Re: [Qemu-devel] [PATCH 08/12] qemu-img: conditionally zero out target on convert

[Peter Lieven <pl@kamp.de>]

On 13.09.2013 12:36, Paolo Bonzini wrote:
> Il 13/09/2013 12:25, Peter Lieven ha scritto:
>> if the target has_zero_init = 0, but supports efficiently
>> writing zeroes by unmapping we call bdrv_zeroize to
>> avoid fully allocating the target. this currently
>> is designed especially for iscsi.
>>
>> Signed-off-by: Peter Lieven <pl@kamp.de>
>> ---
>>   qemu-img.c |   22 ++++++++++++++++------
>>   1 file changed, 16 insertions(+), 6 deletions(-)
>>
>> diff --git a/qemu-img.c b/qemu-img.c
>> index 3e5e388..6eaddc6 100644
>> --- a/qemu-img.c
>> +++ b/qemu-img.c
>> @@ -1354,7 +1354,8 @@ static int img_convert(int argc, char **argv)
>>           }
>>       }
>>   
>> -    flags = BDRV_O_RDWR;
>> +    flags = BDRV_O_RDWR | BDRV_O_UNMAP;
> I think this should be a new command-line flag.
In an earlier version there where no objections. I think it would
make the usage of qemu-img convert more complicated. For
most targets has_zero_init is 1 anyway.

Peter