Am 24.06.2013 18:25, schrieb Paolo Bonzini:
> Il 24/06/2013 18:17, Peter Lieven ha scritto:
>> Am 24.06.2013 16:33, schrieb Paolo Bonzini:
>>> Il 22/06/2013 22:58, Peter Lieven ha scritto:
>>>> Signed-off-by: Peter Lieven <p...@kamp.de>
>>>> ---
>>>> qemu-img.c | 10 +++++++---
>>>> 1 file changed, 7 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/qemu-img.c b/qemu-img.c
>>>> index 809b4f1..5aa53ab 100644
>>>> --- a/qemu-img.c
>>>> +++ b/qemu-img.c
>>>> @@ -1513,9 +1513,13 @@ static int img_convert(int argc, char **argv)
>>>> If the output is to a host device, we also write out
>>>> sectors that are entirely 0, since whatever data was
>>>> already there is garbage, not 0s. */
>>>> - if (!has_zero_init || out_baseimg ||
>>>> - is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
>>>> - ret = bdrv_write(out_bs, sector_num, buf1, n1);
>>>> + int allocated = is_allocated_sectors_min(buf1, n, &n1,
>>>> min_sparse);
>>>> + if (!has_zero_init || out_baseimg || allocated) {
>>>> + if (allocated || out_baseimg) {
>>>> + ret = bdrv_write(out_bs, sector_num, buf1, n1);
>>>> + } else {
>>>> + ret = bdrv_write_zeroes(out_bs, sector_num, n1);
>>> I think it should still do the write only if !has_zero_init.
>> With this I am still in trouble with iSCSI, but Kevin pointed out another
>> possible solution for the allocating everything problem.
>>
>> a) let iscsi_create discard the whole device if lbpz && lbprz
>> b) return 1 for has_zero_init if lbprz.
>>
>> What do you think?
> Fine by me (but the discard may take a looong time! :)).
This was also my concern, but if a target advertises logical block
provisioning it should be able to discard blocks fast (and not overwrite all of
them or sth like that).
Peter
>
> Paolo
>
