btrfs-progs: zoned: implement DUP zone info loading

DUP support is added like the kernel side.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: naota

kernel-shared/zoned.c

@@ -977,6 +977,46 @@ static int btrfs_load_block_group_single(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
+static int btrfs_load_block_group_dup(struct btrfs_fs_info *fs_info,
+				      struct btrfs_block_group *bg,
+				      struct map_lookup *map,
+				      struct zone_info *zone_info,
+				      unsigned long *active)
+{
+	if ((map->type & BTRFS_BLOCK_GROUP_DATA) && !fs_info->stripe_root) {
+		btrfs_err(fs_info, "zoned: data DUP profile needs raid-stripe-tree");
+		return -EINVAL;
+	}
+
+	bg->zone_capacity = min_not_zero(zone_info[0].capacity, zone_info[1].capacity);
+
+	if (zone_info[0].alloc_offset == WP_MISSING_DEV) {
+		btrfs_err(fs_info,
+			  "zoned: cannot recover write pointer for zone %llu",
+			  zone_info[0].physical);
+		return -EIO;
+	}
+	if (zone_info[1].alloc_offset == WP_MISSING_DEV) {
+		btrfs_err(fs_info,
+			  "zoned: cannot recover write pointer for zone %llu",
+			  zone_info[1].physical);
+		return -EIO;
+	}
+	if (zone_info[0].alloc_offset != zone_info[1].alloc_offset) {
+		btrfs_err(fs_info,
+			  "zoned: write pointer offset mismatch of zones in DUP profile");
+		return -EIO;
+	}
+
+	if (test_bit(0, active) != test_bit(1, active)) {
+		return -EIO;
+	} else if (test_bit(0, active)) {
+		bg->zone_is_active = 1;
+	}
+
+	bg->alloc_offset = zone_info[0].alloc_offset;
+	return 0;
+}
 
 int btrfs_load_block_group_zone_info(struct btrfs_fs_info *fs_info,
 				     struct btrfs_block_group *cache)
@@ -1067,6 +1107,8 @@ int btrfs_load_block_group_zone_info(struct btrfs_fs_info *fs_info,
 		ret = btrfs_load_block_group_single(fs_info, cache, &zone_info[0], active);
 		break;
 	case BTRFS_BLOCK_GROUP_DUP:
+		ret = btrfs_load_block_group_dup(fs_info, cache, map, zone_info, active);
+		break;
 	case BTRFS_BLOCK_GROUP_RAID1:
 	case BTRFS_BLOCK_GROUP_RAID1C3:
 	case BTRFS_BLOCK_GROUP_RAID1C4: