diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index d9bf53d9ff90..28e202e89660 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -325,7 +325,8 @@ struct btrfs_dio_private {
 	struct inode *inode;
 	u64 logical_offset;
 	u64 disk_bytenr;
-	u64 bytes;
+	/* Used for bio::bi_size */
+	u32 bytes;
 
 	/*
 	 * References to this structure. There is one reference per in-flight