Integrates Packages 3-5 over a single shared CubeStore, the literal
CUBELinux premise (data addressed by coordinate, not path). Adds the
cubesys crate (lib + cube CLI + cube-demo) proving two end-to-end
properties: a cubefs path IS a runnable code cell at the same coordinate,
and a sealed record reopens and runs on the same store.
Two latent cross-crate bugs surfaced and fixed while integrating:
- cubecoords: refresh_flags() now preserves out-of-band flag bits
(8..=15), so cubecrypt's HEADER_FLAG_ENCRYPTED survives refresh.
- cubestore: record codec now serializes raw flag bits (TLV tag 12) so
the encrypted bit survives the store round-trip.
All gates green (./check, incl. cubefs --features mount).
Implements the PDF's Package 3 with new code:
- path: bijective POSIX path <-> Czyx mapping (/c001/z002/y003/x004).
Axis-letter + 3-digit zero-padded canonical names so lexical order equals
numeric order and each coordinate has exactly one spelling. Inode IS the
packed u32 coordinate — no inode side table.
- nullspace: the PDF's 'use Null cubes for ACLs, xattrs, journaling, volume
metadata', with the Z-plane allocation fixed and documented (Z=1 volume,
Z=2 ACL, Z=3 xattr, Z=4 journal ring). ACL/xattr tables are FNV
hash-bucketed with exact-match resolution inside the bucket, because 4
axes of subject cannot injectively mirror into 2 axes of Null space.
Journal is a bounded ring; wraps are detectable via a monotonic counter.
- vfs: the whole filesystem, kernel-free and unit-testable — lookup,
readdir, create/read/write/truncate/unlink, mkdir/rmdir, ACL enforcement,
xattrs, journaling, POSIX errno mapping.
- fuse (feature 'mount'): thin kernel adapter, zero TTL (the store is
writable out-of-band, so cached metadata would go stale).
- cubestore: added the PDF's 'optional scanning primitives' (keys,
scan_prefix) and the Package 2 association API (associate, linked_to)
that cubefs needs for directory listings.
Two defects were found by LIVE MOUNT testing and fixed, not by unit tests:
1. mkdir succeeded then the kernel's revalidating lookup returned ENOENT,
so 'mkdir -p' could never reach depth 4. Directories were purely
inferred from records, making an empty directory unrepresentable. Fixed
with an explicit Null-space directory marker; rmdir removes it; readdir
merges markers in. 5 regression tests added.
2. Multi-user ACL behaviour was untestable because the mount lacked
AllowOther — the kernel returned EACCES at the mountpoint before any
request reached us. Added --allow-other.
Verified: 58 unit tests pass; clippy clean; live mount exercised with cat,
echo, dd, truncate, cp, chmod, chown, getfattr/setfattr, mkdir -p, rmdir,
find, a 200-record write loop, and cross-user reads/writes as luulu.
CUBELinux-2