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: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jarek Poplawski 2008-08-13 15:20:24 -07:00 committed by David S. Miller
parent b9a3b1102b
commit d4766692e7

View file

@ -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);
}
}