Re: [PATCH 1/4] scsi: core: constify pointer to scsi_host_template

From: Bart Van Assche <bvanassche@acm.org>
To: dgilbert@interlog.com, John Garry <john.garry@huawei.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Christoph Hellwig <hch@infradead.org>
Cc: "Ewan D. Milne" <emilne@redhat.com>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Avri Altman <avri.altman@wdc.com>,
	linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
	james.smart@broadcom.com
Subject: Re: [PATCH 1/4] scsi: core: constify pointer to scsi_host_template
Date: Mon, 25 Apr 2022 21:13:33 -0700	[thread overview]
Message-ID: <f6516c7f-16c7-689c-b6cd-ebff95e931a4@acm.org> (raw)
In-Reply-To: <5485f529-e99a-0bdd-07bd-b5b559da91e6@interlog.com>

On 4/25/22 18:54, Douglas Gilbert wrote:
> On 2022-04-25 21:16, Bart Van Assche wrote:
>> How about removing scsi_proc_hostdir_add(), scsi_proc_hostdir_rm() and 
>> all other code that creates files or directories under /proc/scsi? 
>> There should be corresponding entries in sysfs for all /proc/scsi 
>> entries. Some tools in sg3_utils use that directory so sg3_utils will 
>> have to be updated.
> 
> ... breaking this:
> 
> ~$ cat /proc/scsi/scsi
> 
> Attached devices:
> 
> Host: scsi3 Channel: 00 Id: 00 Lun: 00
> 
>    Vendor: IBM-207x Model: HUSMM8020ASS20   Rev: J4B6
> 
>    Type:   Direct-Access                    ANSI  SCSI revision: 06
> 
> Host: scsi3 Channel: 00 Id: 01 Lun: 00
> 
>    Vendor: IBM-207x Model: HUSMM8020ASS20   Rev: J4B6
> 
>    Type:   Direct-Access                    ANSI  SCSI revision: 06
> 
> Host: scsi3 Channel: 00 Id: 02 Lun: 00
> 
>    Vendor: SEAGATE  Model: ST200FM0073      Rev: 0007
> 
>    Type:   Direct-Access                    ANSI  SCSI revision: 06
> ...
> 
> A deprecation notice would be helpful, then removal after a few kernel
> cycles.

Agreed with the deprecation notice + delayed removal, but is anyone 
using cat /proc/scsi/scsi?

> Yes, lsscsi can give that output:
> 
> $ lsscsi -c
> 
> Attached devices:
> 
> Host: scsi2 Channel: 00 Target: 00 Lun: 00
> 
>    Vendor: SEAGATE  Model: ST200FM0073      Rev: 0007
> 
>    Type:   Direct-Access                    ANSI SCSI revision: 06
> 
> Host: scsi2 Channel: 00 Target: 01 Lun: 00
> 
>    Vendor: WDC      Model: WSH722020AL5204  Rev: C421
> 
>    Type:   Zoned Block                      ANSI SCSI revision: 07
> 
> Host: scsi2 Channel: 00 Target: 02 Lun: 00
> 
>    Vendor: Areca Te Model: ARC-802801.37.69 Rev: 0137
> 
>    Type:   Enclosure                        ANSI SCSI revision: 05
> ...
> 
> [Hmmm, in a different order.]
> 
> However no distribution that I'm aware of includes lsscsi in its 
> installation.
> [Most recent example: Ubuntu 22.04]

Hmm ... are you sure? Last time I looked into this an lsscsi package was 
available for every distro I tried (RHEL, SLES, Debian and openSUSE). 
See also 
https://packages.debian.org/search?searchon=contents&keywords=lsscsi&mode=path&suite=stable&arch=any.

Are there other utilities in sg3_utils that would break if the 
/proc/scsi directory would be removed?

$ cd sg3_utils && git grep /proc/scsi | wc -l
51

Thanks,

Bart.