Re: [Qemu-devel] [PATCH] exit if -drive specified is invalid instead of ignoring the "wrong" -drive

[Michael Tokarev]

30.03.2011 17:08, Jes Sorensen wrote:
> On 03/30/11 14:31, Michael Tokarev wrote:
>> This fixes the problem when qemu continues even if -drive specification
>> is somehow invalid, resulting in a mess.  Applicable for both current
>> master and for stable-0.14 (and the same issue exist 0.13 and 0.12 too).
>>
>> The prob can actually be seriuos: when you start guest with two drives
>> and make an error in the specification of one of them, and the guest
>> has something like a raid array on the two drives, guest may start failing
>> that array or kick "missing" drives which may result in a mess - this is
>> what actually happened to me, I did't want a resync at all, and a resync
>> resulted in re-writing (and allocating) a 4TB virtual drive I used for
>> testing, which in turn resulted in my filesystem filling up and whole
>> thing failing badly.  Yes it was just testing VM, I experimented with
>> larger raid arrays, but the end result was quite, well, unexpected.
>>
>> Signed-off-by: Michael Tokarev <address@hidden>
>> ---
>>  vl.c |    4 +++-
>>  1 files changed, 3 insertions(+), 1 deletions(-)
>>
>> diff --git a/vl.c b/vl.c
>> index 8bcf2ae..3792afb 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -2098,7 +2098,9 @@ int main(int argc, char **argv, char **envp)
>>                            HD_OPTS);
>>                  break;
>>              case QEMU_OPTION_drive:
>> -                drive_def(optarg);
>> +                if (drive_def(optarg) == NULL) {
>> +                    exit(1);
>> +                }
> 
> Looks good, however it would be nice if you added an error message here.

It's already printed by drive_def():

 $ kvm -drive foo=bar
 kvm: -drive foo=bar: Invalid parameter 'foo'

I can add something like "unable to initialize -drive, exiting"
but to mee it looks sorta redundrand, no?

Thanks!

/mjt