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tipc: initialize broadcast link stale counter correctly

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In the commit referred to below we added link tolerance as an additional
criteria for declaring broadcast transmission "stale" and resetting the
unicast links to the affected node.

Unfortunately, this 'improvement' introduced two bugs, which each and
one alone cause only limited problems, but combined lead to seemingly
stochastic unicast link resets, depending on the amount of broadcast
traffic transmitted.

The first issue, a missing initialization of the 'tolerance' field of
the receiver broadcast link, was recently fixed by commit 047491ea33
("tipc: set link tolerance correctly in broadcast link").

Ths second issue, where we omit to reset the 'stale_cnt' field of
the same link after a 'stale' period is over, leads to this counter
accumulating over time, and in the absence of the 'tolerance' criteria
leads to the above described symptoms. This commit adds the missing
initialization.

Fixes: a4dc70d46c ("tipc: extend link reset criteria for stale packet retransmission")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jon Maloy 2018-10-11 22:02:29 +02:00 committed by David S. Miller
parent 5a8e7aea95
commit 4af00f4cc1
1 changed files with 1 additions and 0 deletions
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net/tipc/link.c
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@ -1041,6 +1041,7 @@ static int tipc_link_retrans(struct tipc_link *l, struct tipc_link *r,
if (r->last_retransm != buf_seqno(skb)) {
r->last_retransm = buf_seqno(skb);
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);
if (link_is_bc_sndlink(l))