Commit 6a6b5c8b authored by Tuong Lien's avatar Tuong Lien Committed by David S. Miller
Browse files

tipc: include retrans failure detection for unicast 



In patch series, commit 9195948f ("tipc: improve TIPC throughput by
Gap ACK blocks"), as for simplicity, the repeated retransmit failures'
detection in the function - "tipc_link_retrans()" was kept there for
broadcast retransmissions only.

This commit now reapplies this feature for link unicast retransmissions
that has been done via the function - "tipc_link_advance_transmq()".

Also, the "tipc_link_retrans()" is renamed to "tipc_link_bc_retrans()"
as it is used only for broadcast.

Acked-by: default avatarJon Maloy <jon.maloy@ericsson.se>
Signed-off-by: default avatarTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9ed68ca0

net/tipc/link.c

+70 −36
Original line number Diff line number Diff line
@@ -249,7 +249,7 @@ static void tipc_link_build_bc_init_msg(struct tipc_link *l, 
					struct sk_buff_head *xmitq);

static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);

static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data);

static void tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,

static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,

				     struct tipc_gap_ack_blks *ga,

				     struct sk_buff_head *xmitq);
@@ -1044,32 +1044,69 @@ static void tipc_link_advance_backlog(struct tipc_link *l, 
	l->snd_nxt = seqno;

}



static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)

/**

 * link_retransmit_failure() - Detect repeated retransmit failures

 * @l: tipc link sender

 * @r: tipc link receiver (= l in case of unicast)

 * @from: seqno of the 1st packet in retransmit request

 * @rc: returned code

 *

 * Return: true if the repeated retransmit failures happens, otherwise

 * false

 */

static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,

				    u16 from, int *rc)

{

	struct tipc_msg *hdr = buf_msg(skb);

	struct sk_buff *skb = skb_peek(&l->transmq);

	struct tipc_msg *hdr;



	if (!skb)

		return false;

	hdr = buf_msg(skb);



	/* Detect repeated retransmit failures on same packet */

	if (r->prev_from != from) {

		r->prev_from = from;

		r->stale_limit = jiffies + msecs_to_jiffies(r->tolerance);

		r->stale_cnt = 0;

	} else if (++r->stale_cnt > 99 && time_after(jiffies, r->stale_limit)) {

		pr_warn("Retransmission failure on link <%s>\n", l->name);

		link_print(l, "State of link ");

		pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",

		msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));

			msg_user(hdr), msg_type(hdr), msg_size(hdr),

			msg_errcode(hdr));

		pr_info("sqno %u, prev: %x, src: %x\n",

			msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));



		trace_tipc_list_dump(&l->transmq, true, "retrans failure!");

		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");

		trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");



		if (link_is_bc_sndlink(l))

			*rc = TIPC_LINK_DOWN_EVT;



		*rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);

		return true;

	}



	return false;

}



/* tipc_link_retrans() - retransmit one or more packets

/* tipc_link_bc_retrans() - retransmit zero or more packets

 * @l: the link to transmit on

 * @r: the receiving link ordering the retransmit. Same as l if unicast

 * @from: retransmit from (inclusive) this sequence number

 * @to: retransmit to (inclusive) this sequence number

 * xmitq: queue for accumulating the retransmitted packets

 */

static int tipc_link_retrans(struct tipc_link *l, struct tipc_link *r,

static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,

				u16 from, u16 to, struct sk_buff_head *xmitq)

{

	struct sk_buff *_skb, *skb = skb_peek(&l->transmq);

	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;

	u16 ack = l->rcv_nxt - 1;

	struct tipc_msg *hdr;

	int rc = 0;



	if (!skb)

		return 0;
@@ -1077,20 +1114,9 @@ static int tipc_link_retrans(struct tipc_link *l, struct tipc_link *r, 
		return 0;



	trace_tipc_link_retrans(r, from, to, &l->transmq);

	/* Detect repeated retransmit failures on same packet */

	if (r->prev_from != from) {

		r->prev_from = from;

		r->stale_limit = jiffies + msecs_to_jiffies(r->tolerance);

		r->stale_cnt = 0;

	} else if (++r->stale_cnt > 99 && time_after(jiffies, r->stale_limit)) {

		link_retransmit_failure(l, skb);

		trace_tipc_list_dump(&l->transmq, true, "retrans failure!");

		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");

		trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");

		if (link_is_bc_sndlink(l))

			return TIPC_LINK_DOWN_EVT;

		return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);

	}



	if (link_retransmit_failure(l, r, from, &rc))

		return rc;



	skb_queue_walk(&l->transmq, skb) {

		hdr = buf_msg(skb);
@@ -1324,8 +1350,11 @@ exit: 
 * @gap: # of gap packets

 * @ga: buffer pointer to Gap ACK blocks from peer

 * @xmitq: queue for accumulating the retransmitted packets if any

 *

 * In case of a repeated retransmit failures, the call will return shortly

 * with a returned code (e.g. TIPC_LINK_DOWN_EVT)

 */

static void tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,

static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,

				     struct tipc_gap_ack_blks *ga,

				     struct sk_buff_head *xmitq)

{
@@ -1333,8 +1362,11 @@ static void tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap, 
	struct tipc_msg *hdr;

	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;

	u16 ack = l->rcv_nxt - 1;

	u16 seqno;

	u16 n = 0;

	u16 seqno, n = 0;

	int rc = 0;



	if (gap && link_retransmit_failure(l, l, acked + 1, &rc))

		return rc;



	skb_queue_walk_safe(&l->transmq, skb, tmp) {

		seqno = buf_seqno(skb);
@@ -1369,6 +1401,8 @@ next_gap_ack: 
			goto next_gap_ack;

		}

	}



	return 0;

}



/* tipc_link_build_state_msg: prepare link state message for transmission
@@ -1919,7 +1953,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, 
			tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,

						  rcvgap, 0, 0, xmitq);



		tipc_link_advance_transmq(l, ack, gap, ga, xmitq);

		rc |= tipc_link_advance_transmq(l, ack, gap, ga, xmitq);



		/* If NACK, retransmit will now start at right position */

		if (gap)
@@ -2036,7 +2070,7 @@ int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, 
	if (more(peers_snd_nxt, l->rcv_nxt + l->window))

		return rc;



	rc = tipc_link_retrans(snd_l, l, from, to, xmitq);

	rc = tipc_link_bc_retrans(snd_l, l, from, to, xmitq);



	l->snd_nxt = peers_snd_nxt;

	if (link_bc_rcv_gap(l))
@@ -2132,7 +2166,7 @@ int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb, 


	if (dnode == tipc_own_addr(l->net)) {

		tipc_link_bc_ack_rcv(l, acked, xmitq);

		rc = tipc_link_retrans(l->bc_sndlink, l, from, to, xmitq);

		rc = tipc_link_bc_retrans(l->bc_sndlink, l, from, to, xmitq);

		l->stats.recv_nacks++;

		return rc;

	}

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