[PATCH net-next 00/15] TIPC updates for upcoming v3.4

[PATCH net-next 00/15] TIPC updates for upcoming v3.4

[Paul Gortmaker]

Hi Dave,

No real trend or correlation from one patch to the next here,
just continued chiseling away at what were deemed to be the
worthwhile bits that were squirreled away on sourceforge.
I think there is on the order of 50 left after this.

I haven't forgot about your earlier request to see some of
the tipc_printbuf related stuff go away (at least I think that
was what you wanted to see replaced).  I'm not entirely 100%
sure how to proceed there just yet, so I may tackle a few
more from the remaining 50 in the interim while the log.c
cleanup gets more thought.

Runtime tested from 64 to 32 bit x86 machines; I had to revert
an skge commit to get my 32 bit machine functional, but that
is largely of no interest here.

Thanks,
Paul

---

The following changes since commit 3238a9be4d7ad95c741bcfe6c147406eeef62d95:

  cnic: Add FCoE parity error recovery (2012-02-05 22:42:00 -0500)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux.git tipc_net-next

for you to fetch changes up to dff10e9e637663c8c5dd0bae1a8f0e899cbb4a36:

  tipc: Minor optimization to rejection of connection-based messages (2012-02-06 16:59:19 -0500)

----------------------------------------------------------------
Allan Stephens (15):
  tipc: improve the link deferred queue insertion algorithm
  tipc: Prevent transmission of outdated link protocol messages
  tipc: Prevent broadcast link stalling in dual LAN environments
  tipc: Ensure broadcast link re-acquires node after link failure
  tipc: Fix problem with broadcast link synchronization between nodes
  tipc: Add missing broadcast link lock when sending NACK
  tipc: Fix node lock reclamation issues in broadcast link reception
  tipc: Fix bug in broadcast link duplicate message statistics
  tipc: Add missing locks in broadcast link statistics accumulation
  tipc: Major redesign of broadcast link ACK/NACK algorithms
  tipc: Remove obsolete broadcast tag capability
  tipc: Prevent loss of fragmented messages over unicast links
  tipc: Prevent loss of fragmented messages over broadcast link
  tipc: Eliminate alteration of publication key during name table purging
  tipc: Minor optimization to rejection of connection-based messages

 net/tipc/bcast.c      |  324 +++++++++++++++++++++++-------------------------
 net/tipc/bcast.h      |    2 +-
 net/tipc/link.c       |  148 +++++++++++++----------
 net/tipc/name_distr.c |    4 -
 net/tipc/node.c       |   14 +--
 net/tipc/node.h       |   18 ++--
 net/tipc/port.c       |    5 +-
 7 files changed, 255 insertions(+), 260 deletions(-)

-- 
1.7.9

[PATCH net-next 01/15] tipc: improve the link deferred queue insertion algorithm

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Re-code the algorithm for inserting an out-of-sequence message into
a unicast or broadcast link's deferred message queue.  It remains
functionally equivalent but should be easier to understand/maintain.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/link.c |   48 +++++++++++++++++++++++-------------------------
 1 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index ac1832a..c317abf 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1853,17 +1853,16 @@ cont:
 }
 
 /*
- * link_defer_buf(): Sort a received out-of-sequence packet
- *                   into the deferred reception queue.
- * Returns the increase of the queue length,i.e. 0 or 1
+ * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
+ *
+ * Returns increase in queue length (i.e. 0 or 1)
  */
 
-u32 tipc_link_defer_pkt(struct sk_buff **head,
-			struct sk_buff **tail,
+u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
 			struct sk_buff *buf)
 {
-	struct sk_buff *prev = NULL;
-	struct sk_buff *crs = *head;
+	struct sk_buff *queue_buf;
+	struct sk_buff **prev;
 	u32 seq_no = buf_seqno(buf);
 
 	buf->next = NULL;
@@ -1881,31 +1880,30 @@ u32 tipc_link_defer_pkt(struct sk_buff **head,
 		return 1;
 	}
 
-	/* Scan through queue and sort it in */
-	do {
-		struct tipc_msg *msg = buf_msg(crs);
+	/* Locate insertion point in queue, then insert; discard if duplicate */
+	prev = head;
+	queue_buf = *head;
+	for (;;) {
+		u32 curr_seqno = buf_seqno(queue_buf);
 
-		if (less(seq_no, msg_seqno(msg))) {
-			buf->next = crs;
-			if (prev)
-				prev->next = buf;
-			else
-				*head = buf;
-			return 1;
+		if (seq_no == curr_seqno) {
+			buf_discard(buf);
+			return 0;
 		}
-		if (seq_no == msg_seqno(msg))
+
+		if (less(seq_no, curr_seqno))
 			break;
-		prev = crs;
-		crs = crs->next;
-	} while (crs);
 
-	/* Message is a duplicate of an existing message */
+		prev = &queue_buf->next;
+		queue_buf = queue_buf->next;
+	}
 
-	buf_discard(buf);
-	return 0;
+	buf->next = queue_buf;
+	*prev = buf;
+	return 1;
 }
 
-/**
+/*
  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
  */
 
-- 
1.7.9

[PATCH net-next 02/15] tipc: Prevent transmission of outdated link protocol messages

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Ensures that a link endpoint discards any previously deferred link
protocol message whenever it attempts to send a new one.

Previously, it was possible for a link protocol message that was unsent
due to congestion to be transmitted after newer protocol messages had
been sent. The stale link protocol message might then cause the receiving
link endpoint to malfunction because of its outdated conent.

Thanks to Osamu Kaminuma [okaminum@avaya.com] for diagnosing the problem
and contributing a prototype patch.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/link.c |   53 +++++++++++++++++++++++++++--------------------------
 1 files changed, 27 insertions(+), 26 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index c317abf..bee316c 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1954,6 +1954,13 @@ void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
 	u32 msg_size = sizeof(l_ptr->proto_msg);
 	int r_flag;
 
+	/* Discard any previous message that was deferred due to congestion */
+
+	if (l_ptr->proto_msg_queue) {
+		buf_discard(l_ptr->proto_msg_queue);
+		l_ptr->proto_msg_queue = NULL;
+	}
+
 	if (link_blocked(l_ptr))
 		return;
 
@@ -1962,6 +1969,8 @@ void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
 	if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
 		return;
 
+	/* Create protocol message with "out-of-sequence" sequence number */
+
 	msg_set_type(msg, msg_typ);
 	msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
 	msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
@@ -2018,44 +2027,36 @@ void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
 	r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
 	msg_set_redundant_link(msg, r_flag);
 	msg_set_linkprio(msg, l_ptr->priority);
-
-	/* Ensure sequence number will not fit : */
+	msg_set_size(msg, msg_size);
 
 	msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
 
-	/* Congestion? */
-
-	if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
-		if (!l_ptr->proto_msg_queue) {
-			l_ptr->proto_msg_queue =
-				tipc_buf_acquire(sizeof(l_ptr->proto_msg));
-		}
-		buf = l_ptr->proto_msg_queue;
-		if (!buf)
-			return;
-		skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
-		return;
-	}
-
-	/* Message can be sent */
-
 	buf = tipc_buf_acquire(msg_size);
 	if (!buf)
 		return;
 
 	skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
-	msg_set_size(buf_msg(buf), msg_size);
 
-	if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
-		l_ptr->unacked_window = 0;
-		buf_discard(buf);
+	/* Defer message if bearer is already congested */
+
+	if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
+		l_ptr->proto_msg_queue = buf;
+		return;
+	}
+
+	/* Defer message if attempting to send results in bearer congestion */
+
+	if (!tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
+		tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
+		l_ptr->proto_msg_queue = buf;
+		l_ptr->stats.bearer_congs++;
 		return;
 	}
 
-	/* New congestion */
-	tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
-	l_ptr->proto_msg_queue = buf;
-	l_ptr->stats.bearer_congs++;
+	/* Discard message if it was sent successfully */
+
+	l_ptr->unacked_window = 0;
+	buf_discard(buf);
 }
 
 /*
-- 
1.7.9

[PATCH net-next 03/15] tipc: Prevent broadcast link stalling in dual LAN environments

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Ensure that sequence number information about incoming broadcast link
messages is initialized only by the activation of the first link to a
given cluster node.  Previously, a race condition allowed reset and/or
activation messages for a second link to re-initialize this sequence
number information with obsolete values. This could trigger TIPC to
request the retransmission of previously acknowledged broadcast link
messages from that node, resulting in broadcast link processing becoming
stalled if the node had already released one or more of those messages
and was unable to perform the required retransmission.

Thanks to Laser <gotolaser@gmail.com> for identifying this problem
and assisting in the development of this fix.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/link.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index bee316c..4ea6cad 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2128,14 +2128,15 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
 		}
 		l_ptr->owner->bclink.supported = (max_pkt_info != 0);
 
+		/* Synchronize broadcast link info, if not done previously */
+
+		if (!tipc_node_is_up(l_ptr->owner))
+			l_ptr->owner->bclink.last_in = msg_last_bcast(msg);
+
 		link_state_event(l_ptr, msg_type(msg));
 
 		l_ptr->peer_session = msg_session(msg);
 		l_ptr->peer_bearer_id = msg_bearer_id(msg);
-
-		/* Synchronize broadcast sequence numbers */
-		if (!tipc_node_redundant_links(l_ptr->owner))
-			l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
 		break;
 	case STATE_MSG:
 
-- 
1.7.9

[PATCH net-next 04/15] tipc: Ensure broadcast link re-acquires node after link failure

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Fix a bug that can prevent TIPC from sending broadcast messages to a node
if contact with the node is lost and then regained. The problem occurs if
the broadcast link first clears the flag indicating the node is part of the
link's distribution set (when it loses contact with the node), and later
fails to restore the flag (when contact is regained); restoration fails
if contact with the node is regained by implicit unicast link activation
triggered by the arrival of a data message, rather than explicitly by the
arrival of a link activation message.

The broadcast link now uses separate fields to track whether a node is
theoretically capable of receiving broadcast messages versus whether it is
actually part of the link's distribution set. The former member is updated
by the receipt of link protocol messages, which can occur at any time; the
latter member is updated only when contact with the node is gained or lost.
This change also permits the simplification of several conditional
expressions since the broadcast link's "supported" field can now only be
set if there are working links to the associated node.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/link.c |    5 +++--
 net/tipc/node.c |    3 ++-
 net/tipc/node.h |    4 +++-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 4ea6cad..3405f56 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1502,6 +1502,7 @@ static void link_retransmit_failure(struct tipc_link *l_ptr,
 
 		tipc_addr_string_fill(addr_string, n_ptr->addr);
 		info("Multicast link info for %s\n", addr_string);
+		info("Supportable: %d,  ", n_ptr->bclink.supportable);
 		info("Supported: %d,  ", n_ptr->bclink.supported);
 		info("Acked: %u\n", n_ptr->bclink.acked);
 		info("Last in: %u,  ", n_ptr->bclink.last_in);
@@ -1736,7 +1737,7 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
 		/* Release acked messages */
 
-		if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
+		if (n_ptr->bclink.supported)
 			tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
 
 		crs = l_ptr->first_out;
@@ -2126,7 +2127,7 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
 		} else {
 			l_ptr->max_pkt = l_ptr->max_pkt_target;
 		}
-		l_ptr->owner->bclink.supported = (max_pkt_info != 0);
+		l_ptr->owner->bclink.supportable = (max_pkt_info != 0);
 
 		/* Synchronize broadcast link info, if not done previously */
 
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 6b226fa..9196f94 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -306,8 +306,9 @@ static void node_established_contact(struct tipc_node *n_ptr)
 	/* Syncronize broadcast acks */
 	n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 
-	if (n_ptr->bclink.supported) {
+	if (n_ptr->bclink.supportable) {
 		tipc_bclink_add_node(n_ptr->addr);
+		n_ptr->bclink.supported = 1;
 		if (n_ptr->addr < tipc_own_addr)
 			tipc_own_tag++;
 	}
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 0b1c5f8..90689f4 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -62,6 +62,7 @@
  * @link_cnt: number of links to node
  * @permit_changeover: non-zero if node has redundant links to this system
  * @bclink: broadcast-related info
+ *    @supportable: non-zero if node supports TIPC b'cast link capability
  *    @supported: non-zero if node supports TIPC b'cast capability
  *    @acked: sequence # of last outbound b'cast message acknowledged by node
  *    @last_in: sequence # of last in-sequence b'cast message received from node
@@ -86,7 +87,8 @@ struct tipc_node {
 	int block_setup;
 	int permit_changeover;
 	struct {
-		int supported;
+		u8 supportable;
+		u8 supported;
 		u32 acked;
 		u32 last_in;
 		u32 gap_after;
-- 
1.7.9

[PATCH net-next 05/15] tipc: Fix problem with broadcast link synchronization between nodes

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Corrects a problem in which a link endpoint that activates as the
result of receiving a RESET/STATE sequence of link protocol messages
fails to properly record the broadcast link status information about
the node to which it is now communicating with. (The problem does
not occur with the more common RESET/ACTIVATE sequence of messages.)
The fix ensures that the broadcast link status info is updated after
the RESET message resets the link endpoint, rather than before, thereby
preventing new information from being overwritten by the reset operation.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/link.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 3405f56..1150ba5 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2105,6 +2105,8 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
 			l_ptr->owner->block_setup = WAIT_NODE_DOWN;
 		}
 
+		link_state_event(l_ptr, RESET_MSG);
+
 		/* fall thru' */
 	case ACTIVATE_MSG:
 		/* Update link settings according other endpoint's values */
@@ -2134,10 +2136,11 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
 		if (!tipc_node_is_up(l_ptr->owner))
 			l_ptr->owner->bclink.last_in = msg_last_bcast(msg);
 
-		link_state_event(l_ptr, msg_type(msg));
-
 		l_ptr->peer_session = msg_session(msg);
 		l_ptr->peer_bearer_id = msg_bearer_id(msg);
+
+		if (msg_type(msg) == ACTIVATE_MSG)
+			link_state_event(l_ptr, ACTIVATE_MSG);
 		break;
 	case STATE_MSG:
 
-- 
1.7.9

[PATCH net-next 06/15] tipc: Add missing broadcast link lock when sending NACK

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Ensures that any attempt to send a NACK message over TIPC's broadcast
link has exclusive access to the link's main data structures, to prevent
interference with a simultaneous attempt to send other broadcast link
traffic (such as application-generated multicast messages).

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 8eb87b1..7342abc 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -340,8 +340,10 @@ static void bclink_send_nack(struct tipc_node *n_ptr)
 		msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
 		msg_set_bcast_tag(msg, tipc_own_tag);
 
+		spin_lock_bh(&bc_lock);
 		tipc_bearer_send(&bcbearer->bearer, buf, NULL);
 		bcl->stats.sent_nacks++;
+		spin_unlock_bh(&bc_lock);
 		buf_discard(buf);
 
 		/*
-- 
1.7.9

[PATCH net-next 07/15] tipc: Fix node lock reclamation issues in broadcast link reception

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Fixes a pair of problems in broadcast link message reception code
relating to the reclamation of the node lock after consuming an
in-sequence message.

1) Now retests to see if the sending node is still up after reclaiming
   the node lock, and bails out if it is non-operational.

2) Now manipulates the node's deferred message queue only after
   reclaiming the node lock, rather than using queue head pointer
   information that was cached previously.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |   58 +++++++++++++++++++++++++++++++++++++----------------
 1 files changed, 40 insertions(+), 18 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 7342abc..e7df313 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -474,7 +474,7 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 	struct tipc_node *node;
 	u32 next_in;
 	u32 seqno;
-	struct sk_buff *deferred;
+	int deferred;
 
 	/* Screen out unwanted broadcast messages */
 
@@ -489,6 +489,8 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 	if (unlikely(!node->bclink.supported))
 		goto unlock;
 
+	/* Handle broadcast protocol message */
+
 	if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
 		if (msg_type(msg) != STATE_MSG)
 			goto unlock;
@@ -513,11 +515,11 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 
 	/* Handle in-sequence broadcast message */
 
-receive:
-	next_in = mod(node->bclink.last_in + 1);
 	seqno = msg_seqno(msg);
+	next_in = mod(node->bclink.last_in + 1);
 
 	if (likely(seqno == next_in)) {
+receive:
 		bcl->stats.recv_info++;
 		node->bclink.last_in++;
 		bclink_set_gap(node);
@@ -551,23 +553,40 @@ receive:
 			buf_discard(buf);
 		}
 		buf = NULL;
+
+		/* Determine new synchronization state */
+
 		tipc_node_lock(node);
-		deferred = node->bclink.deferred_head;
-		if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
-			buf = deferred;
-			msg = buf_msg(buf);
-			node->bclink.deferred_head = deferred->next;
-			goto receive;
-		}
-	} else if (less(next_in, seqno)) {
+		if (unlikely(!tipc_node_is_up(node)))
+			goto unlock;
+
+		if (!node->bclink.deferred_head)
+			goto unlock;
+
+		msg = buf_msg(node->bclink.deferred_head);
+		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;
+		goto receive;
+	}
+
+	/* Handle out-of-sequence broadcast message */
+
+	if (less(next_in, seqno)) {
 		u32 gap_after = node->bclink.gap_after;
 		u32 gap_to = node->bclink.gap_to;
 
-		if (tipc_link_defer_pkt(&node->bclink.deferred_head,
-					&node->bclink.deferred_tail,
-					buf)) {
+		deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
+					       &node->bclink.deferred_tail,
+					       buf);
+		if (deferred) {
 			node->bclink.nack_sync++;
-			bcl->stats.deferred_recv++;
 			if (seqno == mod(gap_after + 1))
 				node->bclink.gap_after = seqno;
 			else if (less(gap_after, seqno) && less(seqno, gap_to))
@@ -579,9 +598,12 @@ receive:
 				bclink_send_nack(node);
 			bclink_set_gap(node);
 		}
-	} else {
-		bcl->stats.duplicates++;
-	}
+	} else
+		deferred = 0;
+
+	if (deferred)
+		bcl->stats.deferred_recv++;
+
 unlock:
 	tipc_node_unlock(node);
 exit:
-- 
1.7.9

[PATCH net-next 08/15] tipc: Fix bug in broadcast link duplicate message statistics

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Modifies broadcast link so that it increments the "received duplicate
message" count if an incoming message cannot be added to the deferred
message queue because it is already present in the queue. (The aligns
broadcast link behavior with that of TIPC's unicast links.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index e7df313..035b350 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -603,6 +603,8 @@ receive:
 
 	if (deferred)
 		bcl->stats.deferred_recv++;
+	else
+		bcl->stats.duplicates++;
 
 unlock:
 	tipc_node_unlock(node);
-- 
1.7.9

[PATCH net-next 09/15] tipc: Add missing locks in broadcast link statistics accumulation

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Ensures that all attempts to update broadcast link statistics are done
only while holding the lock that protects the link's main data structures,
to prevent interference by simultaneous updates caused by messages
arriving on other interfaces.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 035b350..facc216 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -520,6 +520,7 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 
 	if (likely(seqno == next_in)) {
 receive:
+		spin_lock_bh(&bc_lock);
 		bcl->stats.recv_info++;
 		node->bclink.last_in++;
 		bclink_set_gap(node);
@@ -527,7 +528,9 @@ receive:
 			bclink_send_ack(node);
 			bcl->stats.sent_acks++;
 		}
+
 		if (likely(msg_isdata(msg))) {
+			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			if (likely(msg_mcast(msg)))
 				tipc_port_recv_mcast(buf, NULL);
@@ -536,6 +539,7 @@ receive:
 		} else if (msg_user(msg) == MSG_BUNDLER) {
 			bcl->stats.recv_bundles++;
 			bcl->stats.recv_bundled += msg_msgcnt(msg);
+			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			tipc_link_recv_bundle(buf);
 		} else if (msg_user(msg) == MSG_FRAGMENTER) {
@@ -543,12 +547,15 @@ receive:
 			if (tipc_link_recv_fragment(&node->bclink.defragm,
 						    &buf, &msg))
 				bcl->stats.recv_fragmented++;
+			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			tipc_net_route_msg(buf);
 		} else if (msg_user(msg) == NAME_DISTRIBUTOR) {
+			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			tipc_named_recv(buf);
 		} else {
+			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			buf_discard(buf);
 		}
@@ -601,11 +608,15 @@ receive:
 	} else
 		deferred = 0;
 
+	spin_lock_bh(&bc_lock);
+
 	if (deferred)
 		bcl->stats.deferred_recv++;
 	else
 		bcl->stats.duplicates++;
 
+	spin_unlock_bh(&bc_lock);
+
 unlock:
 	tipc_node_unlock(node);
 exit:
-- 
1.7.9

[PATCH net-next 10/15] tipc: Major redesign of broadcast link ACK/NACK algorithms

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Completely redesigns broadcast link ACK and NACK mechanisms to prevent
spurious retransmit requests in dual LAN networks, and to prevent the
broadcast link from stalling due to the failure of a receiving node to
acknowledge receiving a broadcast message or request its retransmission.

Note: These changes only impact the timing of when ACK and NACK messages
are sent, and not the basic broadcast link protocol itself, so inter-
operability with nodes using the "classic" algorithms is maintained.

The revised algorithms are as follows:

1) An explicit ACK message is still sent after receiving 16 in-sequence
messages, and implicit ACK information continues to be carried in other
unicast link message headers (including link state messages).  However,
the timing of explicit ACKs is now based on the receiving node's absolute
network address rather than its relative network address to ensure that
the failure of another node does not delay the ACK beyond its 16 message
target.

2) A NACK message is now typically sent only when a message gap persists
for two consecutive incoming link state messages; this ensures that a
suspected gap is not confirmed until both LANs in a dual LAN network have
had an opportunity to deliver the message, thereby preventing spurious NACKs.
A NACK message can also be generated by the arrival of a single link state
message, if the deferred queue is so big that the current message gap
cannot be the result of "normal" mis-ordering due to the use of dual LANs
(or one LAN using a bonded interface). Since link state messages typically
arrive at different nodes at different times the problem of multiple nodes
issuing identical NACKs simultaneously is inherently avoided.

3) Nodes continue to "peek" at NACK messages sent by other nodes. If
another node requests retransmission of a message gap suspected (but not
yet confirmed) by the peeking node, the peeking node forgets about the
gap and does not generate a duplicate retransmit request. (If the peeking
node subsequently fails to receive the lost message, later link state
messages will cause it to rediscover and confirm the gap and send another
NACK.)

4) Message gap "equality" is now determined by the start of the gap only.
This is sufficient to deal with the most common cases of message loss,
and eliminates the need for complex end of gap computations.

5) A peeking node no longer tries to determine whether it should send a
complementary NACK, since the most common cases of message loss don't
require it to be sent. Consequently, the node no longer examines the
"broadcast tag" field of a NACK message when peeking.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |  226 +++++++++++++++++++-----------------------------------
 net/tipc/bcast.h |    2 +-
 net/tipc/link.c  |   21 +++--
 net/tipc/node.c  |    4 +-
 net/tipc/node.h  |   12 ++--
 5 files changed, 100 insertions(+), 165 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index facc216..1f3b160 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -157,39 +157,14 @@ u32 tipc_bclink_get_last_sent(void)
 	return bcl->fsm_msg_cnt;
 }
 
-/**
- * bclink_set_gap - set gap according to contents of current deferred pkt queue
- *
- * Called with 'node' locked, bc_lock unlocked
- */
-
-static void bclink_set_gap(struct tipc_node *n_ptr)
-{
-	struct sk_buff *buf = n_ptr->bclink.deferred_head;
-
-	n_ptr->bclink.gap_after = n_ptr->bclink.gap_to =
-		mod(n_ptr->bclink.last_in);
-	if (unlikely(buf != NULL))
-		n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1);
-}
-
-/**
- * bclink_ack_allowed - test if ACK or NACK message can be sent at this moment
- *
- * This mechanism endeavours to prevent all nodes in network from trying
- * to ACK or NACK at the same time.
- *
- * Note: TIPC uses a different trigger to distribute ACKs than it does to
- *       distribute NACKs, but tries to use the same spacing (divide by 16).
- */
-
-static int bclink_ack_allowed(u32 n)
+static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
 {
-	return (n % TIPC_MIN_LINK_WIN) == tipc_own_tag;
+	node->bclink.last_sent = less_eq(node->bclink.last_sent, seqno) ?
+						seqno : node->bclink.last_sent;
 }
 
 
-/**
+/*
  * tipc_bclink_retransmit_to - get most recent node to request retransmission
  *
  * Called with bc_lock locked
@@ -300,44 +275,56 @@ exit:
 	spin_unlock_bh(&bc_lock);
 }
 
-/**
- * bclink_send_ack - unicast an ACK msg
+/*
+ * tipc_bclink_update_link_state - update broadcast link state
  *
  * tipc_net_lock and node lock set
  */
 
-static void bclink_send_ack(struct tipc_node *n_ptr)
+void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 {
-	struct tipc_link *l_ptr = n_ptr->active_links[n_ptr->addr & 1];
+	struct sk_buff *buf;
 
-	if (l_ptr != NULL)
-		tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
-}
+	/* Ignore "stale" link state info */
 
-/**
- * bclink_send_nack- broadcast a NACK msg
- *
- * tipc_net_lock and node lock set
- */
+	if (less_eq(last_sent, n_ptr->bclink.last_in))
+		return;
 
-static void bclink_send_nack(struct tipc_node *n_ptr)
-{
-	struct sk_buff *buf;
-	struct tipc_msg *msg;
+	/* 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 (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
+	if ((++n_ptr->bclink.oos_state) == 1) {
+		if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
+			return;
+		n_ptr->bclink.oos_state++;
+	}
+
+	/* 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) {
-		msg = buf_msg(buf);
+		struct tipc_msg *msg = buf_msg(buf);
+
 		tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
-			 INT_H_SIZE, n_ptr->addr);
+			      INT_H_SIZE, n_ptr->addr);
 		msg_set_non_seq(msg, 1);
 		msg_set_mc_netid(msg, tipc_net_id);
-		msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in));
-		msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
-		msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
+		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_bcast_tag(msg, tipc_own_tag);
 
 		spin_lock_bh(&bc_lock);
@@ -346,96 +333,37 @@ static void bclink_send_nack(struct tipc_node *n_ptr)
 		spin_unlock_bh(&bc_lock);
 		buf_discard(buf);
 
-		/*
-		 * Ensure we doesn't send another NACK msg to the node
-		 * until 16 more deferred messages arrive from it
-		 * (i.e. helps prevent all nodes from NACK'ing at same time)
-		 */
-
-		n_ptr->bclink.nack_sync = tipc_own_tag;
+		n_ptr->bclink.oos_state++;
 	}
 }
 
-/**
- * tipc_bclink_check_gap - send a NACK if a sequence gap exists
+/*
+ * bclink_peek_nack - monitor retransmission requests sent by other nodes
  *
- * tipc_net_lock and node lock set
- */
-
-void tipc_bclink_check_gap(struct tipc_node *n_ptr, u32 last_sent)
-{
-	if (!n_ptr->bclink.supported ||
-	    less_eq(last_sent, mod(n_ptr->bclink.last_in)))
-		return;
-
-	bclink_set_gap(n_ptr);
-	if (n_ptr->bclink.gap_after == n_ptr->bclink.gap_to)
-		n_ptr->bclink.gap_to = last_sent;
-	bclink_send_nack(n_ptr);
-}
-
-/**
- * tipc_bclink_peek_nack - process a NACK msg meant for another node
+ * Delay any upcoming NACK by this node if another node has already
+ * requested the first message this node is going to ask for.
  *
  * Only tipc_net_lock set.
  */
 
-static void tipc_bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to)
+static void bclink_peek_nack(struct tipc_msg *msg)
 {
-	struct tipc_node *n_ptr = tipc_node_find(dest);
-	u32 my_after, my_to;
+	struct tipc_node *n_ptr = tipc_node_find(msg_destnode(msg));
 
-	if (unlikely(!n_ptr || !tipc_node_is_up(n_ptr)))
+	if (unlikely(!n_ptr))
 		return;
+
 	tipc_node_lock(n_ptr);
-	/*
-	 * Modify gap to suppress unnecessary NACKs from this node
-	 */
-	my_after = n_ptr->bclink.gap_after;
-	my_to = n_ptr->bclink.gap_to;
-
-	if (less_eq(gap_after, my_after)) {
-		if (less(my_after, gap_to) && less(gap_to, my_to))
-			n_ptr->bclink.gap_after = gap_to;
-		else if (less_eq(my_to, gap_to))
-			n_ptr->bclink.gap_to = n_ptr->bclink.gap_after;
-	} else if (less_eq(gap_after, my_to)) {
-		if (less_eq(my_to, gap_to))
-			n_ptr->bclink.gap_to = gap_after;
-	} else {
-		/*
-		 * Expand gap if missing bufs not in deferred queue:
-		 */
-		struct sk_buff *buf = n_ptr->bclink.deferred_head;
-		u32 prev = n_ptr->bclink.gap_to;
 
-		for (; buf; buf = buf->next) {
-			u32 seqno = buf_seqno(buf);
+	if (n_ptr->bclink.supported &&
+	    (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
+	    (n_ptr->bclink.last_in == msg_bcgap_after(msg)))
+		n_ptr->bclink.oos_state = 2;
 
-			if (mod(seqno - prev) != 1) {
-				buf = NULL;
-				break;
-			}
-			if (seqno == gap_after)
-				break;
-			prev = seqno;
-		}
-		if (buf == NULL)
-			n_ptr->bclink.gap_to = gap_after;
-	}
-	/*
-	 * Some nodes may send a complementary NACK now:
-	 */
-	if (bclink_ack_allowed(sender_tag + 1)) {
-		if (n_ptr->bclink.gap_to != n_ptr->bclink.gap_after) {
-			bclink_send_nack(n_ptr);
-			bclink_set_gap(n_ptr);
-		}
-	}
 	tipc_node_unlock(n_ptr);
 }
 
-/**
+/*
  * tipc_bclink_send_msg - broadcast a packet to all nodes in cluster
  */
 
@@ -505,10 +433,7 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 			spin_unlock_bh(&bc_lock);
 		} else {
 			tipc_node_unlock(node);
-			tipc_bclink_peek_nack(msg_destnode(msg),
-					      msg_bcast_tag(msg),
-					      msg_bcgap_after(msg),
-					      msg_bcgap_to(msg));
+			bclink_peek_nack(msg);
 		}
 		goto exit;
 	}
@@ -519,16 +444,28 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 	next_in = mod(node->bclink.last_in + 1);
 
 	if (likely(seqno == next_in)) {
+		bclink_update_last_sent(node, seqno);
 receive:
+		node->bclink.last_in = seqno;
+		node->bclink.oos_state = 0;
+
 		spin_lock_bh(&bc_lock);
 		bcl->stats.recv_info++;
-		node->bclink.last_in++;
-		bclink_set_gap(node);
-		if (unlikely(bclink_ack_allowed(seqno))) {
-			bclink_send_ack(node);
+
+		/*
+		 * 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_send_proto_msg(
+				node->active_links[node->addr & 1],
+				STATE_MSG, 0, 0, 0, 0, 0);
 			bcl->stats.sent_acks++;
 		}
 
+		/* Deliver message to destination */
+
 		if (likely(msg_isdata(msg))) {
 			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
@@ -567,9 +504,14 @@ receive:
 		if (unlikely(!tipc_node_is_up(node)))
 			goto unlock;
 
-		if (!node->bclink.deferred_head)
+		if (node->bclink.last_in == node->bclink.last_sent)
 			goto unlock;
 
+		if (!node->bclink.deferred_head) {
+			node->bclink.oos_state = 1;
+			goto unlock;
+		}
+
 		msg = buf_msg(node->bclink.deferred_head);
 		seqno = msg_seqno(msg);
 		next_in = mod(next_in + 1);
@@ -580,31 +522,19 @@ receive:
 
 		buf = node->bclink.deferred_head;
 		node->bclink.deferred_head = buf->next;
+		node->bclink.deferred_size--;
 		goto receive;
 	}
 
 	/* Handle out-of-sequence broadcast message */
 
 	if (less(next_in, seqno)) {
-		u32 gap_after = node->bclink.gap_after;
-		u32 gap_to = node->bclink.gap_to;
-
 		deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
 					       &node->bclink.deferred_tail,
 					       buf);
-		if (deferred) {
-			node->bclink.nack_sync++;
-			if (seqno == mod(gap_after + 1))
-				node->bclink.gap_after = seqno;
-			else if (less(gap_after, seqno) && less(seqno, gap_to))
-				node->bclink.gap_to = seqno;
-		}
+		node->bclink.deferred_size += deferred;
+		bclink_update_last_sent(node, seqno);
 		buf = NULL;
-		if (bclink_ack_allowed(node->bclink.nack_sync)) {
-			if (gap_to != gap_after)
-				bclink_send_nack(node);
-			bclink_set_gap(node);
-		}
 	} else
 		deferred = 0;
 
diff --git a/net/tipc/bcast.h b/net/tipc/bcast.h
index b009666..5571394 100644
--- a/net/tipc/bcast.h
+++ b/net/tipc/bcast.h
@@ -96,7 +96,7 @@ int  tipc_bclink_send_msg(struct sk_buff *buf);
 void tipc_bclink_recv_pkt(struct sk_buff *buf);
 u32  tipc_bclink_get_last_sent(void);
 u32  tipc_bclink_acks_missing(struct tipc_node *n_ptr);
-void tipc_bclink_check_gap(struct tipc_node *n_ptr, u32 seqno);
+void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent);
 int  tipc_bclink_stats(char *stats_buf, const u32 buf_size);
 int  tipc_bclink_reset_stats(void);
 int  tipc_bclink_set_queue_limits(u32 limit);
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 1150ba5..cce9537 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1501,14 +1501,13 @@ static void link_retransmit_failure(struct tipc_link *l_ptr,
 		tipc_node_lock(n_ptr);
 
 		tipc_addr_string_fill(addr_string, n_ptr->addr);
-		info("Multicast link info for %s\n", addr_string);
+		info("Broadcast link info for %s\n", addr_string);
 		info("Supportable: %d,  ", n_ptr->bclink.supportable);
 		info("Supported: %d,  ", n_ptr->bclink.supported);
 		info("Acked: %u\n", n_ptr->bclink.acked);
 		info("Last in: %u,  ", n_ptr->bclink.last_in);
-		info("Gap after: %u,  ", n_ptr->bclink.gap_after);
-		info("Gap to: %u\n", n_ptr->bclink.gap_to);
-		info("Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
+		info("Oos state: %u,  ", n_ptr->bclink.oos_state);
+		info("Last sent: %u\n", n_ptr->bclink.last_sent);
 
 		tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
 
@@ -1974,7 +1973,7 @@ void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
 
 	msg_set_type(msg, msg_typ);
 	msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
-	msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
+	msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 	msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
 
 	if (msg_typ == STATE_MSG) {
@@ -2133,8 +2132,12 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
 
 		/* Synchronize broadcast link info, if not done previously */
 
-		if (!tipc_node_is_up(l_ptr->owner))
-			l_ptr->owner->bclink.last_in = msg_last_bcast(msg);
+		if (!tipc_node_is_up(l_ptr->owner)) {
+			l_ptr->owner->bclink.last_sent =
+				l_ptr->owner->bclink.last_in =
+				msg_last_bcast(msg);
+			l_ptr->owner->bclink.oos_state = 0;
+		}
 
 		l_ptr->peer_session = msg_session(msg);
 		l_ptr->peer_bearer_id = msg_bearer_id(msg);
@@ -2181,7 +2184,9 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
 
 		/* Protocol message before retransmits, reduce loss risk */
 
-		tipc_bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
+		if (l_ptr->owner->bclink.supported)
+			tipc_bclink_update_link_state(l_ptr->owner,
+						      msg_last_bcast(msg));
 
 		if (rec_gap || (msg_probe(msg))) {
 			tipc_link_send_proto_msg(l_ptr, STATE_MSG,
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 9196f94..6d8bdfd 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -339,12 +339,12 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 	/* Flush broadcast link info associated with lost node */
 
 	if (n_ptr->bclink.supported) {
-		n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = 0;
 		while (n_ptr->bclink.deferred_head) {
 			struct sk_buff *buf = n_ptr->bclink.deferred_head;
 			n_ptr->bclink.deferred_head = buf->next;
 			buf_discard(buf);
 		}
+		n_ptr->bclink.deferred_size = 0;
 
 		if (n_ptr->bclink.defragm) {
 			buf_discard(n_ptr->bclink.defragm);
@@ -450,7 +450,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 
 	read_lock_bh(&tipc_net_lock);
 
-	/* Get space for all unicast links + multicast link */
+	/* Get space for all unicast links + broadcast link */
 
 	payload_size = TLV_SPACE(sizeof(link_info)) *
 		(atomic_read(&tipc_num_links) + 1);
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 90689f4..c88ce64 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -66,9 +66,9 @@
  *    @supported: non-zero if node supports TIPC b'cast capability
  *    @acked: sequence # of last outbound b'cast message acknowledged by node
  *    @last_in: sequence # of last in-sequence b'cast message received from node
- *    @gap_after: sequence # of last message not requiring a NAK request
- *    @gap_to: sequence # of last message requiring a NAK request
- *    @nack_sync: counter that determines when NAK requests should be sent
+ *    @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
  *    @defragm: list of partially reassembled b'cast message fragments from node
@@ -91,9 +91,9 @@ struct tipc_node {
 		u8 supported;
 		u32 acked;
 		u32 last_in;
-		u32 gap_after;
-		u32 gap_to;
-		u32 nack_sync;
+		u32 last_sent;
+		u32 oos_state;
+		u32 deferred_size;
 		struct sk_buff *deferred_head;
 		struct sk_buff *deferred_tail;
 		struct sk_buff *defragm;
-- 
1.7.9

[PATCH net-next 11/15] tipc: Remove obsolete broadcast tag capability

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Eliminates support for the broadcast tag field, which is no longer
used by broadcast link NACK messages.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |    1 -
 net/tipc/node.c  |    7 +------
 net/tipc/node.h  |    2 --
 3 files changed, 1 insertions(+), 9 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 1f3b160..a9b7132 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -325,7 +325,6 @@ void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 		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_bcast_tag(msg, tipc_own_tag);
 
 		spin_lock_bh(&bc_lock);
 		tipc_bearer_send(&bcbearer->bearer, buf, NULL);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 6d8bdfd..7bc45e1 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -49,9 +49,8 @@ LIST_HEAD(tipc_node_list);
 static u32 tipc_num_nodes;
 
 static atomic_t tipc_num_links = ATOMIC_INIT(0);
-u32 tipc_own_tag;
 
-/**
+/*
  * tipc_node_find - locate specified node object, if it exists
  */
 
@@ -309,8 +308,6 @@ static void node_established_contact(struct tipc_node *n_ptr)
 	if (n_ptr->bclink.supportable) {
 		tipc_bclink_add_node(n_ptr->addr);
 		n_ptr->bclink.supported = 1;
-		if (n_ptr->addr < tipc_own_addr)
-			tipc_own_tag++;
 	}
 }
 
@@ -353,8 +350,6 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 
 		tipc_bclink_remove_node(n_ptr->addr);
 		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
-		if (n_ptr->addr < tipc_own_addr)
-			tipc_own_tag--;
 
 		n_ptr->bclink.supported = 0;
 	}
diff --git a/net/tipc/node.h b/net/tipc/node.h
index c88ce64..e1b78a2 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -114,8 +114,6 @@ static inline unsigned int tipc_hashfn(u32 addr)
 	return addr & (NODE_HTABLE_SIZE - 1);
 }
 
-extern u32 tipc_own_tag;
-
 struct tipc_node *tipc_node_find(u32 addr);
 struct tipc_node *tipc_node_create(u32 addr);
 void tipc_node_delete(struct tipc_node *n_ptr);
-- 
1.7.9

[PATCH net-next 12/15] tipc: Prevent loss of fragmented messages over unicast links

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Modifies unicast link endpoint logic so an incoming fragmented message
is not lost if reassembly cannot begin because there is no buffer big
enough to hold the entire reassembled message. The link endpoint now
ignores the first fragment completely, which causes the sending node to
retransmit the first fragment so that reassembly can be re-attempted.

Previously, the sender would have had no reason to retransmit the 1st
fragment, so we would never have a chance to re-try the allocation.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
---
 net/tipc/link.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index cce9537..d8b0a22 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1774,6 +1774,7 @@ protocol_check:
 					head = link_insert_deferred_queue(l_ptr,
 									  head);
 				if (likely(msg_is_dest(msg, tipc_own_addr))) {
+					int ret;
 deliver:
 					if (likely(msg_isdata(msg))) {
 						tipc_node_unlock(n_ptr);
@@ -1798,11 +1799,15 @@ deliver:
 						continue;
 					case MSG_FRAGMENTER:
 						l_ptr->stats.recv_fragments++;
-						if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
-									    &buf, &msg)) {
+						ret = tipc_link_recv_fragment(
+							&l_ptr->defragm_buf,
+							&buf, &msg);
+						if (ret == 1) {
 							l_ptr->stats.recv_fragmented++;
 							goto deliver;
 						}
+						if (ret == -1)
+							l_ptr->next_in_no--;
 						break;
 					case CHANGEOVER_PROTOCOL:
 						type = msg_type(msg);
@@ -2632,7 +2637,9 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
 			set_fragm_size(pbuf, fragm_sz);
 			set_expected_frags(pbuf, exp_fragm_cnt - 1);
 		} else {
-			warn("Link unable to reassemble fragmented message\n");
+			dbg("Link unable to reassemble fragmented message\n");
+			buf_discard(fbuf);
+			return -1;
 		}
 		buf_discard(fbuf);
 		return 0;
-- 
1.7.9

[PATCH net-next 13/15] tipc: Prevent loss of fragmented messages over broadcast link

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Modifies broadcast link so that an incoming fragmented message is not
lost if reassembly cannot begin because there currently is no buffer
big enough to hold the entire reassembled message. The broadcast link
now ignores the first fragment completely, which causes the sending node
to retransmit the first fragment so that reassembly can be re-attempted.

Previously, the sender would have had no reason to retransmit the 1st
fragment, so we would never have a chance to re-try the allocation.

To do this cleanly without duplicaton, a new bclink_accept_pkt()
function is introduced.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/bcast.c |   64 +++++++++++++++++++++++++++++++++++------------------
 1 files changed, 42 insertions(+), 22 deletions(-)

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index a9b7132..41ecf31 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -389,7 +389,33 @@ exit:
 	return res;
 }
 
-/**
+/*
+ * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
+ *
+ * Called with both sending node's lock and bc_lock taken.
+ */
+
+static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
+{
+	bclink_update_last_sent(node, seqno);
+	node->bclink.last_in = seqno;
+	node->bclink.oos_state = 0;
+	bcl->stats.recv_info++;
+
+	/*
+	 * 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_send_proto_msg(
+			node->active_links[node->addr & 1],
+			STATE_MSG, 0, 0, 0, 0, 0);
+		bcl->stats.sent_acks++;
+	}
+}
+
+/*
  * tipc_bclink_recv_pkt - receive a broadcast packet, and deliver upwards
  *
  * tipc_net_lock is read_locked, no other locks set
@@ -443,29 +469,12 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
 	next_in = mod(node->bclink.last_in + 1);
 
 	if (likely(seqno == next_in)) {
-		bclink_update_last_sent(node, seqno);
 receive:
-		node->bclink.last_in = seqno;
-		node->bclink.oos_state = 0;
-
-		spin_lock_bh(&bc_lock);
-		bcl->stats.recv_info++;
-
-		/*
-		 * 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_send_proto_msg(
-				node->active_links[node->addr & 1],
-				STATE_MSG, 0, 0, 0, 0, 0);
-			bcl->stats.sent_acks++;
-		}
-
 		/* Deliver message to destination */
 
 		if (likely(msg_isdata(msg))) {
+			spin_lock_bh(&bc_lock);
+			bclink_accept_pkt(node, seqno);
 			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			if (likely(msg_mcast(msg)))
@@ -473,24 +482,35 @@ receive:
 			else
 				buf_discard(buf);
 		} else if (msg_user(msg) == MSG_BUNDLER) {
+			spin_lock_bh(&bc_lock);
+			bclink_accept_pkt(node, seqno);
 			bcl->stats.recv_bundles++;
 			bcl->stats.recv_bundled += msg_msgcnt(msg);
 			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			tipc_link_recv_bundle(buf);
 		} else if (msg_user(msg) == MSG_FRAGMENTER) {
+			int ret = tipc_link_recv_fragment(&node->bclink.defragm,
+						      &buf, &msg);
+			if (ret < 0)
+				goto unlock;
+			spin_lock_bh(&bc_lock);
+			bclink_accept_pkt(node, seqno);
 			bcl->stats.recv_fragments++;
-			if (tipc_link_recv_fragment(&node->bclink.defragm,
-						    &buf, &msg))
+			if (ret > 0)
 				bcl->stats.recv_fragmented++;
 			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			tipc_net_route_msg(buf);
 		} else if (msg_user(msg) == NAME_DISTRIBUTOR) {
+			spin_lock_bh(&bc_lock);
+			bclink_accept_pkt(node, seqno);
 			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			tipc_named_recv(buf);
 		} else {
+			spin_lock_bh(&bc_lock);
+			bclink_accept_pkt(node, seqno);
 			spin_unlock_bh(&bc_lock);
 			tipc_node_unlock(node);
 			buf_discard(buf);
-- 
1.7.9

[PATCH net-next 14/15] tipc: Eliminate alteration of publication key during name table purging

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Removes code that alters the publication key of a name table entry
that is being forcibly purged from TIPC's name table after contact
with the publishing node has been lost.

Current TIPC ensures that all defunct names are purged before
re-establishing contact with a failed node.  There used to be a risk
that the publication might be accidentally deleted because it might be
re-added to the name table before the purge operation was completed.
But now there is no longer a need to ensure that the new key is different
than the old one.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/name_distr.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c
index 98ebb37..acecfda 100644
--- a/net/tipc/name_distr.c
+++ b/net/tipc/name_distr.c
@@ -239,9 +239,6 @@ exit:
  *
  * Invoked for each publication issued by a newly failed node.
  * Removes publication structure from name table & deletes it.
- * In rare cases the link may have come back up again when this
- * function is called, and we have two items representing the same
- * publication. Nudge this item's key to distinguish it from the other.
  */
 
 static void named_purge_publ(struct publication *publ)
@@ -249,7 +246,6 @@ static void named_purge_publ(struct publication *publ)
 	struct publication *p;
 
 	write_lock_bh(&tipc_nametbl_lock);
-	publ->key += 1222345;
 	p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 				     publ->node, publ->ref, publ->key);
 	if (p)
-- 
1.7.9

[PATCH net-next 15/15] tipc: Minor optimization to rejection of connection-based messages

[Paul Gortmaker]

From: Allan Stephens <allan.stephens@windriver.com>

Modifies message rejection logic so that TIPC doesn't attempt to
send a FIN message to the rejecting port if it is known in advance
that there is no such message because the rejecting port doesn't exist.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 net/tipc/port.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/tipc/port.c b/net/tipc/port.c
index d91efc6..ba3268b 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -400,15 +400,16 @@ int tipc_reject_msg(struct sk_buff *buf, u32 err)
 
 	/* send self-abort message when rejecting on a connected port */
 	if (msg_connected(msg)) {
-		struct sk_buff *abuf = NULL;
 		struct tipc_port *p_ptr = tipc_port_lock(msg_destport(msg));
 
 		if (p_ptr) {
+			struct sk_buff *abuf = NULL;
+
 			if (p_ptr->connected)
 				abuf = port_build_self_abort_msg(p_ptr, err);
 			tipc_port_unlock(p_ptr);
+			tipc_net_route_msg(abuf);
 		}
-		tipc_net_route_msg(abuf);
 	}
 
 	/* send returned message & dispose of rejected message */
-- 
1.7.9

Re: [PATCH net-next 00/15] TIPC updates for upcoming v3.4

[David Miller]

From: Paul Gortmaker <paul.gortmaker@windriver.com>
Date: Mon,  6 Feb 2012 19:52:33 -0500

> No real trend or correlation from one patch to the next here,
> just continued chiseling away at what were deemed to be the
> worthwhile bits that were squirreled away on sourceforge.
> I think there is on the order of 50 left after this.
> 
> I haven't forgot about your earlier request to see some of
> the tipc_printbuf related stuff go away (at least I think that
> was what you wanted to see replaced).  I'm not entirely 100%
> sure how to proceed there just yet, so I may tackle a few
> more from the remaining 50 in the interim while the log.c
> cleanup gets more thought.
> 
> Runtime tested from 64 to 32 bit x86 machines; I had to revert
> an skge commit to get my 32 bit machine functional, but that
> is largely of no interest here.

Pulled, thanks Paul.