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 9355BC71135 for ; Mon, 16 Jun 2025 06:45:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4S+5NsBHeTgRw6H79+RvgGJnEakQUo0TwVJizMOnyBI=; b=XCbPI7L4sygYnL 7GlC+Jnh3WHK+1quHWbsqh3jd+ewHVUb1ge+EpNI0QY/N6gfAGI6AAf1fibQkkLeDUw9xa2m2v7IL Rj9jk46QRE6w4FLsXpe4iLTmCkpyX/xSi4PAO5dJ2qP4O0mOWOJXwlMdzg0/efIjF6TK21ceCfAUi VTAqTksnOa8nnWv79jNO6yJwrf2ZY4rMLixN4MmRpDtlg0pvbME5YXv8OACgLU8j/fYpkus3rCk12 C7N03BFveR8mYRWUtWWToDXhQ3+u4qPOZ8u34owbtu0nb6/UAsg4DGEQQLw4HbPFuXk7lnXK0oolO QG0/11iwoPuUTfRjuu6g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uR3bL-00000003Y51-3Q8I; Mon, 16 Jun 2025 06:45:51 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uR3Z1-00000003XTY-0Nxz for linux-nvme@lists.infradead.org; Mon, 16 Jun 2025 06:43:28 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id F1D215C532E; Mon, 16 Jun 2025 06:41:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DCCDC4CEEA; Mon, 16 Jun 2025 06:43:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750056206; bh=i8eZ5db7jwLf3O2OU4sJwtCvyGnyULzOXR46Z6sekOg=; h=Date:Reply-To:Subject:To:Cc:References:From:In-Reply-To:From; b=Ea2GD93oQhfMVYrQqOBlhv16244neKYQsZ5tMJvqX4kKmN7Cu7dUxD6fMUJhdufGQ D6iPWyjHsx48zcXJTnZtaOuAupGhsUInQzo5yhmnnqm1VvfdYVdNCTlG4CRmnC594E cqI9WHBK0swPEqvw05iJgLssF6bWQUi3GLFIR31MO+9vGN6c2gR8zP7Jfsu3b4/v7V /IMHMQlqFoRNYu9BprdLtUt5hKiobkNmnPPokSQm0OcNOaWzE7XUQh2KXtb7FXIkw4 ROJrXWpn78imzqt/xuKQU0bgd/DbXvwHEWBCs7p96qNzE59E20ZLC/a1mrnde4DxT+ Rkj2ZwzBNG2uA== Message-ID: <2105172c-5540-40d0-9573-15001b745648@kernel.org> Date: Mon, 16 Jun 2025 08:43:22 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/9] block: add scatterlist-less DMA mapping helpers To: Christoph Hellwig Cc: Jens Axboe , Keith Busch , Sagi Grimberg , Chaitanya Kulkarni , Kanchan Joshi , Leon Romanovsky , Nitesh Shetty , Logan Gunthorpe , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org References: <20250610050713.2046316-1-hch@lst.de> <20250610050713.2046316-3-hch@lst.de> <20250616050247.GA860@lst.de> Content-Language: en-US From: Daniel Gomez Organization: kernel.org In-Reply-To: <20250616050247.GA860@lst.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250615_234327_196098_994C367A X-CRM114-Status: GOOD ( 12.65 ) 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: , Reply-To: Daniel Gomez Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 16/06/2025 07.02, Christoph Hellwig wrote: > On Wed, Jun 11, 2025 at 03:43:07PM +0200, Daniel Gomez wrote: >>> +struct blk_dma_iter { >>> + /* Output address range for this iteration */ >>> + dma_addr_t addr; >>> + u32 len; >>> + >>> + /* Status code. Only valid when blk_rq_dma_map_iter_* returned false */ >>> + blk_status_t status; >> >> This comment does not match with blk_rq_dma_map_iter_start(). It returns false >> and status is BLK_STS_INVAL. > > I went over you comment a few times and still don't understand it. The way I read the comment is that status is only valid when blk_rq_dma_map_iter_* returns false. But blk_rq_dma_map_iter_start() can return false and an invalid status (in the default switch case). Assuming the comment is the right thing, I'd expect a valid status for that case: --- a/block/blk-mq-dma.c +++ b/block/blk-mq-dma.c @@ -179,7 +179,6 @@ bool blk_rq_dma_map_iter_start(struct request *req, struct device *dma_dev, req->cmd_flags &= ~REQ_P2PDMA; break; default: - iter->status = BLK_STS_INVAL; return false; } }