[PATCH v4 04/13] nvmet: Allow ZNS target to support non-power_of_2 zone sizes

[Pankaj Raghav]

A generic bdev_zone_no helper is added to calculate zone number for a given
sector in a block device. This helper internally uses blk_queue_zone_no to
find the zone number.

Use the helper bdev_zone_no() to calculate nr of zones. This let's us
make modifications to the math if needed in one place and adds now
support for npo2 zone devices.

Reviewed by: Adam Manzanares <a.manzanares at samsung.com>
Reviewed-by: Bart Van Assche <bvanassche at acm.org>
Reviewed-by: Hannes Reinecke <hare at suse.de>
Signed-off-by: Luis Chamberlain <mcgrof at kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav at samsung.com>
---
 drivers/nvme/target/zns.c | 2 +-
 include/linux/blkdev.h    | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
index 82b61acf7..5516dd6cc 100644
--- a/drivers/nvme/target/zns.c
+++ b/drivers/nvme/target/zns.c
@@ -242,7 +242,7 @@ static unsigned long nvmet_req_nr_zones_from_slba(struct nvmet_req *req)
 	unsigned int sect = nvmet_lba_to_sect(req->ns, req->cmd->zmr.slba);
 
 	return blkdev_nr_zones(req->ns->bdev->bd_disk) -
-		(sect >> ilog2(bdev_zone_sectors(req->ns->bdev)));
+	       bdev_zone_no(req->ns->bdev, sect);
 }
 
 static unsigned long get_nr_zones_from_buf(struct nvmet_req *req, u32 bufsize)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 32d7bd7b1..967790f51 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1370,6 +1370,13 @@ static inline sector_t bdev_zone_sectors(struct block_device *bdev)
 	return 0;
 }
 
+static inline unsigned int bdev_zone_no(struct block_device *bdev, sector_t sec)
+{
+	struct request_queue *q = bdev_get_queue(bdev);
+
+	return blk_queue_zone_no(q, sec);
+}
+
 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
-- 
2.25.1