[Libguestfs] [PATCH] v2v: Allow output modes to rewrite disk copying

[Richard W.M. Jones]

On Tue, Apr 30, 2019 at 08:48:30AM +0200, Martin Kletzander wrote:
> All the current output modes use the default, It's just that I have a patch that
> uses this, so there might be someone in the future who wants to use this and if
> not, then at least you can tell me if this is wrong or not.

It's a straightforward enough refactoring.  I see no problem with the
patch as it stands, but I'd want to see the dependent patches before
we push the whole lot as a series.

Rich.

> Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
> ---
>  v2v/types.ml  | 15 +++++++++++++++
>  v2v/types.mli |  8 +++++++-
>  v2v/v2v.ml    | 17 +++--------------
>  3 files changed, 25 insertions(+), 15 deletions(-)
> 
> diff --git a/v2v/types.ml b/v2v/types.ml
> index 77f879200a26..2780f05fdfbf 100644
> --- a/v2v/types.ml
> +++ b/v2v/types.ml
> @@ -521,6 +521,21 @@ class virtual output = object
>    method override_output_format (_ : overlay) = (None : string option)
>    method virtual prepare_targets : source -> (string * overlay) list -> target_buses -> guestcaps -> inspect -> target_firmware -> target_file list
>    method disk_create = (open_guestfs ())#disk_create
> +  method disk_copy target compressed =
> +    let filename =
> +      match target.target_file with
> +      | TargetFile filename -> qemu_input_filename filename
> +      | TargetURI uri -> uri in
> +    let cmd =
> +      [ "qemu-img"; "convert" ] @
> +      (if not (quiet ()) then [ "-p" ] else []) @
> +      [ "-n"; "-f"; "qcow2"; "-O"; target.target_format ] @
> +      (if compressed then [ "-c" ] else []) @
> +      [ target.target_overlay.ov_overlay_file; filename ] in
> +    message (f_"Copying disk to %s (%s)") filename target.target_format;
> +    if run_command cmd <> 0 then
> +      error (f_"qemu-img command failed, see earlier errors");
> +
>    method virtual create_metadata : source -> target list -> target_buses -> guestcaps -> inspect -> target_firmware -> unit
>    method keep_serial_console = true
>    method install_rhev_apt = false
> diff --git a/v2v/types.mli b/v2v/types.mli
> index be9406100785..a3b89bbcc9b3 100644
> --- a/v2v/types.mli
> +++ b/v2v/types.mli
> @@ -438,7 +438,9 @@ end
>          │                     this by defining output#disk_create.
>          ▼
>      copying                   Guest data is copied to the target disks
> -        │                     by running ‘qemu-img convert’.
> +    (output#disk_copy)        by running ‘qemu-img convert’.  In rare
> +        │                     case output modules can affect the
> +        │                     behaviour of this in output#disk_copy
>          │
>          ▼
>      output#create_metadata    VM should be created from the metadata
> @@ -485,6 +487,10 @@ class virtual output : object
>    (** Called in order to create disks on the target.  The method has the
>        same signature as Guestfs#disk_create.  Normally you should {b not}
>        define this since the default method calls Guestfs#disk_create. *)
> +  method disk_copy : target -> bool -> unit
> +  (** Called in order to copy disks on the target.  Normally you should
> +     {b not} define this unless you handle the copy yourself in a very
> +     special way. *)
>    method virtual create_metadata : source -> target list -> target_buses -> guestcaps -> inspect -> target_firmware -> unit
>    (** Called after conversion and copying to create metadata and
>        do any finalization. *)
> diff --git a/v2v/v2v.ml b/v2v/v2v.ml
> index 277d8f2c7a3e..1bd2225f7334 100644
> --- a/v2v/v2v.ml
> +++ b/v2v/v2v.ml
> @@ -687,10 +687,10 @@ and copy_targets cmdline targets input output =
>      fun i t ->
>        (match t.target_file with
>         | TargetFile s ->
> -          message (f_"Copying disk %d/%d to %s (%s)")
> +          message (f_"Preparing disk %d/%d in %s (%s)")
>                    (i+1) nr_disks s t.target_format;
>         | TargetURI s ->
> -          message (f_"Copying disk %d/%d to qemu URI %s (%s)")
> +          message (f_"Preparing disk %d/%d on qemu URI %s (%s)")
>                    (i+1) nr_disks s t.target_format
>        );
>        debug "%s" (string_of_overlay t.target_overlay);
> @@ -744,19 +744,8 @@ and copy_targets cmdline targets input output =
>            ()
>        );
>  
> -      let cmd =
> -        let filename =
> -          match t.target_file with
> -          | TargetFile filename -> qemu_input_filename filename
> -          | TargetURI uri -> uri in
> -        [ "qemu-img"; "convert" ] @
> -        (if not (quiet ()) then [ "-p" ] else []) @
> -        [ "-n"; "-f"; "qcow2"; "-O"; t.target_format ] @
> -        (if cmdline.compressed then [ "-c" ] else []) @
> -        [ overlay_file; filename ] in
>        let start_time = gettimeofday () in
> -      if run_command cmd <> 0 then
> -        error (f_"qemu-img command failed, see earlier errors");
> +      output#disk_copy t cmdline.compressed;
>        let end_time = gettimeofday () in
>  
>        (* Calculate the actual size on the target. *)
> -- 
> 2.21.0

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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