Re: [dm-devel] [RFC PATCH v2 1/2] scsi: convert scsi_result_to_blk_status() to inline

[Bart Van Assche <bvanassche@acm.org>]

On 4/29/21 1:33 PM, Martin Wilck wrote:
> On Thu, 2021-04-29 at 09:20 -0700, Bart Van Assche wrote:
>> On 4/29/21 8:50 AM, mwilck@suse.com wrote:
>>> This makes it possible to use scsi_result_to_blk_status() from
>>> code that shouldn't depend on scsi_mod (e.g. device mapper).
>>
>> I think that's the wrong reason to make a function inline. Please
>> consider moving scsi_result_to_blk_status() into one of the block
>> layer
>> source code files that already deals with SG I/O, e.g.
>> block/scsi_ioctl.c.
> 
> scsi_ioctl.c, are you certain? scsi_result_to_blk_status() is an
> important part of the block/scsi interface... You're right that that
> this function is not a prime candidate for inlining, but I'm still
> wondering where it belongs if we don't.

The block/scsi_ioctl.c file is included in the kernel if and only if
BLK_SCSI_REQUEST is enabled. And that Kconfig symbol only selects the
block/scsi_ioctl.c file. Additionally, the following occurs in the SCSI
Kconfig file:

config SCSI
	tristate "SCSI device support"
	[ ... ]
	select BLK_SCSI_REQUEST

In other words, block/scsi_ioctl.c is built unconditionally if SCSI is
enabled. Adding the scsi_result_to_blk_status() function to the
block/scsi_ioctl.c file would increase the size of kernels that enable
bsg, ide, the SCSI target code or nfsd but not the SCSI initiator code.
If the latter is a concern, how about moving scsi_result_to_blk_status()
into a new file in the block directory?

Thanks,

Bart.