*/
 struct dmz_sb {
        sector_t                block;
+       struct dmz_dev          *dev;
        struct dmz_mblock       *mblk;
        struct dmz_super        *sb;
        struct dm_zone          *zone;
        return (sector_t)zone->id << zmd->dev->zone_nr_blocks_shift;
 }
 
+struct dmz_dev *dmz_zone_to_dev(struct dmz_metadata *zmd, struct dm_zone *zone)
+{
+       return &zmd->dev[0];
+}
+
 unsigned int dmz_nr_zones(struct dmz_metadata *zmd)
 {
        return zmd->dev->nr_zones;
 {
        struct dmz_mblock *mblk, *m;
        sector_t block = zmd->sb[zmd->mblk_primary].block + mblk_no;
+       struct dmz_dev *dev = zmd->sb[zmd->mblk_primary].dev;
        struct bio *bio;
 
-       if (dmz_bdev_is_dying(zmd->dev))
+       if (dmz_bdev_is_dying(dev))
                return ERR_PTR(-EIO);
 
        /* Get a new block and a BIO to read it */
 
        /* Submit read BIO */
        bio->bi_iter.bi_sector = dmz_blk2sect(block);
-       bio_set_dev(bio, zmd->dev->bdev);
+       bio_set_dev(bio, dev->bdev);
        bio->bi_private = mblk;
        bio->bi_end_io = dmz_mblock_bio_end_io;
        bio_set_op_attrs(bio, REQ_OP_READ, REQ_META | REQ_PRIO);
                                         sector_t mblk_no)
 {
        struct dmz_mblock *mblk;
+       struct dmz_dev *dev = zmd->sb[zmd->mblk_primary].dev;
 
        /* Check rbtree */
        spin_lock(&zmd->mblk_lock);
                       TASK_UNINTERRUPTIBLE);
        if (test_bit(DMZ_META_ERROR, &mblk->state)) {
                dmz_release_mblock(zmd, mblk);
-               dmz_check_bdev(zmd->dev);
+               dmz_check_bdev(dev);
                return ERR_PTR(-EIO);
        }
 
 static int dmz_write_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk,
                            unsigned int set)
 {
+       struct dmz_dev *dev = zmd->sb[set].dev;
        sector_t block = zmd->sb[set].block + mblk->no;
        struct bio *bio;
 
-       if (dmz_bdev_is_dying(zmd->dev))
+       if (dmz_bdev_is_dying(dev))
                return -EIO;
 
        bio = bio_alloc(GFP_NOIO, 1);
        set_bit(DMZ_META_WRITING, &mblk->state);
 
        bio->bi_iter.bi_sector = dmz_blk2sect(block);
-       bio_set_dev(bio, zmd->dev->bdev);
+       bio_set_dev(bio, dev->bdev);
        bio->bi_private = mblk;
        bio->bi_end_io = dmz_mblock_bio_end_io;
        bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_META | REQ_PRIO);
 /*
  * Read/write a metadata block.
  */
-static int dmz_rdwr_block(struct dmz_metadata *zmd, int op, sector_t block,
-                         struct page *page)
+static int dmz_rdwr_block(struct dmz_dev *dev, int op,
+                         sector_t block, struct page *page)
 {
        struct bio *bio;
        int ret;
 
-       if (dmz_bdev_is_dying(zmd->dev))
+       if (dmz_bdev_is_dying(dev))
                return -EIO;
 
        bio = bio_alloc(GFP_NOIO, 1);
                return -ENOMEM;
 
        bio->bi_iter.bi_sector = dmz_blk2sect(block);
-       bio_set_dev(bio, zmd->dev->bdev);
+       bio_set_dev(bio, dev->bdev);
        bio_set_op_attrs(bio, op, REQ_SYNC | REQ_META | REQ_PRIO);
        bio_add_page(bio, page, DMZ_BLOCK_SIZE, 0);
        ret = submit_bio_wait(bio);
        bio_put(bio);
 
        if (ret)
-               dmz_check_bdev(zmd->dev);
+               dmz_check_bdev(dev);
        return ret;
 }
 
        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;
        u64 sb_gen = zmd->sb_gen + 1;
        int ret;
 
        sb->crc = 0;
        sb->crc = cpu_to_le32(crc32_le(sb_gen, (unsigned char *)sb, DMZ_BLOCK_SIZE));
 
-       ret = dmz_rdwr_block(zmd, REQ_OP_WRITE, block, mblk->page);
+       ret = dmz_rdwr_block(dev, REQ_OP_WRITE, block, mblk->page);
        if (ret == 0)
-               ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL);
+               ret = blkdev_issue_flush(dev->bdev, GFP_NOIO, NULL);
 
        return ret;
 }
                                   unsigned int set)
 {
        struct dmz_mblock *mblk;
+       struct dmz_dev *dev = zmd->sb[set].dev;
        struct blk_plug plug;
        int ret = 0, nr_mblks_submitted = 0;
 
                               TASK_UNINTERRUPTIBLE);
                if (test_bit(DMZ_META_ERROR, &mblk->state)) {
                        clear_bit(DMZ_META_ERROR, &mblk->state);
-                       dmz_check_bdev(zmd->dev);
+                       dmz_check_bdev(dev);
                        ret = -EIO;
                }
                nr_mblks_submitted--;
 
        /* Flush drive cache (this will also sync data) */
        if (ret == 0)
-               ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL);
+               ret = blkdev_issue_flush(dev->bdev, GFP_NOIO, NULL);
 
        return ret;
 }
 {
        struct dmz_mblock *mblk;
        struct list_head write_list;
+       struct dmz_dev *dev;
        int ret;
 
        if (WARN_ON(!zmd))
         * from modifying metadata.
         */
        down_write(&zmd->mblk_sem);
+       dev = zmd->sb[zmd->mblk_primary].dev;
 
        /*
         * This is called from the target flush work and reclaim work.
         */
        dmz_lock_flush(zmd);
 
-       if (dmz_bdev_is_dying(zmd->dev)) {
+       if (dmz_bdev_is_dying(dev)) {
                ret = -EIO;
                goto out;
        }
 
        /* If there are no dirty metadata blocks, just flush the device cache */
        if (list_empty(&write_list)) {
-               ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL);
+               ret = blkdev_issue_flush(dev->bdev, GFP_NOIO, NULL);
                goto err;
        }
 
                list_splice(&write_list, &zmd->mblk_dirty_list);
                spin_unlock(&zmd->mblk_lock);
        }
-       if (!dmz_check_bdev(zmd->dev))
+       if (!dmz_check_bdev(dev))
                ret = -EIO;
        goto out;
 }
 static int dmz_check_sb(struct dmz_metadata *zmd, unsigned int set)
 {
        struct dmz_super *sb = zmd->sb[set].sb;
+       struct dmz_dev *dev = zmd->sb[set].dev;
        unsigned int nr_meta_zones, nr_data_zones;
-       struct dmz_dev *dev = zmd->dev;
        u32 crc, stored_crc;
        u64 gen;
 
  */
 static int dmz_read_sb(struct dmz_metadata *zmd, unsigned int set)
 {
-       return dmz_rdwr_block(zmd, REQ_OP_READ, zmd->sb[set].block,
-                             zmd->sb[set].mblk->page);
+       return dmz_rdwr_block(zmd->sb[set].dev, REQ_OP_READ,
+                             zmd->sb[set].block, zmd->sb[set].mblk->page);
 }
 
 /*
        /* Bad first super block: search for the second one */
        zmd->sb[1].block = zmd->sb[0].block + zone_nr_blocks;
        zmd->sb[1].zone = zmd->sb[0].zone + 1;
+       zmd->sb[1].dev = dmz_zone_to_dev(zmd, zmd->sb[1].zone);
        for (i = 0; i < zmd->nr_rnd_zones - 1; i++) {
                if (dmz_read_sb(zmd, 1) != 0)
                        break;
                        return 0;
                }
                zmd->sb[1].block += zone_nr_blocks;
+               zmd->sb[1].dev = dmz_zone_to_dev(zmd, zmd->sb[1].zone + i);
        }
 
        dmz_free_mblock(zmd, mblk);
        zmd->sb[1].mblk = NULL;
        zmd->sb[1].zone = NULL;
+       zmd->sb[1].dev = NULL;
 
        return -EIO;
 }
        struct page *page;
        int i, ret;
 
-       dmz_dev_warn(zmd->dev, "Metadata set %u invalid: recovering", dst_set);
+       dmz_dev_warn(zmd->sb[dst_set].dev,
+                    "Metadata set %u invalid: recovering", dst_set);
 
        if (dst_set == 0)
                zmd->sb[0].block = dmz_start_block(zmd, zmd->sb[0].zone);
 
        /* Copy metadata blocks */
        for (i = 1; i < zmd->nr_meta_blocks; i++) {
-               ret = dmz_rdwr_block(zmd, REQ_OP_READ,
+               ret = dmz_rdwr_block(zmd->sb[src_set].dev, REQ_OP_READ,
                                     zmd->sb[src_set].block + i, page);
                if (ret)
                        goto out;
-               ret = dmz_rdwr_block(zmd, REQ_OP_WRITE,
+               ret = dmz_rdwr_block(zmd->sb[dst_set].dev, REQ_OP_WRITE,
                                     zmd->sb[dst_set].block + i, page);
                if (ret)
                        goto out;
 
        /* Read and check the primary super block */
        zmd->sb[0].block = dmz_start_block(zmd, zmd->sb[0].zone);
+       zmd->sb[0].dev = dmz_zone_to_dev(zmd, zmd->sb[0].zone);
        ret = dmz_get_sb(zmd, 0);
        if (ret) {
-               dmz_dev_err(zmd->dev, "Read primary super block failed");
+               dmz_dev_err(zmd->sb[0].dev, "Read primary super block failed");
                return ret;
        }
 
                if (!zmd->sb[1].zone)
                        zmd->sb[1].zone = zmd->sb[0].zone + zmd->nr_meta_zones;
                zmd->sb[1].block = dmz_start_block(zmd, zmd->sb[1].zone);
+               zmd->sb[1].dev = dmz_zone_to_dev(zmd, zmd->sb[1].zone);
                ret = dmz_get_sb(zmd, 1);
        } else
                ret = dmz_lookup_secondary_sb(zmd);
 
        if (ret) {
-               dmz_dev_err(zmd->dev, "Read secondary super block failed");
+               dmz_dev_err(zmd->sb[1].dev, "Read secondary super block failed");
                return ret;
        }
 
 
        if (sb_good[0])
                sb_gen[0] = le64_to_cpu(zmd->sb[0].sb->gen);
-       else
+       else {
                ret = dmz_recover_mblocks(zmd, 0);
+               if (ret) {
+                       dmz_dev_err(zmd->sb[0].dev,
+                                   "Recovery of superblock 0 failed");
+                       return -EIO;
+               }
+       }
 
        if (sb_good[1])
                sb_gen[1] = le64_to_cpu(zmd->sb[1].sb->gen);
-       else
+       else {
                ret = dmz_recover_mblocks(zmd, 1);
 
-       if (ret) {
-               dmz_dev_err(zmd->dev, "Recovery failed");
-               return -EIO;
+               if (ret) {
+                       dmz_dev_err(zmd->sb[1].dev,
+                                   "Recovery of superblock 1 failed");
+                       return -EIO;
+               }
        }
 
        if (sb_gen[0] >= sb_gen[1]) {
                zmd->mblk_primary = 1;
        }
 
-       dmz_dev_debug(zmd->dev, "Using super block %u (gen %llu)",
+       dmz_dev_debug(zmd->sb[zmd->mblk_primary].dev,
+                     "Using super block %u (gen %llu)",
                      zmd->mblk_primary, zmd->sb_gen);
 
        return 0;