[PATCH 3.2 105/149] resubmit bridge: fix message_age_timercalculation

[Ben Hutchings]

3.2.52-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Chris Healy <cphealy@xxxxxxxxx>

[ Upstream commit 9a0620133ccce9dd35c00a96405c8d80938c2cc0 ]

This changes the message_age_timer calculation to use the BPDU's max age as
opposed to the local bridge's max age.  This is in accordance with section
8.6.2.3.2 Step 2 of the 802.1D-1998 sprecification.

With the current implementation, when running with very large bridge
diameters, convergance will not always occur even if a root bridge is
configured to have a longer max age.

Tested successfully on bridge diameters of ~200.

Signed-off-by: Chris Healy <cphealy@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 net/bridge/br_stp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index dd147d7..8ac946f 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c
@@ -189,7 +189,7 @@ static void br_record_config_information(struct net_bridge_port *p,
 	p->designated_age = jiffies + bpdu->message_age;
 
 	mod_timer(&p->message_age_timer, jiffies
-		  + (p->br->max_age - bpdu->message_age));
+		  + (bpdu->max_age - bpdu->message_age));
 }
 
 /* called under bridge lock */

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