Add VDI.export_changed_blocks call

Signed-off-by: Gabor Igloi <[email protected]>

Author: gaborigloi

storage/storage_interface.ml

@@ -413,6 +413,9 @@ module VDI = struct
   (** [data_destroy dbg sr vdi] deletes the data of the snapshot [vdi] without deleting its changed block tracking metadata *)
   external data_destroy: dbg:debug_info -> sr:sr -> vdi:vdi -> unit = ""
 
+  (** [export_changed_blocks dbg sr vdi_from vdi_to] returns the blocks that have changed between [vdi_from] and [vdi_to] as a base64-encoded bitmap string *)
+  external export_changed_blocks: dbg:debug_info -> sr:sr -> vdi_from:vdi -> vdi_to:vdi -> string = ""
+
 end
 
 (** [get_by_name task name] returns a vdi with [name] (which may be in any SR) *)

storage/storage_skeleton.ml

@@ -79,6 +79,7 @@ module VDI = struct
   let enable_cbt ctx ~dbg ~sr ~vdi = u "VDI.enable_cbt"
   let disable_cbt ctx ~dbg ~sr ~vdi = u "VDI.disable_cbt"
   let data_destroy ctx ~dbg ~sr ~vdi = u "VDI.data_destroy"
+  let export_changed_blocks ctx ~dbg ~sr ~vdi_from ~vdi_to = u "VDI.export_changed_blocks"
 end
 
 let get_by_name ctx ~dbg ~name = u "get_by_name"