diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 35dec3e..10ca010 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -19,6 +19,8 @@
 #ifndef __BTRFS_VOLUMES_
 #define __BTRFS_VOLUMES_
 
+#include <linux/bio.h>
+
 struct btrfs_device {
 	struct list_head dev_list;
 	struct btrfs_root *dev_root;
@@ -69,12 +71,29 @@
 	struct list_head list;
 };
 
+struct btrfs_bio_stripe {
+	struct btrfs_device *dev;
+	u64 physical;
+};
+
+struct btrfs_multi_bio {
+	atomic_t stripes_pending;
+	bio_end_io_t *end_io;
+	void *private;
+	int error;
+	int num_stripes;
+	struct btrfs_bio_stripe stripes[];
+};
+
+#define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
+			    (sizeof(struct btrfs_bio_stripe) * (n)))
+
 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
 			   struct btrfs_device *device,
 			   u64 owner, u64 num_bytes, u64 *start);
-int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, int stripe_nr,
-		    u64 logical, u64 *phys, u64 *length,
-		    struct btrfs_device **dev, int *total_stripes);
+int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
+		    u64 logical, u64 *length,
+		    struct btrfs_multi_bio **multi_ret);
 int btrfs_read_sys_array(struct btrfs_root *root);
 int btrfs_read_chunk_tree(struct btrfs_root *root);
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,