RDMA/uverbs: Remove needs_kfree_rcu from uverbs_obj_type_class

static void uverbs_uobject_free(struct kref *ref)

{

	struct ib_uobject *uobj =

		container_of(ref, struct ib_uobject, ref);

	if (uobj->uapi_object->type_class->needs_kfree_rcu)

		kfree_rcu(uobj, rcu);

	else

		kfree(uobj);

	kfree_rcu(container_of(ref, struct ib_uobject, ref), rcu);

}

void uverbs_uobject_put(struct ib_uobject *uobject)

	.lookup_put = lookup_put_idr_uobject,

	.destroy_hw = destroy_hw_idr_uobject,

	.remove_handle = remove_handle_idr_uobject,

	/*

	 * When we destroy an object, we first just lock it for WRITE and

	 * actually DESTROY it in the finalize stage. So, the problematic

	 * scenario is when we just started the finalize stage of the

	 * destruction (nothing was executed yet). Now, the other thread

	 * fetched the object for READ access, but it didn't lock it yet.

	 * The DESTROY thread continues and starts destroying the object.

	 * When the other thread continue - without the RCU, it would

	 * access freed memory. However, the rcu_read_lock delays the free

	 * until the rcu_read_lock of the READ operation quits. Since the

	 * exclusive lock of the object is still taken by the DESTROY flow, the

	 * READ operation will get -EBUSY and it'll just bail out.

	 */

	.needs_kfree_rcu = true,

};

EXPORT_SYMBOL(uverbs_idr_class);

	.lookup_put = lookup_put_fd_uobject,

	.destroy_hw = destroy_hw_fd_uobject,

	.remove_handle = remove_handle_fd_uobject,

	.needs_kfree_rcu = false,

};

EXPORT_SYMBOL(uverbs_fd_class);

				       enum rdma_remove_reason why,

				       struct uverbs_attr_bundle *attrs);

	void (*remove_handle)(struct ib_uobject *uobj);

	u8    needs_kfree_rcu;

};

struct uverbs_obj_type {