blk-integrity: use iterator for mapping sg

Modify blk_rq_map_integrity_sg to use the blk-mq mapping iterator. This
produces more efficient code and converges the integrity mapping
implementations to reduce future maintenance burdens.

The function implementation moves from blk-integrity.c to blk-mq-dma.c
in order to use the types and functions private to that file.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250813153153.3260897-8-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 0 insertions, 58 deletions

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 056b8948369d..dd97b27366e0 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -122,64 +122,6 @@ out:
 				   NULL);
 }
 
-/**
- * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
- * @rq:		request to map
- * @sglist:	target scatterlist
- *
- * Description: Map the integrity vectors in request into a
- * scatterlist.  The scatterlist must be big enough to hold all
- * elements.  I.e. sized using blk_rq_count_integrity_sg() or
- * rq->nr_integrity_segments.
- */
-int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist)
-{
-	struct bio_vec iv, ivprv = { NULL };
-	struct request_queue *q = rq->q;
-	struct scatterlist *sg = NULL;
-	struct bio *bio = rq->bio;
-	unsigned int segments = 0;
-	struct bvec_iter iter;
-	int prev = 0;
-
-	bio_for_each_integrity_vec(iv, bio, iter) {
-		if (prev) {
-			if (!biovec_phys_mergeable(q, &ivprv, &iv))
-				goto new_segment;
-			if (sg->length + iv.bv_len > queue_max_segment_size(q))
-				goto new_segment;
-
-			sg->length += iv.bv_len;
-		} else {
-new_segment:
-			if (!sg)
-				sg = sglist;
-			else {
-				sg_unmark_end(sg);
-				sg = sg_next(sg);
-			}
-
-			sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
-			segments++;
-		}
-
-		prev = 1;
-		ivprv = iv;
-	}
-
-	if (sg)
-		sg_mark_end(sg);
-
-	/*
-	 * Something must have been wrong if the figured number of segment
-	 * is bigger than number of req's physical integrity segments
-	 */
-	BUG_ON(segments > rq->nr_integrity_segments);
-	BUG_ON(segments > queue_max_integrity_segments(q));
-	return segments;
-}
-EXPORT_SYMBOL(blk_rq_map_integrity_sg);
-
 int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf,
 			      ssize_t bytes)
 {