From 9e4e948a3edafd2b7f4dc14c395e146ffd0d9611 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Wed, 9 Oct 2013 09:24:27 +0300 Subject: ipvs: avoid rcu_barrier during netns cleanup commit 578bc3ef1e473a ("ipvs: reorganize dest trash") added rcu_barrier() on cleanup to wait dest users and schedulers like LBLC and LBLCR to put their last dest reference. Using rcu_barrier with many namespaces is problematic. Trying to fix it by freeing dest with kfree_rcu is not a solution, RCU callbacks can run in parallel and execution order is random. Fix it by creating new function ip_vs_dest_put_and_free() which is heavier than ip_vs_dest_put(). We will use it just for schedulers like LBLC, LBLCR that can delay their dest release. By default, dests reference is above 0 if they are present in service and it is 0 when deleted but still in trash list. Change the dest trash code to use ip_vs_dest_put_and_free(), so that refcnt -1 can be used for freeing. As result, such checks remain in slow path and the rcu_barrier() from netns cleanup can be removed. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_lblcr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/netfilter/ipvs/ip_vs_lblcr.c') diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c index 0b8550089a2e..3f21a2f47de1 100644 --- a/net/netfilter/ipvs/ip_vs_lblcr.c +++ b/net/netfilter/ipvs/ip_vs_lblcr.c @@ -130,7 +130,7 @@ static void ip_vs_lblcr_elem_rcu_free(struct rcu_head *head) struct ip_vs_dest_set_elem *e; e = container_of(head, struct ip_vs_dest_set_elem, rcu_head); - ip_vs_dest_put(e->dest); + ip_vs_dest_put_and_free(e->dest); kfree(e); } -- cgit v1.2.3