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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 2E9CEC433E0 for ; Wed, 8 Jul 2020 14:59:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07F7120720 for ; Wed, 8 Jul 2020 14:59:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="WPlORj9u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729022AbgGHO7B (ORCPT ); Wed, 8 Jul 2020 10:59:01 -0400 Received: from casper.infradead.org ([90.155.50.34]:36584 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728932AbgGHO7B (ORCPT ); Wed, 8 Jul 2020 10:59:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=HXY6HyjdszjWPlFmwnu7PpLohHyegjNp5zS3C0BgjdM=; b=WPlORj9uxpDZmh4ZtrCe+13y0J TTC5I/io9fZVm04GjLP53C1pskY9DoFzCXzafhan+OEHLFqMzALjBb3+iX3ygsiFypEe4QXWI9465 JFmq+bUhkNm6OIBZ4+dtJzW0eoL9yhBeAuICktm4q90n/WDglp6KgEjT57ACusXeBFppQSlinK4XS PpxEZ1+VRg9HopJ0sw8oVuLBaWETsvEQFLqA5mF+KOEQtXY0fsbqMIBSeSBQ9hrjVrR//bC3btKQD NhBLIt0wWyk0l6dUK/2j8LO+2ZVhOOnfvaxEVNe6UgRB+U7YrO34j3x/3BJxqmF354/HXA30/QPqU Ea+Hhm4g==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jtBWl-0000r7-8z; Wed, 08 Jul 2020 14:58:27 +0000 Date: Wed, 8 Jul 2020 15:58:26 +0100 From: Matthew Wilcox To: Jens Axboe Cc: Kanchan Joshi , viro@zeniv.linux.org.uk, bcrl@kvack.org, hch@infradead.org, Damien.LeMoal@wdc.com, asml.silence@gmail.com, linux-fsdevel@vger.kernel.org, mb@lightnvm.io, linux-kernel@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-block@vger.kernel.org, Selvakumar S , Nitesh Shetty , Javier Gonzalez Subject: Re: [PATCH v3 4/4] io_uring: add support for zone-append Message-ID: <20200708145826.GS25523@casper.infradead.org> References: <20200706143208.GA25523@casper.infradead.org> <20200707151105.GA23395@test-zns> <20200707155237.GM25523@casper.infradead.org> <20200707202342.GA28364@test-zns> <7a44d9c6-bf7d-0666-fc29-32c3cba9d1d8@kernel.dk> <20200707221812.GN25523@casper.infradead.org> <145cc0ad-af86-2d6a-78b3-9ade007aae52@kernel.dk> <20200708125805.GA16495@test-zns> <2962cd68-de34-89be-0464-8b102a3f1d0e@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2962cd68-de34-89be-0464-8b102a3f1d0e@kernel.dk> Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Jul 08, 2020 at 08:54:07AM -0600, Jens Axboe wrote: > On 7/8/20 6:58 AM, Kanchan Joshi wrote: > >>> +#define IOCB_NO_CMPL (15 << 28) > >>> > >>> struct kiocb { > >>> [...] > >>> - void (*ki_complete)(struct kiocb *iocb, long ret, long ret2); > >>> + loff_t __user *ki_uposp; > >>> - int ki_flags; > >>> + unsigned int ki_flags; > >>> > >>> +typedef void ki_cmpl(struct kiocb *, long ret, long ret2); > >>> +static ki_cmpl * const ki_cmpls[15]; > >>> > >>> +void ki_complete(struct kiocb *iocb, long ret, long ret2) > >>> +{ > >>> + unsigned int id = iocb->ki_flags >> 28; > >>> + > >>> + if (id < 15) > >>> + ki_cmpls[id](iocb, ret, ret2); > >>> +} > >>> > >>> +int kiocb_cmpl_register(void (*cb)(struct kiocb *, long, long)) > >>> +{ > >>> + for (i = 0; i < 15; i++) { > >>> + if (ki_cmpls[id]) > >>> + continue; > >>> + ki_cmpls[id] = cb; > >>> + return id; > >>> + } > >>> + WARN(); > >>> + return -1; > >>> +} > >> > >> That could work, we don't really have a lot of different completion > >> types in the kernel. > > > > Thanks, this looks sorted. > > Not really, someone still needs to do that work. I took a quick look, and > most of it looks straight forward. The only potential complication is > ocfs2, which does a swap of the completion for the kiocb. That would just > turn into an upper flag swap. And potential sync kiocb with NULL > ki_complete. The latter should be fine, I think we just need to reserve > completion nr 0 for being that. I was reserving completion 15 for that ;-) +#define IOCB_NO_CMPL (15 << 28) ... + if (id < 15) + ki_cmpls[id](iocb, ret, ret2); Saves us one pointer in the array ...