diff --git a/fs/io_uring.c b/fs/io_uring.c index c06082bb039a..1b2517291b78 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -191,7 +191,6 @@ struct fixed_file_data { struct llist_head put_llist; struct work_struct ref_work; struct completion done; - struct rcu_head rcu; }; struct io_ring_ctx { @@ -5331,26 +5330,23 @@ static void io_file_ref_kill(struct percpu_ref *ref) 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); + struct fixed_file_data *data; + + data = container_of(work, struct fixed_file_data, ref_work); + + /* + * 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. + */ + rcu_barrier(); percpu_ref_exit(&data->refs); kfree(data); } -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. - */ - call_rcu(rcu, __io_file_ref_exit_and_free); -} - static int io_sqe_files_unregister(struct io_ring_ctx *ctx) { struct fixed_file_data *data = ctx->file_data; @@ -5369,7 +5365,8 @@ 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;