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-rw-r--r--net/sched/sch_generic.c35
1 files changed, 12 insertions, 23 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 52eb3439d7c..3385ee59254 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -36,34 +36,27 @@
/* Main transmission queue. */
-/* Main qdisc structure lock.
-
- However, modifications
- to data, participating in scheduling must be additionally
- protected with dev->queue_lock spinlock.
-
- The idea is the following:
- - enqueue, dequeue are serialized via top level device
- spinlock dev->queue_lock.
- - tree walking is protected by read_lock(qdisc_tree_lock)
- and this lock is used only in process context.
- - updates to tree are made only under rtnl semaphore,
- hence this lock may be made without local bh disabling.
-
- qdisc_tree_lock must be grabbed BEFORE dev->queue_lock!
+/* Modifications to data participating in scheduling must be protected with
+ * dev->queue_lock spinlock.
+ *
+ * The idea is the following:
+ * - enqueue, dequeue are serialized via top level device
+ * spinlock dev->queue_lock.
+ * - ingress filtering is serialized via top level device
+ * spinlock dev->ingress_lock.
+ * - updates to tree and tree walking are only done under the rtnl mutex.
*/
-DEFINE_RWLOCK(qdisc_tree_lock);
void qdisc_lock_tree(struct net_device *dev)
{
- write_lock(&qdisc_tree_lock);
spin_lock_bh(&dev->queue_lock);
+ spin_lock(&dev->ingress_lock);
}
void qdisc_unlock_tree(struct net_device *dev)
{
+ spin_unlock(&dev->ingress_lock);
spin_unlock_bh(&dev->queue_lock);
- write_unlock(&qdisc_tree_lock);
}
/*
@@ -442,7 +435,6 @@ struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops)
sch->dequeue = ops->dequeue;
sch->dev = dev;
dev_hold(dev);
- sch->stats_lock = &dev->queue_lock;
atomic_set(&sch->refcnt, 1);
return sch;
@@ -458,6 +450,7 @@ struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops,
sch = qdisc_alloc(dev, ops);
if (IS_ERR(sch))
goto errout;
+ sch->stats_lock = &dev->queue_lock;
sch->parent = parentid;
if (!ops->init || ops->init(sch, NULL) == 0)
@@ -528,15 +521,11 @@ void dev_activate(struct net_device *dev)
printk(KERN_INFO "%s: activation failed\n", dev->name);
return;
}
- write_lock(&qdisc_tree_lock);
list_add_tail(&qdisc->list, &dev->qdisc_list);
- write_unlock(&qdisc_tree_lock);
} else {
qdisc = &noqueue_qdisc;
}
- write_lock(&qdisc_tree_lock);
dev->qdisc_sleeping = qdisc;
- write_unlock(&qdisc_tree_lock);
}
if (!netif_carrier_ok(dev))