[patch 18/29] ipvs: fix dst_lock locking on dest update

From: Greg KH
Date: Thu Mar 10 2011 - 18:59:54 EST


2.6.37-stable review patch. If anyone has any objections, please let us know.

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

From: Julian Anastasov <ja@xxxxxx>

commit ff75f40f44ae9b79d520bf32a05d35af74a805c0 upstream.

Fix dst_lock usage in __ip_vs_update_dest. We need
_bh locking because destination is updated in user context.
Can cause lockups on frequent destination updates.
Problem reported by Simon Kirby. Bug was introduced
in 2.6.37 from the "ipvs: changes for local real server"
change.

Signed-off-by: Julian Anastasov <ja@xxxxxx>
Signed-off-by: Hans Schillstrom <hans@xxxxxxxxxxxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
Cc: Simon Kirby <sim@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
net/netfilter/ipvs/ip_vs_ctl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -810,9 +810,9 @@ __ip_vs_update_dest(struct ip_vs_service
dest->u_threshold = udest->u_threshold;
dest->l_threshold = udest->l_threshold;

- spin_lock(&dest->dst_lock);
+ spin_lock_bh(&dest->dst_lock);
ip_vs_dst_reset(dest);
- spin_unlock(&dest->dst_lock);
+ spin_unlock_bh(&dest->dst_lock);

if (add)
ip_vs_new_estimator(&dest->stats);


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