Merge branch 'tipc-next'

Ying Xue says:

====================
standardize TIPC SKB queue operations

Now the following SKB queues are created and maintained within internal
TIPC stack:

- link transmission queue
- link deferred queue
- link receive queue
- socket outgoing packet chain
- name table outgoing packet chain

In order to manage above queues, TIPC stack declares a sk_buff pointer
for each queue to record its head, and directly modifies "prev" and
"next" SKB pointers of SKB structure when inserting or deleting a SKB
to or from the queue. As these operations are pretty complex, they
easily involve fatal mistakes. If these sk_buff pointers are replaced
with sk_buff_head instances as queue heads and corresponding generic
SKB list APIs are used to manage them, the entire TIPC code would
become quite clean and readable. But before make the change, we need
to clean up below redundant functionalities:

- remove node subscribe infrastructure
- remove protocol message queue
- remove retransmission queue
- clean up process of pushing packets in link layer
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/Makefile

@@ -7,8 +7,8 @@ obj-$(CONFIG_TIPC) := tipc.o
 tipc-y	+= addr.o bcast.o bearer.o config.o \
 	   core.o link.o discover.o msg.o  \
 	   name_distr.o  subscr.o name_table.o net.o  \
-	   netlink.o node.o node_subscr.o \
-	   socket.o log.o eth_media.o server.o
+	   netlink.o node.o socket.o log.o eth_media.o \
+	   server.o
 
 tipc-$(CONFIG_TIPC_MEDIA_IB)	+= ib_media.o
 tipc-$(CONFIG_SYSCTL)		+= sysctl.o

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 */
@@ -271,43 +272,43 @@ 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_queue(bcl);
+		tipc_link_push_packets(bcl);
 		bclink_set_last_sent();
 	}
 	if (unlikely(released && !skb_queue_empty(&bcl->waiting_sks)))
@@ -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;
@@ -347,15 +345,15 @@ 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);
+		struct sk_buff *skb = skb_peek(&n_ptr->bclink.deferred_queue);
+		u32 to = skb ? buf_seqno(skb) - 1 : n_ptr->bclink.last_sent;
 
 		tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
 			      INT_H_SIZE, n_ptr->addr);
@@ -363,9 +361,7 @@ void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 		msg_set_mc_netid(msg, tipc_net_id);
 		msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
 		msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
-		msg_set_bcgap_to(msg, n_ptr->bclink.deferred_head
-				 ? buf_seqno(n_ptr->bclink.deferred_head) - 1
-				 : n_ptr->bclink.last_sent);
+		msg_set_bcgap_to(msg, to);
 
 		tipc_bclink_lock();
 		tipc_bearer_send(MAX_BEARERS, buf, NULL);
@@ -402,20 +398,20 @@ static void bclink_peek_nack(struct tipc_msg *msg)
 
 /* tipc_bclink_xmit - broadcast buffer chain to all nodes in cluster
  *                    and to identified node local sockets
- * @buf: chain of buffers containing message
+ * @list: chain of buffers containing message
  * Consumes the buffer chain, except when returning -ELINKCONG
  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
  */
-int tipc_bclink_xmit(struct sk_buff *buf)
+int tipc_bclink_xmit(struct sk_buff_head *list)
 {
 	int rc = 0;
 	int bc = 0;
-	struct sk_buff *clbuf;
+	struct sk_buff *skb;
 
 	/* Prepare clone of message for local node */
-	clbuf = tipc_msg_reassemble(buf);
-	if (unlikely(!clbuf)) {
-		kfree_skb_list(buf);
+	skb = tipc_msg_reassemble(list);
+	if (unlikely(!skb)) {
+		__skb_queue_purge(list);
 		return -EHOSTUNREACH;
 	}
 
@@ -423,11 +419,13 @@ int tipc_bclink_xmit(struct sk_buff *buf)
 	if (likely(bclink)) {
 		tipc_bclink_lock();
 		if (likely(bclink->bcast_nodes.count)) {
-			rc = __tipc_link_xmit(bcl, buf);
+			rc = __tipc_link_xmit(bcl, list);
 			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;
 		}
@@ -435,13 +433,13 @@ int tipc_bclink_xmit(struct sk_buff *buf)
 	}
 
 	if (unlikely(!bc))
-		kfree_skb_list(buf);
+		__skb_queue_purge(list);
 
 	/* Deliver message clone */
 	if (likely(!rc))
-		tipc_sk_mcast_rcv(clbuf);
+		tipc_sk_mcast_rcv(skb);
 	else
-		kfree_skb(clbuf);
+		kfree_skb(skb);
 
 	return rc;
 }
@@ -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;
@@ -582,33 +574,26 @@ void tipc_bclink_rcv(struct sk_buff *buf)
 		if (node->bclink.last_in == node->bclink.last_sent)
 			goto unlock;
 
-		if (!node->bclink.deferred_head) {
+		if (skb_queue_empty(&node->bclink.deferred_queue)) {
 			node->bclink.oos_state = 1;
 			goto unlock;
 		}
 
-		msg = buf_msg(node->bclink.deferred_head);
+		msg = buf_msg(skb_peek(&node->bclink.deferred_queue));
 		seqno = msg_seqno(msg);
 		next_in = mod(next_in + 1);
 		if (seqno != next_in)
 			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;
-		node->bclink.deferred_size--;
+		buf = __skb_dequeue(&node->bclink.deferred_queue);
 		goto receive;
 	}
 
 	/* Handle out-of-sequence broadcast message */
-
 	if (less(next_in, seqno)) {
-		deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
-					       &node->bclink.deferred_tail,
+		deferred = tipc_link_defer_pkt(&node->bclink.deferred_queue,
 					       buf);
-		node->bclink.deferred_size += deferred;
 		bclink_update_last_sent(node, seqno);
 		buf = NULL;
 	}
@@ -963,6 +948,8 @@ 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->deferred_queue);
 	__skb_queue_head_init(&bcl->waiting_sks);
 	bcl->next_out_no = 1;
 	spin_lock_init(&bclink->node.lock);

net/tipc/bcast.h

@@ -100,7 +100,7 @@ int  tipc_bclink_reset_stats(void);
 int  tipc_bclink_set_queue_limits(u32 limit);
 void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action);
 uint  tipc_bclink_get_mtu(void);
-int tipc_bclink_xmit(struct sk_buff *buf);
+int tipc_bclink_xmit(struct sk_buff_head *list);
 void tipc_bclink_wakeup_users(void);
 int tipc_nl_add_bc_link(struct tipc_nl_msg *msg);
 

net/tipc/bearer.h

@@ -165,7 +165,7 @@ extern struct tipc_bearer __rcu *bearer_list[];
  * TIPC routines available to supported media types
  */
 
-void tipc_rcv(struct sk_buff *buf, struct tipc_bearer *tb_ptr);
+void tipc_rcv(struct sk_buff *skb, struct tipc_bearer *tb_ptr);
 int tipc_enable_bearer(const char *bearer_name, u32 disc_domain, u32 priority);
 int tipc_disable_bearer(const char *name);
 

net/tipc/core.h

@@ -192,6 +192,7 @@ struct tipc_skb_cb {
 	struct sk_buff *tail;
 	bool deferred;
 	bool wakeup_pending;
+	bool bundling;
 	u16 chain_sz;
 	u16 chain_imp;
 };

net/tipc/link.h

@@ -119,20 +119,13 @@ 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
  * @next_in_no: next sequence number to expect for inbound messages
- * @deferred_inqueue_sz: # of messages in inbound message queue
- * @oldest_deferred_in: ptr to first inbound message in queue
- * @newest_deferred_in: ptr to last inbound message in queue
+ * @deferred_queue: deferred queue saved OOS b'cast message received from node
  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
- * @proto_msg_queue: ptr to (single) outbound control message
- * @retransm_queue_size: number of messages to retransmit
- * @retransm_queue_head: sequence number of first message to retransmit
  * @next_out: ptr to first unsent outbound message in queue
  * @waiting_sks: linked list of sockets waiting for link congestion to abate
  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
@@ -176,24 +169,17 @@ 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;
 
 	/* Reception */
 	u32 next_in_no;
-	u32 deferred_inqueue_sz;
-	struct sk_buff *oldest_deferred_in;
-	struct sk_buff *newest_deferred_in;
+	struct sk_buff_head deferred_queue;
 	u32 unacked_window;
 
 	/* Congestion handling */
-	struct sk_buff *proto_msg_queue;
-	u32 retransm_queue_size;
-	u32 retransm_queue_head;
 	struct sk_buff *next_out;
 	struct sk_buff_head waiting_sks;
 
@@ -227,18 +213,20 @@ struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area,
 void tipc_link_reset_all(struct tipc_node *node);
 void tipc_link_reset(struct tipc_link *l_ptr);
 void tipc_link_reset_list(unsigned int bearer_id);
-int tipc_link_xmit(struct sk_buff *buf, u32 dest, u32 selector);
-int __tipc_link_xmit(struct tipc_link *link, struct sk_buff *buf);
+int tipc_link_xmit_skb(struct sk_buff *skb, u32 dest, u32 selector);
+int tipc_link_xmit(struct sk_buff_head *list, u32 dest, u32 selector);
+int __tipc_link_xmit(struct tipc_link *link, struct sk_buff_head *list);
 u32 tipc_link_get_max_pkt(u32 dest, u32 selector);
 void tipc_link_bundle_rcv(struct sk_buff *buf);
 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int prob,
 			  u32 gap, u32 tolerance, u32 priority, u32 acked_mtu);
-void tipc_link_push_queue(struct tipc_link *l_ptr);
-u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
-			struct sk_buff *buf);
+void tipc_link_push_packets(struct tipc_link *l_ptr);
+u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *buf);
 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);
@@ -259,18 +247,14 @@ static inline u32 mod(u32 x)
 	return x & 0xffffu;
 }
 
-static inline int between(u32 lower, u32 upper, u32 n)
+static inline int less_eq(u32 left, u32 right)
 {
-	if ((lower < n) && (n < upper))
-		return 1;
-	if ((upper < lower) && ((n > lower) || (n < upper)))
-		return 1;
-	return 0;
+	return mod(right - left) < 32768u;
 }
 
-static inline int less_eq(u32 left, u32 right)
+static inline int more(u32 left, u32 right)
 {
-	return mod(right - left) < 32768u;
+	return !less_eq(left, right);
 }
 
 static inline int less(u32 left, u32 right)
@@ -309,7 +293,7 @@ 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

@@ -166,11 +166,12 @@ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
  * @offset: Posision in iov to start copying from
  * @dsz: Total length of user data
  * @pktmax: Max packet size that can be used
- * @chain: Buffer or chain of buffers to be returned to caller
+ * @list: Buffer or chain of buffers to be returned to caller
+ *
  * Returns message data size or errno: -ENOMEM, -EFAULT
  */
-int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
-		   int offset, int dsz, int pktmax , struct sk_buff **chain)
+int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
+		   int dsz, int pktmax, struct sk_buff_head *list)
 {
 	int mhsz = msg_hdr_sz(mhdr);
 	int msz = mhsz + dsz;
@@ -179,22 +180,22 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 	int pktrem = pktmax;
 	int drem = dsz;
 	struct tipc_msg pkthdr;
-	struct sk_buff *buf, *prev;
+	struct sk_buff *skb;
 	char *pktpos;
 	int rc;
-	uint chain_sz = 0;
+
 	msg_set_size(mhdr, msz);
 
 	/* No fragmentation needed? */
 	if (likely(msz <= pktmax)) {
-		buf = tipc_buf_acquire(msz);
-		*chain = buf;
-		if (unlikely(!buf))
+		skb = tipc_buf_acquire(msz);
+		if (unlikely(!skb))
 			return -ENOMEM;
-		skb_copy_to_linear_data(buf, mhdr, mhsz);
-		pktpos = buf->data + mhsz;
-		TIPC_SKB_CB(buf)->chain_sz = 1;
-		if (!dsz || !memcpy_fromiovecend(pktpos, m->msg_iov, offset, dsz))
+		__skb_queue_tail(list, skb);
+		skb_copy_to_linear_data(skb, mhdr, mhsz);
+		pktpos = skb->data + mhsz;
+		if (!dsz || !memcpy_fromiovecend(pktpos, m->msg_iov, offset,
+						 dsz))
 			return dsz;
 		rc = -EFAULT;
 		goto error;
@@ -207,15 +208,15 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 	msg_set_fragm_no(&pkthdr, pktno);
 
 	/* Prepare first fragment */
-	*chain = buf = tipc_buf_acquire(pktmax);
-	if (!buf)
+	skb = tipc_buf_acquire(pktmax);
+	if (!skb)
 		return -ENOMEM;
-	chain_sz = 1;
-	pktpos = buf->data;
-	skb_copy_to_linear_data(buf, &pkthdr, INT_H_SIZE);
+	__skb_queue_tail(list, skb);
+	pktpos = skb->data;
+	skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
 	pktpos += INT_H_SIZE;
 	pktrem -= INT_H_SIZE;
-	skb_copy_to_linear_data_offset(buf, INT_H_SIZE, mhdr, mhsz);
+	skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
 	pktpos += mhsz;
 	pktrem -= mhsz;
 
@@ -238,43 +239,41 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 			pktsz = drem + INT_H_SIZE;
 		else
 			pktsz = pktmax;
-		prev = buf;
-		buf = tipc_buf_acquire(pktsz);
-		if (!buf) {
+		skb = tipc_buf_acquire(pktsz);
+		if (!skb) {
 			rc = -ENOMEM;
 			goto error;
 		}
-		chain_sz++;
-		prev->next = buf;
+		__skb_queue_tail(list, skb);
 		msg_set_type(&pkthdr, FRAGMENT);
 		msg_set_size(&pkthdr, pktsz);
 		msg_set_fragm_no(&pkthdr, ++pktno);
-		skb_copy_to_linear_data(buf, &pkthdr, INT_H_SIZE);
-		pktpos = buf->data + INT_H_SIZE;
+		skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
+		pktpos = skb->data + INT_H_SIZE;
 		pktrem = pktsz - INT_H_SIZE;
 
 	} while (1);
-	TIPC_SKB_CB(*chain)->chain_sz = chain_sz;
-	msg_set_type(buf_msg(buf), LAST_FRAGMENT);
+	msg_set_type(buf_msg(skb), LAST_FRAGMENT);
 	return dsz;
 error:
-	kfree_skb_list(*chain);
-	*chain = NULL;
+	__skb_queue_purge(list);
+	__skb_queue_head_init(list);
 	return rc;
 }
 
 /**
  * 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 +288,36 @@ 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(msg_type(bmsg) != BUNDLE_OPEN))
+	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;
 
@@ -330,20 +330,19 @@ 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);
-	tipc_msg_init(bmsg, MSG_BUNDLER, BUNDLE_OPEN, INT_H_SIZE, dnode);
+	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_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);
 }
 
 /**
@@ -429,22 +428,23 @@ int tipc_msg_eval(struct sk_buff *buf, u32 *dnode)
 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
  *                         reassemble the clones into one message
  */
-struct sk_buff *tipc_msg_reassemble(struct sk_buff *chain)
+struct sk_buff *tipc_msg_reassemble(struct sk_buff_head *list)
 {
-	struct sk_buff *buf = chain;
-	struct sk_buff *frag = buf;
+	struct sk_buff *skb;
+	struct sk_buff *frag = NULL;
 	struct sk_buff *head = NULL;
 	int hdr_sz;
 
 	/* Copy header if single buffer */
-	if (!buf->next) {
-		hdr_sz = skb_headroom(buf) + msg_hdr_sz(buf_msg(buf));
-		return __pskb_copy(buf, hdr_sz, GFP_ATOMIC);
+	if (skb_queue_len(list) == 1) {
+		skb = skb_peek(list);
+		hdr_sz = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
+		return __pskb_copy(skb, hdr_sz, GFP_ATOMIC);
 	}
 
 	/* Clone all fragments and reassemble */
-	while (buf) {
-		frag = skb_clone(buf, GFP_ATOMIC);
+	skb_queue_walk(list, skb) {
+		frag = skb_clone(skb, GFP_ATOMIC);
 		if (!frag)
 			goto error;
 		frag->next = NULL;
@@ -452,7 +452,6 @@ struct sk_buff *tipc_msg_reassemble(struct sk_buff *chain)
 			break;
 		if (!head)
 			goto error;
-		buf = buf->next;
 	}
 	return frag;
 error:

net/tipc/msg.h

@@ -464,11 +464,6 @@ static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m)
 #define FRAGMENT		1
 #define LAST_FRAGMENT		2
 
-/* Bundling protocol message types
- */
-#define BUNDLE_OPEN             0
-#define BUNDLE_CLOSED           1
-
 /*
  * Link management protocol message types
  */
@@ -739,13 +734,14 @@ 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);
+int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
+		   int dsz, int mtu, struct sk_buff_head *list);
 
-struct sk_buff *tipc_msg_reassemble(struct sk_buff *chain);
+struct sk_buff *tipc_msg_reassemble(struct sk_buff_head *list);
 
 #endif

net/tipc/name_distr.c

@@ -114,9 +114,9 @@ static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
 	return buf;
 }
 
-void named_cluster_distribute(struct sk_buff *buf)
+void named_cluster_distribute(struct sk_buff *skb)
 {
-	struct sk_buff *obuf;
+	struct sk_buff *oskb;
 	struct tipc_node *node;
 	u32 dnode;
 
@@ -127,15 +127,15 @@ void named_cluster_distribute(struct sk_buff *buf)
 			continue;
 		if (!tipc_node_active_links(node))
 			continue;
-		obuf = skb_copy(buf, GFP_ATOMIC);
-		if (!obuf)
+		oskb = skb_copy(skb, GFP_ATOMIC);
+		if (!oskb)
 			break;
-		msg_set_destnode(buf_msg(obuf), dnode);
-		tipc_link_xmit(obuf, dnode, dnode);
+		msg_set_destnode(buf_msg(oskb), dnode);
+		tipc_link_xmit_skb(oskb, dnode, dnode);
 	}
 	rcu_read_unlock();
 
-	kfree_skb(buf);
+	kfree_skb(skb);
 }
 
 /**
@@ -190,15 +190,15 @@ struct sk_buff *tipc_named_withdraw(struct publication *publ)
 
 /**
  * named_distribute - prepare name info for bulk distribution to another node
- * @msg_list: list of messages (buffers) to be returned from this function
+ * @list: list of messages (buffers) to be returned from this function
  * @dnode: node to be updated
  * @pls: linked list of publication items to be packed into buffer chain
  */
-static void named_distribute(struct list_head *msg_list, u32 dnode,
+static void named_distribute(struct sk_buff_head *list, u32 dnode,
 			     struct publ_list *pls)
 {
 	struct publication *publ;
-	struct sk_buff *buf = NULL;
+	struct sk_buff *skb = NULL;
 	struct distr_item *item = NULL;
 	uint dsz = pls->size * ITEM_SIZE;
 	uint msg_dsz = (tipc_node_get_mtu(dnode, 0) / ITEM_SIZE) * ITEM_SIZE;
@@ -207,15 +207,15 @@ static void named_distribute(struct list_head *msg_list, u32 dnode,
 
 	list_for_each_entry(publ, &pls->list, local_list) {
 		/* Prepare next buffer: */
-		if (!buf) {
+		if (!skb) {
 			msg_rem = min_t(uint, rem, msg_dsz);
 			rem -= msg_rem;
-			buf = named_prepare_buf(PUBLICATION, msg_rem, dnode);
-			if (!buf) {
+			skb = named_prepare_buf(PUBLICATION, msg_rem, dnode);
+			if (!skb) {
 				pr_warn("Bulk publication failure\n");
 				return;
 			}
-			item = (struct distr_item *)msg_data(buf_msg(buf));
+			item = (struct distr_item *)msg_data(buf_msg(skb));
 		}
 
 		/* Pack publication into message: */
@@ -225,8 +225,8 @@ static void named_distribute(struct list_head *msg_list, u32 dnode,
 
 		/* Append full buffer to list: */
 		if (!msg_rem) {
-			list_add_tail((struct list_head *)buf, msg_list);
-			buf = NULL;
+			__skb_queue_tail(list, skb);
+			skb = NULL;
 		}
 	}
 }
@@ -236,27 +236,57 @@ static void named_distribute(struct list_head *msg_list, u32 dnode,
  */
 void tipc_named_node_up(u32 dnode)
 {
-	LIST_HEAD(msg_list);
-	struct sk_buff *buf_chain;
+	struct sk_buff_head head;
+
+	__skb_queue_head_init(&head);
 
 	read_lock_bh(&tipc_nametbl_lock);
-	named_distribute(&msg_list, dnode, &publ_cluster);
-	named_distribute(&msg_list, dnode, &publ_zone);
+	named_distribute(&head, dnode, &publ_cluster);
+	named_distribute(&head, dnode, &publ_zone);
 	read_unlock_bh(&tipc_nametbl_lock);
 
-	/* Convert circular list to linear list and send: */
-	buf_chain = (struct sk_buff *)msg_list.next;
-	((struct sk_buff *)msg_list.prev)->next = NULL;
-	tipc_link_xmit(buf_chain, dnode, dnode);
+	tipc_link_xmit(&head, dnode, dnode);
+}
+
+static void tipc_publ_subscribe(struct publication *publ, u32 addr)
+{
+	struct tipc_node *node;
+
+	if (in_own_node(addr))
+		return;
+
+	node = tipc_node_find(addr);
+	if (!node) {
+		pr_warn("Node subscription rejected, unknown node 0x%x\n",
+			addr);
+		return;
+	}
+
+	tipc_node_lock(node);
+	list_add_tail(&publ->nodesub_list, &node->publ_list);
+	tipc_node_unlock(node);
+}
+
+static void tipc_publ_unsubscribe(struct publication *publ, u32 addr)
+{
+	struct tipc_node *node;
+
+	node = tipc_node_find(addr);
+	if (!node)
+		return;
+
+	tipc_node_lock(node);
+	list_del_init(&publ->nodesub_list);
+	tipc_node_unlock(node);
 }
 
 /**
- * named_purge_publ - remove publication associated with a failed node
+ * tipc_publ_purge - remove publication associated with a failed node
  *
  * Invoked for each publication issued by a newly failed node.
  * Removes publication structure from name table & deletes it.
  */
-static void named_purge_publ(struct publication *publ)
+static void tipc_publ_purge(struct publication *publ, u32 addr)
 {
 	struct publication *p;
 
@@ -264,7 +294,7 @@ static void named_purge_publ(struct publication *publ)
 	p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 				     publ->node, publ->ref, publ->key);
 	if (p)
-		tipc_nodesub_unsubscribe(&p->subscr);
+		tipc_publ_unsubscribe(p, addr);
 	write_unlock_bh(&tipc_nametbl_lock);
 
 	if (p != publ) {
@@ -277,6 +307,14 @@ static void named_purge_publ(struct publication *publ)
 	kfree(p);
 }
 
+void tipc_publ_notify(struct list_head *nsub_list, u32 addr)
+{
+	struct publication *publ, *tmp;
+
+	list_for_each_entry_safe(publ, tmp, nsub_list, nodesub_list)
+		tipc_publ_purge(publ, addr);
+}
+
 /**
  * tipc_update_nametbl - try to process a nametable update and notify
  *			 subscribers
@@ -294,9 +332,7 @@ static bool tipc_update_nametbl(struct distr_item *i, u32 node, u32 dtype)
 						TIPC_CLUSTER_SCOPE, node,
 						ntohl(i->ref), ntohl(i->key));
 		if (publ) {
-			tipc_nodesub_subscribe(&publ->subscr, node, publ,
-					       (net_ev_handler)
-					       named_purge_publ);
+			tipc_publ_subscribe(publ, node);
 			return true;
 		}
 	} else if (dtype == WITHDRAWAL) {
@@ -304,7 +340,7 @@ static bool tipc_update_nametbl(struct distr_item *i, u32 node, u32 dtype)
 						node, ntohl(i->ref),
 						ntohl(i->key));
 		if (publ) {
-			tipc_nodesub_unsubscribe(&publ->subscr);
+			tipc_publ_unsubscribe(publ, node);
 			kfree(publ);
 			return true;
 		}

net/tipc/name_distr.h

@@ -74,5 +74,6 @@ void tipc_named_node_up(u32 dnode);
 void tipc_named_rcv(struct sk_buff *buf);
 void tipc_named_reinit(void);
 void tipc_named_process_backlog(void);
+void tipc_publ_notify(struct list_head *nsub_list, u32 addr);
 
 #endif

net/tipc/name_table.c

@@ -144,7 +144,7 @@ static struct publication *publ_create(u32 type, u32 lower, u32 upper,
 	publ->key = key;
 	INIT_LIST_HEAD(&publ->local_list);
 	INIT_LIST_HEAD(&publ->pport_list);
-	INIT_LIST_HEAD(&publ->subscr.nodesub_list);
+	INIT_LIST_HEAD(&publ->nodesub_list);
 	return publ;
 }
 

net/tipc/name_table.h

@@ -37,8 +37,6 @@
 #ifndef _TIPC_NAME_TABLE_H
 #define _TIPC_NAME_TABLE_H
 
-#include "node_subscr.h"
-
 struct tipc_subscription;
 struct tipc_port_list;
 
@@ -56,7 +54,7 @@ struct tipc_port_list;
  * @node: network address of publishing port's node
  * @ref: publishing port
  * @key: publication key
- * @subscr: subscription to "node down" event (for off-node publications only)
+ * @nodesub_list: subscription to "node down" event (off-node publication only)
  * @local_list: adjacent entries in list of publications made by this node
  * @pport_list: adjacent entries in list of publications made by this port
  * @node_list: adjacent matching name seq publications with >= node scope
@@ -73,7 +71,7 @@ struct publication {
 	u32 node;
 	u32 ref;
 	u32 key;
-	struct tipc_node_subscr subscr;
+	struct list_head nodesub_list;
 	struct list_head local_list;
 	struct list_head pport_list;
 	struct list_head node_list;

net/tipc/node.c

@@ -113,9 +113,10 @@ struct tipc_node *tipc_node_create(u32 addr)
 	spin_lock_init(&n_ptr->lock);
 	INIT_HLIST_NODE(&n_ptr->hash);
 	INIT_LIST_HEAD(&n_ptr->list);
-	INIT_LIST_HEAD(&n_ptr->nsub);
+	INIT_LIST_HEAD(&n_ptr->publ_list);
 	INIT_LIST_HEAD(&n_ptr->conn_sks);
 	__skb_queue_head_init(&n_ptr->waiting_sks);
+	__skb_queue_head_init(&n_ptr->bclink.deferred_queue);
 
 	hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
 
@@ -381,8 +382,7 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 
 	/* Flush broadcast link info associated with lost node */
 	if (n_ptr->bclink.recv_permitted) {
-		kfree_skb_list(n_ptr->bclink.deferred_head);
-		n_ptr->bclink.deferred_size = 0;
+		__skb_queue_purge(&n_ptr->bclink.deferred_queue);
 
 		if (n_ptr->bclink.reasm_buf) {
 			kfree_skb(n_ptr->bclink.reasm_buf);
@@ -574,7 +574,7 @@ void tipc_node_unlock(struct tipc_node *node)
 		skb_queue_splice_init(&node->waiting_sks, &waiting_sks);
 
 	if (flags & TIPC_NOTIFY_NODE_DOWN) {
-		list_replace_init(&node->nsub, &nsub_list);
+		list_replace_init(&node->publ_list, &nsub_list);
 		list_replace_init(&node->conn_sks, &conn_sks);
 	}
 	node->action_flags &= ~(TIPC_WAKEUP_USERS | TIPC_NOTIFY_NODE_DOWN |
@@ -591,7 +591,7 @@ void tipc_node_unlock(struct tipc_node *node)
 		tipc_node_abort_sock_conns(&conn_sks);
 
 	if (!list_empty(&nsub_list))
-		tipc_nodesub_notify(&nsub_list);
+		tipc_publ_notify(&nsub_list, addr);
 
 	if (flags & TIPC_WAKEUP_BCAST_USERS)
 		tipc_bclink_wakeup_users();

net/tipc/node.h

@@ -37,7 +37,6 @@
 #ifndef _TIPC_NODE_H
 #define _TIPC_NODE_H
 
-#include "node_subscr.h"
 #include "addr.h"
 #include "net.h"
 #include "bearer.h"
@@ -72,9 +71,7 @@ enum {
  * @last_in: sequence # of last in-sequence b'cast message received from node
  * @last_sent: sequence # of last b'cast message sent by node
  * @oos_state: state tracker for handling OOS b'cast messages
- * @deferred_size: number of OOS b'cast messages in deferred queue
- * @deferred_head: oldest OOS b'cast message received from node
- * @deferred_tail: newest OOS b'cast message received from node
+ * @deferred_queue: deferred queue saved OOS b'cast message received from node
  * @reasm_buf: broadcast reassembly queue head from node
  * @recv_permitted: true if node is allowed to receive b'cast messages
  */
@@ -84,8 +81,7 @@ struct tipc_node_bclink {
 	u32 last_sent;
 	u32 oos_state;
 	u32 deferred_size;
-	struct sk_buff *deferred_head;
-	struct sk_buff *deferred_tail;
+	struct sk_buff_head deferred_queue;
 	struct sk_buff *reasm_buf;
 	bool recv_permitted;
 };
@@ -104,7 +100,7 @@ struct tipc_node_bclink {
  * @link_cnt: number of links to node
  * @signature: node instance identifier
  * @link_id: local and remote bearer ids of changing link, if any
- * @nsub: list of "node down" subscriptions monitoring node
+ * @publ_list: list of publications
  * @rcu: rcu struct for tipc_node
  */
 struct tipc_node {
@@ -121,7 +117,7 @@ struct tipc_node {
 	int working_links;
 	u32 signature;
 	u32 link_id;
-	struct list_head nsub;
+	struct list_head publ_list;
 	struct sk_buff_head waiting_sks;
 	struct list_head conn_sks;
 	struct rcu_head rcu;

net/tipc/node_subscr.c

-/*
- * net/tipc/node_subscr.c: TIPC "node down" subscription handling
- *
- * Copyright (c) 1995-2006, Ericsson AB
- * Copyright (c) 2005, 2010-2011, Wind River Systems
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the names of the copyright holders nor the names of its
- *    contributors may be used to endorse or promote products derived from
- *    this software without specific prior written permission.
- *
- * Alternatively, this software may be distributed under the terms of the
- * GNU General Public License ("GPL") version 2 as published by the Free
- * Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "core.h"
-#include "node_subscr.h"
-#include "node.h"
-
-/**
- * tipc_nodesub_subscribe - create "node down" subscription for specified node
- */
-void tipc_nodesub_subscribe(struct tipc_node_subscr *node_sub, u32 addr,
-			    void *usr_handle, net_ev_handler handle_down)
-{
-	if (in_own_node(addr)) {
-		node_sub->node = NULL;
-		return;
-	}
-
-	node_sub->node = tipc_node_find(addr);
-	if (!node_sub->node) {
-		pr_warn("Node subscription rejected, unknown node 0x%x\n",
-			addr);
-		return;
-	}
-	node_sub->handle_node_down = handle_down;
-	node_sub->usr_handle = usr_handle;
-
-	tipc_node_lock(node_sub->node);
-	list_add_tail(&node_sub->nodesub_list, &node_sub->node->nsub);
-	tipc_node_unlock(node_sub->node);
-}
-
-/**
- * tipc_nodesub_unsubscribe - cancel "node down" subscription (if any)
- */
-void tipc_nodesub_unsubscribe(struct tipc_node_subscr *node_sub)
-{
-	if (!node_sub->node)
-		return;
-
-	tipc_node_lock(node_sub->node);
-	list_del_init(&node_sub->nodesub_list);
-	tipc_node_unlock(node_sub->node);
-}
-
-/**
- * tipc_nodesub_notify - notify subscribers that a node is unreachable
- *
- * Note: node is locked by caller
- */
-void tipc_nodesub_notify(struct list_head *nsub_list)
-{
-	struct tipc_node_subscr *ns, *safe;
-	net_ev_handler handle_node_down;
-
-	list_for_each_entry_safe(ns, safe, nsub_list, nodesub_list) {
-		handle_node_down = ns->handle_node_down;
-		if (handle_node_down) {
-			ns->handle_node_down = NULL;
-			handle_node_down(ns->usr_handle);
-		}
-	}
-}

net/tipc/node_subscr.h

-/*
- * net/tipc/node_subscr.h: Include file for TIPC "node down" subscription handling
- *
- * Copyright (c) 1995-2006, Ericsson AB
- * Copyright (c) 2005, 2010-2011, Wind River Systems
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the names of the copyright holders nor the names of its
- *    contributors may be used to endorse or promote products derived from
- *    this software without specific prior written permission.
- *
- * Alternatively, this software may be distributed under the terms of the
- * GNU General Public License ("GPL") version 2 as published by the Free
- * Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef _TIPC_NODE_SUBSCR_H
-#define _TIPC_NODE_SUBSCR_H
-
-#include "addr.h"
-
-typedef void (*net_ev_handler) (void *usr_handle);
-
-/**
- * struct tipc_node_subscr - "node down" subscription entry
- * @node: ptr to node structure of interest (or NULL, if none)
- * @handle_node_down: routine to invoke when node fails
- * @usr_handle: argument to pass to routine when node fails
- * @nodesub_list: adjacent entries in list of subscriptions for the node
- */
-struct tipc_node_subscr {
-	struct tipc_node *node;
-	net_ev_handler handle_node_down;
-	void *usr_handle;
-	struct list_head nodesub_list;
-};
-
-void tipc_nodesub_subscribe(struct tipc_node_subscr *node_sub, u32 addr,
-			    void *usr_handle, net_ev_handler handle_down);
-void tipc_nodesub_unsubscribe(struct tipc_node_subscr *node_sub);
-void tipc_nodesub_notify(struct list_head *nsub_list);
-
-#endif