Re: [Qemu-devel] [Qemu-block] [PULL 08/23] file-posix: Forbid trying to change unsupported options during reopen

[Alberto Garcia]

On Fri 05 Oct 2018 02:55:13 PM CEST, Peter Maydell wrote:
>> +    rs->check_cache_dropped =
>> +        qemu_opt_get_bool_del(opts, "x-check-cache-dropped", false);
>> +
>> +    /* This driver's reopen function doesn't currently allow changing
>> +     * other options, so let's put them back in the original QDict and
>> +     * bdrv_reopen_prepare() will detect changes and complain. */
>> +    qemu_opts_to_qdict(opts, state->options);
>
> Hi. Coverity is suspicious about this call to qemu_opts_to_qdict()
> because it returns a value which this callsite is ignoring but almost
> all others don't ignore (CID 1395991). Is it correct?

It's a false positive because qemu_opts_to_qdict() returns the same
value that is passed (unless that value is NULL).

We can fix the warning by doing

   state->options = qemu_opts_to_qdict(opts, state->options);

or by modifying qemu_opts_to_qdict() to get a QDict ** and return void.

Berto