Please use a more meaningful patch summary. This one is too generic.

On Mon, May 14, 2018 at 05:27:11PM +0300, Vlad Buslov wrote:
...

+int tcf_idr_find_delete(struct tc_action_net *tn, u32 index)

What about naming it tcf_idr_delete_index() instead?
The find operation is always implicit when you don't specify the
object itself directly, and then it describes which key will be used.

+{
+	struct tcf_idrinfo *idrinfo = tn->idrinfo;
+	struct tc_action *p;
+	int ret = 0;
+
+	spin_lock_bh(&idrinfo->lock);
+	p = idr_find(&idrinfo->action_idr, index);
+	if (!p) {
+		spin_unlock(&idrinfo->lock);
+		return -ENOENT;
+	}
+
+	if (!atomic_read(&p->tcfa_bindcnt)) {
+		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
+			struct module *owner = p->ops->owner;
+
+			WARN_ON(p != idr_remove(&idrinfo->action_idr,
+						p->tcfa_index));
+			spin_unlock_bh(&idrinfo->lock);
+
+			tcf_action_cleanup(p);
+			module_put(owner);
+			return 0;
+		}
+		ret = 0;
+	} else {
+		ret = -EPERM;
+	}
+
+	spin_unlock_bh(&idrinfo->lock);
+	return ret;
+}
+EXPORT_SYMBOL(tcf_idr_find_delete);

...