[dm-devel] [PATCH v3 09/11] block: Expose queue nr_zones in sysfs

[Christoph Hellwig]

On Fri, Oct 12, 2018 at 11:30:10AM +0900, Damien Le Moal wrote:
> Expose through sysfs the nr_zones field of struct request_queue.
> Exposing this value helps in debugging disk issues as well as
> facilitating scripts based use of the disk (e.g. blktests).
> 
> For zoned block devices, the nr_zones field indicates the total number
> of zones of the device calculated using the known disk capacity and
> zone size. This number of zones is always 0 for regular block devices.
> 
> Since nr_zones is defined conditionally with CONFIG_BLK_DEV_ZONED,
> introduce the blk_queue_nr_zones() function to return the correct value
> for any device, regardless if CONFIG_BLK_DEV_ZONED is set.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch at lst.de>