diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7fb59d4..7b38d06 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -145,6 +145,17 @@
 	u64 max_avail;
 };
 
+struct map_lookup {
+	u64 type;
+	int io_align;
+	int io_width;
+	int stripe_len;
+	int sector_size;
+	int num_stripes;
+	int sub_stripes;
+	struct btrfs_bio_stripe stripes[];
+};
+
 /* Used to sort the devices by max_avail(descending sort) */
 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2);