Re: [Qemu-devel] [PATCH RFC v3 for-2.9 02/11] rbd: Fix to cleanly reject -drive without pool or image

[Markus Armbruster]

Jeff Cody <address@hidden> writes:

> On Mon, Mar 27, 2017 at 03:26:26PM +0200, Markus Armbruster wrote:
>> qemu_rbd_open() neglects to check pool and image are present.
>> Reproducer:
>> 
>>     $ qemu-system-x86_64 -nodefaults -drive if=none,driver=rbd,pool=p
>>     Segmentation fault (core dumped)
>
> This reproducer is wrong, I think.  Omitting the image should be caught
> earlier, but it is an error caught by the rbd_open() call.

Turns out the crash I observed was an artifact of my testing
instrumentation.

> What doesn't work is omitting the pool name, and that causes an abort()
> from rados_ioctx_create(), e.g.:
>
>
> $ qemu-system-x86_64 -nodefaults -drive 
> driver=rbd,id=rbd,image=i,server.0.port=6789,server.0.host=192.168.15.180
> terminate called after throwing an instance of 'std::logic_error'
>   what():  basic_string::_M_construct null not valid
> Aborted (core dumped)
>
>
>>     $ qemu-system-x86_64 -nodefaults -drive if=none,driver=rbd,image=i
>>     qemu-system-x86_64: -drive if=none,driver=rbd,image=i: error opening 
>> pool (null)
>> 
>> Doesn't affect -drive with file=..., because qemu_rbd_parse_filename()
>> always sets both pool and image.
>> 
>> Doesn't affect -blockdev, because pool and image are mandatory in the
>> QAPI schema.
>> 
>> Fix by adding the missing checks.
>> 
>> Signed-off-by: Markus Armbruster <address@hidden>
>> Reviewed-by: Eric Blake <address@hidden>
>
> With an updated commit message:
>
> Reviewed-by: Jeff Cody <address@hidden>

Thanks!