net: sched: introduce block mechanism to handle netif_keep_dst calls

Couple of classifiers call netif_keep_dst directly on q->dev. That is
not possible to do directly for shared blocke where multiple qdiscs are
owning the block. So introduce a infrastructure to keep track of the
block owners in list and use this list to implement block variant of
netif_keep_dst.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index c40d60e..789d818 100644 (file)
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -39,6 +39,7 @@ bool tcf_queue_work(struct work_struct *work);
 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
                                bool create);
 void tcf_chain_put(struct tcf_chain *chain);
+void tcf_block_netif_keep_dst(struct tcf_block *block);
 int tcf_block_get(struct tcf_block **p_block,
                  struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
                  struct netlink_ext_ack *extack);

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index cc0c1e4..f655e66 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -289,6 +289,8 @@ struct tcf_block {
        struct net *net;
        struct Qdisc *q;
        struct list_head cb_list;
+       struct list_head owner_list;
+       bool keep_dst;
 };
 
 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 700595a..1ca8423 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -375,6 +375,7 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
        }
        INIT_LIST_HEAD(&block->chain_list);
        INIT_LIST_HEAD(&block->cb_list);
+       INIT_LIST_HEAD(&block->owner_list);
 
        /* Create chain 0 by default, it has to be always present. */
        chain = tcf_chain_create(block, 0);
@@ -406,6 +407,65 @@ static struct tcf_chain *tcf_block_chain_zero(struct tcf_block *block)
        return list_first_entry(&block->chain_list, struct tcf_chain, list);
 }
 
+struct tcf_block_owner_item {
+       struct list_head list;
+       struct Qdisc *q;
+       enum tcf_block_binder_type binder_type;
+};
+
+static void
+tcf_block_owner_netif_keep_dst(struct tcf_block *block,
+                              struct Qdisc *q,
+                              enum tcf_block_binder_type binder_type)
+{
+       if (block->keep_dst &&
+           binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
+           binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
+               netif_keep_dst(qdisc_dev(q));
+}
+
+void tcf_block_netif_keep_dst(struct tcf_block *block)
+{
+       struct tcf_block_owner_item *item;
+
+       block->keep_dst = true;
+       list_for_each_entry(item, &block->owner_list, list)
+               tcf_block_owner_netif_keep_dst(block, item->q,
+                                              item->binder_type);
+}
+EXPORT_SYMBOL(tcf_block_netif_keep_dst);
+
+static int tcf_block_owner_add(struct tcf_block *block,
+                              struct Qdisc *q,
+                              enum tcf_block_binder_type binder_type)
+{
+       struct tcf_block_owner_item *item;
+
+       item = kmalloc(sizeof(*item), GFP_KERNEL);
+       if (!item)
+               return -ENOMEM;
+       item->q = q;
+       item->binder_type = binder_type;
+       list_add(&item->list, &block->owner_list);
+       return 0;
+}
+
+static void tcf_block_owner_del(struct tcf_block *block,
+                               struct Qdisc *q,
+                               enum tcf_block_binder_type binder_type)
+{
+       struct tcf_block_owner_item *item;
+
+       list_for_each_entry(item, &block->owner_list, list) {
+               if (item->q == q && item->binder_type == binder_type) {
+                       list_del(&item->list);
+                       kfree(item);
+                       return;
+               }
+       }
+       WARN_ON(1);
+}
+
 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                      struct tcf_block_ext_info *ei,
                      struct netlink_ext_ack *extack)
@@ -435,6 +495,12 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                }
        }
 
+       err = tcf_block_owner_add(block, q, ei->binder_type);
+       if (err)
+               goto err_block_owner_add;
+
+       tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
+
        err = tcf_chain_head_change_cb_add(tcf_block_chain_zero(block),
                                           ei, extack);
        if (err)
@@ -444,6 +510,8 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
        return 0;
 
 err_chain_head_change_cb_add:
+       tcf_block_owner_del(block, q, ei->binder_type);
+err_block_owner_add:
        if (created) {
                if (tcf_block_shared(block))
                        tcf_block_remove(block, net);
@@ -489,6 +557,7 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
        if (!block)
                return;
        tcf_chain_head_change_cb_del(tcf_block_chain_zero(block), ei);
+       tcf_block_owner_del(block, q, ei->binder_type);
 
        if (--block->refcnt == 0) {
                if (tcf_block_shared(block))

diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 8d78e7f..d79cc50 100644 (file)
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -392,8 +392,8 @@ static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
        prog->bpf_name = name;
        prog->filter = fp;
 
-       if (fp->dst_needed && !(tp->q->flags & TCQ_F_INGRESS))
-               netif_keep_dst(qdisc_dev(tp->q));
+       if (fp->dst_needed)
+               tcf_block_netif_keep_dst(tp->chain->block);
 
        return 0;
 }

diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 25c2a88..28cd6fb 100644 (file)
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -526,7 +526,7 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
 
        timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE);
 
-       netif_keep_dst(qdisc_dev(tp->q));
+       tcf_block_netif_keep_dst(tp->chain->block);
 
        if (tb[TCA_FLOW_KEYS]) {
                fnew->keymask = keymask;

diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index ac9a5b8..a1f2b1b 100644 (file)
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -527,7 +527,7 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
                if (f->handle < f1->handle)
                        break;
 
-       netif_keep_dst(qdisc_dev(tp->q));
+       tcf_block_netif_keep_dst(tp->chain->block);
        rcu_assign_pointer(f->next, f1);
        rcu_assign_pointer(*fp, f);