|FSCTL_OFFLOAD_READ|+|FSCTL_OFFLOAD_WRITE| support

[gisburn]

Could you please add |FSCTL_OFFLOAD_READ|+|FSCTL_OFFLOAD_WRITE| support ?

This is technically intended for intra-server and inter-server copies, but it is also useful to implement in-kernel copies (so no data are copied to the userland and back) when block cloning is not desired.

xcopy.exe (on Win11 /NOCLONE must be set, otherwise block cloning is used by default), robotcopy and Windows Explorer use this. Please make sure to handle sparse files correctly (i.e. copy holes in sparse files as-is).

[maharmstone]

Interesting, thank you. Yes, this looks like it would be both feasible and useful - I'll look into it.