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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 5E001CA9EB5 for ; Mon, 4 Nov 2019 14:51:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EA91218BA for ; Mon, 4 Nov 2019 14:51:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Venzl/R8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728840AbfKDOvV (ORCPT ); Mon, 4 Nov 2019 09:51:21 -0500 Received: from mail-yw1-f66.google.com ([209.85.161.66]:45334 "EHLO mail-yw1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727838AbfKDOvU (ORCPT ); Mon, 4 Nov 2019 09:51:20 -0500 Received: by mail-yw1-f66.google.com with SMTP id j137so811709ywa.12 for ; Mon, 04 Nov 2019 06:51:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7r5lBU/w2GioMOAscwus/pOsp6TqJGFS95RYlRLl5V8=; b=Venzl/R840Ayp+mx/PlwfO6Axz6jr9KMlduM9SwZzTH0OB0LSCWPAHDamRh2JWa5QE KBdL9KUnnhCmFx3Z+TMApBLGk+BsaJ7GZL1VMYvp9FVAQU59YxpLe1lXdW7R5ovZtzJN j6O8k9OeYyLaBJt7BaZkKKxB6pjnHzCWDX5ogyBKR4zzZv67cxH3Vm2I1M7ksbeqlJwF WZRhhTlbAekMTvxxxWtMSo7De6Vfr+ryAN7WbJdudze+VhZO0rpbCQcEO6mg1kEHH5aS 9u2zWioBMTpNVBtx2dMRoEXEzGin1meDBK13RPw9YPxXYKsjo5EJdDgF+sDiPqFHdbRa Yl4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7r5lBU/w2GioMOAscwus/pOsp6TqJGFS95RYlRLl5V8=; b=T1aH4D/75ZZmhLqVO87xX1PlGhsCvoH/x8s6zzRZ5OPVi39xBYm6J8klcmFUHf9mf7 K+hJbqgfQLM1/VgHneeO5U5OxJ5hi+Z30XjxK4yT7ndSVHoST4cvKdGlRlkVQCWk7hxk WYH9Si1xjyg+CJd4e1XFKeKqpQmbxQ8cClRuGz2C67qUReUG0luPe7gSRZhXPtXWlN3C 4tNoalbAEDiRi72JJ3N/Y132ZmxB9XwjSQpgMGyTQII57JNqnNdG5qbyB6N5jLqTUhV9 R0ltYzRIebX/gAF1wu29NK+BOzHbGtXM/dlk8qE8REMc0z2uri9hZ5YhtEahiTN7y7Kb JUNQ== X-Gm-Message-State: APjAAAXJokDGdEU0XYUDbjJ4EByMAsbOvKuRO32DGzehgAq1/NQo/lNn zmRBHM2tpTDqskQT2hpjLljXP0P1Q2t40h1JGTA= X-Google-Smtp-Source: APXvYqxUd0xWCqIUtntR2MSva2pBZIV+Ro4QgagTcr5dCjl2LTVg3D7IcZWj5sEmy7mgGKbUBZPxM7ZolD8xbtB0rbs= X-Received: by 2002:a81:3644:: with SMTP id d65mr4848747ywa.10.1572879079753; Mon, 04 Nov 2019 06:51:19 -0800 (PST) MIME-Version: 1.0 References: <20191031050338.12700-1-csm10495@gmail.com> <20191031133921.GA4763@lst.de> <1977598237.90293761.1572878080625.JavaMail.zimbra@kalray.eu> In-Reply-To: <1977598237.90293761.1572878080625.JavaMail.zimbra@kalray.eu> From: Charles Machalow Date: Mon, 4 Nov 2019 06:51:08 -0800 Message-ID: Subject: Re: [PATCH] nvme: change nvme_passthru_cmd64's result field. To: Marta Rybczynska Cc: Christoph Hellwig , linux-nvme , kbusch , axboe , Sagi Grimberg , linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For this one yes, UAPI size changes. Though I believe this IOCTL hasn't been in a released Kernel yet (just RC). Technically it may be changeable as a fix until the next Kernel is released. I do think its a useful enough change to warrant a late fix. - Charlie Scott Machalow On Mon, Nov 4, 2019 at 6:34 AM Marta Rybczynska wrote: > > > > ----- On 31 Oct, 2019, at 14:39, Christoph Hellwig hch@lst.de wrote: > > > On Wed, Oct 30, 2019 at 10:03:38PM -0700, Charles Machalow wrote: > >> Changing nvme_passthru_cmd64's result field to be backwards compatible > >> with the nvme_passthru_cmd/nvme_admin_cmd struct in terms of the result > >> field. With this change the first 32 bits of result in either case > >> point to CQE DW0. This allows userspace tools to use the new structure > >> when using the old ADMIN/IO_CMD ioctls or new ADMIN/IO_CMD64 ioctls. > > > > All that casting is a pretty bad idea. please just add an explicit > > reserved field before the result, and check that it always is zero > > in the ioctl handler. > > That would change the size of a structure in UAPI, won't it? > I wanted to avoid it when adding the *64 ioctls and that's why > I added separate ones instead of extending the ones that exist. > > Marta