mod(left));
@@ -294,7 +297,7 @@ static inline int link_reset_reset(struct tipc_link *l_ptr)
 
 static inline int link_congested(struct tipc_link *l_ptr)
 {
-	return l_ptr->out_queue_size >= l_ptr->queue_limit[0];
+	return skb_queue_len(&l_ptr->outqueue) >= l_ptr->queue_limit[0];
 }
 
 #endif

net/tipc/msg.c

@@ -265,16 +265,17 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 
 /**
  * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
- * @bbuf: the existing buffer ("bundle")
- * @buf:  buffer to be appended
+ * @list: the buffer chain of the existing buffer ("bundle")
+ * @skb:  buffer to be appended
  * @mtu:  max allowable size for the bundle buffer
  * Consumes buffer if successful
  * Returns true if bundling could be performed, otherwise false
  */
-bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu)
+bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu)
 {
-	struct tipc_msg *bmsg = buf_msg(bbuf);
-	struct tipc_msg *msg = buf_msg(buf);
+	struct sk_buff *bskb = skb_peek_tail(list);
+	struct tipc_msg *bmsg = buf_msg(bskb);
+	struct tipc_msg *msg = buf_msg(skb);
 	unsigned int bsz = msg_size(bmsg);
 	unsigned int msz = msg_size(msg);
 	u32 start = align(bsz);
@@ -289,35 +290,36 @@ bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu)
 		return false;
 	if (likely(msg_user(bmsg) != MSG_BUNDLER))
 		return false;
-	if (likely(!TIPC_SKB_CB(bbuf)->bundling))
+	if (likely(!TIPC_SKB_CB(bskb)->bundling))
 		return false;
-	if (unlikely(skb_tailroom(bbuf) < (pad + msz)))
+	if (unlikely(skb_tailroom(bskb) < (pad + msz)))
 		return false;
 	if (unlikely(max < (start + msz)))
 		return false;
 
-	skb_put(bbuf, pad + msz);
-	skb_copy_to_linear_data_offset(bbuf, start, buf->data, msz);
+	skb_put(bskb, pad + msz);
+	skb_copy_to_linear_data_offset(bskb, start, skb->data, msz);
 	msg_set_size(bmsg, start + msz);
 	msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
-	bbuf->next = buf->next;
-	kfree_skb(buf);
+	kfree_skb(skb);
 	return true;
 }
 
 /**
  * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
- * @buf:  buffer to be appended and replaced
- * @mtu:  max allowable size for the bundle buffer, inclusive header
+ * @list: the buffer chain
+ * @skb: buffer to be appended and replaced
+ * @mtu: max allowable size for the bundle buffer, inclusive header
  * @dnode: destination node for message. (Not always present in header)
  * Replaces buffer if successful
  * Returns true if success, otherwise false
  */
-bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode)
+bool tipc_msg_make_bundle(struct sk_buff_head *list, struct sk_buff *skb,
+			  u32 mtu, u32 dnode)
 {
-	struct sk_buff *bbuf;
+	struct sk_buff *bskb;
 	struct tipc_msg *bmsg;
-	struct tipc_msg *msg = buf_msg(*buf);
+	struct tipc_msg *msg = buf_msg(skb);
 	u32 msz = msg_size(msg);
 	u32 max = mtu - INT_H_SIZE;
 
@@ -330,21 +332,19 @@ bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode)
 	if (msz > (max / 2))
 		return false;
 
-	bbuf = tipc_buf_acquire(max);
-	if (!bbuf)
+	bskb = tipc_buf_acquire(max);
+	if (!bskb)
 		return false;
 
-	skb_trim(bbuf, INT_H_SIZE);
-	bmsg = buf_msg(bbuf);
+	skb_trim(bskb, INT_H_SIZE);
+	bmsg = buf_msg(bskb);
 	tipc_msg_init(bmsg, MSG_BUNDLER, 0, INT_H_SIZE, dnode);
 	msg_set_seqno(bmsg, msg_seqno(msg));
 	msg_set_ack(bmsg, msg_ack(msg));
 	msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
-	bbuf->next = (*buf)->next;
-	TIPC_SKB_CB(bbuf)->bundling = true;
-	tipc_msg_bundle(bbuf, *buf, mtu);
-	*buf = bbuf;
-	return true;
+	TIPC_SKB_CB(bskb)->bundling = true;
+	__skb_queue_tail(list, bskb);
+	return tipc_msg_bundle(list, skb, mtu);
 }
 
 /**

net/tipc/msg.h

@@ -734,9 +734,10 @@ struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,
 
 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf);
 
-bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu);
+bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu);
 
-bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode);
+bool tipc_msg_make_bundle(struct sk_buff_head *list, struct sk_buff *skb,
+			  u32 mtu, u32 dnode);
 
 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 		   int offset, int dsz, int mtu , struct sk_buff **chain);