net: rcu-ify tcf_proto
rcu'ify tcf_proto this allows calling tc_classify() without holding
any locks. Updaters are protected by RTNL.
This patch prepares the core net_sched infrastracture for running
the classifier/action chains without holding the qdisc lock however
it does nothing to ensure cls_xxx and act_xxx types also work without
locking. Additional patches are required to address the fall out.
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_qfq.c b/net/sched/sch_qfq.c
index 8056fb4..602ea01 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -181,7 +181,7 @@
};
struct qfq_sched {
- struct tcf_proto *filter_list;
+ struct tcf_proto __rcu *filter_list;
struct Qdisc_class_hash clhash;
u64 oldV, V; /* Precise virtual times. */
@@ -576,7 +576,8 @@
qfq_destroy_class(sch, cl);
}
-static struct tcf_proto **qfq_tcf_chain(struct Qdisc *sch, unsigned long cl)
+static struct tcf_proto __rcu **qfq_tcf_chain(struct Qdisc *sch,
+ unsigned long cl)
{
struct qfq_sched *q = qdisc_priv(sch);
@@ -704,6 +705,7 @@
struct qfq_sched *q = qdisc_priv(sch);
struct qfq_class *cl;
struct tcf_result res;
+ struct tcf_proto *fl;
int result;
if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
@@ -714,7 +716,8 @@
}
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
- result = tc_classify(skb, q->filter_list, &res);
+ fl = rcu_dereference_bh(q->filter_list);
+ result = tc_classify(skb, fl, &res);
if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
switch (result) {