copy offload for SMB?

[David Disseldorp]

On Thu, 21 Feb 2013 21:49:35 -0800
Richard Sharpe <realrichardsharpe at gmail.com> wrote:

> Thanks for that. It looks like the steps are:
> 
> 1. Open the source file and send an FSCTL asking for a resume key.
> 
> 2. Create the destination file.
> 
> 3. Issue an FSCTL on the newly created destination file specifying the
> resume key and the blocks to copy.
> 
> 4. Close files.

Yes, see the smb2.ioctl.copy_chunk_* torture tests.

> 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.

Cheers, David