Hi This patch series adds copy offload (the XCOPY command) to the block layer, SCSI subsystems and device mapper. The principle of operation is this: We create two bios with REQ_COPY flag, one for read and one for write. The bios have no data pages and they both point to the same bio_copy structure. The bios may be submitted to the same logical volume or to different logical volumes. The bios go independently through the device mapper stack and when they both reach the physical device (the function blk_queue_bio), the bio pair is collected and the XCOPY request is sent to the SCSI device. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
