4 files changed, 427 insertions, 109 deletions

diff --git a/Documentation/admin-guide/device-mapper/dm-zoned.rst b/Documentation/admin-guide/device-mapper/dm-zoned.rst
index 7547ce635161..553752ea2521 100644
--- a/Documentation/admin-guide/device-mapper/dm-zoned.rst
+++ b/Documentation/admin-guide/device-mapper/dm-zoned.rst
@@ -37,9 +37,13 @@ Algorithm
 dm-zoned implements an on-disk buffering scheme to handle non-sequential
 write accesses to the sequential zones of a zoned block device.
 Conventional zones are used for caching as well as for storing internal
-metadata.
+metadata. It can also use a regular block device together with the zoned
+block device; in that case the regular block device will be split logically
+in zones with the same size as the zoned block device. These zones will be
+placed in front of the zones from the zoned block device and will be handled
+just like conventional zones.
 
-The zones of the device are separated into 2 types:
+The zones of the device(s) are separated into 2 types:
 
 1) Metadata zones: these are conventional zones used to store metadata.
 Metadata zones are not reported as useable capacity to the user.
@@ -127,6 +131,13 @@ resumed. Flushing metadata thus only temporarily delays write and
 discard requests. Read requests can be processed concurrently while
 metadata flush is being executed.
 
+If a regular device is used in conjunction with the zoned block device,
+a third set of metadata (without the zone bitmaps) is written to the
+start of the zoned block device. This metadata has a generation counter of
+'0' and will never be updated during normal operation; it just serves for
+identification purposes. The first and second copy of the metadata
+are located at the start of the regular block device.
+
 Usage
 =====
 
@@ -138,12 +149,21 @@ Ex::
 
 	dmzadm --format /dev/sdxx
 
-For a formatted device, the target can be created normally with the
-dmsetup utility. The only parameter that dm-zoned requires is the
-underlying zoned block device name. Ex::
 
-	echo "0 `blockdev --getsize ${dev}` zoned ${dev}" | \
-	dmsetup create dmz-`basename ${dev}`
+If two drives are to be used, both devices must be specified, with the
+regular block device as the first device.
+
+Ex::
+
+	dmzadm --format /dev/sdxx /dev/sdyy
+
+
+Fomatted device(s) can be started with the dmzadm utility, too.:
+
+Ex::
+
+	dmzadm --start /dev/sdxx /dev/sdyy
+
 
 Information about the internal layout and current usage of the zones can
 be obtained with the 'status' callback from dmsetup:
diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 939deed1606a..fba690dd37f5 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -16,7 +16,7 @@
 /*
  * Metadata version.
  */
-#define DMZ_META_VER	1
+#define DMZ_META_VER	2
 
 /*
  * On-disk super block magic.
@@ -69,8 +69,17 @@ struct dmz_super {
 	/* Checksum */
 	__le32		crc;			/*  48 */
 
+	/* DM-Zoned label */
+	u8		dmz_label[32];		/*  80 */
+
+	/* DM-Zoned UUID */
+	u8		dmz_uuid[16];		/*  96 */
+
+	/* Device UUID */
+	u8		dev_uuid[16];		/* 112 */
+
 	/* Padding to full 512B sector */
-	u8		reserved[464];		/* 512 */
+	u8		reserved[400];		/* 512 */
 };
 
 /*
@@ -133,8 +142,11 @@ struct dmz_sb {
  */
 struct dmz_metadata {
 	struct dmz_dev		*dev;
+	unsigned int		nr_devs;
 
 	char			devname[BDEVNAME_SIZE];
+	char			label[BDEVNAME_SIZE];
+	uuid_t			uuid;
 
 	sector_t		zone_bitmap_size;
 	unsigned int		zone_nr_bitmap_blocks;
@@ -161,8 +173,9 @@ struct dmz_metadata {
 	/* Zone information array */
 	struct dm_zone		*zones;
 
-	struct dmz_sb		sb[2];
+	struct dmz_sb		sb[3];
 	unsigned int		mblk_primary;
+	unsigned int		sb_version;
 	u64			sb_gen;
 	unsigned int		min_nr_mblks;
 	unsigned int		max_nr_mblks;
@@ -195,31 +208,56 @@ struct dmz_metadata {
 };
 
 #define dmz_zmd_info(zmd, format, args...)	\
-	DMINFO("(%s): " format, (zmd)->devname, ## args)
+	DMINFO("(%s): " format, (zmd)->label, ## args)
 
 #define dmz_zmd_err(zmd, format, args...)	\
-	DMERR("(%s): " format, (zmd)->devname, ## args)
+	DMERR("(%s): " format, (zmd)->label, ## args)
 
 #define dmz_zmd_warn(zmd, format, args...)	\
-	DMWARN("(%s): " format, (zmd)->devname, ## args)
+	DMWARN("(%s): " format, (zmd)->label, ## args)
 
 #define dmz_zmd_debug(zmd, format, args...)	\
-	DMDEBUG("(%s): " format, (zmd)->devname, ## args)
+	DMDEBUG("(%s): " format, (zmd)->label, ## args)
 /*
  * Various accessors
  */
+static unsigned int dmz_dev_zone_id(struct dmz_metadata *zmd, struct dm_zone *zone)
+{
+	unsigned int zone_id;
+
+	if (WARN_ON(!zone))
+		return 0;
+
+	zone_id = zone->id;
+	if (zmd->nr_devs > 1 &&
+	    (zone_id >= zmd->dev[1].zone_offset))
+		zone_id -= zmd->dev[1].zone_offset;
+	return zone_id;
+}
+
 sector_t dmz_start_sect(struct dmz_metadata *zmd, struct dm_zone *zone)
 {
-	return (sector_t)zone->id << zmd->zone_nr_sectors_shift;
+	unsigned int zone_id = dmz_dev_zone_id(zmd, zone);
+
+	return (sector_t)zone_id << zmd->zone_nr_sectors_shift;
 }
 
 sector_t dmz_start_block(struct dmz_metadata *zmd, struct dm_zone *zone)
 {
-	return (sector_t)zone->id << zmd->zone_nr_blocks_shift;
+	unsigned int zone_id = dmz_dev_zone_id(zmd, zone);
+
+	return (sector_t)zone_id << zmd->zone_nr_blocks_shift;
 }
 
 struct dmz_dev *dmz_zone_to_dev(struct dmz_metadata *zmd, struct dm_zone *zone)
 {
+	if (WARN_ON(!zone))
+		return &zmd->dev[0];
+
+	if (zmd->nr_devs > 1 &&
+	    zone->id >= zmd->dev[1].zone_offset)
+		return &zmd->dev[1];
+
 	return &zmd->dev[0];
 }
 
@@ -275,17 +313,29 @@ unsigned int dmz_nr_unmap_seq_zones(struct dmz_metadata *zmd)
 
 const char *dmz_metadata_label(struct dmz_metadata *zmd)
 {
-	return (const char *)zmd->devname;
+	return (const char *)zmd->label;
 }
 
 bool dmz_check_dev(struct dmz_metadata *zmd)
 {
-	return dmz_check_bdev(&zmd->dev[0]);
+	unsigned int i;
+
+	for (i = 0; i < zmd->nr_devs; i++) {
+		if (!dmz_check_bdev(&zmd->dev[i]))
+			return false;
+	}
+	return true;
 }
 
 bool dmz_dev_is_dying(struct dmz_metadata *zmd)
 {
-	return dmz_bdev_is_dying(&zmd->dev[0]);
+	unsigned int i;
+
+	for (i = 0; i < zmd->nr_devs; i++) {
+		if (dmz_bdev_is_dying(&zmd->dev[i]))
+			return true;
+	}
+	return false;
 }
 
 /*
@@ -687,6 +737,9 @@ static int dmz_rdwr_block(struct dmz_dev *dev, int op,
 	struct bio *bio;
 	int ret;
 
+	if (WARN_ON(!dev))
+		return -EIO;
+
 	if (dmz_bdev_is_dying(dev))
 		return -EIO;
 
@@ -711,19 +764,32 @@ static int dmz_rdwr_block(struct dmz_dev *dev, int op,
  */
 static int dmz_write_sb(struct dmz_metadata *zmd, unsigned int set)
 {
-	sector_t block = zmd->sb[set].block;
 	struct dmz_mblock *mblk = zmd->sb[set].mblk;
 	struct dmz_super *sb = zmd->sb[set].sb;
 	struct dmz_dev *dev = zmd->sb[set].dev;
+	sector_t sb_block;
 	u64 sb_gen = zmd->sb_gen + 1;
 	int ret;
 
 	sb->magic = cpu_to_le32(DMZ_MAGIC);
-	sb->version = cpu_to_le32(DMZ_META_VER);
+
+	sb->version = cpu_to_le32(zmd->sb_version);
+	if (zmd->sb_version > 1) {
+		BUILD_BUG_ON(UUID_SIZE != 16);
+		export_uuid(sb->dmz_uuid, &zmd->uuid);
+		memcpy(sb->dmz_label, zmd->label, BDEVNAME_SIZE);
+		export_uuid(sb->dev_uuid, &dev->uuid);
+	}
 
 	sb->gen = cpu_to_le64(sb_gen);
 
-	sb->sb_block = cpu_to_le64(block);
+	/*
+	 * The metadata always references the absolute block address,
+	 * ie relative to the entire block range, not the per-device
+	 * block address.
+	 */
+	sb_block = zmd->sb[set].zone->id << zmd->zone_nr_blocks_shift;
+	sb->sb_block = cpu_to_le64(sb_block);
 	sb->nr_meta_blocks = cpu_to_le32(zmd->nr_meta_blocks);
 	sb->nr_reserved_seq = cpu_to_le32(zmd->nr_reserved_seq);
 	sb->nr_chunks = cpu_to_le32(zmd->nr_chunks);
@@ -734,7 +800,8 @@ static int dmz_write_sb(struct dmz_metadata *zmd, unsigned int set)
 	sb->crc = 0;
 	sb->crc = cpu_to_le32(crc32_le(sb_gen, (unsigned char *)sb, DMZ_BLOCK_SIZE));
 
-	ret = dmz_rdwr_block(dev, REQ_OP_WRITE, block, mblk->page);
+	ret = dmz_rdwr_block(dev, REQ_OP_WRITE, zmd->sb[set].block,
+			     mblk->page);
 	if (ret == 0)
 		ret = blkdev_issue_flush(dev->bdev, GFP_NOIO, NULL);
 
@@ -915,6 +982,23 @@ static int dmz_check_sb(struct dmz_metadata *zmd, unsigned int set)
 	u32 crc, stored_crc;
 	u64 gen;
 
+	if (le32_to_cpu(sb->magic) != DMZ_MAGIC) {
+		dmz_dev_err(dev, "Invalid meta magic (needed 0x%08x, got 0x%08x)",
+			    DMZ_MAGIC, le32_to_cpu(sb->magic));
+		return -ENXIO;
+	}
+
+	zmd->sb_version = le32_to_cpu(sb->version);
+	if (zmd->sb_version > DMZ_META_VER) {
+		dmz_dev_err(dev, "Invalid meta version (needed %d, got %d)",
+			    DMZ_META_VER, zmd->sb_version);
+		return -EINVAL;
+	}
+	if ((zmd->sb_version < 1) && (set == 2)) {
+		dmz_dev_err(dev, "Tertiary superblocks are not supported");
+		return -EINVAL;
+	}
+
 	gen = le64_to_cpu(sb->gen);
 	stored_crc = le32_to_cpu(sb->crc);
 	sb->crc = 0;
@@ -925,16 +1009,45 @@ static int dmz_check_sb(struct dmz_metadata *zmd, unsigned int set)
 		return -ENXIO;
 	}
 
-	if (le32_to_cpu(sb->magic) != DMZ_MAGIC) {
-		dmz_dev_err(dev, "Invalid meta magic (needed 0x%08x, got 0x%08x)",
-			    DMZ_MAGIC, le32_to_cpu(sb->magic));
-		return -ENXIO;
-	}
+	if (zmd->sb_version > 1) {
+		uuid_t sb_uuid;
+
+		import_uuid(&sb_uuid, sb->dmz_uuid);
+		if (uuid_is_null(&sb_uuid)) {
+			dmz_dev_err(dev, "NULL DM-Zoned uuid");
+			return -ENXIO;
+		} else if (uuid_is_null(&zmd->uuid)) {
+			uuid_copy(&zmd->uuid, &sb_uuid);
+		} else if (!uuid_equal(&zmd->uuid, &sb_uuid)) {
+			dmz_dev_err(dev, "mismatching DM-Zoned uuid, "
+				    "is %pUl expected %pUl",
+				    &sb_uuid, &zmd->uuid);
+			return -ENXIO;
+		}
+		if (!strlen(zmd->label))
+			memcpy(zmd->label, sb->dmz_label, BDEVNAME_SIZE);
+		else if (memcmp(zmd->label, sb->dmz_label, BDEVNAME_SIZE)) {
+			dmz_dev_err(dev, "mismatching DM-Zoned label, "
+				    "is %s expected %s",
+				    sb->dmz_label, zmd->label);
+			return -ENXIO;
+		}
+		import_uuid(&dev->uuid, sb->dev_uuid);
+		if (uuid_is_null(&dev->uuid)) {
+			dmz_dev_err(dev, "NULL device uuid");
+			return -ENXIO;
+		}
 
-	if (le32_to_cpu(sb->version) != DMZ_META_VER) {
-		dmz_dev_err(dev, "Invalid meta version (needed %d, got %d)",
-			    DMZ_META_VER, le32_to_cpu(sb->version));
-		return -ENXIO;
+		if (set == 2) {
+			/*
+			 * Generation number should be 0, but it doesn't
+			 * really matter if it isn't.
+			 */
+			if (gen != 0)
+				dmz_dev_warn(dev, "Invalid generation %llu",
+					    gen);
+			return 0;
+		}
 	}
 
 	nr_meta_zones = (le32_to_cpu(sb->nr_meta_blocks) + zmd->zone_nr_blocks - 1)
@@ -1185,21 +1298,38 @@ static int dmz_load_sb(struct dmz_metadata *zmd)
 		      "Using super block %u (gen %llu)",
 		      zmd->mblk_primary, zmd->sb_gen);
 
+	if ((zmd->sb_version > 1) && zmd->sb[2].zone) {
+		zmd->sb[2].block = dmz_start_block(zmd, zmd->sb[2].zone);
+		zmd->sb[2].dev = dmz_zone_to_dev(zmd, zmd->sb[2].zone);
+		ret = dmz_get_sb(zmd, 2);
+		if (ret) {
+			dmz_dev_err(zmd->sb[2].dev,
+				    "Read tertiary super block failed");
+			return ret;
+		}
+		ret = dmz_check_sb(zmd, 2);
+		if (ret == -EINVAL)
+			return ret;
+	}
 	return 0;
 }
 
 /*
  * Initialize a zone descriptor.
  */
-static int dmz_init_zone(struct blk_zone *blkz, unsigned int idx, void *data)
+static int dmz_init_zone(struct blk_zone *blkz, unsigned int num, void *data)
 {
 	struct dmz_metadata *zmd = data;
+	struct dmz_dev *dev = zmd->nr_devs > 1 ? &zmd->dev[1] : &zmd->dev[0];
+	int idx = num + dev->zone_offset;
 	struct dm_zone *zone = &zmd->zones[idx];
-	struct dmz_dev *dev = zmd->dev;
 
-	/* Ignore the eventual last runt (smaller) zone */
 	if (blkz->len != zmd->zone_nr_sectors) {
-		if (blkz->start + blkz->len == dev->capacity)
+		if (zmd->sb_version > 1) {
+			/* Ignore the eventual runt (smaller) zone */
+			set_bit(DMZ_OFFLINE, &zone->flags);
+			return 0;
+		} else if (blkz->start + blkz->len == dev->capacity)
 			return 0;
 		return -ENXIO;
 	}
@@ -1234,16 +1364,45 @@ static int dmz_init_zone(struct blk_zone *blkz, unsigned int idx, void *data)
 		zmd->nr_useable_zones++;
 		if (dmz_is_rnd(zone)) {
 			zmd->nr_rnd_zones++;
-			if (!zmd->sb[0].zone) {
-				/* Super block zone */
+			if (zmd->nr_devs == 1 && !zmd->sb[0].zone) {
+				/* Primary super block zone */
 				zmd->sb[0].zone = zone;
 			}
 		}
+		if (zmd->nr_devs > 1 && !zmd->sb[2].zone) {
+			/* Tertiary superblock zone */
+			zmd->sb[2].zone = zone;
+		}
 	}
 
 	return 0;
 }
 
+static void dmz_emulate_zones(struct dmz_metadata *zmd, struct dmz_dev *dev)
+{
+	int idx;
+	sector_t zone_offset = 0;
+
+	for(idx = 0; idx < dev->nr_zones; idx++) {
+		struct dm_zone *zone = &zmd->zones[idx];
+
+		INIT_LIST_HEAD(&zone->link);
+		atomic_set(&zone->refcount, 0);
+		zone->id = idx;
+		zone->chunk = DMZ_MAP_UNMAPPED;
+		set_bit(DMZ_RND, &zone->flags);
+		zone->wp_block = 0;
+		zmd->nr_rnd_zones++;
+		zmd->nr_useable_zones++;
+		if (dev->capacity - zone_offset < zmd->zone_nr_sectors) {
+			/* Disable runt zone */
+			set_bit(DMZ_OFFLINE, &zone->flags);
+			break;
+		}
+		zone_offset += zmd->zone_nr_sectors;
+	}
+}
+
 /*
  * Free zones descriptors.
  */
@@ -1259,11 +1418,11 @@ static void dmz_drop_zones(struct dmz_metadata *zmd)
  */
 static int dmz_init_zones(struct dmz_metadata *zmd)
 {
-	struct dmz_dev *dev = &zmd->dev[0];
-	int ret;
+	int i, ret;
+	struct dmz_dev *zoned_dev = &zmd->dev[0];
 
 	/* Init */
-	zmd->zone_nr_sectors = dev->zone_nr_sectors;
+	zmd->zone_nr_sectors = zmd->dev[0].zone_nr_sectors;
 	zmd->zone_nr_sectors_shift = ilog2(zmd->zone_nr_sectors);
 	zmd->zone_nr_blocks = dmz_sect2blk(zmd->zone_nr_sectors);
 	zmd->zone_nr_blocks_shift = ilog2(zmd->zone_nr_blocks);
@@ -1274,7 +1433,14 @@ static int dmz_init_zones(struct dmz_metadata *zmd)
 					DMZ_BLOCK_SIZE_BITS);
 
 	/* Allocate zone array */
-	zmd->nr_zones = dev->nr_zones;
+	zmd->nr_zones = 0;
+	for (i = 0; i < zmd->nr_devs; i++)
+		zmd->nr_zones += zmd->dev[i].nr_zones;
+
+	if (!zmd->nr_zones) {
+		DMERR("(%s): No zones found", zmd->devname);
+		return -ENXIO;
+	}
 	zmd->zones = kcalloc(zmd->nr_zones, sizeof(struct dm_zone), GFP_KERNEL);
 	if (!zmd->zones)
 		return -ENOMEM;
@@ -1282,14 +1448,27 @@ static int dmz_init_zones(struct dmz_metadata *zmd)
 	DMDEBUG("(%s): Using %zu B for zone information",
 		zmd->devname, sizeof(struct dm_zone) * zmd->nr_zones);
 
+	if (zmd->nr_devs > 1) {
+		dmz_emulate_zones(zmd, &zmd->dev[0]);
+		/*
+		 * Primary superblock zone is always at zone 0 when multiple
+		 * drives are present.
+		 */
+		zmd->sb[0].zone = &zmd->zones[0];
+
+		zoned_dev = &zmd->dev[1];
+	}
+
 	/*
 	 * Get zone information and initialize zone descriptors.  At the same
 	 * time, determine where the super block should be: first block of the
 	 * first randomly writable zone.
 	 */
-	ret = blkdev_report_zones(dev->bdev, 0, BLK_ALL_ZONES, dmz_init_zone,
-				  zmd);
+	ret = blkdev_report_zones(zoned_dev->bdev, 0, BLK_ALL_ZONES,
+				  dmz_init_zone, zmd);
 	if (ret < 0) {
+		DMDEBUG("(%s): Failed to report zones, error %d",
+			zmd->devname, ret);
 		dmz_drop_zones(zmd);
 		return ret;
 	}
@@ -1325,6 +1504,9 @@ static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
 	unsigned int noio_flag;
 	int ret;
 
+	if (dev->flags & DMZ_BDEV_REGULAR)
+		return 0;
+
 	/*
 	 * Get zone information from disk. Since blkdev_report_zones() uses
 	 * GFP_KERNEL by default for memory allocations, set the per-task
@@ -2475,19 +2657,34 @@ static void dmz_print_dev(struct dmz_metadata *zmd, int num)
 {
 	struct dmz_dev *dev = &zmd->dev[num];
 
-	dmz_dev_info(dev, "Host-%s zoned block device",
-		     bdev_zoned_model(dev->bdev) == BLK_ZONED_HA ?
-		     "aware" : "managed");
-	dmz_dev_info(dev, "  %llu 512-byte logical sectors",
-		     (u64)dev->capacity);
-	dmz_dev_info(dev, "  %u zones of %llu 512-byte logical sectors",
-		     dev->nr_zones, (u64)zmd->zone_nr_sectors);
+	if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE)
+		dmz_dev_info(dev, "Regular block device");
+	else
+		dmz_dev_info(dev, "Host-%s zoned block device",
+			     bdev_zoned_model(dev->bdev) == BLK_ZONED_HA ?
+			     "aware" : "managed");
+	if (zmd->sb_version > 1) {
+		sector_t sector_offset =
+			dev->zone_offset << zmd->zone_nr_sectors_shift;
+
+		dmz_dev_info(dev, "  %llu 512-byte logical sectors (offset %llu)",
+			     (u64)dev->capacity, (u64)sector_offset);
+		dmz_dev_info(dev, "  %u zones of %llu 512-byte logical sectors (offset %llu)",
+			     dev->nr_zones, (u64)zmd->zone_nr_sectors,
+			     (u64)dev->zone_offset);
+	} else {
+		dmz_dev_info(dev, "  %llu 512-byte logical sectors",
+			     (u64)dev->capacity);
+		dmz_dev_info(dev, "  %u zones of %llu 512-byte logical sectors",
+			     dev->nr_zones, (u64)zmd->zone_nr_sectors);
+	}
 }
 
 /*
  * Initialize the zoned metadata.
  */
-int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **metadata,
+int dmz_ctr_metadata(struct dmz_dev *dev, int num_dev,
+		     struct dmz_metadata **metadata,
 		     const char *devname)
 {
 	struct dmz_metadata *zmd;
@@ -2501,6 +2698,7 @@ int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **metadata,
 
 	strcpy(zmd->devname, devname);
 	zmd->dev = dev;
+	zmd->nr_devs = num_dev;
 	zmd->mblk_rbtree = RB_ROOT;
 	init_rwsem(&zmd->mblk_sem);
 	mutex_init(&zmd->mblk_flush_lock);
@@ -2535,11 +2733,24 @@ int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **metadata,
 	/* Set metadata zones starting from sb_zone */
 	for (i = 0; i < zmd->nr_meta_zones << 1; i++) {
 		zone = dmz_get(zmd, zmd->sb[0].zone->id + i);
-		if (!dmz_is_rnd(zone))
+		if (!dmz_is_rnd(zone)) {
+			dmz_zmd_err(zmd,
+				    "metadata zone %d is not random", i);
+			ret = -ENXIO;
 			goto err;
+		}
+		set_bit(DMZ_META, &zone->flags);
+	}
+	if (zmd->sb[2].zone) {
+		zone = dmz_get(zmd, zmd->sb[2].zone->id);
+		if (!zone) {
+			dmz_zmd_err(zmd,
+				    "Tertiary metadata zone not present");
+			ret = -ENXIO;
+			goto err;
+		}
 		set_bit(DMZ_META, &zone->flags);
 	}
-
 	/* Load mapping table */
 	ret = dmz_load_mapping(zmd);
 	if (ret)
@@ -2564,8 +2775,9 @@ int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **metadata,
 		goto err;
 	}
 
-	dmz_zmd_info(zmd, "DM-Zoned metadata version %d", DMZ_META_VER);
-	dmz_print_dev(zmd, 0);
+	dmz_zmd_info(zmd, "DM-Zoned metadata version %d", zmd->sb_version);
+	for (i = 0; i < zmd->nr_devs; i++)
+		dmz_print_dev(zmd, i);
 
 	dmz_zmd_info(zmd, "  %u zones of %llu 512-byte logical sectors",
 		     zmd->nr_zones, (u64)zmd->zone_nr_sectors);
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index a09fb78ffe88..ea43f6892ced 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -13,6 +13,8 @@
 
 #define DMZ_MIN_BIOS		8192
 
+#define DMZ_MAX_DEVS		2
+
 /*
  * Zone BIO context.
  */
@@ -38,7 +40,7 @@ struct dm_chunk_work {
  * Target descriptor.
  */
 struct dmz_target {
-	struct dm_dev		*ddev;
+	struct dm_dev		*ddev[DMZ_MAX_DEVS];
 
 	unsigned long		flags;
 
@@ -81,7 +83,7 @@ static inline void dmz_bio_endio(struct bio *bio, blk_status_t status)
 
 	if (status != BLK_STS_OK && bio->bi_status == BLK_STS_OK)
 		bio->bi_status = status;
-	if (bio->bi_status != BLK_STS_OK)
+	if (bioctx->dev && bio->bi_status != BLK_STS_OK)
 		bioctx->dev->flags |= DMZ_CHECK_BDEV;
 
 	if (refcount_dec_and_test(&bioctx->ref)) {
@@ -690,60 +692,64 @@ static int dmz_map(struct dm_target *ti, struct bio *bio)
 /*
  * Get zoned device information.
  */
-static int dmz_get_zoned_device(struct dm_target *ti, char *path)
+static int dmz_get_zoned_device(struct dm_target *ti, char *path,
+				int idx, int nr_devs)
 {
 	struct dmz_target *dmz = ti->private;
-	struct request_queue *q;
+	struct dm_dev *ddev;
 	struct dmz_dev *dev;
-	sector_t aligned_capacity;
 	int ret;
+	struct block_device *bdev;
 
 	/* Get the target device */
-	ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &dmz->ddev);
+	ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &ddev);
 	if (ret) {
 		ti->error = "Get target device failed";
-		dmz->ddev = NULL;
 		return ret;
 	}
 
-	dev = kzalloc(sizeof(struct dmz_dev), GFP_KERNEL);
-	if (!dev) {
-		ret = -ENOMEM;
-		goto err;
+	bdev = ddev->bdev;
+	if (bdev_zoned_model(bdev) == BLK_ZONED_NONE) {
+		if (nr_devs == 1) {
+			ti->error = "Invalid regular device";
+			goto err;
+		}
+		if (idx != 0) {
+			ti->error = "First device must be a regular device";
+			goto err;
+		}
+		if (dmz->ddev[0]) {
+			ti->error = "Too many regular devices";
+			goto err;
+		}
+		dev = &dmz->dev[idx];
+		dev->flags = DMZ_BDEV_REGULAR;
+	} else {
+		if (dmz->ddev[idx]) {
+			ti->error = "Too many zoned devices";
+			goto err;
+		}
+		if (nr_devs > 1 && idx == 0) {
+			ti->error = "First device must be a regular device";
+			goto err;
+		}
+		dev = &dmz->dev[idx];
 	}
-
-	dev->bdev = dmz->ddev->bdev;
+	dev->bdev = bdev;
 	(void)bdevname(dev->bdev, dev->name);
 
-	if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE) {
-		ti->error = "Not a zoned block device";
-		ret = -EINVAL;
-		goto err;
-	}
-
-	q = bdev_get_queue(dev->bdev);
-	dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT;
-	aligned_capacity = dev->capacity &
-				~((sector_t)blk_queue_zone_sectors(q) - 1);
-	if (ti->begin ||
-	    ((ti->len != dev->capacity) && (ti->len != aligned_capacity))) {
-		ti->error = "Partial mapping not supported";
-		ret = -EINVAL;
+	dev->capacity = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
+	if (ti->begin) {
+		ti->error = "Partial mapping is not supported";
 		goto err;
 	}
 
-	dev->zone_nr_sectors = blk_queue_zone_sectors(q);
-
-	dev->nr_zones = blkdev_nr_zones(dev->bdev->bd_disk);
-
-	dmz->dev = dev;
+	dmz->ddev[idx] = ddev;
 
 	return 0;
 err:
-	dm_put_device(ti, dmz->ddev);
-	kfree(dev);
-
-	return ret;
+	dm_put_device(ti, ddev);
+	return -EINVAL;
 }
 
 /*
@@ -752,10 +758,56 @@ err:
 static void dmz_put_zoned_device(struct dm_target *ti)
 {
 	struct dmz_target *dmz = ti->private;
+	int i;
 
-	dm_put_device(ti, dmz->ddev);
-	kfree(dmz->dev);
-	dmz->dev = NULL;
+	for (i = 0; i < DMZ_MAX_DEVS; i++) {
+		if (dmz->ddev[i]) {
+			dm_put_device(ti, dmz->ddev[i]);
+			dmz->ddev[i] = NULL;
+		}
+	}
+}
+
+static int dmz_fixup_devices(struct dm_target *ti)
+{
+	struct dmz_target *dmz = ti->private;
+	struct dmz_dev *reg_dev, *zoned_dev;
+	struct request_queue *q;
+
+	/*
+	 * When we have two devices, the first one must be a regular block
+	 * device and the second a zoned block device.
+	 */
+	if (dmz->ddev[0] && dmz->ddev[1]) {
+		reg_dev = &dmz->dev[0];
+		if (!(reg_dev->flags & DMZ_BDEV_REGULAR)) {
+			ti->error = "Primary disk is not a regular device";
+			return -EINVAL;
+		}
+		zoned_dev = &dmz->dev[1];
+		if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
+			ti->error = "Secondary disk is not a zoned device";
+			return -EINVAL;
+		}
+	} else {
+		reg_dev = NULL;
+		zoned_dev = &dmz->dev[0];
+		if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
+			ti->error = "Disk is not a zoned device";
+			return -EINVAL;
+		}
+	}
+	q = bdev_get_queue(zoned_dev->bdev);
+	zoned_dev->zone_nr_sectors = blk_queue_zone_sectors(q);
+	zoned_dev->nr_zones = blkdev_nr_zones(zoned_dev->bdev->bd_disk);
+
+	if (reg_dev) {
+		reg_dev->zone_nr_sectors = zoned_dev->zone_nr_sectors;
+		reg_dev->nr_zones = DIV_ROUND_UP(reg_dev->capacity,
+						 reg_dev->zone_nr_sectors);
+		zoned_dev->zone_offset = reg_dev->nr_zones;
+	}
+	return 0;
 }
 
 /*
@@ -764,11 +816,10 @@ static void dmz_put_zoned_device(struct dm_target *ti)
 static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
 	struct dmz_target *dmz;
-	struct dmz_dev *dev;
 	int ret;
 
 	/* Check arguments */
-	if (argc != 1) {
+	if (argc < 1 || argc > 2) {
 		ti->error = "Invalid argument count";
 		return -EINVAL;
 	}
@@ -779,18 +830,34 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		ti->error = "Unable to allocate the zoned target descriptor";
 		return -ENOMEM;
 	}
+	dmz->dev = kcalloc(2, sizeof(struct dmz_dev), GFP_KERNEL);
+	if (!dmz->dev) {
+		ti->error = "Unable to allocate the zoned device descriptors";
+		kfree(dmz);
+		return -ENOMEM;
+	}
 	ti->private = dmz;
 
 	/* Get the target zoned block device */
-	ret = dmz_get_zoned_device(ti, argv[0]);
+	ret = dmz_get_zoned_device(ti, argv[0], 0, argc);
+	if (ret)
+		goto err;
+
+	if (argc == 2) {
+		ret = dmz_get_zoned_device(ti, argv[1], 1, argc);
+		if (ret) {
+			dmz_put_zoned_device(ti);
+			goto err;
+		}
+	}
+	ret = dmz_fixup_devices(ti);
 	if (ret) {
-		dmz->ddev = NULL;
+		dmz_put_zoned_device(ti);
 		goto err;
 	}
 
 	/* Initialize metadata */
-	dev = dmz->dev;
-	ret = dmz_ctr_metadata(dev, &dmz->metadata,
+	ret = dmz_ctr_metadata(dmz->dev, argc, &dmz->metadata,
 			       dm_table_device_name(ti->table));
 	if (ret) {
 		ti->error = "Metadata initialization failed";
@@ -867,6 +934,7 @@ err_meta:
 err_dev:
 	dmz_put_zoned_device(ti);
 err:
+	kfree(dmz->dev);
 	kfree(dmz);
 
 	return ret;
@@ -897,6 +965,7 @@ static void dmz_dtr(struct dm_target *ti)
 
 	mutex_destroy(&dmz->chunk_lock);
 
+	kfree(dmz->dev);
 	kfree(dmz);
 }
 
@@ -971,10 +1040,17 @@ static int dmz_iterate_devices(struct dm_target *ti,
 			       iterate_devices_callout_fn fn, void *data)
 {
 	struct dmz_target *dmz = ti->private;
-	struct dmz_dev *dev = dmz->dev;
-	sector_t capacity = dev->capacity & ~(dmz_zone_nr_sectors(dmz->metadata) - 1);
-
-	return fn(ti, dmz->ddev, 0, capacity, data);
+	unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
+	sector_t capacity;
+	int r;
+
+	capacity = dmz->dev[0].capacity & ~(zone_nr_sectors - 1);
+	r = fn(ti, dmz->ddev[0], 0, capacity, data);
+	if (!r && dmz->ddev[1]) {
+		capacity = dmz->dev[1].capacity & ~(zone_nr_sectors - 1);
+		r = fn(ti, dmz->ddev[1], 0, capacity, data);
+	}
+	return r;
 }
 
 static void dmz_status(struct dm_target *ti, status_type_t type,
@@ -984,6 +1060,7 @@ static void dmz_status(struct dm_target *ti, status_type_t type,
 	struct dmz_target *dmz = ti->private;
 	ssize_t sz = 0;
 	char buf[BDEVNAME_SIZE];
+	struct dmz_dev *dev;
 
 	switch (type) {
 	case STATUSTYPE_INFO:
@@ -995,8 +1072,14 @@ static void dmz_status(struct dm_target *ti, status_type_t type,
 		       dmz_nr_seq_zones(dmz->metadata));
 		break;
 	case STATUSTYPE_TABLE:
-		format_dev_t(buf, dmz->dev->bdev->bd_dev);
+		dev = &dmz->dev[0];
+		format_dev_t(buf, dev->bdev->bd_dev);
 		DMEMIT("%s", buf);
+		if (dmz->dev[1].bdev) {
+			dev = &dmz->dev[1];
+			format_dev_t(buf, dev->bdev->bd_dev);
+			DMEMIT(" %s", buf);
+		}
 		break;
 	}
 	return;
@@ -1018,7 +1101,7 @@ static int dmz_message(struct dm_target *ti, unsigned int argc, char **argv,
 
 static struct target_type dmz_type = {
 	.name		 = "zoned",
-	.version	 = {1, 1, 0},
+	.version	 = {2, 0, 0},
 	.features	 = DM_TARGET_SINGLETON | DM_TARGET_ZONED_HM,
 	.module		 = THIS_MODULE,
 	.ctr		 = dmz_ctr,
diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h
index 2629bd51fa26..4971a765be55 100644
--- a/drivers/md/dm-zoned.h
+++ b/drivers/md/dm-zoned.h
@@ -52,10 +52,12 @@ struct dmz_dev {
 	struct block_device	*bdev;
 
 	char			name[BDEVNAME_SIZE];
+	uuid_t			uuid;
 
 	sector_t		capacity;
 
 	unsigned int		nr_zones;
+	unsigned int		zone_offset;
 
 	unsigned int		flags;
 
@@ -69,6 +71,7 @@ struct dmz_dev {
 /* Device flags. */
 #define DMZ_BDEV_DYING		(1 << 0)
 #define DMZ_CHECK_BDEV		(2 << 0)
+#define DMZ_BDEV_REGULAR	(4 << 0)
 
 /*
  * Zone descriptor.
@@ -163,8 +166,8 @@ struct dmz_reclaim;
 /*
  * Functions defined in dm-zoned-metadata.c
  */
-int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **zmd,
-		     const char *devname);
+int dmz_ctr_metadata(struct dmz_dev *dev, int num_dev,
+		     struct dmz_metadata **zmd, const char *devname);
 void dmz_dtr_metadata(struct dmz_metadata *zmd);
 int dmz_resume_metadata(struct dmz_metadata *zmd);