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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 95F5CC433FF for ; Thu, 8 Aug 2019 22:25:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72DF2217F4 for ; Thu, 8 Aug 2019 22:25:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404651AbfHHWZN (ORCPT ); Thu, 8 Aug 2019 18:25:13 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:38381 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732708AbfHHWZN (ORCPT ); Thu, 8 Aug 2019 18:25:13 -0400 Received: by mail-pl1-f196.google.com with SMTP id m12so5507288plt.5; Thu, 08 Aug 2019 15:25:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=bpHV3e8JAuW9jPJJ+orVfIVb/Mkhh2ezFJLfJa1sqUo=; b=oGIB1KHvJJdRdmqHBZuOSslDBsf/CD2aubpAkchu2ooiR0g+f95NW+t+KuaNsVjIDh udfGxzWU7cvg/GIZNOVzd48hET2DJLMvPpdztyob//xOfqk0mhHp5D5Rp2k0MAlNa7K+ vxpODL7TqOdOTjcrs5X4wpfDNlfIuaruTU6Xay9RtlL/GYIbXhKAnDXCDeG8//0pMh6U VOnc70JRBTRe7PJYPU+iEguW3VuwK1y5gfgriVbxjmOtgaap46l2eX24jYrLtKmQFmG4 E/53jQReEUP3aF1/UIcbz3Zx/Tk2Rah4EQPuqoenwzE1lOUbiPqFaLKCKoCxjod7Jzsv LI4Q== X-Gm-Message-State: APjAAAXr6oqsJYUA+GHPsgBfd+wOYc+cf368fZK4YMLRQliIjzzQC4wl Z3yy51NlI6CjdfY1mxYBdDxaV49M X-Google-Smtp-Source: APXvYqyrkrJ7oPFLymWiDXa3nWhvwoWBV3ZZ7HTkjdUbYtz/V+0rjh+rTul8sAay6t9sbFaTLpGAcA== X-Received: by 2002:a17:902:8d97:: with SMTP id v23mr15608397plo.157.1565303112424; Thu, 08 Aug 2019 15:25:12 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id 64sm97296085pfe.128.2019.08.08.15.25.11 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Thu, 08 Aug 2019 15:25:11 -0700 (PDT) Subject: Re: [PATCH v3 00/20] sg: add v4 interface To: Tony Battersby , dgilbert@interlog.com, James Bottomley , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: martin.petersen@oracle.com, hare@suse.de, Arnd Bergmann References: <20190807114252.2565-1-dgilbert@interlog.com> <1565291455.3435.48.camel@linux.vnet.ibm.com> <7edab448-22cc-493a-f745-acc5be38f6a5@interlog.com> <5a80d09c-c1a5-429d-d46a-5e108b6292df@cybernetics.com> From: Bart Van Assche Message-ID: <517f279d-38ec-79eb-cc7f-77d1e873ea62@acm.org> Date: Thu, 8 Aug 2019 15:25:10 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <5a80d09c-c1a5-429d-d46a-5e108b6292df@cybernetics.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 8/8/19 2:37 PM, Tony Battersby wrote: > On 8/8/19 5:08 PM, Douglas Gilbert wrote: >> *** Tony Battersby is a sg driver power user. He has lamented wading through >> very large logs looking for some hint of why the sg driver is playing >> up. He has stated the strong preference for more, not less, ioctls. >> > One of the reasons ioctls have a bad reputation is because they can be > used to implement poorly-thought-out interfaces.  So kernel maintainers > push back on adding new ioctls.  But the push back isn't about the > number of ioctls, it is about the poor interfaces.  My advice was that > in general, to implement a given API, it would be better to add more > ioctls with a simple interface for each one rather than to add fewer > extremely complex multiplexing ioctls. Hi Tony, What is your motivation to use the SG_IO API? Is it controlling SMR drives or are you using SG_IO for another reason? I'm asking because depending on the use case there may be a better solution than using the SG_IO API. Thanks, Bart.