# Test Case: Plain metabox container

**Test ID**: TC073-metabox-container
**Fixture**: `metabox-plain.erofs`, `/metabox-a`, `/metabox-b`

## Objective

Verify metadata and xattrs read from a plain regular metabox carrier. Before
guest use, require manifest fields `METABOX`, `sb_extslots=1`, relocated
`meta_blkaddr`, `metabox_nid`, bit-63 dirent NIDs, and image/source hashes.

## Manual steps

```sh
unit=$(mdconfig -a -t vnode -f /tmp/repo22-g4/images/metabox-plain.erofs)
mount -t erofs -o ro /dev/${unit} /mnt/repo22-g4
stat -f 'mode=%Sp size=%z inode=%i' /mnt/repo22-g4/metabox-a \
  /mnt/repo22-g4/metabox-b
sha256 -q /mnt/repo22-g4/metabox-a /mnt/repo22-g4/metabox-b
lsextattr user /mnt/repo22-g4/metabox-a
getextattr -qq -x user metaboxshared /mnt/repo22-g4/metabox-a
getextattr -qq -x user metaboxshared /mnt/repo22-g4/metabox-b
umount /mnt/repo22-g4
mdconfig -d -u "${unit#md}"
```

## Expected results

The inode numbers retain bit 63; file hashes match the generated source;
`metaboxshared` is `nonzero-base` for both files. No mount/md remains.