[dm-devel] [PATCH 0/15] copy offload patches

Douglas Gilbert dgilbert at interlog.com
Tue Dec 15 03:43:04 UTC 2015


On 15-12-14 08:22 PM, Mikulas Patocka wrote:
>
>
> On Thu, 10 Dec 2015, Martin K. Petersen wrote:
>
>>>>>>> "Mikulas" == Mikulas Patocka <mpatocka at redhat.com> writes:
>>
>> Mikulas,
>>
>> Mikulas> This patch series adds copy offload (the XCOPY command) to the
>> Mikulas> block layer, SCSI subsystems and device mapper.
>>
>> Now that the VFS stuff appears to stabilize I agree it's a good time to
>> revisit all this. I just merged the required VPD patches from Hannes so
>> those will be in 4.5.
>>
>> I have a bunch of changes to the SCSI code that I worked on over the
>> spring/summer based on a feedback from the array vendors after
>> discussions we started at LSF/MM. Generally speaking, their comments
>> didn't make things easier, nor prettier :( But your two bio approach is
>> a requirement to accommodate those needs (token-based copy) so I'll work
>> on consolidating your changes with mine.
>
> Let me know when you make some progress with that.
>
> Is there some software iSCSI implementation that supports token-based
> copy? So that I could try to make support for it.

FreeNAS. See:
    http://www.freenas.org/

It has the best ODX implementation (thanks to Alexander Motin) that
I have come across for testing my ddpt based ODX client. It also
supports large parts of the more general xcopy LID1 and LID4.


BTW In SPC-5 xcopy LID1 has been dropped and "xcopy" now means
xcopy LID4 (as found in SPC-4).

Doug Gilbert

>> That said, we still need Mike Christie's patches to go in first.
>>
>> Mike: What's your status? I'm afraid I didn't get a chance to dig very
>> deep in your series since it coincided with me scrambling to sort out
>> SCSI for 4.4. Do you think there's a chance we could get your patches in
>> shape for 4.5? Is there an up-to-date tree I can look at?
>>
>> --
>> Martin K. Petersen	Oracle Linux Engineering





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