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_dsmark.c b/net/sched/sch_dsmark.c
index 49d6ef3..485e456 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -37,7 +37,7 @@
struct dsmark_qdisc_data {
struct Qdisc *q;
- struct tcf_proto *filter_list;
+ struct tcf_proto __rcu *filter_list;
u8 *mask; /* "owns" the array */
u8 *value;
u16 indices;
@@ -186,8 +186,8 @@
}
}
-static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,
- unsigned long cl)
+static inline struct tcf_proto __rcu **dsmark_find_tcf(struct Qdisc *sch,
+ unsigned long cl)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
return &p->filter_list;
@@ -229,7 +229,8 @@
skb->tc_index = TC_H_MIN(skb->priority);
else {
struct tcf_result res;
- int result = tc_classify(skb, p->filter_list, &res);
+ struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
+ int result = tc_classify(skb, fl, &res);
pr_debug("result %d class 0x%04x\n", result, res.classid);