On 2020/07/03 3:20, Niklas Cassel wrote:
> Add a new max_active zones definition in the sysfs documentation.
> This definition will be common for all devices utilizing the zoned block
> device support in the kernel.
>
> Export max_active_zones according to this new definition for NVMe Zoned
> Namespace devices, ZAC ATA devices (which are treated as SCSI devices by
> the kernel), and ZBC SCSI devices.
>
> Add the new max_active_zones member to struct request_queue, rather
> than as a queue limit, since this property cannot be split across stacking
> drivers.
>
> For SCSI devices, even though max active zones is not part of the ZBC/ZAC
> spec, export max_active_zones as 0, signifying "no limit".
>
> Signed-off-by: Niklas Cassel <niklas.cas...@wdc.com>
> Reviewed-by: Javier González <jav...@javigon.com>
> ---
> Documentation/block/queue-sysfs.rst | 7 +++++++
> block/blk-sysfs.c | 14 +++++++++++++-
> drivers/nvme/host/zns.c | 1 +
> drivers/scsi/sd_zbc.c | 1 +
> include/linux/blkdev.h | 16 ++++++++++++++++
> 5 files changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/block/queue-sysfs.rst
> b/Documentation/block/queue-sysfs.rst
> index f01cf8530ae4..f261a5c84170 100644
> --- a/Documentation/block/queue-sysfs.rst
> +++ b/Documentation/block/queue-sysfs.rst
> @@ -117,6 +117,13 @@ Maximum number of elements in a DMA scatter/gather list
> with integrity
> data that will be submitted by the block layer core to the associated
> block driver.
>
> +max_active_zones (RO)
> +---------------------
> +For zoned block devices (zoned attribute indicating "host-managed" or
> +"host-aware"), the sum of zones belonging to any of the zone states:
> +EXPLICIT OPEN, IMPLICIT OPEN or CLOSED, is limited by this value.
> +If this value is 0, there is no limit.
> +
> max_open_zones (RO)
> -------------------
> For zoned block devices (zoned attribute indicating "host-managed" or
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index fa42961e9678..624bb4d85fc7 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -310,6 +310,11 @@ static ssize_t queue_max_open_zones_show(struct
> request_queue *q, char *page)
> return queue_var_show(queue_max_open_zones(q), page);
> }
>
> +static ssize_t queue_max_active_zones_show(struct request_queue *q, char
> *page)
> +{
> + return queue_var_show(queue_max_active_zones(q), page);
> +}
> +
> static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
> {
> return queue_var_show((blk_queue_nomerges(q) << 1) |
> @@ -677,6 +682,11 @@ static struct queue_sysfs_entry
> queue_max_open_zones_entry = {
> .show = queue_max_open_zones_show,
> };
>
> +static struct queue_sysfs_entry queue_max_active_zones_entry = {
> + .attr = {.name = "max_active_zones", .mode = 0444 },
> + .show = queue_max_active_zones_show,
> +};
> +
> static struct queue_sysfs_entry queue_nomerges_entry = {
> .attr = {.name = "nomerges", .mode = 0644 },
> .show = queue_nomerges_show,
> @@ -776,6 +786,7 @@ static struct attribute *queue_attrs[] = {
> &queue_zoned_entry.attr,
> &queue_nr_zones_entry.attr,
> &queue_max_open_zones_entry.attr,
> + &queue_max_active_zones_entry.attr,
> &queue_nomerges_entry.attr,
> &queue_rq_affinity_entry.attr,
> &queue_iostats_entry.attr,
> @@ -803,7 +814,8 @@ static umode_t queue_attr_visible(struct kobject *kobj,
> struct attribute *attr,
> (!q->mq_ops || !q->mq_ops->timeout))
> return 0;
>
> - if (attr == &queue_max_open_zones_entry.attr &&
> + if ((attr == &queue_max_open_zones_entry.attr ||
> + attr == &queue_max_active_zones_entry.attr) &&
> !blk_queue_is_zoned(q))
> return 0;
>
> diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
> index 3d80b9cf6bfc..57cfd78731fb 100644
> --- a/drivers/nvme/host/zns.c
> +++ b/drivers/nvme/host/zns.c
> @@ -97,6 +97,7 @@ int nvme_update_zone_info(struct gendisk *disk, struct
> nvme_ns *ns,
> q->limits.zoned = BLK_ZONED_HM;
> blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
> blk_queue_max_open_zones(q, le32_to_cpu(id->mor) + 1);
> + blk_queue_max_active_zones(q, le32_to_cpu(id->mar) + 1);
> free_data:
> kfree(id);
> return status;
> diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
> index aa3564139b40..d8b2c49d645b 100644
> --- a/drivers/scsi/sd_zbc.c
> +++ b/drivers/scsi/sd_zbc.c
> @@ -721,6 +721,7 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned
> char *buf)
> blk_queue_max_open_zones(q, 0);
> else
> blk_queue_max_open_zones(q, sdkp->zones_max_open);
> + blk_queue_max_active_zones(q, 0);
> nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
>
> /* READ16/WRITE16 is mandatory for ZBC disks */
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index fe168abcfdda..bb9e6eb6a7e6 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -521,6 +521,7 @@ struct request_queue {
> unsigned long *conv_zones_bitmap;
> unsigned long *seq_zones_wlock;
> unsigned int max_open_zones;
> + unsigned int max_active_zones;
> #endif /* CONFIG_BLK_DEV_ZONED */
>
> /*
> @@ -741,6 +742,17 @@ static inline unsigned int queue_max_open_zones(const
> struct request_queue *q)
> {
> return q->max_open_zones;
> }
> +
> +static inline void blk_queue_max_active_zones(struct request_queue *q,
> + unsigned int max_active_zones)
> +{
> + q->max_active_zones = max_active_zones;
> +}
> +
> +static inline unsigned int queue_max_active_zones(const struct request_queue
> *q)
> +{
> + return q->max_active_zones;
> +}
> #else /* CONFIG_BLK_DEV_ZONED */
> static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
> {
> @@ -760,6 +772,10 @@ static inline unsigned int queue_max_open_zones(const
> struct request_queue *q)
> {
> return 0;
> }
> +static inline unsigned int queue_max_active_zones(const struct request_queue
> *q)
> +{
> + return 0;
> +}
> #endif /* CONFIG_BLK_DEV_ZONED */
>
> static inline bool rq_is_sync(struct request *rq)
>
Looks good to me.
Reviewed-by: Damien Le Moal <damien.lem...@wdc.com>
--
Damien Le Moal
Western Digital Research
