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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 2DAFFC4BA15 for ; Wed, 26 Feb 2020 15:57:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBA4624691 for ; Wed, 26 Feb 2020 15:57:30 +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="LXgY2HyV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728728AbgBZP53 (ORCPT ); Wed, 26 Feb 2020 10:57:29 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:53260 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728725AbgBZP53 (ORCPT ); Wed, 26 Feb 2020 10:57:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=q6+/Qd2Y2JYGSuVZkpzMJBymUWB4oioDyaoc9EA54Mk=; b=LXgY2HyV62m0jZoriJzn9lW1Vo 1rcWuVS6DQyaDEyT8m1/KLrbKN+DKjK6bih5KPHbY+pNX3P1JcdIk4UcTZkyZmHVyWUuLbZzGvJkw EmGuKm0Ss0qYMWC8JrCq8ttlOMOgmg80NINVJNFRzkotRIvbQ9Ejby2QJN1aO2aWGleI6pnBHVoxn kdNVPOhsUpmkoTyzhKEVYzWscEIxwqWbThBQwtgQHrTbxlcm17f/TLO+tZaLPA/fQxBf5CF9DnTBy nFySCmtHbzeRTJcRe/SOiQM7g0vULK3XTyVDzhGtDDSTkPAojrMopVqqRCLezZ27CY/s3yUWrQKSS 3Urlv3IQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6z3w-00007H-7d; Wed, 26 Feb 2020 15:57:28 +0000 Date: Wed, 26 Feb 2020 07:57:28 -0800 From: Christoph Hellwig To: Jens Axboe Cc: Bob Liu , linux-block@vger.kernel.org, martin.petersen@oracle.com, linux-fsdevel@vger.kernel.org, darrick.wong@oracle.com, io-uring@vger.kernel.org Subject: Re: [PATCH 1/4] io_uring: add IORING_OP_READ{WRITE}V_PI cmd Message-ID: <20200226155728.GA32543@infradead.org> References: <20200226083719.4389-1-bob.liu@oracle.com> <20200226083719.4389-2-bob.liu@oracle.com> <6e466774-4dc5-861c-58b5-f0cc728bacff@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6e466774-4dc5-861c-58b5-f0cc728bacff@kernel.dk> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Feb 26, 2020 at 07:24:06AM -0700, Jens Axboe wrote: > On 2/26/20 1:37 AM, Bob Liu wrote: > > diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h > > index a3300e1..98fa3f1 100644 > > --- a/include/uapi/linux/io_uring.h > > +++ b/include/uapi/linux/io_uring.h > > @@ -62,6 +62,8 @@ enum { > > IORING_OP_NOP, > > IORING_OP_READV, > > IORING_OP_WRITEV, > > + IORING_OP_READV_PI, > > + IORING_OP_WRITEV_PI, > > IORING_OP_FSYNC, > > IORING_OP_READ_FIXED, > > IORING_OP_WRITE_FIXED, > > So this one renumbers everything past IORING_OP_WRITEV, breaking the > ABI in a very bad way. I'm guessing that was entirely unintentional? > Any new command must go at the end of the list. > > You're also not updating io_op_defs[] with the two new commands, > which means it won't compile at all. I'm guessing you tested this on > an older version of the kernel which didn't have io_op_defs[]? And the real question is why we need ops insted of just a flag and using previously reserved fields for the PI pointer.