[patch net-next 4/9] net: sched: teach tcf_bind/unbind_filter to use block->q

[Jiri Pirko]

From: Jiri Pirko <j...@mellanox.com>

Whenever the block->q is set, it can be used instead of tp->q as it
contains the same value. When it is not set, which can't happen now but
it might happen with the follow-up shared blocks introduction, the class
is not set in the result. That would lead to a class lookup instead
of direct class pointer use for classful qdiscs. However, it is not
planned to support classful qdisqs sharing filter blocks, so that may
never happen.

Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
 include/net/pkt_cls.h | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 01ffda5..bf6c853 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -74,36 +74,43 @@ __cls_set_class(unsigned long *clp, unsigned long cl)
 }
 
 static inline unsigned long
-cls_set_class(struct tcf_proto *tp, unsigned long *clp, 
-       unsigned long cl)
+cls_set_class(struct Qdisc *q, unsigned long *clp, unsigned long cl)
 {
        unsigned long old_cl;
-       
-       tcf_tree_lock(tp);
+
+       sch_tree_lock(q);
        old_cl = __cls_set_class(clp, cl);
-       tcf_tree_unlock(tp);
- 
+       sch_tree_unlock(q);
        return old_cl;
 }
 
 static inline void
 tcf_bind_filter(struct tcf_proto *tp, struct tcf_result *r, unsigned long base)
 {
+       struct Qdisc *q = tp->chain->block->q;
        unsigned long cl;
 
-       cl = tp->q->ops->cl_ops->bind_tcf(tp->q, base, r->classid);
-       cl = cls_set_class(tp, &r->class, cl);
+       /* Check q as it is not set for shared blocks. In that case,
+        * setting class is not supported.
+        */
+       if (!q)
+               return;
+       cl = q->ops->cl_ops->bind_tcf(q, base, r->classid);
+       cl = cls_set_class(q, &r->class, cl);
        if (cl)
-               tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
+               q->ops->cl_ops->unbind_tcf(q, cl);
 }
 
 static inline void
 tcf_unbind_filter(struct tcf_proto *tp, struct tcf_result *r)
 {
+       struct Qdisc *q = tp->chain->block->q;
        unsigned long cl;
 
+       if (!q)
+               return;
        if ((cl = __cls_set_class(&r->class, 0)) != 0)
-               tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
+               q->ops->cl_ops->unbind_tcf(q, cl);
 }
 
 struct tcf_exts {
-- 
2.9.5