[PATCH v2 13/14] block: blk-integrity: change sg-table configuration method for integrity

[Jinyoung CHOI <j-young.choi@samsung.com>]

Previously, a bio_vec of bip was made of one page in the block layer, and
sg_list was generated using hw information in lld.

This is done in the block layer and the bio_vec has been changed to
multi-page, so it is changed to configure the sg-table using the existing
api, such as the sg-table setting for the bio. (e.g. multi-page map)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: Jinyoung Choi <j-young.choi@samsung.com>
---
 block/blk-integrity.c | 52 -----------------------------------------
 block/blk-merge.c     | 54 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 52 deletions(-)

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 64407b412947..c50954652177 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -55,58 +55,6 @@ int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
 }
 EXPORT_SYMBOL(blk_rq_count_integrity_sg);
 
-/**
- * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
- * @q:		request queue
- * @bio:	bio with integrity metadata attached
- * @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().
- */
-int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
-			    struct scatterlist *sglist)
-{
-	struct bio_vec iv, ivprv = { NULL };
-	struct scatterlist *sg = NULL;
-	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);
-
-	return segments;
-}
-EXPORT_SYMBOL(blk_rq_map_integrity_sg);
-
 /**
  * blk_integrity_compare - Compare integrity profile of two disks
  * @gd1:	Disk to compare
diff --git a/block/blk-merge.c b/block/blk-merge.c
index c6a0958e8df1..f17e19ff3a11 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -524,6 +524,60 @@ __blk_segment_map_sg_merge(struct request_queue *q, struct bio_vec *bvec,
 	return true;
 }
 
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+/**
+ * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
+ * @q:		request queue
+ * @bio:	bio with integrity metadata attached
+ * @sglist:	target scatterlist
+ *
+ * Description: Map the integrity vectors in request into a scatterlist.
+ * The scatterlist must be big enough to hold all elements.
+ */
+int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
+			    struct scatterlist *sglist)
+{
+	struct bio_vec iv, ivprv = { NULL };
+	struct scatterlist *sg = NULL;
+	unsigned int nsegs = 0;
+	struct bvec_iter iter;
+	bool new_bio = false;
+
+	for_each_bio(bio) {
+		struct bio_integrity_payload *bip = bio->bi_integrity;
+
+		bip_for_each_mp_bvec(iv, bip, iter) {
+			/*
+			 * Only try to merge bvecs from two bios given we
+			 * have done bio internal merge when adding pages
+			 * to bio
+			 */
+			if (new_bio &&
+			    __blk_segment_map_sg_merge(q, &iv, &ivprv, &sg))
+				goto next_iv;
+
+			if (iv.bv_offset + iv.bv_len <= PAGE_SIZE)
+				nsegs += __blk_bvec_map_sg(iv, sglist, &sg);
+			else
+				nsegs += blk_bvec_map_sg(q, &iv, sglist, &sg);
+ next_iv:
+			new_bio = false;
+		}
+
+		if (likely(bip->bip_iter.bi_size)) {
+			ivprv = iv;
+			new_bio = true;
+		}
+	}
+
+	if (sg)
+		sg_mark_end(sg);
+
+	return nsegs;
+}
+EXPORT_SYMBOL(blk_rq_map_integrity_sg);
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
 static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
 			     struct scatterlist *sglist,
 			     struct scatterlist **sg)
-- 
2.34.1