diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 2d609a5..e8116a4 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -69,10 +69,10 @@
 static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
-
+#ifdef CONFIG_BLOCK
 	if (sb_is_blkdev_sb(sb))
-		return inode->i_mapping->backing_dev_info;
-
+		return blk_get_backing_dev_info(I_BDEV(inode));
+#endif
 	return sb->s_bdi;
 }