Re: [PATCH v4 1/4] ublk: change ublk IO command defines to enum

[Andreas Hindborg (Samsung)]

Damien Le Moal <dlemoal@xxxxxxxxxx> writes:

> On 6/29/23 04:06, Andreas Hindborg wrote:
>> From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
>> 
>> This change is in preparation for zoned storage support.
>> 
>> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
>> ---
>>  include/uapi/linux/ublk_cmd.h | 23 +++++++++++++++++------
>>  1 file changed, 17 insertions(+), 6 deletions(-)
>> 
>> diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
>> index 4b8558db90e1..471b3b983045 100644
>> --- a/include/uapi/linux/ublk_cmd.h
>> +++ b/include/uapi/linux/ublk_cmd.h
>> @@ -229,12 +229,23 @@ struct ublksrv_ctrl_dev_info {
>>  	__u64   reserved2;
>>  };
>>  
>> -#define		UBLK_IO_OP_READ		0
>> -#define		UBLK_IO_OP_WRITE		1
>> -#define		UBLK_IO_OP_FLUSH		2
>> -#define		UBLK_IO_OP_DISCARD	3
>> -#define		UBLK_IO_OP_WRITE_SAME	4
>> -#define		UBLK_IO_OP_WRITE_ZEROES	5
>> +enum ublk_op {
>> +	UBLK_IO_OP_READ = 0,
>> +	UBLK_IO_OP_WRITE = 1,
>> +	UBLK_IO_OP_FLUSH = 2,
>> +	UBLK_IO_OP_DISCARD = 3,
>> +	UBLK_IO_OP_WRITE_SAME = 4,
>> +	UBLK_IO_OP_WRITE_ZEROES = 5,
>> +	UBLK_IO_OP_ZONE_OPEN = 10,
>> +	UBLK_IO_OP_ZONE_CLOSE = 11,
>> +	UBLK_IO_OP_ZONE_FINISH = 12,
>> +	UBLK_IO_OP_ZONE_APPEND = 13,
>> +	UBLK_IO_OP_ZONE_RESET = 15,
>> +	__UBLK_IO_OP_DRV_IN_START = 32,
>> +	__UBLK_IO_OP_DRV_IN_END = 96,
>> +	__UBLK_IO_OP_DRV_OUT_START = __UBLK_IO_OP_DRV_IN_END,
>> +	__UBLK_IO_OP_DRV_OUT_END = 160,
>> +};
>
> This patch does not do what the title says. You are also introducing the zone
> operations, and the very obscure __UBLK_IO_OP_DRV_XXX operations without an
> explanation. Also, why the "__" prefix for these ? I do not see the point...
> Given that this is a uapi, a comment to explain the less obvious commands would
> be nice.

It is a little vague, I'll make sure to include a better description 👍

>
> So I think the change to an enum for the existing ops can be done either in
> patch 2 or as a separate patch and the introduction of the zone operations done
> in patch 3 or as a separate patch.

I agree, the zone ops should not be introduced in this patch, I will
move them to patch 3. That is a mistake.

Best regards,
Andreas