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Commit ae638c47 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

pkt_sched: gen_estimator: add a new lock 



gen_kill_estimator() / gen_new_estimator() is not always called with
RTNL held.

net/netfilter/xt_RATEEST.c is one user of these API that do not hold
RTNL, so random corruptions can occur between "tc" and "iptables".

Add a new fine grained lock instead of trying to use RTNL in netfilter.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 597a264b

net/core/gen_estimator.c

+12 −3
Original line number Diff line number Diff line
@@ -107,6 +107,7 @@ static DEFINE_RWLOCK(est_lock); 


/* Protects against soft lockup during large deletion */

static struct rb_root est_root = RB_ROOT;

static DEFINE_SPINLOCK(est_tree_lock);



static void est_timer(unsigned long arg)

{
@@ -201,7 +202,6 @@ struct gen_estimator *gen_find_node(const struct gnet_stats_basic_packed *bstats 
 *

 * Returns 0 on success or a negative error code.

 *

 * NOTE: Called under rtnl_mutex

 */

int gen_new_estimator(struct gnet_stats_basic_packed *bstats,

		      struct gnet_stats_rate_est *rate_est,
@@ -232,6 +232,7 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats, 
	est->last_packets = bstats->packets;

	est->avpps = rate_est->pps<<10;



	spin_lock(&est_tree_lock);

	if (!elist[idx].timer.function) {

		INIT_LIST_HEAD(&elist[idx].list);

		setup_timer(&elist[idx].timer, est_timer, idx);
@@ -242,6 +243,7 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats, 


	list_add_rcu(&est->list, &elist[idx].list);

	gen_add_node(est);

	spin_unlock(&est_tree_lock);



	return 0;

}
@@ -261,13 +263,13 @@ static void __gen_kill_estimator(struct rcu_head *head) 
 *

 * Removes the rate estimator specified by &bstats and &rate_est.

 *

 * NOTE: Called under rtnl_mutex

 */

void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,

			struct gnet_stats_rate_est *rate_est)

{

	struct gen_estimator *e;



	spin_lock(&est_tree_lock);

	while ((e = gen_find_node(bstats, rate_est))) {

		rb_erase(&e->node, &est_root);
@@ -278,6 +280,7 @@ void gen_kill_estimator(struct gnet_stats_basic_packed *bstats, 
		list_del_rcu(&e->list);

		call_rcu(&e->e_rcu, __gen_kill_estimator);

	}

	spin_unlock(&est_tree_lock);

}

EXPORT_SYMBOL(gen_kill_estimator);
@@ -312,8 +315,14 @@ EXPORT_SYMBOL(gen_replace_estimator); 
bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats,

			  const struct gnet_stats_rate_est *rate_est)

{

	bool res;



	ASSERT_RTNL();



	return gen_find_node(bstats, rate_est) != NULL;

	spin_lock(&est_tree_lock);

	res = gen_find_node(bstats, rate_est) != NULL;

	spin_unlock(&est_tree_lock);



	return res;

}

EXPORT_SYMBOL(gen_estimator_active);