net: sched: lock action when translating it to flow_action infra

In order to remove dependency on rtnl lock, take action's tcfa_lock when
constructing its representation as flow_action_entry structure.

Refactor tcf_sample_get_group() to assume that caller holds tcf_lock and
don't take it manually. This callback is only called from flow_action infra
representation translator which now calls it with tcf_lock held, so this
refactoring is necessary to prevent deadlock.

Allocate memory with GFP_ATOMIC flag for ip_tunnel_info copy because
tcf_tunnel_info_copy() is only called from flow_action representation infra
code with tcf_lock spinlock taken.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 2 deletions

diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index ce948c1e24dc..5e2df590bb58 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -267,14 +267,12 @@ tcf_sample_get_group(const struct tc_action *a,
 	struct tcf_sample *s = to_sample(a);
 	struct psample_group *group;
 
-	spin_lock_bh(&s->tcf_lock);
 	group = rcu_dereference_protected(s->psample_group,
 					  lockdep_is_held(&s->tcf_lock));
 	if (group) {
 		psample_group_take(group);
 		*destructor = tcf_psample_group_put;
 	}
-	spin_unlock_bh(&s->tcf_lock);
 
 	return group;
 }