erofs-freebsd-out-tree/docs/pre6-baseline.md

Pre6 Initialization Baseline

Repository Baseline

• Outer starting commit: bfed0431693e7798bdecacd78b7e6258c2d93c5a
• Starting repo-pre-6 tree: b4a40164394b378adc947d6ad14dc7c845e79b2c
• Starting repo-pre-6/src/super.c blob: 03b92560bb5ef01f322b0d052f84bc3c577ef829
• Execution target: the existing repo-pre-6 directory
• Source allowlist for later extraction commits: repo-pre-6/src/super.c

The tree and blob identities above were read from Git before this document was created. Pre6 works directly on repo-pre-6; it does not create another source snapshot.

Stage Scope

Pre6 is an L2-I private mount-initialization responsibility extraction stage. It contains three helper tasks:

1. Extract one decoded external-device initialization block into static int erofs_init_device(...).
2. Extract packed-carrier initialization into static int erofs_init_packed_inode(struct erofs_mount *em).
3. Extract metabox initialization into static int erofs_init_metabox_inode(struct erofs_mount *em).

These tasks move existing statements into private helpers. They must not change features, behavior, public interfaces, error handling, allocation, cleanup, logging, locking, GEOM operations, or object ownership.

Source Commit Strategy

The source work is delivered in two commits:

1. One independent commit for erofs_init_device().
2. One atomic commit for erofs_init_packed_inode() and erofs_init_metabox_inode().

Packed and metabox initialization remain one ownership unit because their blocks are adjacent and a fragment-backed metabox can depend on the packed carrier. No intermediate commit may contain only one internal-inode helper.

Each commit, including this baseline commit, must be pushed immediately to xdm main. Execution must stop if local HEAD, xdm/main, and remote main do not agree after a push.

Protected Paths

The following paths must remain unchanged during Pre6 execution:

• repo-pre-1/
• repo-pre-2/
• repo-pre-3/
• repo-pre-5/
• src-linux/
• planning/reject/
• 1-code-similarity-review/
• existing planning documents and reports

Except for Pre6 documents under repo-pre-6/docs/, no path outside repo-pre-6/src/super.c belongs in the planned source commits.

Behavior-Preservation Invariants

• Preserve the order of every moved statement and every helper call.
• Preserve all conditions, loop direction, values, types, casts, and return values.
• Preserve every errno and log message without translation or normalization.
• Preserve allocations, frees, NULL assignments, and failure paths.
• Preserve the current owner and lifetime of every buffer, device, inode, and mount resource.
• Keep erofs_open_device() unchanged as the FreeBSD GEOM open transaction.
• Keep external-device slot lookup and ascending iteration in erofs_scan_devices().
• Keep packed inode initialization before metabox inode initialization.
• Keep erofs_mountfs() as the common failure owner that calls erofs_sb_free().
• Add no rollback, validation, cleanup, logging, locking, or defensive changes.
• Keep all new helpers private and add no header declarations.

If an extraction requires a behavior, ownership, ordering, or errno change, execution must stop instead of expanding Pre6 scope.

Validation Status at Baseline

Validation item	Status
Static Git baseline capture	RECORDED
Device initialization extraction	NOT RUN
Packed and metabox initialization extraction	NOT RUN
Static equivalence and independent revert gates	NOT RUN
Build with WITH_ZSTDIO=0	NOT RUN
Plain/LZ4 smoke test	NOT RUN
Complete TC099 multi-device smoke test	NOT RUN
Positive TC142 metabox smoke test	NOT RUN
Other build, QEMU, or runtime tests	NOT RUN

No source extraction, build, QEMU run, feature validation, regression test, or runtime result is claimed by this baseline document.