Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d4766692 authored by Jarek Poplawski's avatar Jarek Poplawski Committed by David S. Miller
Browse files

pkt_sched: Protect gen estimators under est_lock. 



gen_kill_estimator() required rtnl_lock() protection, but since it is
moved to an RCU callback __qdisc_destroy() let's use est_lock instead.

Signed-off-by: default avatarJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9a3b110

net/core/gen_estimator.c

+5 −4
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ struct gen_estimator_head 


static struct gen_estimator_head elist[EST_MAX_INTERVAL+1];



/* Protects against NULL dereference */

/* Protects against NULL dereference and RCU write-side */

static DEFINE_RWLOCK(est_lock);



static void est_timer(unsigned long arg)
@@ -185,6 +185,7 @@ int gen_new_estimator(struct gnet_stats_basic *bstats, 
	est->last_packets = bstats->packets;

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



	write_lock_bh(&est_lock);

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

		INIT_LIST_HEAD(&elist[idx].list);

		setup_timer(&elist[idx].timer, est_timer, idx);
@@ -194,6 +195,7 @@ int gen_new_estimator(struct gnet_stats_basic *bstats, 
		mod_timer(&elist[idx].timer, jiffies + ((HZ/4) << idx));



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

	write_unlock_bh(&est_lock);

	return 0;

}
@@ -212,7 +214,6 @@ static void __gen_kill_estimator(struct rcu_head *head) 
 * Removes the rate estimator specified by &bstats and &rate_est

 * and deletes the timer.

 *

 * NOTE: Called under rtnl_mutex

 */

void gen_kill_estimator(struct gnet_stats_basic *bstats,

	struct gnet_stats_rate_est *rate_est)
@@ -226,17 +227,17 @@ void gen_kill_estimator(struct gnet_stats_basic *bstats, 
		if (!elist[idx].timer.function)

			continue;



		write_lock_bh(&est_lock);

		list_for_each_entry_safe(e, n, &elist[idx].list, list) {

			if (e->rate_est != rate_est || e->bstats != bstats)

				continue;



			write_lock_bh(&est_lock);

			e->bstats = NULL;

			write_unlock_bh(&est_lock);



			list_del_rcu(&e->list);

			call_rcu(&e->e_rcu, __gen_kill_estimator);

		}

		write_unlock_bh(&est_lock);

	}

}