From: Damien Le Moal <damien.lemoal@wdc.com>
Date: Fri, 12 Oct 2018 19:08:48 +0900
Subject: [PATCH] block: Expose queue nr_zones in sysfs
Git-commit: 965b652e901886ea54f93c60027b5be76328d958
Patch-mainline: v4.20-rc1
References: bsc#1118139
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.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.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 ca5fdc1b7745..6bb845f9601a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -811,6 +811,11 @@ 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)
{
@@ -826,6 +831,11 @@ 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)
--
2.16.4