[Libguestfs] [PATCH 1/3] v2v: refactor copy_drivers() in Windows_virtio

[Richard W.M. Jones]

On Tue, Nov 06, 2018 at 11:44:13AM +0100, Tomáš Golembiovský wrote:
> Changed the function to be more generic and renamed to copy_files.
> The only change in behavior is in produced debug messages.
> 
> Signed-off-by: Tomáš Golembiovský <tgolembi at redhat.com>
> ---
>  v2v/windows_virtio.ml | 52 ++++++++++++++++++++++++++-----------------
>  1 file changed, 32 insertions(+), 20 deletions(-)
> 
> diff --git a/v2v/windows_virtio.ml b/v2v/windows_virtio.ml
> index 9b45c76f5..91649694d 100644
> --- a/v2v/windows_virtio.ml
> +++ b/v2v/windows_virtio.ml
> @@ -250,32 +250,35 @@ and ddb_regedits inspect drv_name drv_pciid =
>      [ "Configuration", REG_SZ drv_config ];
>    ]

I think it's better to put the copy_drivers function above the new
copy_files function, since the rest of this file is following a
top-to-bottom order.

> -(* Copy the matching drivers to the driverdir; return true if any have
> - * been copied.
> +(* Copy all files from [srcdir] and all its subdirectories to the [destdir].
> + * The file list is filtered based on [filter] function. Return list of copied
> + * files.
>   *)

This comment doesn't accurately describe what the function does, and I
don't think "copy_files" is a good name either (since it sounds
generic).  As far as I can tell [srcdir] is relative to the tools
directory/ISO, so ‘copy_files g inspect "/" ...’ is not copying
everything on the host, but copying every file in the tools
directory/ISO.

It's probably better to call this function something like
‘copy_from_virtio_win’, and update the comment above to make it
clearer what the options mean.

> -and copy_drivers g inspect driverdir =
> -  let ret = ref false in
> +and copy_files g inspect srcdir destdir filter =
> +

Extra blank line added here.

> +  let ret = ref [] in
>    if is_directory virtio_win then (
> -    debug "windows: copy_drivers: source directory virtio_win %s" virtio_win;
> +    let dir = virtio_win // srcdir in
> +    debug "copy_files: guest tools source directory %s" dir;

In the debug messages, let's keep the "windows: " prefix (also applies
below).

> -    let cmd = sprintf "cd %s && find -L -type f" (quote virtio_win) in
> +    let cmd = sprintf "cd %s && find -L -type f" (quote dir) in
>      let paths = external_command cmd in
>      List.iter (
>        fun path ->
> -        if virtio_iso_path_matches_guest_os path inspect then (
> -          let source = virtio_win // path in
> -          let target = driverdir //
> -                         String.lowercase_ascii (Filename.basename path) in
> -          debug "copying virtio driver bits: 'host:%s' -> '%s'"
> +        if filter path inspect then (
> +          let source = dir // path in
> +          let target_name = String.lowercase_ascii (Filename.basename path) in
> +          let target = destdir // target_name in
> +          debug "copying guest tool bits: 'host:%s' -> '%s'"
>                  source target;
>  
>            g#write target (read_whole_file source);
> -          ret := true
> +          List.push_front target_name ret
>          )
>        ) paths
>    )
>    else if is_regular_file virtio_win then (
> -    debug "windows: copy_drivers: source ISO virtio_win %s" virtio_win;
> +    debug "copy_files: guest tools source ISO %s" virtio_win;
>
>      try
>        let g2 = open_guestfs ~identifier:"virtio_win" () in
> @@ -283,19 +286,20 @@ and copy_drivers g inspect driverdir =
>        g2#launch ();
>        let vio_root = "/" in
>        g2#mount_ro "/dev/sda" vio_root;
> -      let paths = g2#find vio_root in
> +      let srcdir = vio_root // srcdir in
> +      let paths = g2#find srcdir in
>        Array.iter (
>          fun path ->
> -          let source = vio_root // path in
> +          let source = srcdir // path in
>            if g2#is_file source ~followsymlinks:false &&
> -               virtio_iso_path_matches_guest_os path inspect then (
> -            let target = driverdir //
> -                           String.lowercase_ascii (Filename.basename path) in
> -            debug "copying virtio driver bits: '%s:%s' -> '%s'"
> +               filter path inspect then (
> +            let target_name = String.lowercase_ascii (Filename.basename path) in
> +            let target = destdir // target_name in
> +            debug "copying guest tool bits: '%s:%s' -> '%s'"
>                    virtio_win path target;
>  
>              g#write target (g2#read_file source);
> -            ret := true
> +            List.push_front target_name ret
>            )
>          ) paths;
>        g2#close()
> @@ -304,6 +308,14 @@ and copy_drivers g inspect driverdir =
>    );
>    !ret
>  
> +(* Copy the matching drivers to the driverdir; return true if any have
> + * been copied.
> + *)
> +and copy_drivers g inspect driverdir =
> +  List.length (
> +    copy_files g inspect "/" driverdir virtio_iso_path_matches_guest_os
> +  ) > 0
> +
>  (* Given a path of a file relative to the root of the directory tree
>   * with virtio-win drivers, figure out if it's suitable for the
>   * specific Windows flavor of the current guest.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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