block: Define bdev_nr_zones() as an inline function

There is no need for bdev_nr_zones() to be an exported function
calculating the number of zones of a block device. Instead, given that
all callers use this helper with a fully initialized block device that
has a gendisk, we can redefine this function as an inline helper in
blkdev.h.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240621031506.759397-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: damien-lemoal

block/blk-zoned.c

@@ -115,24 +115,6 @@ const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
 }
 EXPORT_SYMBOL_GPL(blk_zone_cond_str);
 
-/**
- * bdev_nr_zones - Get number of zones
- * @bdev:	Target device
- *
- * Return the total number of zones of a zoned block device.  For a block
- * device without zone capabilities, the number of zones is always 0.
- */
-unsigned int bdev_nr_zones(struct block_device *bdev)
-{
-	sector_t zone_sectors = bdev_zone_sectors(bdev);
-
-	if (!bdev_is_zoned(bdev))
-		return 0;
-	return (bdev_nr_sectors(bdev) + zone_sectors - 1) >>
-		ilog2(zone_sectors);
-}
-EXPORT_SYMBOL_GPL(bdev_nr_zones);
-
 /**
  * blkdev_report_zones - Get zones information
  * @bdev:	Target block device

include/linux/blkdev.h

@@ -673,7 +673,6 @@ static inline bool blk_queue_is_zoned(struct request_queue *q)
 }
 
 #ifdef CONFIG_BLK_DEV_ZONED
-unsigned int bdev_nr_zones(struct block_device *bdev);
 
 static inline unsigned int disk_nr_zones(struct gendisk *disk)
 {
@@ -687,6 +686,11 @@ static inline unsigned int disk_zone_no(struct gendisk *disk, sector_t sector)
 	return sector >> ilog2(disk->queue->limits.chunk_sectors);
 }
 
+static inline unsigned int bdev_nr_zones(struct block_device *bdev)
+{
+	return disk_nr_zones(bdev->bd_disk);
+}
+
 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
 {
 	return bdev->bd_disk->queue->limits.max_open_zones;