On 01/26/2018 06:39 AM, Edgar Kaziakhmedov wrote:
> PIng
>
> So, let me know if I need to make any changes in patch
>
> On 1/18/18 1:09 PM, Paolo Bonzini wrote:
>> On 18/01/2018 12:51, Edgar Kaziakhmedov wrote:
>>> +static int nbd_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>>> +{
>>> + if (bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP) {
>>> + bdi->can_write_zeroes_with_unmap = true;
>>> + }
>>> + return 0;
>>> +}
>>> +
>> Other drivers set the flag always, while NBD only sets it if the server
>> knows the flag.Well, other drivers may be able to always implement it (NBD can only implement it if the server supports WRITE_ZEROES - and I'm even in the middle of working up an nbdkit patch [1] that makes it easier to write an NBD server that specifically does not support WRITE_ZEROES to make code paths like this easier to test) [1] >> >> I think NBD is more correct, so: >> >> Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> Agreed; I'm fine queueing this on my NBD queue, except I'd first like to hear Kevin's opinion: >> >> However, it would be nice to remove can_write_zeroes_with_unmap from >> BlockDriverInfo, and make bdrv_can_write_zeroes_with_unmap just return >> !!(bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP). Kevin, what do you >> think? Actually, I may even just give a shot at writing this alternative patch, to make Kevin's decision easier. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
signature.asc
Description: OpenPGP digital signature
