Re: [PATCH 3/6] block: Create scsi_sense.h for SCSI and ATAPI

From: Jens Axboe <axboe@kernel.dk>
To: Randy Dunlap <rdunlap@infradead.org>, Kees Cook <keescook@chromium.org>
Cc: Christoph Hellwig <hch@infradead.org>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	James Bottomley <James.Bottomley@hansenpartnership.com>,
	Tejun Heo <tj@kernel.org>, Borislav Petkov <bp@alien8.de>,
	"David S. Miller" <davem@davemloft.net>,
	"Manoj N. Kumar" <manoj@linux.vnet.ibm.com>,
	"Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>,
	Uma Krishnan <ukrishn@linux.vnet.ibm.com>,
	linux-block <linux-block@vger.kernel.org>,
	linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/6] block: Create scsi_sense.h for SCSI and ATAPI
Date: Wed, 23 May 2018 15:22:35 -0600	[thread overview]
Message-ID: <4f95332f-e298-8d7d-1284-5363c10412a8@kernel.dk> (raw)
In-Reply-To: <e9eb326b-aa80-07a3-4579-6828f22cdad2@infradead.org>

On 5/23/18 3:20 PM, Randy Dunlap wrote:
> On 05/23/2018 02:14 PM, Jens Axboe wrote:
>> On 5/23/18 2:52 PM, Kees Cook wrote:
>>> On Wed, May 23, 2018 at 7:31 AM, Jens Axboe <axboe@kernel.dk> wrote:
>>>> On 5/23/18 8:25 AM, Christoph Hellwig wrote:
>>>>> On Wed, May 23, 2018 at 08:13:56AM -0600, Jens Axboe wrote:
>>>>>>> Should I move to code to a new drivers/scsi/scsi_sense.c and add it to
>>>>>>> drivers/scsi/Makefile as:
>>>>>>>
>>>>>>> obj-$(CONFIG_BLK_SCSI_REQUEST)    += scsi_sense.o
>>>>>>>
>>>>>>> Every place I want to use the code is already covered by
>>>>>>> CONFIG_BLK_SCSI_REQUEST, so it seems like I just need to know where to
>>>>>>> put the .c file. :P
>>>>>>
>>>>>> I think this is so much saner than a SCSI select or dependency, so I'll
>>>>>> have to disagree with Martin and Christoph. Just put it in drivers/scsi,
>>>>>> if it's the location they care about.
>>>>>
>>>>> I actually plan to remove CONFIG_BLK_SCSI_REQUEST in a merge window
>>>>> or two.  The only users are scsi and the ide layer, (virtio_blk
>>>>> support has already been accidentally disabled for a while), and getting
>>>>> rid of it allows to to shrink and simply the scsi data structures.
>>>>>
>>>>> But if you want this for now lets keep scsi_sense.c in drivers/scsi
>>>>> but depend on CONFIG_BLK_SCSI_REQUEST, that is easy enough to fix up.
>>>>
>>>> It could be a stand-alone dependency, doesn't have to be BLK_SCSI_REQUEST.
>>>> BLA_SCSI_SENSE or something would do. I don't care too much about that,
>>>> mostly getting rid of the entire stack dependency.
>>>
>>> Aaand, I can't do this and leave it in drivers/scsi because of drivers/Makefile:
>>>
>>> obj-$(CONFIG_SCSI)              += scsi/
>>>
>>> So: this needs to live in block/ just like CONFIG_BLK_SCSI_REQUEST's
>>> scsi_ioctl.c. I will split it into CONFIG_BLK_SCSI_SENSE, but I'll
>>> still need to move the code from drivers/scsi/ to block/. Is this
>>> okay?
>>
>> Ugh, so that would necessitate a change there too. As I said before,
>> I don't really care where it lives. I know the SCSI folks seem bothered
>> by moving it, but in reality, it's not like this stuff will likely ever
>> really change. Of the two choices (select entire SCSI stack, or just move
>> this little bit), I know what I would consider the saner option...
>>
> 
> or option 3:
> 
> obj-y                           += scsi/
> 
> so that make descends into drivers/scsi/ and then builds whatever is needed,
> depending on individual kconfig options.

Right, that was the initial option, the later two are the other options.

-- 
Jens Axboe