[PATCH v8 04/11] nvmet: Allow ZNS target to support non-power_of_2 zone sizes

From: Pankaj Raghav
Date: Wed Jul 27 2022 - 12:24:37 EST


A generic bdev_zone_no() helper is added to calculate zone number for a
given sector in a block device. This helper internally uses disk_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@xxxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
---
drivers/nvme/target/zns.c | 3 +--
include/linux/blkdev.h | 5 +++++
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
index c7ef69f29fe4..662f1a92f39b 100644
--- a/drivers/nvme/target/zns.c
+++ b/drivers/nvme/target/zns.c
@@ -241,8 +241,7 @@ 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 bdev_nr_zones(req->ns->bdev) -
- (sect >> ilog2(bdev_zone_sectors(req->ns->bdev)));
+ return bdev_nr_zones(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 1be805223026..d1ef9b9552ed 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1350,6 +1350,11 @@ static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
return BLK_ZONED_NONE;
}

+static inline unsigned int bdev_zone_no(struct block_device *bdev, sector_t sec)
+{
+ return disk_zone_no(bdev->bd_disk, sec);
+}
+
static inline int queue_dma_alignment(const struct request_queue *q)
{
return q ? q->dma_alignment : 511;
--
2.25.1