# Pre13 L-A1

This batch aligns the remaining low-risk helper vocabulary with Linux:

- `compress.h` now uses the Linux include guard name.
- `erofs_inode_is_data_compressed()` replaces four equivalent FULL/COMPACT
  tests that do not need to distinguish the two layouts.
- `erofs_addrmask()` directly uses the existing 48-bit feature helper.

Static proof:

- For every value from zero through `EROFS_INODE_DATALAYOUT_MAX`, the new
  compressed-layout helper equals the replaced boolean expression.
- The helper was not substituted in `zmap.c`, where FULL and COMPACT remain
  distinct cases.
- `erofs_is_48bit()` and `erofs_sb_has_48bit()` tested the same incompat bit;
  address-mask values and control flow are unchanged.
- The old include guard and duplicate 48-bit helper have no remaining source
  consumers.

No build, QEMU, smoke, or feature test was run for this batch.
