1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e38d1d7d17d6..96bd13e581cd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1013,6 +1013,85 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
 
 /*
+ * The zone descriptors obtained with a zone report indicate
+ * zone positions within the target device. The zone descriptors
+ * must be remapped to match their position within the dm device.
+ * A target may call dm_remap_zone_report after completion of a
+ * REQ_OP_ZONE_REPORT bio to remap the zone descriptors obtained
+ * from the target device mapping to the dm device.
+ */
+void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start)
+{
+#ifdef CONFIG_BLK_DEV_ZONED
+	struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
+	struct bio *report_bio = tio->io->bio;
+	struct blk_zone_report_hdr *hdr = NULL;
+	struct blk_zone *zone;
+	unsigned int nr_rep = 0;
+	unsigned int ofst;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	void *addr;
+
+	if (bio->bi_status)
+		return;
+
+	/*
+	 * Remap the start sector of the reported zones. For sequential zones,
+	 * also remap the write pointer position.
+	 */
+	bio_for_each_segment(bvec, report_bio, iter) {
+		addr = kmap_atomic(bvec.bv_page);
+
+		/* Remember the report header in the first page */
+		if (!hdr) {
+			hdr = addr;
+			ofst = sizeof(struct blk_zone_report_hdr);
+		} else
+			ofst = 0;
+
+		/* Set zones start sector */
+		while (hdr->nr_zones && ofst < bvec.bv_len) {
+			zone = addr + ofst;
+			if (zone->start >= start + ti->len) {
+				hdr->nr_zones = 0;
+				break;
+			}
+			zone->start = zone->start + ti->begin - start;
+			if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
+				if (zone->cond == BLK_ZONE_COND_FULL)
+					zone->wp = zone->start + zone->len;
+				else if (zone->cond == BLK_ZONE_COND_EMPTY)
+					zone->wp = zone->start;
+				else
+					zone->wp = zone->wp + ti->begin - start;
+			}
+			ofst += sizeof(struct blk_zone);
+			hdr->nr_zones--;
+			nr_rep++;
+		}
+
+		if (addr != hdr)
+			kunmap_atomic(addr);
+
+		if (!hdr->nr_zones)
+			break;
+	}
+
+	if (hdr) {
+		hdr->nr_zones = nr_rep;
+		kunmap_atomic(hdr);
+	}
+
+	bio_advance(report_bio, report_bio->bi_iter.bi_size);
+
+#else /* !CONFIG_BLK_DEV_ZONED */
+	bio->bi_status = BLK_STS_NOTSUPP;
+#endif
+}
+EXPORT_SYMBOL_GPL(dm_remap_zone_report);
+
+/*
  * Flush current->bio_list when the target map method blocks.
  * This fixes deadlocks in snapshot and possibly in other targets.
  */