From 6d2cf9eebf4bddbf868aae7e80a2a0f3b22c4545 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Sun, 24 Apr 2016 11:36:20 +0100

Subject: [PATCH] v2v: target_bus_assignment: Various refactorings.

No functional change.

(cherry picked from commit c1adbe61dfd23ba28e286e0ecaf97bba6de9cdcd)

---

 v2v/target_bus_assignment.ml | 28 +++++++++++++++++-----------

 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/v2v/target_bus_assignment.ml b/v2v/target_bus_assignment.ml

index eb3ed58..0546004 100644

--- a/v2v/target_bus_assignment.ml

+++ b/v2v/target_bus_assignment.ml

@@ -34,13 +34,16 @@ let rec target_bus_assignment source targets guestcaps =

   (* Add the fixed disks (targets) to either the virtio-blk or IDE bus,

    * depending on whether the guest has virtio drivers or not.

    *)

-  iteri (

-    fun i t ->

-      let t = BusSlotTarget t in

+  let () =

+    let bus =

       match guestcaps.gcaps_block_bus with

-      | Virtio_blk -> insert virtio_blk_bus i t

-      | IDE -> insert ide_bus i t

-  ) targets;

+      | Virtio_blk -> virtio_blk_bus

+      | IDE -> ide_bus in

+    iteri (

+      fun i t ->

+        let t = BusSlotTarget t in

+        insert bus i t

+    ) targets in

   (* Now try to add the removable disks to the bus at the same slot

    * they originally occupied, but if the slot is occupied, emit a

@@ -48,15 +51,16 @@ let rec target_bus_assignment source targets guestcaps =

    *)

   List.iter (

     fun r ->

+      let t = BusSlotRemovable r in

       let bus = match r.s_removable_controller with

         | None -> ide_bus (* Wild guess, but should be safe. *)

         | Some Source_virtio_blk -> virtio_blk_bus

         | Some Source_IDE -> ide_bus

         | Some Source_SCSI -> scsi_bus in

       match r.s_removable_slot with

-      | None -> ignore (insert_after bus 0 (BusSlotRemovable r))

+      | None -> ignore (insert_after bus 0 t)

       | Some desired_slot_nr ->

-         if not (insert_after bus desired_slot_nr (BusSlotRemovable r)) then

+         if not (insert_after bus desired_slot_nr t) then

            warning (f_"removable %s device in slot %d clashes with another disk, so it has been moved to a higher numbered slot on the same bus.  This may mean that this removable device has a different name inside the guest (for example a CD-ROM originally called /dev/hdc might move to /dev/hdd, or from D: to E: on a Windows guest).")

                    (match r.s_removable_type with

                     | CDROM -> s_"CD-ROM"

@@ -77,16 +81,18 @@ and insert bus i slot =

     Array.blit oldbus 0 !bus 0 oldlen

   );

   assert (!bus.(i) = BusSlotEmpty);

-  Array.set !bus i slot

+  !bus.(i) <- slot

 (* Insert a slot into the bus, but if the desired slot is not empty, then

  * increment the slot number until we find an empty one.  Returns

  * true if we got the desired slot.

  *)

 and insert_after bus i slot =

-  let len = Array.length !bus in

-  if i >= len || Array.get !bus i = BusSlotEmpty then (

+  if slot_is_empty bus i then (

     insert bus i slot; true

   ) else (

     ignore (insert_after bus (i+1) slot); false

   )

+

+(* Return true if slot i is empty in the bus. *)

+and slot_is_empty bus i = i >= Array.length !bus || !bus.(i) = BusSlotEmpty

-- 

2.7.4