net: qdisc: use rcu prefix and silence sparse warnings
Add __rcu notation to qdisc handling by doing this we can make
smatch output more legible. And anyways some of the cases should
be using rcu_dereference() see qdisc_all_tx_empty(),
qdisc_tx_chainging(), and so on.
Also *wake_queue() API is commonly called from driver timer routines
without rcu lock or rtnl lock. So I added rcu_read_lock() blocks
around netif_wake_subqueue and netif_tx_wake_queue.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index aaa8d03..5cd291b 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -96,11 +96,14 @@
struct teql_sched_data *dat = qdisc_priv(sch);
struct netdev_queue *dat_queue;
struct sk_buff *skb;
+ struct Qdisc *q;
skb = __skb_dequeue(&dat->q);
dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
+ q = rcu_dereference_bh(dat_queue->qdisc);
+
if (skb == NULL) {
- struct net_device *m = qdisc_dev(dat_queue->qdisc);
+ struct net_device *m = qdisc_dev(q);
if (m) {
dat->m->slaves = sch;
netif_wake_queue(m);
@@ -108,7 +111,7 @@
} else {
qdisc_bstats_update(sch, skb);
}
- sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
+ sch->q.qlen = dat->q.qlen + q->q.qlen;
return skb;
}
@@ -157,9 +160,9 @@
txq = netdev_get_tx_queue(master->dev, 0);
master->slaves = NULL;
- root_lock = qdisc_root_sleeping_lock(txq->qdisc);
+ root_lock = qdisc_root_sleeping_lock(rtnl_dereference(txq->qdisc));
spin_lock_bh(root_lock);
- qdisc_reset(txq->qdisc);
+ qdisc_reset(rtnl_dereference(txq->qdisc));
spin_unlock_bh(root_lock);
}
}
@@ -266,7 +269,7 @@
struct dst_entry *dst = skb_dst(skb);
int res;
- if (txq->qdisc == &noop_qdisc)
+ if (rcu_access_pointer(txq->qdisc) == &noop_qdisc)
return -ENODEV;
if (!dev->header_ops || !dst)