Re: [Qemu-devel] [PATCH v2] rbd: print a clear error message when write beyond EOF

[jun muzi]

Jun Li
2014-12-11 下午5:13于 "Max Reitz" <address@hidden>写道：
>
> On 2014-12-11 at 10:12, Kevin Wolf wrote:
>>
>> Am 11.12.2014 um 07:25 hat Jun Li geschrieben:
>>>
>>> Currently, as rbd driver do not support dynamic growth when write beyond EOF,
>>> so just print a clear error message.
>>>
>>> Signed-off-by: Jun Li <address@hidden>
>>> ---
>>> v2:
>>> Just use rbd_aio_write to realize error detection.
>>> ---
>>>   block/rbd.c | 4 ++++
>>>   1 file changed, 4 insertions(+)
>>>
>>> diff --git a/block/rbd.c b/block/rbd.c
>>> index 5b5a64a..710ee3e 100644
>>> --- a/block/rbd.c
>>> +++ b/block/rbd.c
>>> @@ -661,6 +661,10 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
>>>       }
>>>         if (r < 0) {
>>> +        if (r == -EINVAL && cmd == RBD_AIO_WRITE) {
>>> +            fprintf(stderr, "Image formats that grow on demand "
>>> +                            "are not supported on rbd.\n");
>>> +        }
>>>           goto failed_completion;
>>>       }
>>
>> You can't fill up the log with messages like that. In general, if you
>> use fprintf() in a function whose call can be triggered by the guest,
>> you're doing it wrong.
>>
>> What needs to be done is to check at open time whether the configuration
>> works. Max has sent a series to that end a while ago, not sure what its
>> status is. I think it ended up depending on some blockdev work.
>
>
> Yes, the status is that we need to remove "growable" from the BDS first.
>

Hi, which serial do you mean? Could you give a link? Thx.

Jun Li