jfs: use sb_bdev_nr_blocks

Use the sb_bdev_nr_blocks helper instead of open coding it.

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/20211018101130.1838532-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/jfs/resize.c

@@ -86,8 +86,7 @@ int jfs_extendfs(struct super_block *sb, s64 newLVSize, int newLogSize)
 		goto out;
 	}
 
-	VolumeSize = i_size_read(sb->s_bdev->bd_inode) >> sb->s_blocksize_bits;
-
+	VolumeSize = sb_bdev_nr_blocks(sb);
 	if (VolumeSize) {
 		if (newLVSize > VolumeSize) {
 			printk(KERN_WARNING "jfs_extendfs: invalid size\n");

fs/jfs/super.c

@@ -284,8 +284,7 @@ static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
 		}
 		case Opt_resize_nosize:
 		{
-			*newLVSize = i_size_read(sb->s_bdev->bd_inode) >>
-				sb->s_blocksize_bits;
+			*newLVSize = sb_bdev_nr_blocks(sb);
 			if (*newLVSize == 0)
 				pr_err("JFS: Cannot determine volume size\n");
 			break;