Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 3/6] block: Create scsi_sense.h for SCSI and ATAPI
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>
References: <20180522183613.GA3784@infradead.org> <yq1efi3bk3g.fsf@oracle.com>
 <CAGXu5jJ0Sice+fdpWgzBhQR=NGz-DT9qmYVdV1GeH73_q9pbmw@mail.gmail.com>
 <732f4249-5681-4a54-ec21-4ecc3d3a74e5@kernel.dk>
 <20180522191309.GA23615@infradead.org>
 <8d4af5c4-96fa-54ee-d5c1-b887b1de5a3c@kernel.dk>
 <CAGXu5j+mgGZkTDS6EDRspJKKbU=vMT4ehv9T-SekPba=ESoGDg@mail.gmail.com>
 <9A0BC289-4203-4C77-A012-AAB07F42061F@kernel.dk>
 <CAGXu5jJsGWDsZNDJvUUqncSaAcvond_B_J7=BbvVW0X3r6Sxww@mail.gmail.com>
 <aa150272-ffeb-fb8f-7303-0d9502cf9a71@kernel.dk>
 <20180523142545.GA16248@infradead.org>
 <24d36869-e037-042d-cb16-20a81b34eb76@kernel.dk>
 <CAGXu5jJn=1Rz=D8VUwv_VoaGoLtaD=+tcPZxQxntweZoZwFa5Q@mail.gmail.com>
 <f4eb4cd5-8976-3990-69b0-26cca054aa45@kernel.dk>
 <e9eb326b-aa80-07a3-4579-6828f22cdad2@infradead.org>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <4f95332f-e298-8d7d-1284-5363c10412a8@kernel.dk>
Date:   Wed, 23 May 2018 15:22:35 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.0
MIME-Version: 1.0
In-Reply-To: <e9eb326b-aa80-07a3-4579-6828f22cdad2@infradead.org>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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