Re: [PATCH 5/6] block: add zone attr. to zone mgmt IOCTL struct

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2020/06/26 15:03, Javier González wrote:
> On 26.06.2020 01:45, Damien Le Moal wrote:
>> On 2020/06/25 21:22, Javier González wrote:
>>> From: Javier González <javier.gonz@samsung.com>
>>>
>>> Add zone attributes field to the blk_zone structure. Use ZNS attributes
>>> as base for zoned block devices in general.
>>>
>>> Signed-off-by: Javier González <javier.gonz@samsung.com>
>>> Signed-off-by: SelvaKumar S <selvakuma.s1@samsung.com>
>>> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
>>> Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
>>> ---
>>>  drivers/nvme/host/zns.c       |  1 +
>>>  include/uapi/linux/blkzoned.h | 13 ++++++++++++-
>>>  2 files changed, 13 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
>>> index 258d03610cc0..7d8381fe7665 100644
>>> --- a/drivers/nvme/host/zns.c
>>> +++ b/drivers/nvme/host/zns.c
>>> @@ -195,6 +195,7 @@ static int nvme_zone_parse_entry(struct nvme_ns *ns,
>>>  	zone.capacity = nvme_lba_to_sect(ns, le64_to_cpu(entry->zcap));
>>>  	zone.start = nvme_lba_to_sect(ns, le64_to_cpu(entry->zslba));
>>>  	zone.wp = nvme_lba_to_sect(ns, le64_to_cpu(entry->wp));
>>> +	zone.attr = entry->za;
>>>
>>>  	return cb(&zone, idx, data);
>>>  }
>>> diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h
>>> index 0c49a4b2ce5d..2e43a00e3425 100644
>>> --- a/include/uapi/linux/blkzoned.h
>>> +++ b/include/uapi/linux/blkzoned.h
>>> @@ -82,6 +82,16 @@ enum blk_zone_report_flags {
>>>  	BLK_ZONE_REP_CAPACITY	= (1 << 0),
>>>  };
>>>
>>> +/**
>>> + * Zone Attributes
>>
>> This is a user interface file. Please document the meaning of each attribute.
>>
> 
> Sure.
> 
>>> + */
>>> +enum blk_zone_attr {
>>> +	BLK_ZONE_ATTR_ZFC	= 1 << 0,
>>> +	BLK_ZONE_ATTR_FZR	= 1 << 1,
>>> +	BLK_ZONE_ATTR_RZR	= 1 << 2,
>>> +	BLK_ZONE_ATTR_ZDEV	= 1 << 7,
>> These are ZNS specific, right ? Integrating the 2 ZBC/ZAC attributes in this
>> list would be nice, namely non_seq and reset. That will imply patching sd.c.
>>
> 
> Of course. I will look at non_seq and reset. Any other that should go
> in here?

See ZBC specs. These are the only 2 zone attributes defined.

> 
>>> +};
>>> +
>>>  /**
>>>   * struct blk_zone - Zone descriptor for BLKREPORTZONE ioctl.
>>>   *
>>> @@ -108,7 +118,8 @@ struct blk_zone {
>>>  	__u8	cond;		/* Zone condition */
>>>  	__u8	non_seq;	/* Non-sequential write resources active */
>>>  	__u8	reset;		/* Reset write pointer recommended */
>>> -	__u8	resv[4];
>>> +	__u8	attr;		/* Zone attributes */
>>> +	__u8	resv[3];
>>>  	__u64	capacity;	/* Zone capacity in number of sectors */
>>>  	__u8	reserved[24];
>>>  };
>>>
>>
>> You are missing a BLK_ZONE_REP_ATTR report flag to indicate to the user that the
>> attr field is present, used and valid.
>>
>> enum blk_zone_report_flags {
>> 	BLK_ZONE_REP_CAPACITY	= (1 << 0),
>> +	BLK_ZONE_REP_ATTR	= (1 << 1),
>> };
>>
>> is I think needed.
> 
> Good point. I will add that on a V2.
> 
> Javier
> 


-- 
Damien Le Moal
Western Digital Research