# Test Case: Unified Address and Flatdev Mapping

**Test ID**: TC101-unified-address-mapping  
**Category**: Multi-Device  
**Priority**: Critical

## Objective

Verify both EROFS mapping forms and fail-closed complete-extent checks:

1. device ID 0 plus a block in a nonzero slot `uniaddr` range selects that
   explicit provider and subtracts the range base;
2. a nonzero device ID in flatdev mode adds `uniaddr` and reads the combined
   primary provider;
3. gaps, cross-slot chunks/pclusters, and out-of-range 48-bit addresses return
   `EINTEGRITY` before physical I/O fallback.

## Positive explicit unified mapping

```sh
I=/root/repo22-g6/images
S=/root/repo22-g6/sources/chunk
mkdir -p /mnt/g6
kldload /root/repo22-g6/erofs.ko
mdconfig -a -t vnode -f "$I/multi2-unified-primary.erofs" -u 90
mdconfig -a -t vnode -f "$I/multi2-unified-slot1.blob" -u 91
mdconfig -a -t vnode -f "$I/multi2-unified-slot2.blob" -u 92
mount -t erofs -o ro -o device.2=/dev/md92 -o device.1=/dev/md91 \
  /dev/md90 /mnt/g6
sha256 "$S/unified-address.bin" /mnt/g6/unified-address.bin
cmp "$S/unified-address.bin" /mnt/g6/unified-address.bin
dd if="$S/unified-address.bin" of=/tmp/tc101.unified.src bs=1 skip=61440 count=8192 2>/dev/null
dd if=/mnt/g6/unified-address.bin of=/tmp/tc101.unified.mnt bs=1 skip=61440 count=8192 2>/dev/null
cmp /tmp/tc101.unified.src /tmp/tc101.unified.mnt
umount /mnt/g6
mdconfig -d -u 92
mdconfig -d -u 91
mdconfig -d -u 90
```

The manifest must show that this index is device ID 0 and pblk equals slot-1
`uniaddr + local_pblk`, not a local primary address.

## Positive flatdev mappings

First test nonzero chunk device IDs in one combined provider:

```sh
mdconfig -a -t vnode -f "$I/multi2-flatdev.erofs" -u 90
mount -t erofs -o ro /dev/md90 /mnt/g6
sha256 "$S/cross-device.bin" /mnt/g6/cross-device.bin
cmp "$S/cross-device.bin" /mnt/g6/cross-device.bin
dd if="$S/cross-device.bin" of=/tmp/tc101.flat.src bs=1 skip=126976 count=139264 2>/dev/null
dd if=/mnt/g6/cross-device.bin of=/tmp/tc101.flat.mnt bs=1 skip=126976 count=139264 2>/dev/null
cmp /tmp/tc101.flat.src /tmp/tc101.flat.mnt
umount /mnt/g6
mdconfig -d -u 90
```

Then test device-ID-0 unified addressing in the combined provider:

```sh
mdconfig -a -t vnode -f "$I/multi2-unified-flatdev.erofs" -u 90
mount -t erofs -o ro /dev/md90 /mnt/g6
cmp "$S/unified-address.bin" /mnt/g6/unified-address.bin
umount /mnt/g6
mdconfig -d -u 90
```

The 139264-byte range spans the slot-1/slot-2 transition.  erofs-utils 1.8.6
cannot qualify these flatdev forms; the kernel full/range comparisons are the
qualification.

## Positive 48-bit high mapping

```sh
mdconfig -a -t vnode -f "$I/multi2-unified48-primary.erofs" -u 90
mdconfig -a -t vnode -f "$I/multi2-unified48-slot1.blob" -u 91
mdconfig -a -t vnode -f "$I/multi2-unified48-slot2.blob" -u 92
mount -t erofs -o ro -o device.1=/dev/md91 -o device.2=/dev/md92 \
  /dev/md90 /mnt/g6
cmp "$S/unified-address.bin" /mnt/g6/unified-address.bin
umount /mnt/g6
mdconfig -d -u 92
mdconfig -d -u 91
mdconfig -d -u 90
```

This requires nonzero `uniaddr_hi` and `startblk_hi`; zero-high truncation
would read the wrong bytes.

## Fail-closed extent cases

Each primary below is checksum-valid.  Mount succeeds, and the named cold read
must return exactly `EINTEGRITY` in `truss`:

| Primary and providers | Mode | Read target |
| --- | --- | --- |
| `bad-unified-gap-*` | explicit and `bad-unified-gap-flatdev.erofs` | `unified-address.bin` |
| `bad-cross-slot-explicit-*` | explicit | `indexed.bin` |
| `bad-cross-slot-unified-*` | explicit and `bad-cross-slot-unified-flatdev.erofs` | `indexed.bin` |
| `bad-lz4-cross-slot-*` | explicit and `bad-lz4-cross-slot-flatdev.erofs` | `external-pcluster.bin` |
| `bad-unified48-out-of-range-*` | explicit | `unified-address.bin` |

For an explicit chunk case, use this direct command shape with the matching
prefix and target:

```sh
PREFIX=bad-cross-slot-explicit
TARGET=indexed.bin
mdconfig -a -t vnode -f "$I/$PREFIX-primary.erofs" -u 90
mdconfig -a -t vnode -f "$I/$PREFIX-slot1.blob" -u 91
mdconfig -a -t vnode -f "$I/$PREFIX-slot2.blob" -u 92
mount -t erofs -o ro -o device.1=/dev/md91 -o device.2=/dev/md92 \
  /dev/md90 /mnt/g6
truss -f -o "/tmp/tc101-$PREFIX.truss" dd if="/mnt/g6/$TARGET" \
  of=/dev/null bs=131072 count=1
tail -20 "/tmp/tc101-$PREFIX.truss"
umount /mnt/g6
mdconfig -d -u 92
mdconfig -d -u 91
mdconfig -d -u 90
```

For a flatdev row, attach only its `*-flatdev.erofs` as md90 and use no
`device.N` options.  For the LZ4 explicit row, use its two one-block slot
providers.  Execute every row and mode separately; do not use a runner.

The explicit crossing providers are physically only as long as their declared
slots.  Therefore both declared range and physical media would be exceeded;
`EINTEGRITY` must win before a possible `ENXIO` from I/O.  The largest non-NULL
48-bit address (`0xfffffffffffe`; all ones is the hole sentinel) is
representable in 64-bit arithmetic but belongs to no declared range, so it
also returns `EINTEGRITY`.

## Cleanup and zero-state check

```sh
umount /mnt/g6 2>/dev/null || true
mdconfig -d -u 92 2>/dev/null || true
mdconfig -d -u 91 2>/dev/null || true
mdconfig -d -u 90 2>/dev/null || true
kldunload erofs
rm -f /tmp/tc101.*.src /tmp/tc101.*.mnt
mount -p | awk '$3 == "erofs" { print }'
mdconfig -l
kldstat -n erofs 2>/dev/null || true
sysctl -n kern.geom.conftxt | grep -E 'md9[0-2]|erofs' || true
```

All four final outputs must be empty, with no panic, trap, or hang.