jfs: use bdev_nr_bytes instead of open coding it

Use the proper helper to read the block device size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Link: https://lore.kernel.org/r/20211018101130.1838532-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/jfs/resize.c

@@ -199,7 +199,7 @@ int jfs_extendfs(struct super_block *sb, s64 newLVSize, int newLogSize)
 	txQuiesce(sb);
 
 	/* Reset size of direct inode */
-	sbi->direct_inode->i_size =  i_size_read(sb->s_bdev->bd_inode);
+	sbi->direct_inode->i_size = bdev_nr_bytes(sb->s_bdev);
 
 	if (sbi->mntflag & JFS_INLINELOG) {
 		/*

fs/jfs/super.c

@@ -551,7 +551,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 		ret = -ENOMEM;
 		goto out_unload;
 	}
-	inode->i_size = i_size_read(sb->s_bdev->bd_inode);
+	inode->i_size = bdev_nr_bytes(sb->s_bdev);
 	inode->i_mapping->a_ops = &jfs_metapage_aops;
 	inode_fake_hash(inode);
 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);