[Libguestfs] [PATCH] inspector: Canonicalize device names (fix RHBZ#526717).

[Jim Meyering]

Richard W.M. Jones wrote:
> This seems to be the completed fix for:
> https://bugzilla.redhat.com/show_bug.cgi?id=526717
...
> Subject: [PATCH] inspector: Canonicalize device names (fix RHBZ#526717).
>
> Make filesystem device names canonical, so they are /dev/sd*
> instead of /dev/vd*.
> ---
>  perl/lib/Sys/Guestfs/Lib.pm |   14 +++++++++++++-
>  1 files changed, 13 insertions(+), 1 deletions(-)
>
> diff --git a/perl/lib/Sys/Guestfs/Lib.pm b/perl/lib/Sys/Guestfs/Lib.pm
> index a9868e2..068cde5 100644
> --- a/perl/lib/Sys/Guestfs/Lib.pm
> +++ b/perl/lib/Sys/Guestfs/Lib.pm
> @@ -575,7 +575,19 @@ sub inspect_all_partitions
>      my $g = shift;
>      my $parts = shift;
>      my @parts = @$parts;
> -    return map { $_ => inspect_partition ($g, $_, @_) } @parts;
> +    return map { _canonical_dev ($_) => inspect_partition ($g, $_, @_) } @parts;
> +}
> +
> +# Turn /dev/vd* and /dev/hd* into canonical device names
> +# (see BLOCK DEVICE NAMING in guestfs(3)).
> +
> +sub _canonical_dev
> +{
> +    local $_ = shift;
> +
> +    return "/dev/sd$1" if m{^/dev/hd(\w+)};
> +    return "/dev/sd$1" if m{^/dev/vd(\w+)};
> +    return $_;
>  }
>
>  =head2 inspect_partition

Hi Rich,

I prefer to define such functions before
their first use, and using the prototype notation,
so that perl can check the number of arguments in any use:

sub _canonical_dev ($)
{
    my ($dev) = @_;
    $dev =~ m{^/dev/[vh]d(\w+)}
      and $dev = "/dev/sd$1";
    return $dev;
}

Also, I find that not using $_ (even when declared local)
improves maintainability.

Finally, you can combine those two matches into one.