From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA9F4C28CF6 for ; Wed, 1 Aug 2018 23:54:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D0FA20855 for ; Wed, 1 Aug 2018 23:54:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D0FA20855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ZenIV.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731639AbeHBBmd (ORCPT ); Wed, 1 Aug 2018 21:42:33 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:43660 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726585AbeHBBmd (ORCPT ); Wed, 1 Aug 2018 21:42:33 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.87 #1 (Red Hat Linux)) id 1fl0wW-0003pr-Bh; Wed, 01 Aug 2018 23:54:12 +0000 Date: Thu, 2 Aug 2018 00:54:12 +0100 From: Al Viro To: Christoph Hellwig Cc: Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/4] aio: implement IOCB_CMD_POLL Message-ID: <20180801235412.GT30522@ZenIV.linux.org.uk> References: <20180730071544.23998-1-hch@lst.de> <20180730071544.23998-4-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180730071544.23998-4-hch@lst.de> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 30, 2018 at 09:15:43AM +0200, Christoph Hellwig wrote: > + apt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */ > + mask = vfs_poll(req->file, &apt.pt) & req->events; > + if (mask || apt.error) { > + bool removed = false; > + > + /* we did not manage to set up a waitqueue, done */ > + if (unlikely(!req->head)) > + goto out_fput; > +out_fput: > + fput(req->file); > + return apt.error; Ugh... So anything that simply returns a constant value, without even bothering to do poll_wait() (on the theory that no matter how much you wait, nothing will change) is going to git -EINVAL? What am I missing here?