rdmsm4x-changelog-20260905-1103-ramdisk-m4-it6-remediation

Summary: Resolved unmount pre-flight dynamic discovery, strict collision rejection, multi-entity APFS container teardown, and test isolation flakiness in macOS-ramDisk-app on rdmsm4x.

• Timestamp: 2026-09-05 11:03:00 EDT
• Host: rdmsm4x (Apple Silicon M4 Max, macOS 27.0)
• Agent: teamwork_preview_worker_m4_it6_1
• Target Estate: ~/dev/apps/macOS-ramDisk-app
• Commit: 738c0ef ("fix(ramdisk): unmount pre-flight dynamic discovery, strict collision rejection, and multi-entity APFS teardown")
• Remotes Updated: fleet (git.ecs0.net), backup (GitHub), origin (GitHub)

Scope & Changes

1. Sources/ramdisk/main.swift:
   • In unmount command, performed dynamic mount discovery DarwinStoragePrimitive.findMountedVolumes(matchingPrefix: "/Volumes/RAMDisk") before evaluating guard engine.volumeState.isMounted.
   • Latched engine.volumeState and engine.config.mountPath to the resolved active mount point.
   • Required sustained consecutive clean checks (consecutiveCleanChecks >= 3, 300ms quiet state) in descriptor drain loop before early exit.
   • Enforced safe refusal exit code 1 with structured JSON when exclusive write locks exist.
2. Sources/RAMDiskCore/RAMDiskEngine.swift:
   • Updated releaseWorkspaceCleanly() descriptor drain loop to require consecutiveCleanChecks >= 3.
3. Sources/RAMDiskCore/StoragePrimitive.swift:
   • Added clearMountPathStub(_ mountPath: String) with lsof -t +D handle termination, specific metadata unlinking (.fseventsd, .DS_Store), recursive removal, /bin/rm -rf, and 2.0s VFS teardown drain.
   • Enforced strict collision rejection in formatVolume: force unmount collision path (/Volumes/RAMDisk 1), clear stub /Volumes/RAMDisk, and remount strictly via diskutil mount <volumeDev>. Never return collision paths.
   • Extended device settling probe to 5.0s with exponential backoff retries and APFS container deletion fallback.
   • Reverse topological detachment in detachVolume (mounts, containers, partitions, root physical parent disks).
4. Tests/E2ETests/run_e2e_tests.sh:
   • Updated cleanup_ramdisks() to terminate handles before unmount, force eject APFS containers + physical parents, remove stubs, and verify triple-point settlement.
5. Tests/E2ETests/e2e_framework.py:
   • Updated ensure_unmounted() with dual lsof/fuser termination, reverse APFS container + root disk ejection, directory stub clearing, and triple-point settlement check.
   • Increased CLI unmount timeout to 15.0s in unmount_volume.
6. Tests/E2ETests/test_tier4_real_world_scenarios.py:
   • Replaced isolated unmount calls at scenario startups (T4.1, T4.2, T4.4, T4.5) with ensure_unmounted().

Verification Evidence

• AST Invariants: All 6 literal strings verified verbatim on rdmsm4x (exit code 0).
• Unit Tests: swift build && swift test passed 4/4 tests.
• ThreadSanitizer: swift test --sanitize=thread passed with 0 data races.
• Rapid Stress: 15/15 consecutive cycles mounted strictly at /Volumes/RAMDisk with 0 collisions.
• Safe Refusal: Confirmed exit code 1 with structured JSON error and activeLocksCount: 1.
• E2E Consistency: Executed zsh Tests/E2ETests/run_e2e_tests.sh 3 consecutive times:
  • Run 1: 192/192 PASSED (34s, exit code 0)
  • Run 2: 192/192 PASSED (32s, exit code 0)
  • Run 3: 192/192 PASSED (33s, exit code 0)
• Zero Residual State: mount | grep -i ramdisk, hdiutil info | grep -i 'ram://', and ls -la /Volumes | grep -i ramdisk all returned exit code 1.
• Git State: git status --porcelain is 0 dirty; ahead-behind on fleet/main, backup/main, and origin/main is 0 0.