net: sched: cls_api: add filter counter

Maintain a count of filters per block.

Counter updates are protected by cb_lock, which is
also used to protect the offload counters.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 120a4ca6ec9b2f070111168b25d31ced50be3782..eb3872c22fcd18d3fb360a931b46ea3e3ccaa297 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -422,6 +422,7 @@ struct tcf_proto {
         */
        spinlock_t              lock;
        bool                    deleting;
+       bool                    counted;
        refcount_t              refcnt;
        struct rcu_head         rcu;
        struct hlist_node       destroy_ht_node;
@@ -471,6 +472,7 @@ struct tcf_block {
        struct flow_block flow_block;
        struct list_head owner_list;
        bool keep_dst;
+       atomic_t filtercnt; /* Number of filters */
        atomic_t skipswcnt; /* Number of skip_sw filters */
        atomic_t offloadcnt; /* Number of oddloaded filters */
        unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 397c3d29659cdcc6fcac40d74ea127493d682119..304a46ab0e0b3749102ee3a74800fc03989cba68 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -410,12 +410,30 @@ static void tcf_proto_get(struct tcf_proto *tp)
        refcount_inc(&tp->refcnt);
 }
 
+static void tcf_block_filter_cnt_update(struct tcf_block *block, bool *counted, bool add)
+{
+       lockdep_assert_not_held(&block->cb_lock);
+
+       down_write(&block->cb_lock);
+       if (*counted != add) {
+               if (add) {
+                       atomic_inc(&block->filtercnt);
+                       *counted = true;
+               } else {
+                       atomic_dec(&block->filtercnt);
+                       *counted = false;
+               }
+       }
+       up_write(&block->cb_lock);
+}
+
 static void tcf_chain_put(struct tcf_chain *chain);
 
 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
                              bool sig_destroy, struct netlink_ext_ack *extack)
 {
        tp->ops->destroy(tp, rtnl_held, extack);
+       tcf_block_filter_cnt_update(tp->chain->block, &tp->counted, false);
        if (sig_destroy)
                tcf_proto_signal_destroyed(tp->chain, tp);
        tcf_chain_put(tp->chain);
@@ -2364,6 +2382,7 @@ replay:
        err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
                              flags, extack);
        if (err == 0) {
+               tcf_block_filter_cnt_update(block, &tp->counted, true);
                tfilter_notify(net, skb, n, tp, block, q, parent, fh,
                               RTM_NEWTFILTER, false, rtnl_held, extack);
                tfilter_put(tp, fh);