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_hfsc.c b/net/sched/sch_hfsc.c
index ec8aeaa..04b0de4 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -116,7 +116,7 @@
struct gnet_stats_queue qstats;
struct gnet_stats_rate_est64 rate_est;
unsigned int level; /* class level in hierarchy */
- struct tcf_proto *filter_list; /* filter list */
+ struct tcf_proto __rcu *filter_list; /* filter list */
unsigned int filter_cnt; /* filter count */
struct hfsc_sched *sched; /* scheduler data */
@@ -1161,7 +1161,7 @@
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
head = &q->root;
- tcf = q->root.filter_list;
+ tcf = rcu_dereference_bh(q->root.filter_list);
while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
#ifdef CONFIG_NET_CLS_ACT
switch (result) {
@@ -1185,7 +1185,7 @@
return cl; /* hit leaf class */
/* apply inner filter chain */
- tcf = cl->filter_list;
+ tcf = rcu_dereference_bh(cl->filter_list);
head = cl;
}
@@ -1285,7 +1285,7 @@
cl->filter_cnt--;
}
-static struct tcf_proto **
+static struct tcf_proto __rcu **
hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg)
{
struct hfsc_sched *q = qdisc_priv(sch);