Merge tag 'io_uring-5.6-2020-03-13' of git://git.kernel.dk/linux-block

	struct llist_head		put_llist;

	struct work_struct		ref_work;

	struct completion		done;

	struct rcu_head			rcu;

};

struct io_ring_ctx {

	complete(&data->done);

}

static void __io_file_ref_exit_and_free(struct rcu_head *rcu)

static void io_file_ref_exit_and_free(struct work_struct *work)

{

	struct fixed_file_data *data = container_of(rcu, struct fixed_file_data,

							rcu);

	percpu_ref_exit(&data->refs);

	kfree(data);

}

	struct fixed_file_data *data;

	data = container_of(work, struct fixed_file_data, ref_work);

static void io_file_ref_exit_and_free(struct rcu_head *rcu)

{

	/*

	 * We need to order our exit+free call against the potentially

	 * existing call_rcu() for switching to atomic. One way to do that

	 * is to have this rcu callback queue the final put and free, as we

	 * could otherwise have a pre-existing atomic switch complete _after_

	 * the free callback we queued.

	 * Ensure any percpu-ref atomic switch callback has run, it could have

	 * been in progress when the files were being unregistered. Once

	 * that's done, we can safely exit and free the ref and containing

	 * data structure.

	 */

	call_rcu(rcu, __io_file_ref_exit_and_free);

	rcu_barrier();

	percpu_ref_exit(&data->refs);

	kfree(data);

}

static int io_sqe_files_unregister(struct io_ring_ctx *ctx)

	for (i = 0; i < nr_tables; i++)

		kfree(data->table[i].files);

	kfree(data->table);

	call_rcu(&data->rcu, io_file_ref_exit_and_free);

	INIT_WORK(&data->ref_work, io_file_ref_exit_and_free);

	queue_work(system_wq, &data->ref_work);

	ctx->file_data = NULL;

	ctx->nr_user_files = 0;

	return 0;