net: sched: notify classifier on successful offload add/delete

To remove dependency on rtnl lock, extend classifier ops with new
ops->hw_add() and ops->hw_del() callbacks. Call them from cls API while
holding cb_lock every time filter if successfully added to or deleted from
hardware.

Implement the new API in flower classifier. Use it to manage hw_filters
list under cb_lock protection, instead of relying on rtnl lock to
synchronize with concurrent fl_reoffload() call.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.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 f90e3b2a30654334367ea746d73a994b3812bedf..c4fbbaff30a2e6717dde9644652a4b792a062e79 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -312,6 +312,10 @@ struct tcf_proto_ops {
        int                     (*reoffload)(struct tcf_proto *tp, bool add,
                                             flow_setup_cb_t *cb, void *cb_priv,
                                             struct netlink_ext_ack *extack);
+       void                    (*hw_add)(struct tcf_proto *tp,
+                                         void *type_data);
+       void                    (*hw_del)(struct tcf_proto *tp,
+                                         void *type_data);
        void                    (*bind_class)(void *, u32, unsigned long);
        void *                  (*tmplt_create)(struct net *net,
                                                struct tcf_chain *chain,

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 6e612984e4a6e809cf834653201f4f8a6a7aa46c..8b807e75fae21e75f7615fad746dcbe9709590a3 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -3099,6 +3099,11 @@ int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
        }
 
        ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
+       if (ok_count < 0)
+               goto err_unlock;
+
+       if (tp->ops->hw_add)
+               tp->ops->hw_add(tp, type_data);
        if (ok_count > 0)
                tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
                                          ok_count, true);
@@ -3130,11 +3135,18 @@ int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
        }
 
        tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
+       if (tp->ops->hw_del)
+               tp->ops->hw_del(tp, type_data);
 
        ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
+       if (ok_count < 0)
+               goto err_unlock;
+
+       if (tp->ops->hw_add)
+               tp->ops->hw_add(tp, type_data);
        if (ok_count > 0)
-               tc_cls_offload_cnt_update(block, tp, new_in_hw_count, new_flags,
-                                         ok_count, true);
+               tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
+                                         new_flags, ok_count, true);
 err_unlock:
        up_read(&block->cb_lock);
        return ok_count < 0 ? ok_count : 0;
@@ -3155,6 +3167,9 @@ int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
        ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
 
        tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
+       if (tp->ops->hw_del)
+               tp->ops->hw_del(tp, type_data);
+
        up_read(&block->cb_lock);
        return ok_count < 0 ? ok_count : 0;
 }

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index cb816bbbd376a94c52efd409921b6a150b28731b..5cb694469b517626667e9a9419a7ff116d0024ee 100644 (file)
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -421,9 +421,6 @@ static void fl_hw_destroy_filter(struct tcf_proto *tp, struct cls_fl_filter *f,
 
        tc_setup_cb_destroy(block, tp, TC_SETUP_CLSFLOWER, &cls_flower, false,
                            &f->flags, &f->in_hw_count, true);
-       spin_lock(&tp->lock);
-       list_del_init(&f->hw_list);
-       spin_unlock(&tp->lock);
 
        if (!rtnl_held)
                rtnl_unlock();
@@ -433,7 +430,6 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
                                struct cls_fl_filter *f, bool rtnl_held,
                                struct netlink_ext_ack *extack)
 {
-       struct cls_fl_head *head = fl_head_dereference(tp);
        struct tcf_block *block = tp->chain->block;
        struct flow_cls_offload cls_flower = {};
        bool skip_sw = tc_skip_sw(f->flags);
@@ -480,9 +476,6 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
                goto errout;
        }
 
-       spin_lock(&tp->lock);
-       list_add(&f->hw_list, &head->hw_filters);
-       spin_unlock(&tp->lock);
 errout:
        if (!rtnl_held)
                rtnl_unlock();
@@ -1856,6 +1849,30 @@ next_flow:
        return 0;
 }
 
+static void fl_hw_add(struct tcf_proto *tp, void *type_data)
+{
+       struct flow_cls_offload *cls_flower = type_data;
+       struct cls_fl_filter *f =
+               (struct cls_fl_filter *) cls_flower->cookie;
+       struct cls_fl_head *head = fl_head_dereference(tp);
+
+       spin_lock(&tp->lock);
+       list_add(&f->hw_list, &head->hw_filters);
+       spin_unlock(&tp->lock);
+}
+
+static void fl_hw_del(struct tcf_proto *tp, void *type_data)
+{
+       struct flow_cls_offload *cls_flower = type_data;
+       struct cls_fl_filter *f =
+               (struct cls_fl_filter *) cls_flower->cookie;
+
+       spin_lock(&tp->lock);
+       if (!list_empty(&f->hw_list))
+               list_del_init(&f->hw_list);
+       spin_unlock(&tp->lock);
+}
+
 static int fl_hw_create_tmplt(struct tcf_chain *chain,
                              struct fl_flow_tmplt *tmplt)
 {
@@ -2516,6 +2533,8 @@ static struct tcf_proto_ops cls_fl_ops __read_mostly = {
        .delete         = fl_delete,
        .walk           = fl_walk,
        .reoffload      = fl_reoffload,
+       .hw_add         = fl_hw_add,
+       .hw_del         = fl_hw_del,
        .dump           = fl_dump,
        .bind_class     = fl_bind_class,
        .tmplt_create   = fl_tmplt_create,