block: Introduce BLKGETNRZONES ioctl
Get a zoned block device total number of zones. The device can be a
partition of the whole device. The number of zones is always 0 for
regular block devices.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/ioctl.c b/block/ioctl.c
index f6d2c6f1..4825c78 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -534,6 +534,8 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
return blkdev_reset_zones_ioctl(bdev, mode, cmd, arg);
case BLKGETZONESZ:
return put_uint(arg, bdev_zone_sectors(bdev));
+ case BLKGETNRZONES:
+ return put_uint(arg, blkdev_nr_zones(bdev));
case HDIO_GETGEO:
return blkdev_getgeo(bdev, argp);
case BLKRAGET:
