On Tue, 27 Jan 2015 12:23:55 -0600, Steve French wrote: > Has anyone tried the new ioctl (MS-FSCC) defined in the most recent > update. See section 2.3.7 > > Looks interesting for a new variant of copy offload > > "A new File System Control (FSCTL) has been added to support the new > FSCTL_DUPLICATE_EXTENTS_TO_FILE operation in [MS-FSA]." I haven't played with it yet, but from the [MS-FCC] 20150119 preview doc it looks very similar to copy-chunk, with a few small differences: - It's only supported on ReFS, which may indicate that it's implemented using COW clones. - It takes a regular file handle for the source, instead of requiring a preliminary SRV_REQUEST_RESUME_KEY exchange. - Only a single chunk can be duplicated per request, rather than multiple. - Overlapping ranges are not supported. - The length field is 64-bits wide, instead of 32. - The response only carries the status code. This may imply there is no server-advertised limit to the length of the request, further indicating that it's COW based. Time to start poking around with smbtorture :) Cheers, David -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
