> On Jun 29, 2020, at 2:06 PM, Keith Busch <kbusch@xxxxxxxxxx> wrote:
>
> From: Matias Bjørling <matias.bjorling@xxxxxxx>
>
> In the zoned storage model, the sectors within a zone are typically all
> writeable. With the introduction of the Zoned Namespace (ZNS) Command
> Set in the NVM Express organization, the model was extended to have a
> specific writeable capacity.
>
> Extend the zone descriptor data structure with a zone capacity field to
> indicate to the user how many sectors in a zone are writeable.
>
> Introduce backward compatibility in the zone report ioctl by extending
> the zone report header data structure with a flags field to indicate if
> the capacity field is available.
>
> Reviewed-by: Jens Axboe <axboe@xxxxxxxxx>
> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
> Reviewed-by: Javier González <javier.gonz@xxxxxxxxxxx>
> Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
> Signed-off-by: Matias Bjørling <matias.bjorling@xxxxxxx>
> ---
> block/blk-zoned.c | 1 +
> drivers/block/null_blk_zoned.c | 2 ++
> drivers/scsi/sd_zbc.c | 1 +
> include/uapi/linux/blkzoned.h | 15 +++++++++++++--
> 4 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> index 23831fa8701d..81152a260354 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -312,6 +312,7 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
> return ret;
>
> rep.nr_zones = ret;
> + rep.flags = BLK_ZONE_REP_CAPACITY;
> if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report)))
> return -EFAULT;
> return 0;
> diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
> index cc47606d8ffe..624aac09b005 100644
> --- a/drivers/block/null_blk_zoned.c
> +++ b/drivers/block/null_blk_zoned.c
> @@ -47,6 +47,7 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
>
> zone->start = sector;
> zone->len = dev->zone_size_sects;
> + zone->capacity = zone->len;
> zone->wp = zone->start + zone->len;
> zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
> zone->cond = BLK_ZONE_COND_NOT_WP;
> @@ -59,6 +60,7 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
>
> zone->start = zone->wp = sector;
> zone->len = dev->zone_size_sects;
> + zone->capacity = zone->len;
> zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
> zone->cond = BLK_ZONE_COND_EMPTY;
>
> diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
> index 6f7eba66687e..183a20720da9 100644
> --- a/drivers/scsi/sd_zbc.c
> +++ b/drivers/scsi/sd_zbc.c
> @@ -59,6 +59,7 @@ static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
> zone.non_seq = 1;
>
> zone.len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
> + zone.capacity = zone.len;
> zone.start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
> zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
> if (zone.type != ZBC_ZONE_TYPE_CONV &&
> diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h
> index 0cdef67135f0..42c3366cc25f 100644
> --- a/include/uapi/linux/blkzoned.h
> +++ b/include/uapi/linux/blkzoned.h
> @@ -73,6 +73,15 @@ enum blk_zone_cond {
> BLK_ZONE_COND_OFFLINE = 0xF,
> };
>
> +/**
> + * enum blk_zone_report_flags - Feature flags of reported zone descriptors.
> + *
> + * @BLK_ZONE_REP_CAPACITY: Zone descriptor has capacity field.
> + */
> +enum blk_zone_report_flags {
> + BLK_ZONE_REP_CAPACITY = (1 << 0),
> +};
> +
> /**
> * struct blk_zone - Zone descriptor for BLKREPORTZONE ioctl.
> *
> @@ -99,7 +108,9 @@ struct blk_zone {
> __u8 cond; /* Zone condition */
> __u8 non_seq; /* Non-sequential write resources active */
> __u8 reset; /* Reset write pointer recommended */
> - __u8 reserved[36];
> + __u8 resv[4];
> + __u64 capacity; /* Zone capacity in number of sectors */
> + __u8 reserved[24];
> };
>
> /**
> @@ -115,7 +126,7 @@ struct blk_zone {
> struct blk_zone_report {
> __u64 sector;
> __u32 nr_zones;
> - __u8 reserved[4];
> + __u32 flags;
> struct blk_zone zones[0];
> };
>
> --
> 2.24.1
>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
--
Himanshu Madhani Oracle Linux Engineering
