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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 CFF87C32789 for ; Tue, 20 Nov 2018 16:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25B822087E for ; Tue, 20 Nov 2018 16:16:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25B822087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729243AbeKUCqs (ORCPT ); Tue, 20 Nov 2018 21:46:48 -0500 Received: from verein.lst.de ([213.95.11.211]:46161 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727733AbeKUCqr (ORCPT ); Tue, 20 Nov 2018 21:46:47 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id 7226368B03; Tue, 20 Nov 2018 17:16:51 +0100 (CET) Date: Tue, 20 Nov 2018 17:16:51 +0100 From: Christoph Hellwig To: Sagi Grimberg Cc: Christoph Hellwig , Ming Lei , Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Kent Overstreet , Mike Snitzer , dm-devel@redhat.com, Alexander Viro , linux-fsdevel@vger.kernel.org, Shaohua Li , linux-raid@vger.kernel.org, linux-erofs@lists.ozlabs.org, David Sterba , linux-btrfs@vger.kernel.org, "Darrick J . Wong" , linux-xfs@vger.kernel.org, Gao Xiang , Theodore Ts'o , linux-ext4@vger.kernel.org, Coly Li , linux-bcache@vger.kernel.org, Boaz Harrosh , Bob Peterson , cluster-devel@redhat.com Subject: Re: [PATCH V10 09/19] block: introduce bio_bvecs() Message-ID: <20181120161651.GB2629@lst.de> References: <20181115085306.9910-1-ming.lei@redhat.com> <20181115085306.9910-10-ming.lei@redhat.com> <20181116134541.GH3165@lst.de> <002fe56b-25e4-573e-c09b-bb12c3e8d25a@grimberg.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <002fe56b-25e4-573e-c09b-bb12c3e8d25a@grimberg.me> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 19, 2018 at 04:49:27PM -0800, Sagi Grimberg wrote: > >> The only user in your final tree seems to be the loop driver, and >> even that one only uses the helper for read/write bios. >> >> I think something like this would be much simpler in the end: > > The recently submitted nvme-tcp host driver should also be a user > of this. Does it make sense to keep it as a helper then? I did take a brief look at the code, and I really don't understand why the heck it even deals with bios to start with. Like all the other nvme transports it is a blk-mq driver and should iterate over segments in a request and more or less ignore bios. Something is horribly wrong in the design.