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.
+ * 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?
+ 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.
+ dst_bio->bi_iter.bi_size = chunk; + dst_bio->bi_iter.bi_sector = pos_out >> SECTOR_SHIFT; + dst_bio->bi_end_io = blkdev_copy_offload_dst_endio; + dst_bio->bi_private = offload_io;
Thanks, Bart.
