Re: [Qemu-devel] [PATCH 4/4] qemu-img: conditionally discard target on convert

[Paolo Bonzini]

Il 17/07/2013 19:48, Peter Lieven ha scritto:
> 
> Am 17.07.2013 um 19:04 schrieb Paolo Bonzini <address@hidden>:
> 
>> Il 17/07/2013 19:02, Peter Lieven ha scritto:
>>> For Disks we always use read/write16 so i think we Should also use 
>>> writesame16. Or not?
>>
>> Yes.
>>
>> Remember you can still use UNMAP if LBPRZ=0.
> 
> I can always use it if writesame is not available, but in this case 
> bdi->discard_zeroes must be 0.
> 
> Maybe we should call it discard_writes_zeroes or similar.
> 
> Discard_zeroes is sth that should only indicate if lbprz == 1. At
> least if we refer to the Linux ioctl. We could include both in BDI.

I don't know... I don't see the usefulness of
discard_zeroes_part_of_what_it_was_told_to... :)

Paolo