read_file rejected the padded ~128 MiB MKB_RO.inf via the 0.31.0
MAX_FILE_BYTES cap, so read_aacs_inputs failed and the online
key-resolve path never contacted the keyserver. Read the MKB's real
record length from its header and read exactly that. Also honor
inline/embedded (AD type 3) files so small AACS .inf files read from
the ICB payload instead of being misparsed as allocation descriptors.
Release 0.31.6.
B-frame video PTS is legitimately non-monotonic in decode/storage order; the
audio-oriented monotonic nudge was clobbering it to prev+1ms, which decoders
flagged as non-monotonic DTS (thousands per title). Apply the nudge to
audio/subtitle only; video keeps its true PES PTS. + regression test.
Test-hardening release, no runtime changes. Adds spec-grounded unit tests
across the silent-corruption surfaces — UDF/MPLS/CLPI/IFO parsing, BD/DVD
title + extent assembly, AACS/CSS key handling, TS/PS demux + codec parsers,
MKV/EBML container output, the mux pipeline, sector prefetch + decrypt
decorator, drive/SCSI sense decoding, label extraction, and core I/O. Each
test is grounded in the format spec or real on-disc behavior and verified to
fail under a targeted source mutation. No behavior changed.
Library-wide review-and-fix pass: tightened AACS keydb/handshake/variant
handling and trailing-partial-unit policy, corrected MPLS mark offset and
added UDF allocation bounds, hardened the mux/codec framing and M2TS paths,
guarded SCSI READ CAPACITY short transfers and unified error mapping, added
overflow guards on untrusted disc input, and made prefetch shutdown
deterministic. Release profile now builds with thin LTO + single codegen unit.
A keyed disc now writes its decrypted AACS unit keys to the mapfile header
(# freemkv-uk: <cps>:<hex>); an unresolved disc writes only the VID. The two are
mutually exclusive (set_unit_keys clears the VID) — unit keys are the final
answer, so deferred-mux / resume decrypts directly with no key lookup, while the
VID alone is the 'still unresolved, retry' marker. CopyOptions/SweepOptions carry
the keys (written when present, else the VID); Disc::inject_unit_keys applies
mapfile-recovered keys to a scanned disc. Round-trip test added.
Rename is_unit_encrypted -> is_aacs_scrambled and decide encryption from the unit's MPEG-TS sync bytes (destroyed by the encrypted body) instead of the TP_extra copy-control (byte 0) or TS scrambling-control (byte 7) flags, which discs do not set reliably. One shared predicate now backs the decrypt gate and out-of-band key validation, so callers agree on what 'encrypted' means. Decryption restores the syncs, so a decrypted unit reads as clear and there is no flag to clear.
Two coherent additions to the AACS resolver:
KeyProvider abstraction (provider.rs) — key material comes from pluggable
backends; KeyDb implements it (device/processing keys, host certs,
disc-by-hash / disc-by-vid lookup) plus orphan-DK parsing. ResolveContext
takes a provider array. Adds the SD-tree PK walker
(derive_media_key_from_pk_walked) and a `probe` module (km_verifies MK
oracle, mkb_* record parsers) used for offline key verification. Cvalue
record selection prefers 0x05, falls back to 0x07.
External-UK key source — the second, mutually-exclusive key source for the
keyserver path. ScanOptions/InputOptions gain `unit_key`; when set,
resolve_encryption_static skips keydb entirely and uses the caller-supplied
Unit Key directly (KeySource::ExternalUk). Disc::read_aacs_inputs exposes a
disc's Unit_Key_RO.inf + MKB so a caller can fetch the UK out-of-band; the
library makes no network call itself.
CHANGELOG: redact test-disc title in historical notes.
Adds a 5th key-resolution path that consumes pre-decrypted unit keys
directly from KEYDB when the entry has no VUK field. Covers ~4,572
entries in the public keydb (~2.5%), heavily skewed toward MKBv76+ UHD
discs where DVDFab/FindVUK can no longer extract a VUK but does extract
unit keys. Partial CPS-unit coverage is rejected so a disc is never
half-decrypted.
Resolver path order reordered root-to-leaf: DK (1) → PK (2) →
KEYDB-derived MK+VID (3) → KEYDB VUK (4) → KEYDB unit keys (5).
Previous order was leaf-first.
API:
- AacsState::vuk is now Option<[u8; 16]> (was [u8; 16])
- ResolvedKeys::vuk is now Option<[u8; 16]> (was [u8; 16])
- KeySource variants reordered + new KeyDbUnitKeys variant
3 new resolver tests (path 4 still works without VID; path 5 succeeds
with pre-decrypted unit keys; path 5 rejects partial CPS coverage).
- Introduce DrmScheme enum (Css/Aacs10/Aacs20/Aacs21) + drm module with
uniform detect/load dispatch across all four protection schemes.
- Land AACS 2.1 Media Key Variant framework in aacs::variants: chain
derivation, MKB record types 0x82/0x83, bit-0x02 SoftKCD and bit-0x04
online-challenge detection. Aacs21 dispatcher arm wired but commented
out pending validation against a Variant-scheme disc.
- Replace aacs2: bool with AacsVersion enum across ContentCertificate,
UnitKeyFile, ResolvedKeys. resolve_keys splits into _v1/_v2/_v21.
- Delete the libredrive raw-read VID shortcut from do_handshake; the
drive enforces the AGID requirement regardless of firmware-upload
state, so the shortcut spuriously dispatched E7017 instead of
surfacing the real downstream walls.
Three coherent threads landing for v0.25.11:
1. Libredrive raw-read VID path. When Mt1959::do_unlock sees both the
MMkv active-mode marker at [12..16] and the LbDr mode-ID marker at
[16..20], Drive::is_libredrive_active() returns true and
do_handshake skips the AACS cert dance — VID is retrieved via
READ_DISC_STRUCTURE format 0x80 with AGID=0 and bus encryption is
already off. This unblocks UHD ripping on drives whose leaked host
cert is on the AACS HRL.
- platform/mt1959/mod.rs: detection + active flag + 4 unit tests.
- platform/mod.rs: PlatformDriver::is_libredrive_active trait method.
- drive/mod.rs: Drive::is_libredrive_active accessor.
- disc/encrypt.rs: do_handshake branches on the flag; new
read_volume_id_libredrive helper. Return type widened to
(Option<HandshakeResult>, Option<Error>) so callers see which
specific failure happened.
- disc/mod.rs: scan_with plumbs the new tuple through and preserves
handshake errors as disc.aacs_error.
2. Revert v0.25.9 built-in AACS keys + plugin slot. Single source of
AACS truth: keydb.cfg. The compiled-in DKs/PKs were a slim
convenience that didn't move the hard problem (no v77+ DKs) and
added a maintenance surface. Plugin slot was overlapping
functionality with the main keydb.
- Deleted src/aacs/builtin_keys.rs (4 DKs + 3 PKs).
- Removed KeyDb::with_builtins, load_or_builtins, merge_from,
merge_local_plugin, local_plugin_path, internal dedup helpers.
KeyDb::empty kept for unit-test use.
- KeyDb::load reverts to pre-0.25.9 form: read file or return I/O
error; no fallback.
- disc::encrypt::resolve_encryption keydb_path back to required
(&Path), not Option<&Path>.
- disc::scan_with surfaces KeydbLoad { path: "<no keydb in search
paths>" } sentinel when encrypted + no keydb — same sentinel
autorip's message switch already handles.
- CSS player keys in src/css/auth.rs stay compiled in; they're
1999-era public inputs separate from AACS and pre-date the 0.25.9
additions.
3. Walker fix follow-through (libaacs-parity validate_processing_key,
cvalues 0x07-then-0x05 preference, path-2/3/4 short-circuit on
zero VID) + NIST AES-CMAC KAT + VID MAC round-trip / mutation /
zero-rejection tests.
5 new Error variants for finer-grained AACS failure reporting:
AacsHostCertRejected (E7015), AacsLibredriveUnsupported (E7016),
AacsVidUnavailable (E7017), AacsMkUnavailable (E7018),
AacsVukNotInKeydb (E7019). Lets CLIs/UIs render which piece of the
AACS chain failed instead of always saying "no keys."
Two changes that make AACS 1.0 / DVD self-sufficient:
1. MKB record-type identification bug fix. `mkb_find_mk_dv` was
searching for type 0x10 (which is Type-and-Version, 12 bytes)
when the Verify Media Key Record is actually type 0x81 for
AACS 1.0 or type 0x86 for AACS 2.0/2.1. `mkb_version` had the
inverse bug. PK and DK derivation paths therefore silently
failed on every disc, masking how often the fallback paths
could have worked. Fix searches the correct types; tests added
covering both the 0x81 and 0x86 verify-record forms and the
0x10 version record at offset 8 of the body.
2. Built-in AACS keys + operator plugin slot. Four device keys
(covering MKB v01-v82+) and three processing keys (covering
v63-v68) compiled directly into the library. Combined with the
31 CSS player keys already in css/auth.rs, DVDs and Blu-rays
(AACS 1.0) now decrypt with zero external files. New plugin
path at ~/.config/freemkv/local_keys.cfg (same syntax as
keydb.cfg) layered additively on top of built-ins and main
keydb. `Disc::scan` no longer errors when keydb.cfg is absent;
AACS 2.0 / UHD still surfaces a specific error when the disc
needs keys none of the layers provide.
Public docstrings in project docs + README updated to describe the
three additive layers (built-ins → keydb.cfg → local_keys.cfg).
Pre-0.25.7 the AACS authenticate loop fired up to 16 host-cert
attempts back-to-back with no pause. Each attempt is 5-10 SCSI
REPORT_KEY/SEND_KEY exchanges, so on a disc whose host cert isn't
in our KEYDB (or one the drive rejects), the drive saw 80-160 SCSI
commands in a few hundred ms and entered a fast-fail firmware
wedge state where every subsequent CDB returns sense 05/24 until
power-cycled.
Three defences:
- MAX_CERT_ATTEMPTS capped at 3 (was 16)
- 1-second sleep between attempts
- Bail immediately on any sense_key == 0x05 (ILLEGAL_REQUEST) so
the loop can't deepen the wedge if a regression undoes the
attempt cap.
- MkvTrack::audio emits A_DTS/MA, A_DTS/HR, A_DTS per the DTS family
instead of mislabelling everything as A_DTS. Plex transcoder and
strict hardware decoders reject DTS-HD MA payload under a plain
A_DTS track.
- PgsParser is now stateful: pairs display PCS with the following
empty PCS to compute a duration. Frame::duration_ns + PesFrame::duration_ns
carry it through; MkvMuxer::write_frame gains a final Option<u64>
parameter that emits BlockGroup + BlockDuration when set. Fixes
subtitle bitmaps lingering past their intended end-time.
Disc::titles previously sorted purely by duration_secs descending,
which puts a play-all virtual playlist at index 0 on UHDs that ship
one. Such playlists reference the same source clips multiple times
for seamless alternate-angle / alternate-ending playback and report
inflated duration AND inflated size_bytes that exceeds the disc's
physical capacity.
Concrete observed case (The Amateur 2025 4K UHD, 58.5 GB BD-100):
Title 1 — 00020.mpls — 4h13m — 92.4 GB — 253 clips ← impossible
Title 2 — 00800.mpls — 2h02m — 57.2 GB — 1 clip ← the movie
92.4 GB > 58.5 GB capacity is proof of clip double-counting. With
the duration-only sort, freemkv -t 1 / disc.titles.first() / autorip's
main-feature picker all selected the 4-hour composite instead of the
2-hour movie.
New canonical_title_order:
1. Real titles (size_bytes <= capacity_bytes) before virtual
composites — capacity gate is hard physical truth.
2. Among real titles, fewer clips first (1-clip wins as the
canonical main feature; multi-clip is either chapter-stitched
or composite).
3. Tiebreak on longer duration first.
Behaviour:
- Non-branching discs: unchanged. The longest 1-clip title is
already the movie.
- Branching UHDs: virtual composite drops to the back, the real
movie surfaces at index 0.
Comparator exposed as Disc::canonical_title_order for downstream
consumers that need the same logic on custom title sets.
Three regression tests (disc::tests::canonical_order_*):
- pushes_oversize_play_all_behind_real_main (The Amateur)
- preserves_natural_ranking_on_normal_disc
- fewer_clips_wins_tiebreak
decrypt::decrypt_sectors now restores chunks when decrypt_unit_full's
TS-sync verification fails, preventing 0.18.1's silent corruption of
MPLS/CLPI navigation files when DecryptingSectorSource decorates the
sweep reader. Fixes E6009 NoStreams on info iso:// for AACS-encrypted
UHDs ripped without --raw.
Disc::sweep progress takes max(snapshot.bytes_good, bytes_done) so
the user-visible counter never regresses below what the producer has
already sent.
The library's public-facing docs were sitting on the 0.17 trait
surface — Disc::copy, pes::Stream, SectorReader, etc. — even though
all in-tree callers migrated in 0.18 rounds 1-3. With 0.18.1 about
to ship, a user copy-pasting the README sample from crates.io would
have hit a compile error.
This commit is purely doc-side:
- README.md: Quick Start rewritten onto Disc::sweep + Disc::patch
with caller-orchestrated multipass; Streams table footnote and
Architecture row reference FrameSource / FrameSink.
- CHANGELOG.md: 0.18.1 entry describing the redesign — primitives,
trait splits, deprecations (kept alive through 0.18.x, deletion
target 0.18.2), throughput numbers.
- docs/{rip-recovery,api-design,architecture,disc-to-rip,
drive-access,udf}.md: every Disc::copy / pes::Stream /
SectorReader reference updated to the 0.18 trait surface.
- FEATURES.md: deleted (8+ versions stale; capabilities live in
README.md and CHANGELOG.md now, matching the workspace-top
FEATURES.md removal in 84acd65).
- examples/iso_dump.rs: verified compiles against 0.18.1.
No code changes.
See (internal)/memory/0_18_redesign.md.
Single contributor: MattJackson.
The bounded-cache writeback wrapper (crate::io::Writer) was added in
0.17.10 and wired into Disc::sweep in 0.17.11, but the other two
paths in the crate that write large amounts of data sequentially —
Disc::patch and the MKV/M2TS mux — were still operating on raw
std::fs::File. That meant the dirty-page burst pathology the wrapper
exists to prevent could still bite on slow / network-attached staging
during recovery and mux phases.
This release plugs those gaps:
- Disc::patch (disc/mod.rs:1981) now wraps the reopened ISO in
Writer before any seek / write. sync_all on Writer cleanly drains
the in-flight chunk before the existing fsync.
- mux/resolve.rs MKV and M2TS branches wrap the output File in
Writer underneath BufWriter. UHD MKV mux routinely produces 70+ GB
of sequential output; the page cache no longer absorbs that as a
single hot blast on slow targets.
Mapfile, log, settings, history, and stream-pipeline byte buffers
remain unchanged: those are either small one-shot writes (where
the wrapper has zero benefit and adds a stream_position syscall) or
already use bounded persistence (mapfile time-batched in 0.17.12).
The principle: any path that writes substantial sequential data to
a single file uses Writer; trivial writes don't.
Pre-0.17.12 every Mapfile::record() persisted the full mapfile via
tempfile-create + write + atomic-rename. On local LVM that's
microseconds; on NFS each rename is multiple RPCs through the
unraid user-share fuse layer, dragging a Black Mass UHD rip from
~11 MB/s on local to ~1.5 MB/s on NFS — the mapfile path alone burned
multiple seconds of wall time per real-world second of work.
Mapfile now batches the rename to once per second:
- record() always updates in-memory state and stats; only fires
write_to_disk when last_flushed.elapsed() >= FLUSH_INTERVAL (1 s).
- New flush() API forces a persist; called by sweep_pipeline's
consumer at end-of-sweep and by Disc::patch at end-of-patch,
after the file's sync_all.
- Drop impl best-effort flushes so an early-return / unwind doesn't
silently lose pending state.
Crash-safety changes from "lose at most one block" to "lose at most
1 s of recorded progress" — the ISO file's payload bytes are unaffected;
only the mapfile's authority over which sectors are already-good is at
risk, and a resume re-reads anything Pass 1 had already covered.
Measured on the BU40N test bed against Black Mass UHD inner zone:
- NFS staging: 1.5 MB/s → 16.48 MB/s (10.9× recovery)
- Local LVM staging: 11.09 MB/s → 11.83 MB/s (+6.7 % bonus)
Internal round_trip_load test now flushes before reading back from
disk. External patch / copy tests are unaffected: patch and
sweep_pipeline flush at completion before returning.
Pre-0.17.11 sweep ran strictly serialised: SCSI read → decrypt → seek
+ write → mapfile.record → next read. Drive idled for the post-read
work; throughput capped at the sum of both costs. On a healthy disc
that's ~7-12 ms read + ~5-15 ms write/record per 64 KB batch, limiting
sustained throughput to ~10-12 MB/s on the test bed (BU40N + UHD inner
zone), well below the ~14-16 MB/s drive ceiling.
Decouples them: producer thread (caller's) owns SectorReader +
read_error state + decrypt + set_speed + halt; consumer thread (one
spawn) owns Writer + Mapfile, receives WorkItem messages, applies
file write + mapfile record. Bounded mpsc::sync_channel(4) gives
natural back-pressure. While the consumer writes batch N, the
producer is already reading batch N+1 — steady-state throughput is
now bound by the slower of the two pipelines (drive on healthy
discs), not their sum.
Side effects:
- Bisect path now decrypts. Pre-0.17.11 the bisect inner loop wrote
raw cyphertext for single-sector recoveries on encrypted discs —
quiet correctness bug exercised only by batch-fail-then-
bisect-succeed on encrypted media. New producer-side decrypt
covers main + bisect success paths uniformly.
- All read_ctx state stays single-threaded on producer (damage
window, jump multiplier, etc.). No locking added.
- Mapfile remains single-writer on consumer. No locking.
- Halt latency: producer breaks loop, sends Finish, consumer drains
≤4 in-flight items + sync_all. ~1 batch (~12 ms) typical.
- BU40N + Initio bridge wedge concern unchanged: still single SCSI
command in flight, error-path timing identical, no new retries.
New module: src/disc/sweep_pipeline.rs (WorkItem, ProgressSnapshot,
ConsumerInputs, spawn_consumer, consumer_loop, helpers). Public API
unchanged — Disc::copy / CopyOptions / CopyResult identical.
Patch (Pass N) is NOT changed; it's bound by drive recovery time, not
the read/write serialisation.
Pass 1 sweep speed on a healthy disc previously dipped from ~15 MB/s
to ~1 MB/s every ~30 s on a host with default Linux dirty-page
settings. Empirical cause: the kernel's vm.dirty_ratio (~20% of RAM)
lets hundreds of MB of dirty pages accumulate, then bursts a flush at
99% disk utilisation that blocks app writes for ~1 s. Confirmed on
the BU40N test bed — dirty pages grew 112 → 563 MB between bursts;
lowering vm.dirty_bytes to 64 MB at the host sysctl level eliminated
the dips. Shipping the equivalent inside libfreemkv so users do not
need to tune the host kernel.
- New crate::io::Writer: drop-in File wrapper (impl Write + Seek).
Wraps a per-platform WritebackPipeline that on Linux schedules
sync_file_range(WRITE) + lagging sync_file_range(WAIT_AFTER) +
posix_fadvise(DONTNEED) in 32 MB chunks, bounding dirty cache at
~64 MB. macOS and Windows ship a no-op stub.
- Disc::sweep wraps its output File in Writer. Loop body unchanged.
- Module is purpose-built so any large sequential output (patch,
mux) can adopt the same wrapper as a one-line change later.
Version bump to keep the four freemkv crates at unified versioning
after autorip's v0.17.6 + v0.17.7 work today. No libfreemkv code
changes; republished to crates.io so downstream consumers stay
aligned on the latest patch version.
Direct-SATA BU40N + Dune Part Two UHD live testing exposed that the
v0.17.3 single-shot SCSI READ path matched 0/22 of the small bad-
sector LBAs that dd if=/dev/sr0 recovers on the same drive. This
release closes that gap and fixes adjacent bugs silently capping
recovery.
- /dev/sr0 pread fallback in Drive::read (Linux only): on SCSI READ
Err, fall back to posix_fadvise(DONTNEED) + pread() against the
corresponding block device. Kernel sr_mod runs ~5 internal retries
with no per-attempt mid-layer escalation overhead — the mechanism
behind dd's recovery advantage. End-to-end byte verification
confirms the fallback path returns real disc data.
- Disc::patch per-range watchdog fix: MAX_RANGE_SECS was breaking
'outer (one slow range killed the entire patch). Now skips to the
next range. Pre-fix patch died after 4 sectors of range 1 of 47.
- Per-sector range budget: range_budget = sectors × 25 s, capped at
1800 s. Replaces the flat 180 s/range that was unfair to medium
ranges and pointlessly generous to single-sector ones.
- consecutive_failures resets per range. The wedge-exit detector is
for stuck-on-one-range, not many-small-ranges-with-one-fail-each.
- Reverted inline 5× retry experiment (was hurting: each retry paid
kernel SCSI escalation overhead). Restored READ_RECOVERY_TIMEOUT_MS
to 60 s. The kernel-auto-retry pattern is now provided by sr0
fallback.
Empirical: pass 1 recovered 94.6 MB / 11 s of main title (33 sr0
saves). Pass 2 added 0.6 MB. Remaining ~233 MB on the test disc
appears physically unrecoverable on this hardware.
- Fix unwrap in disc/mod.rs sweep() hot path using pattern matching
- Patch pass excludes Unreadable sectors from work list
- Expose bytes_bad_in_title for accurate UI reporting
- All 256 tests pass, cargo clippy clean with -D warnings
bytes_pending was an opaque aggregate of NonTried + NonTrimmed +
NonScraped. UIs that wanted a "will retry in Pass 2-N" bucket were
stuck showing the entire unread disc as Maybe at pct=0.
Adds two granular fields to MapStats:
bytes_nontried — Pass 1 hasn't read these yet
bytes_retryable — NonTrimmed + NonScraped, Pass 2-N will retry
bytes_pending stays for back-compat (= bytes_nontried + bytes_retryable).
Also picks up the cargo fmt --check lint that's been red on main CI
since v0.13.18 (rustfmt fold differences on a few long format-string
layouts; functional no-op).
Through the entire 0.13.x line, every CHECK CONDITION reply from the
drive (the standard way SCSI tells you why a sector failed) was being
collapsed into a synthetic status=0xFF, sense_key=0 transport-wedge
sentinel and the actual sense data was thrown away. Confirmed live on
the BU40N reading Dune 2 on 2026-04-27: drive returned host_status=0,
driver_status=8, status=2, exec_elapsed_ms=1416 on every bad sector
— a clean CHECK CONDITION carrying full sense data — and Disc::copy
was bailing on it as if the bridge had wedged.
Root cause: scsi/linux.rs's wedge check was
`host_status != 0 || driver_status != 0`
SG's DRIVER_SENSE bit (0x08) is set on every CHECK CONDITION reply
just to flag "sense buffer is populated" — it's not a transport
failure on its own. Pre-fix we conflated the two and silently lost
every drive-reported error reason. macOS and Windows backends had
the same shape: they extracted sense_key only, dropping ASC/ASCQ.
API restructure (clean separation):
Error::ScsiError {
opcode: u8,
status: u8, // 0xFF = synthetic transport-failure
sense: Option<ScsiSense>, // None ⇔ no sense delivered
}
pub struct ScsiSense { sense_key: u8, asc: u8, ascq: u8 }
impl ScsiSense {
pub fn is_marginal(&self) -> bool // keys 0/1/3/B
pub fn is_medium_error(&self) -> bool
pub fn is_hardware_error(&self) -> bool
pub fn is_unit_attention(&self) -> bool
pub fn is_data_protect(&self) -> bool
pub fn is_not_ready(&self) -> bool
pub fn is_illegal_request(&self) -> bool
pub fn is_aborted_command(&self) -> bool
}
impl Error {
pub fn scsi_sense(&self) -> Option<&ScsiSense>
pub fn is_scsi_transport_failure(&self) -> bool
pub fn is_marginal_read(&self) -> bool
}
SCSI protocol constants (SCSI_STATUS_*, SENSE_KEY_*) moved from
error.rs to scsi/mod.rs where they belong alongside SCSI_INQUIRY,
SCSI_READ_10, etc. parse_sense replaces parse_sense_key (returns the
full triple, not just the key); inline tests now exercise ASC/ASCQ
extraction at the right offsets for both descriptor (0x72/0x73) and
fixed (0x70/0x71) sense formats.
Disc::copy + Disc::patch sense-aware dispatch:
- marginal sense (MEDIUM ERROR / ABORTED COMMAND / RECOVERED ERROR
/ NO SENSE) → engage hysteresis (Block→Single, bpt=1)
- non-marginal sense (HARDWARE / DATA PROTECT / UNIT ATTENTION /
NOT READY / ILLEGAL REQUEST / transport failure / kernel
IoError) → bail with full sense info preserved; caller (autorip)
surfaces "physical replug" / "drive failing" / "media changed"
Pre-fix: every CHECK CONDITION → 0xFF synthetic → Disc::copy bailed
→ bytes_good froze at the bad zone. The hysteresis from v0.13.22
was correct but never got to run. This release unblocks it.
Disc::patch's wedged_threshold (50 consecutive failures) stays as
defense-in-depth for chains of marginal failures; a single
non-marginal sense now short-circuits it.
New phase=bail trace event records the bail reason with the sense
triple. phase=transport_err remains for genuine bridge wedges /
kernel timeouts; phase=scsi_err carries the parsed sense_key, asc,
ascq for drive-reported errors.
All 350 tests pass. Clippy clean across all targets.
The v0.13.21 bisect-on-fail recovery was correct (100% of recoverable
sectors picked up) but slow on dense damage clusters. Live test on
Dune 2 v0.13.21 burned ~30 s per damaged 60-block — paying a ~5 s
kernel ABORT/timeout at every level of a log₂(60) ≈ 6 deep DFS, on
the failing branch each time.
Replaced with a two-state hysteresis machine in Disc::copy:
Block(batch):
read(batch) ok → write, advance, stay Block
read(batch) fail → switch to Single, retry SAME range at bpt=1
Single:
read(1) ok → write, consecutive_good++
if consecutive_good >= BPT1_EXIT_THRESHOLD:
switch to Block, reset counter
read(1) fail → mark NonTrimmed, consecutive_good = 0
BPT1_EXIT_THRESHOLD = 10_000 sectors (= 20 MB clean run). Calibrated
from the 2026-04-26 BU40N empirical probe data; tunable.
Per-block math on a damaged 60-block with 1 truly bad sector:
Bisect (v0.13.21): ~30 s (5 s × 6 levels)
Hysteresis (v0.13.22): ~10 s (5 s bpt=batch fail
+ 59 × 1 ms good
+ 1 × 5 s bad)
Inside a damaged cluster spanning many 60-blocks the win compounds:
hysteresis pays the bpt=batch fail cost ONCE on entry, then stays at
bpt=1 across the cluster; bisection re-paid it every 60 sectors. For
Dune 2's ~1248-sector boundary cluster that's ~21 fewer 5-sec
kernel timeouts ≈ 100 s saved per pass.
Telemetry: new phase=mode_change trace event with from, to, lba, and
consecutive_good. Replaces v0.13.21's phase=bisect. Worklist DFS is
gone — single iterative for s in 0..count on the failure path.
Test rename, same fixture and same 100% recovery expectation:
test_disc_copy_bisect_recovers_via_single_sector_reads
→ test_disc_copy_hysteresis_recovers_via_single_sector_reads
Also adds DamageSeverity (Clean / Cosmetic / Moderate / Serious) +
classify_damage(bad_sectors, lost_ms), re-exported from libfreemkv,
so applications can render structured severity instead of formatting
their own from raw counters.
Fixes the BU40N wedge cycle that has been chasing us through
v0.13.18-20. Two changes, both backed by empirical live-hardware
probes recorded in (internal)/docs/TEST_PLAN.md:
1. scsi/mod.rs: READ_TIMEOUT_MS 1500 → 10000 ms.
Cold-start seek on the BU40N takes ~1.5 s. The old timeout
cancelled normal reads at the boundary, triggering the kernel's
ABORT/RESET escalation, which the Initio bridge couldn't drain —
firmware-level wedge. 10 s catches every legitimate slow read
(max successful ECC recovery: 2.6 s; cold-start: 1.5 s) with
margin and short-circuits truly bad sectors at ~10 s.
2. disc/mod.rs: Disc::copy bisect-on-fail (replaces skip-forward).
Live data showed the drive fails multi-sector READs in the bad
zone but reads each sector cleanly when asked at bpt=1. Old
skip-forward jumped 845 MB on the first multi-sector failure,
marking everything in between as bad — losing clean territory
sandwiched between bad sectors. New algorithm bisects: split the
failed block in half, retry each half, recurse to single-sector
reads. Sectors recoverable individually are picked up in Pass 1;
only sectors that fail at bpt=1 are marked NonTrimmed for the
patch passes. Stack-based DFS, log2(batch) = 6 levels for the
default 60-sector batch.
Multi-pass machinery is untouched. Pass 2..N walk the mapfile and
become fast no-ops when bisect already recovered everything.
Wedged-drive early-exit, 30 s settle, batch taper, F-R-F-R direction
alternation — all preserved.
New test: integration_progress_and_halt::
test_disc_copy_bisect_recovers_via_single_sector_reads — synthetic
BU40N-pattern reader (multi-sector reads fail, single-sector
succeed). Pre-patch: lost everything to skip-forward. Post-patch:
100 % bytes_good. Plus the 10 sense-key parser tests from the
0.13.20 test-coverage pass.
Empirical recovery on Dune 2 UHD on the BU40N (per TEST_PLAN.md run
log): old algorithm ~25 GB recovered + 6 GB skipped-forward and
mostly lost; new algorithm projects ~99 % recovery in Pass 1.
Audits + raw probe data:
- (internal)/docs/TEST_PLAN.md (run log)
- (internal)/docs/audits/2026-04-26-scsi-architecture-research.md
- scsi/linux.rs: full rewrite from async write/poll/read+1.5s timeout+
close-on-timeout to one synchronous ioctl(fd, SG_IO, &hdr). Kernel
honors hdr.timeout and runs its own ABORT/RESET escalation. Errors
check host_status and driver_status (both 0xFF-synthesised) plus
status. Sense-key parser handles descriptor (0x72/0x73) + fixed
(0x70/0x71) formats. Deleted fd_recovery, bg close+open thread, fd
swap dance. -331/+155 lines.
- scsi/macos.rs: try_recover() removed (userspace handle-recovery on
task failure was the same anti-pattern stripped from Linux). bsd_name
field deleted. Errors bubble up directly.
- scsi/windows.rs: try_recover() removed, wide_path field deleted,
INVALID_HANDLE guard removed.
- scsi/mod.rs: parse_sense_key() helper extracted (used by all three
platforms now — single canonical sense-key parse rather than three
inlined copies). +10 unit tests covering descriptor format, fixed
format, truncated buffers, unknown response codes.
- drive/mod.rs: Drive::reset() deleted (escalating eject + STOP/START +
reinit recovery — per audit, kernel handles its own escalation;
userspace shouldn't).
pub fn find_drives() -> Vec<Drive> deleted (opened N drives just to
throw most away). find_drive() now uses discover_drives() directly.
wait_ready() simplified — drops the reset path on sense_key=5,
just keeps polling TUR for 60 iterations.
- lib.rs: find_drives re-export removed.
- benches/sgio_read.rs: switched to find_drive() (no longer iterates a
drive list).
Net: 9 files changed, 226 insertions(+), 473 deletions(-). 329 tests
pass, clippy -D warnings clean. No consumer breakage (CLI, autorip,
bdemu compile + test green).
Architecture decision documented in
(internal)/docs/audits/2026-04-26-scsi-architecture-research.md
(primary-source survey of MakeMKV, sg_dd, ddrescue, and the kernel
mid-layer's own scsi_eh.rst escalation ladder).
Matthew Jackson