Re: [Qemu-devel] [PATCH 02/16] cutils: Support 'P' and 'E' suffixes in strtosz()

[Eric Blake <eblake@redhat.com>]

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On 05/28/2013 09:27 AM, Kevin Wolf wrote:
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  include/qemu-common.h      |  2 ++
>  monitor.c                  |  8 ++++----
>  qemu-img.c                 | 10 ++++++----
>  tests/qemu-iotests/049.out |  8 ++++----
>  util/cutils.c              |  4 ++++
>  5 files changed, 20 insertions(+), 12 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

> +++ b/qemu-img.c
> @@ -84,8 +84,9 @@ static void help(void)
>             "    options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
>             "    'directsync' and 'unsafe' (default for convert)\n"
>             "  'size' is the disk image size in bytes. Optional suffixes\n"
> -           "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M)\n"
> -           "    and T (terabyte, 1024G) are supported. 'b' is ignored.\n"
> +           "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M),\n"
> +           "    'T' (terabyte, 1024G), 'P' (petabyte, 1024T) and 'E' (exabyte, 1024P)  are\n"

Pre-existing, but should we be favoring the technically correct
kibibyte, mebibyte, gibibyte, ... terms, since we are treating it as
powers of 1024, rather than the potentially confusing kilobyte term
(since disk vendors favor powers of 1000)?

> +++ b/util/cutils.c
> @@ -267,6 +267,10 @@ static int64_t suffix_mul(char suffix, int64_t unit)
>          return unit * unit * unit;
>      case STRTOSZ_DEFSUFFIX_TB:
>          return unit * unit * unit * unit;
> +    case STRTOSZ_DEFSUFFIX_PB:
> +        return unit * unit * unit * unit * unit;
> +    case STRTOSZ_DEFSUFFIX_EB:
> +        return unit * unit * unit * unit * unit * unit;

Pre-existing, but this code is not robust against overflow.  And now
that you are adding E, it's 6 fewer decimal characters that I have to
type to pass in a value that will exceed even int64_t.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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