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@xxxxxxx>
---
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@xxxxxxx +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)
