Re: [PATCH v2 1/5] vvfat: introduce partitioned option

[Markus Armbruster <armbru@redhat.com>]

Clément Chigot <chigot@adacore.com> writes:

> This option tells whether a hard disk should be partitioned or not. It
> defaults to true and have the prime effect of preventing a master boot
> record (MBR) to be initialized.
>
> This is useful as some operating system (QNX, Rtems) don't
> recognized FAT mounted disks (especially SD cards) if a MBR is present.
>
> Signed-off-by: Clément Chigot <chigot@adacore.com>

[...]

> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index b82af74256..8a479ba090 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -3464,8 +3464,8 @@
>  #
>  # @fat-type: FAT type: 12, 16 or 32
>  #
> -# @floppy: whether to export a floppy image (true) or partitioned hard
> -#     disk (false; default)
> +# @floppy: whether to export a floppy image (true) or hard disk
> +#     (false; default)
>  #
>  # @label: set the volume label, limited to 11 bytes.  FAT16 and FAT32
>  #     traditionally have some restrictions on labels, which are
> @@ -3474,11 +3474,15 @@
>  #
>  # @rw: whether to allow write operations (default: false)
>  #
> +# @partitioned: whether a hard disk will be partitioned

How does "partitioned" combine with "floppy": true?

Is it silently ignored?

Is it an error if present?

Is it an error if true?

Does it add a partition table if true?

> +#     (default: true)

Hmm, this suggests it's silently ignored.

Silently ignoring nonsensical configuration is usually a bad idea.

> +#     (since 10.2)
> +#

Not sure I like "partitioned".  Is a disk with an MBR and a partition
table contraining a single partition partitioned?  Call it "mbr"?

>  # Since: 2.9
>  ##
>  { 'struct': 'BlockdevOptionsVVFAT',
>    'data': { 'dir': 'str', '*fat-type': 'int', '*floppy': 'bool',
> -            '*label': 'str', '*rw': 'bool' } }
> +            '*label': 'str', '*rw': 'bool', '*partitioned': 'bool' } }
>  
>  ##
>  # @BlockdevOptionsGenericFormat: