[dm-devel] [PATCH v3 09/11] block: Expose queue nr_zones in sysfs
Hannes Reinecke
hare at suse.de
Fri Oct 12 07:41:28 UTC 2018
On 10/12/18 4:30 AM, 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>
> ---
> block/blk-sysfs.c | 11 +++++++++++
> include/linux/blkdev.h | 10 ++++++++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index 3772671cf2bc..92be8092ca4f 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -300,6 +300,11 @@ static ssize_t queue_zoned_show(struct request_queue *q, char *page)
> }
> }
>
> +static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
> +{
> + return queue_var_show(blk_queue_nr_zones(q), page);
> +}
> +
> static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
> {
> return queue_var_show((blk_queue_nomerges(q) << 1) |
> @@ -637,6 +642,11 @@ static struct queue_sysfs_entry queue_zoned_entry = {
> .show = queue_zoned_show,
> };
>
> +static struct queue_sysfs_entry queue_nr_zones_entry = {
> + .attr = {.name = "nr_zones", .mode = 0444 },
> + .show = queue_nr_zones_show,
> +};
> +
> static struct queue_sysfs_entry queue_nomerges_entry = {
> .attr = {.name = "nomerges", .mode = 0644 },
> .show = queue_nomerges_show,
> @@ -727,6 +737,7 @@ static struct attribute *default_attrs[] = {
> &queue_write_zeroes_max_entry.attr,
> &queue_nonrot_entry.attr,
> &queue_zoned_entry.attr,
> + &queue_nr_zones_entry.attr,
> &queue_nomerges_entry.attr,
> &queue_rq_affinity_entry.attr,
> &queue_iostats_entry.attr,
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index c24969b1741b..879753b10263 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -804,6 +804,11 @@ static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
> }
>
> #ifdef CONFIG_BLK_DEV_ZONED
> +static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
> +{
> + return blk_queue_is_zoned(q) ? q->nr_zones : 0;
> +}
> +
> static inline unsigned int blk_queue_zone_no(struct request_queue *q,
> sector_t sector)
> {
> @@ -819,6 +824,11 @@ static inline bool blk_queue_zone_is_seq(struct request_queue *q,
> return false;
> return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
> }
> +#else /* CONFIG_BLK_DEV_ZONED */
> +static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
> +{
> + return 0;
> +}
> #endif /* CONFIG_BLK_DEV_ZONED */
>
> static inline bool rq_is_sync(struct request *rq)
>
Actually, we should be checking whether we can't blank out this
attribute via the is_visible mechanism; after all, not every block
device is zoned, and those which are not have no need of the attribute...
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare at suse.de +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
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