output_rhv: restrict block status collection to the old RHV output

Nir reports that, despite the comment we removed in commit a2a4f7a,
we generally cannot access the output NBD servers in the finalization
stage. In particular, in the "rhv_upload_finalize" function
[output/output_rhv_upload.ml], the output disks are disconnected before
"create_ovf" is called.

Consequently, the "get_disk_allocated" call in the "create_ovf" ->
"add_disks" -> "get_disk_allocated" chain fails.

Rich suggests that we explicitly restrict the "get_disk_allocated" call
with a new optional boolean parameter to the one output plugin that really
needs it, namely the old RHV one.

Accordingly, revert the VDSM test case to its state at (a2a4f7a^).

Cc: Nir Soffer <nsoffer@redhat.com>
Fixes: a2a4f7a
Reported-by: Nir Soffer <nsoffer@redhat.com>
Suggested-by: Richard W.M. Jones <rjones@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2034240
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20211220135640.12436-1-lersek@redhat.com>
Tested-by: Nir Soffer <nsoffer@redhat.com>
[lersek@redhat.com: drop parens around condition in "if"; thanks: Rich]
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

lib/create_ovf.ml

@@ -531,7 +531,8 @@ let rec create_ovf source inspect
           { output_name; guestcaps; target_firmware; target_nics }
           sizes
           output_alloc output_format
-          sd_uuid image_uuids vol_uuids dir vm_uuid ovf_flavour =
+          sd_uuid image_uuids vol_uuids ?(need_actual_sizes = false) dir
+          vm_uuid ovf_flavour =
   assert (List.length sizes = List.length vol_uuids);
 
   let memsize_mb = source.s_memory /^ 1024L /^ 1024L in
@@ -745,7 +746,7 @@ let rec create_ovf source inspect
 
   (* Add disks to the OVF XML. *)
   add_disks sizes guestcaps output_alloc output_format
-    sd_uuid image_uuids vol_uuids dir ovf_flavour ovf;
+    sd_uuid image_uuids vol_uuids need_actual_sizes dir ovf_flavour ovf;
 
   (* Old virt-v2v ignored removable media. XXX *)
 
@@ -791,7 +792,7 @@ and get_flavoured_section ovf ovirt_path rhv_path rhv_path_attr = function
 
 (* This modifies the OVF DOM, adding a section for each disk. *)
 and add_disks sizes guestcaps output_alloc output_format
-    sd_uuid image_uuids vol_uuids dir ovf_flavour ovf =
+    sd_uuid image_uuids vol_uuids need_actual_sizes dir ovf_flavour ovf =
   let references =
     let nodes = path_to_nodes ovf ["ovf:Envelope"; "References"] in
     match nodes with
@@ -839,7 +840,12 @@ and add_disks sizes guestcaps output_alloc output_format
         b /^ 1073741824L
       in
       let size_gb = bytes_to_gb size in
-      let actual_size = get_disk_allocated ~dir ~disknr:i in
+      let actual_size =
+        if need_actual_sizes then
+          get_disk_allocated ~dir ~disknr:i
+        else
+          None
+      in
 
       let format_for_rhv =
         match output_format with
@@ -891,16 +897,17 @@ and add_disks sizes guestcaps output_alloc output_format
           "ovf:disk-type", "System"; (* RHBZ#744538 *)
           "ovf:boot", if is_bootable_drive then "True" else "False";
         ] in
-        (* Ovirt-engine considers the "ovf:actual_size" attribute mandatory. If
-         * we don't know the actual size, we must create the attribute with
-         * empty contents.
-         *)
-        List.push_back attrs
-          ("ovf:actual_size",
-           match actual_size with
-            | None -> ""
-            | Some actual_size -> Int64.to_string (bytes_to_gb actual_size)
-          );
+        if need_actual_sizes then
+          (* Ovirt-engine considers the "ovf:actual_size" attribute mandatory.
+           * If we don't know the actual size, we must create the attribute
+           * with empty contents.
+           *)
+          List.push_back attrs
+            ("ovf:actual_size",
+             match actual_size with
+              | None -> ""
+              | Some actual_size -> Int64.to_string (bytes_to_gb actual_size)
+            );
         e "Disk" !attrs [] in
       append_child disk disk_section;
 

lib/create_ovf.mli

@@ -46,7 +46,8 @@ val ovf_flavour_to_string : ovf_flavour -> string
 val create_ovf : Types.source -> Types.inspect ->
                  Types.target_meta -> int64 list ->
                  Types.output_allocation -> string -> string -> string list ->
-                 string list -> string -> string -> ovf_flavour -> DOM.doc
+                 string list -> ?need_actual_sizes:bool -> string -> string ->
+                 ovf_flavour -> DOM.doc
 (** Create the OVF file.
 
     Actually a {!DOM} document is created, not a file.  It can be written

output/output_rhv.ml

@@ -183,8 +183,8 @@ and rhv_finalize dir source inspect target_meta
   (* Create the metadata. *)
   let ovf =
     Create_ovf.create_ovf source inspect target_meta sizes
-      output_alloc output_format esd_uuid image_uuids vol_uuids dir vm_uuid
-      Create_ovf.RHVExportStorageDomain in
+      output_alloc output_format esd_uuid image_uuids vol_uuids
+      ~need_actual_sizes:true dir vm_uuid Create_ovf.RHVExportStorageDomain in
 
   (* Write it to the metadata file. *)
   let dir = esd_mp // esd_uuid // "master" // "vms" // vm_uuid in

tests/test-v2v-o-vdsm-options.ovf.expected

@@ -2,15 +2,15 @@
 <ovf:Envelope xmlns:rasd='http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData' xmlns:vssd='http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_VirtualSystemSettingData' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:ovf='http://schemas.dmtf.org/ovf/envelope/1/' xmlns:ovirt='http://www.ovirt.org/ovf' ovf:version='0.9'>
   <!-- generated by virt-v2v -->
   <References>
-    <File ovf:href='VOL' ovf:id='VOL' ovf:description='generated by virt-v2v' ovf:size='#SIZE#'/>
+    <File ovf:href='VOL' ovf:id='VOL' ovf:description='generated by virt-v2v'/>
   </References>
   <NetworkSection>
     <Info>List of networks</Info>
     <Network ovf:name='default'/>
   </NetworkSection>
   <DiskSection>
     <Info>List of Virtual Disks</Info>
-    <Disk ovf:diskId='IMAGE' ovf:size='1' ovf:capacity='536870912' ovf:fileRef='VOL' ovf:parentRef='' ovf:vm_snapshot_id='#UUID#' ovf:volume-format='COW' ovf:volume-type='Sparse' ovf:format='http://en.wikipedia.org/wiki/Byte' ovf:disk-interface='VirtIO' ovf:disk-type='System' ovf:boot='True' ovf:actual_size='1'/>
+    <Disk ovf:diskId='IMAGE' ovf:size='1' ovf:capacity='536870912' ovf:fileRef='VOL' ovf:parentRef='' ovf:vm_snapshot_id='#UUID#' ovf:volume-format='COW' ovf:volume-type='Sparse' ovf:format='http://en.wikipedia.org/wiki/Byte' ovf:disk-interface='VirtIO' ovf:disk-type='System' ovf:boot='True'/>
   </DiskSection>
   <VirtualSystem ovf:id='VM'>
     <Name>windows</Name>