Merge tag 'for-5.13/block-2021-04-27' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Pretty quiet round this time, which is nice. In detail:

   - Series revamping bounce buffer support (Christoph)

   - Dead code removal (Christoph, Bart)

   - Partition iteration revamp, now using xarray (Christoph)

   - Passthrough request scheduler improvements (Lin)

   - Series of BFQ improvements (Paolo)

   - Fix ioprio task iteration (Peter)

   - Various little tweaks and fixes (Tejun, Saravanan, Bhaskar, Max,
     Nikolay)"

* tag 'for-5.13/block-2021-04-27' of git://git.kernel.dk/linux-block: (41 commits)
  blk-iocost: don't ignore vrate_min on QD contention
  blk-mq: Fix spurious debugfs directory creation during initialization
  bfq/mq-deadline: remove redundant check for passthrough request
  blk-mq: bypass IO scheduler's limit_depth for passthrough request
  block: Remove an obsolete comment from sg_io()
  block: move bio_list_copy_data to pktcdvd
  block: remove zero_fill_bio_iter
  block: add queue_to_disk() to get gendisk from request_queue
  block: remove an incorrect check from blk_rq_append_bio
  block: initialize ret in bdev_disk_changed
  block: Fix sys_ioprio_set(.which=IOPRIO_WHO_PGRP) task iteration
  block: remove disk_part_iter
  block: simplify diskstats_show
  block: simplify show_partition
  block: simplify printk_all_partitions
  block: simplify partition_overlaps
  block: simplify partition removal
  block: take bd_mutex around delete_partitions in del_gendisk
  block: refactor blk_drop_partitions
  block: move more syncing and invalidation to delete_partition
  ...

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index fc4b0f1aa86d..bd3556585122 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1199,6 +1199,42 @@ try_next_bio:
 	return 1;
 }
 
+/**
+ * bio_list_copy_data - copy contents of data buffers from one chain of bios to
+ * another
+ * @src: source bio list
+ * @dst: destination bio list
+ *
+ * Stops when it reaches the end of either the @src list or @dst list - that is,
+ * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
+ * bios).
+ */
+static void bio_list_copy_data(struct bio *dst, struct bio *src)
+{
+	struct bvec_iter src_iter = src->bi_iter;
+	struct bvec_iter dst_iter = dst->bi_iter;
+
+	while (1) {
+		if (!src_iter.bi_size) {
+			src = src->bi_next;
+			if (!src)
+				break;
+
+			src_iter = src->bi_iter;
+		}
+
+		if (!dst_iter.bi_size) {
+			dst = dst->bi_next;
+			if (!dst)
+				break;
+
+			dst_iter = dst->bi_iter;
+		}
+
+		bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
+	}
+}
+
 /*
  * Assemble a bio to write one packet and queue the bio for processing
  * by the underlying block device.