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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 8B5E0C31E5B for ; Tue, 18 Jun 2019 01:07:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6692520861 for ; Tue, 18 Jun 2019 01:07:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726898AbfFRBH5 (ORCPT ); Mon, 17 Jun 2019 21:07:57 -0400 Received: from kvm5.telegraphics.com.au ([98.124.60.144]:34586 "EHLO kvm5.telegraphics.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbfFRBH5 (ORCPT ); Mon, 17 Jun 2019 21:07:57 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id C87BF29544; Mon, 17 Jun 2019 21:07:52 -0400 (EDT) Date: Tue, 18 Jun 2019 11:08:03 +1000 (AEST) From: Finn Thain To: Douglas Gilbert cc: Bart Van Assche , Marc Gonzalez , James Bottomley , Martin Petersen , SCSI , LKML , Christoph Hellwig Subject: Re: [PATCH v1] scsi: Don't select SCSI_PROC_FS by default In-Reply-To: Message-ID: References: <2de15293-b9be-4d41-bc67-a69417f27f7a@free.fr> <621306ee-7ab6-9cd2-e934-94b3d6d731fc@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 17 Jun 2019, Douglas Gilbert wrote: > On 2019-06-17 5:11 p.m., Bart Van Assche wrote: > > On 6/12/19 6:59 AM, Marc Gonzalez wrote: > > > According to the option's help message, SCSI_PROC_FS has been > > > superseded for ~15 years. Don't select it by default anymore. > > > > > > Signed-off-by: Marc Gonzalez > > > --- > > > drivers/scsi/Kconfig | 3 --- > > > 1 file changed, 3 deletions(-) > > > > > > diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig > > > index 73bce9b6d037..8c95e9ad6470 100644 > > > --- a/drivers/scsi/Kconfig > > > +++ b/drivers/scsi/Kconfig > > > @@ -54,14 +54,11 @@ config SCSI_NETLINK > > > config SCSI_PROC_FS > > > bool "legacy /proc/scsi/ support" > > > depends on SCSI && PROC_FS > > > - default y > > > ---help--- > > > This option enables support for the various files in > > > /proc/scsi. In Linux 2.6 this has been superseded by > > > files in sysfs but many legacy applications rely on this. > > > - If unsure say Y. > > > - > > > comment "SCSI support type (disk, tape, CD-ROM)" > > > depends on SCSI > > > > Hi Doug, > > > > If I run grep "/proc/scsi" over the sg3_utils source code then grep reports > > 38 matches for that string. Does sg3_utils break with SCSI_PROC_FS=n? > > First, the sg driver. If placing > #undef CONFIG_SCSI_PROC_FS > > prior to the includes in sg.c is a valid way to test that then the > answer is no. Ah, but you are talking about sg3_utils . > > Or are you? For sg3_utils: > > $ find . -name '*.c' -exec grep "/proc/scsi" {} \; -print > static const char * proc_allow_dio = "/proc/scsi/sg/allow_dio"; > ./src/sg_read.c > static const char * proc_allow_dio = "/proc/scsi/sg/allow_dio"; > ./src/sgp_dd.c > static const char * proc_allow_dio = "/proc/scsi/sg/allow_dio"; > ./src/sgm_dd.c > static const char * proc_allow_dio = "/proc/scsi/sg/allow_dio"; > ./src/sg_dd.c > "'echo 1 > /proc/scsi/sg/allow_dio'\n", q_len, dirio_count); > ./testing/sg_tst_bidi.c > static const char * proc_allow_dio = "/proc/scsi/sg/allow_dio"; > ./examples/sgq_dd.c > > > That is 6 (not 38) by my count. Those 6 are all for direct IO > (see below) which is off by default. I suspect old scanning > utilities like sg_scan and sg_map might also use /proc/scsi/* . > That is one reason why I wrote lsscsi. However I can't force folks > to use lsscsi. As a related example, I still get bug reports for > sginfo which I inherited from Eric Youngdale. > > If I was asked to debug a problem with the sg driver in a > system without CONFIG_SCSI_PROC_FS defined, I would decline. > > The absence of /proc/scsi/sg/debug would be my issue. Can this > be set up to do the same thing: > cat /sys/class/scsi_generic/debug > Is that breaking any sysfs rules? > > > Also folks who rely on this to work: > cat /proc/scsi/sg/devices > 0 0 0 0 0 1 255 0 1 > 0 0 0 1 0 1 255 0 1 > 0 0 0 2 0 1 255 0 1 > > would be disappointed. Further I note that setting allow_dio via > /proc/scsi/sg/allow_dio can also be done via /sys/module/sg/allow_dio . > So that would be an interface breakage, but with an alternative. > > Doug Gilbert > You can grep for /proc/scsi/ across all Debian packages: https://codesearch.debian.net/ This reveals that /proc/scsi/sg/ appears in smartmontools and other packages, for example. --