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

["Javier González" <javier@javigon.com>]

On 25.06.2020 17:13, Matias Bjørling wrote:
>On 25/06/2020 14.21, 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
>>+ */
>>+enum blk_zone_attr {
>>+	BLK_ZONE_ATTR_ZFC	= 1 << 0,
>>+	BLK_ZONE_ATTR_FZR	= 1 << 1,
>>+	BLK_ZONE_ATTR_RZR	= 1 << 2,
>
>The RZR bit is equivalent to the RESET bit accessible through the 
>reset byte in struct blk_zone.
>
>ZFC is tied to Zone Active Excursions, as there is no support in the 
>kernel zone model for that. This should probably not be added until 
>there is generic support.
>
>Damien, could we overload the struct blk_zine reset variable for FZR? 
>I don't believe we can due to backward compatibility. Is that your 
>understanding as well?
>
>>+	BLK_ZONE_ATTR_ZDEV	= 1 << 7,
>
>There is not currently an equivalent for zone descriptor extensions in 
>ZAC/ZBC. The addition of this field should probably be in a patch that 
>adds generic support for zone descriptor extensions.

The intention was to just report the values on the IOCTL and make sure
that changes to struct blk_zone are OK.

>>+};
>>+
>>  /**
>>   * 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];
>>  };
>
>