On Thu, Feb 03, 2022 at 01:50:06PM -0500, Mikulas Patocka wrote:

On Tue, 1 Feb 2022, Bart Van Assche wrote:

quoted

Only supporting copying between contiguous LBA ranges seems restrictive to me.
I expect garbage collection by filesystems for UFS devices to perform better
if multiple LBA ranges are submitted as a single SCSI XCOPY command.

NVMe has a possibility to copy multiple source ranges into one destination 
range. But I think that leveraging this capability would just make the 
code excessively complex.

The point is to defrag discontiguous blocks into a single range. The
capability loses a major value proposition without multiple sources.