On Sat, Aug 12, 2023 at 3:10 AM Bart Van Assche <bvanassche@xxxxxxx> wrote: > > On 8/11/23 03:52, Nitesh Shetty wrote: > > + * Description: > > + * Copy source offset to destination offset within block device, using > > + * device's native copy offload feature. > > Offloading the copy operation is not guaranteed so I think that needs to > be reflected in the above comment. > Acked. > > + * We perform copy operation by sending 2 bio's. > > + * 1. We take a plug and send a REQ_OP_COPY_SRC bio along with source > > + * sector and length. Once this bio reaches request layer, we form a > > + * request and wait for dst bio to arrive. > > What will happen if the queue depth of the request queue at the bottom > is one? > For any reason if a request reaches the driver with only one of the src/dst bio, copy will fail. This design requires only one request to do a copy, so it should work fine. > > + blk_start_plug(&plug); > > + dst_bio = blk_next_bio(src_bio, bdev, 0, REQ_OP_COPY_DST, gfp); > > blk_next_bio() can return NULL so its return value should be checked. > Acked. Thank you, Nitesh Shetty
