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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ECF8AC77B76 for ; Mon, 24 Apr 2023 05:09:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=P4No43ZKEl1utDQ4+hUc8IIQ8EmV6YA+zJppOylJESI=; b=zqnNqOlWUecfBYVgI3AMfVcH90 xSTeN8ZPTxN+fo8p/ipDOeFOvTNBlrCrIGoOEDBQA6qaVrXEl6gW8tEGtW6x6QgJFjYuf5cDPXpPr 5Z4d3tO4jNbRNs/GtsSpwTOTyZc+xB4GjHybMZwPpXs7FJF/Bog+JlH1g5p0WXWyJNYkLcq6Ja4AU 4bcgCgqNRmTts9g0RkBx8+f3iUWSRFB3iTl1z4eeIqEkrZ5FCA/La0lNG/1IjLhHh1u5G1744KqcO YxkT7vo2wyi7b/YeFxKcmUT074z3RzrM1FTX3K0f95I7dl619wUk4FjXSmRI65W2JNPdKQNn2ocK3 6trGJ47w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pqoRf-00FLFi-1x; Mon, 24 Apr 2023 05:08:59 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pqoRc-00FLF0-2N for linux-nvme@lists.infradead.org; Mon, 24 Apr 2023 05:08:58 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id D845F67373; Mon, 24 Apr 2023 07:08:43 +0200 (CEST) Date: Mon, 24 Apr 2023 07:08:43 +0200 From: Christoph Hellwig To: Breno Leitao Cc: Christoph Hellwig , io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, asml.silence@gmail.com, axboe@kernel.dk, leit@fb.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, sagi@grimberg.me, kbusch@kernel.org, ming.lei@redhat.com Subject: Re: [PATCH 1/2] io_uring: Pass whole sqe to commands Message-ID: <20230424050843.GA9252@lst.de> References: <20230419102930.2979231-1-leitao@debian.org> <20230419102930.2979231-2-leitao@debian.org> <20230420045712.GA4239@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230423_220856_943123_C6412A41 X-CRM114-Status: GOOD ( 15.93 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Fri, Apr 21, 2023 at 08:11:31AM -0700, Breno Leitao wrote: > On Thu, Apr 20, 2023 at 06:57:12AM +0200, Christoph Hellwig wrote: > > On Wed, Apr 19, 2023 at 03:29:29AM -0700, Breno Leitao wrote: > > > struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd); > > > - const struct nvme_uring_cmd *cmd = ioucmd->cmd; > > > + const struct nvme_uring_cmd *cmd = (struct nvme_uring_cmd *)ioucmd->sqe->cmd; > > > > Please don't add the pointless cast. And in general avoid the overly > > long lines. > > If I don't add this cast, the compiler complains with the follow error: > > drivers/nvme/host/ioctl.c: In function ‘nvme_uring_cmd_io’: > drivers/nvme/host/ioctl.c:555:37: error: initialization of ‘const struct nvme_uring_cmd *’ from incompatible pointer type ‘const __u8 *’ {aka ‘const unsigned char *’} [-Werror=incompatible-pointer-types] > const struct nvme_uring_cmd *cmd = ioucmd->sqe->cmd; Oh. I think then we need a helper to get the private data from the io_uring_cmd as an interface that requires casts in all callers is one asking for bugs.