copy offload for SMB?

[Richard Sharpe]

On Fri, Feb 22, 2013 at 7:08 AM, David Disseldorp <ddiss at suse.de> wrote:
> Hi Richard,
>
> On Fri, 22 Feb 2013 06:45:36 -0800
> Richard Sharpe <realrichardsharpe at gmail.com> wrote:
>
>> On Fri, Feb 22, 2013 at 2:30 AM, David Disseldorp <ddiss at suse.de> wrote:
>> > On Thu, 21 Feb 2013 21:49:35 -0800
>> > Richard Sharpe <realrichardsharpe at gmail.com> wrote:
>> >> Now to check if W2K08 sends such an FSCTL to see if it can get a resume key.
>> >
>> > 2k8 doesn't use it for copies initiated via Explorer, 2k12 does though.
>> > See source3/smbd/smb2_ioctl_network_fs.c for the Samba implementation.
>>
>> Thanks. Do you know if it is exposed on W2K08 via CopyFileEx or
>> something like that?
>
> Server support is there, with a few quirks[1]. I'm not aware of anything
> pre-2k12 that uses it on the client side, but the ioctl itself has been
> around for donkey's years (SMB1), so there's likely something obscure
> using it.
>
> Cheers, David
>
> 1. [cifs-protocol] FSCTL_SRV_COPYCHUNK locking discrepancies
>  https://lists.samba.org/archive/cifs-protocol/2012-December/002407.html

Ahhh, right, it is probably accessed via DeviceIoControl on clients.

I am interested in how to access this functionality from a client.

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)