block: add a bdev_nr_bytes helper

Add a helper to query the size of a block device in bytes.  This
will be used to remove open coded access to ->bd_inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211018101130.1838532-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index cd4038fd57436c34bed8056fa071418b705c8fda..01d27f3a970e613d5482d7133b45a5098c5932c4 100644 (file)
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -236,9 +236,14 @@ static inline sector_t get_start_sect(struct block_device *bdev)
        return bdev->bd_start_sect;
 }
 
+static inline loff_t bdev_nr_bytes(struct block_device *bdev)
+{
+       return i_size_read(bdev->bd_inode);
+}
+
 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
 {
-       return i_size_read(bdev->bd_inode) >> 9;
+       return bdev_nr_bytes(bdev) >> SECTOR_SHIFT;
 }
 
 static inline sector_t get_capacity(struct gendisk *disk)