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.
tests/scsi_recovery.rs:
- Add `use std::time::Duration` inside both `#[cfg(target_os = "linux")]`
blocks. Locally on macOS the linux blocks are cfg-out so the missing
import was invisible to precommit on macOS.
- Bug pre-dated this branch but only surfaced when v0.17.2 release CI
ran the test compile on Linux.
Cargo.toml: 0.17.2 -> 0.17.3.
Cargo.toml: 0.17.1 -> 0.17.2. Functionally identical to the prior
commit; 0.17.1 was never published to crates.io but a tag exists on
the remote pointing at an unrelated commit. Bumping past it.
src/disc/mod.rs:
- Cache priming (3-sector lookback) before patch's single-sector reads.
Drive read-ahead pulls in adjacent pages so the target may already be
cached when we ask for it. Throwaway reads — failures here don't
update mapfile state.
- When patch hits skip-limit on a range, leave remaining sectors
NonTrimmed instead of marking Unreadable. We never tried to read those
sectors, so don't give them terminal status — drive state evolves
between passes (cache, mechanical settle), and a later pass may
succeed.
tests/pass_n_patch_fix.rs:
- New regression test for the decrypt key inversion bug at
src/disc/mod.rs:1938-1942. Asserts decrypt_sectors is invoked with
the correct key when opts.decrypt=true.
tests/pass_n_size_aware_skip.rs:
- rustfmt-only changes.
Cargo.toml: 0.17.0 -> 0.17.1.
New disc/read_error.rs as the single entry point all read failures flow
through. Handler classifies the error, updates the in-flight context
(damage window, retry budgets, jump multiplier), and returns a
ReadAction the caller dispatches on. Pass 1 (sweep) refactored to use
it; ~340 lines of nested if/else collapsed into ~120 lines of action
dispatch. Adding a new error class = one match arm. Logging is in one
place. Bisect inner failures don't poison the damage window. Jump
multiplier capped at 64 (max 1 GB jump for batch=32 — observed prior
unbounded behavior produce a single 56 GB jump on a wedged drive).
Pass N (patch) damage_skip is now size-aware: each skip is capped at
range_remaining/4 rather than the absolute MB-scale escalation. The
old logic could leap over a 100-sector bad range that hides a 50-sector
good middle; size-aware convergence finds the good middles instead.
Tests in tests/pass_n_size_aware_skip.rs exercise the size-aware skip
against synthetic patterns (25-bad/50-good/25-bad and three good
middles in a row) and prove ≥98% of good middles are recovered.
Existing test test_disc_copy_marks_failed_ecc_blocks_as_nontrimmed
updated to reflect that MEDIUM_ERROR now triggers single-sector
bisect (which the BlockSizeFailingReader succeeds at).
- 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
- DAMAGE_WINDOW 50→16, DAMAGE_THRESHOLD_PCT 25→12: triggers on 2nd scattered failure
- Previous 50/25% was too diluted by good reads between sparse failures
- copy() dispatch checks mapfile total_size == disc capacity_bytes (covers_disc)
- NonTried regions → sweep with resume=true (preserves mapfile)
- Only NonTrimmed/NonScraped/Unreadable → patch
- sweep_internal takes resume param: true when dispatching from existing mapfile
- Verified: Pass 1 from 30-100% completes in ~20 min with correct jumps through 3 damage zones
- CopyOptions: replace resume/skip_on_error/batch_sectors with single multipass bool
- Disc::copy() auto-detects pass from mapfile state: no mapfile or NonTried → sweep, only NonTrimmed/Unreadable → patch
- Fix bug where mapfile with NonTried regions incorrectly dispatched to patch mode
- SectorReader::set_speed() default method, Drive impl sends SET CD SPEED
- On damage zone entry: set_speed(0x0000) for better error recovery
- On damage zone exit (50 consecutive good): set_speed(0xFFFF) to restore max speed
- Disc::mapfile_for() returns /tmp/<name>.mapfile for null:// output
- patch_internal/sweep_internal as private helpers, CopyResult gains recovered_this_pass
- Adaptive probe algorithm in Disc::copy skip_on_error mode: after 4
consecutive errors, probe 1 sector at 256x batch (8 MB) ahead. If
good, zero-fill gap, mark NonTrimmed, jump. Clears bad zones in
seconds instead of hours.
- NOT_READY sense key (0x02) now retries up to 3x with 3s pause before
marking NonTrimmed. BU40N returns NOT READY for bad sectors, not
MEDIUM ERROR.
- PassProgress struct gains bytes_bad_total field for consumer-side
bad/retryable byte counts.
- Mapfile header version string fix: no longer duplicates 'libfreemkv v'
prefix on each write.
- Structured sense_key/asc/ascq logging in copy error path.
macOS SCSI transport rewritten from hybrid MMC+pread to single-path
raw CDB dispatch through SCSITaskDeviceInterface. All CDBs (INQUIRY,
READ, REPORT KEY, etc.) now go through ExecuteTaskSync — 1:1 with
the Linux SG_IO backend.
Key changes:
- New macos_shim.c: diskutil unmount → find IOBDServices →
ObtainExclusiveAccess → raw CDB dispatch. Eliminates Rust-side
IOKit COM vtable complexity.
- build.rs compiles macos_shim.c via cc into static lib
- macos.rs simplified to three FFI calls (open/close/execute)
- disc/mod.rs: graduated batch restore after errors, skip-ahead
through bad zones, configurable error pause
- as_bytes() requires OsStrExt import which is platform-specific
- as_encoded_bytes() is the portable API available on all platforms
- Fixes CI failure on Linux (Ubuntu) in GitHub Actions
0.13.28 - when drive returns MEDIUM ERROR (bad sector), skip the sector
and continue instead of retrying or bailing. Write zero-fill, mark as
Unreadable for pass 2+ recovery.
Closes: (internal)#20260427
Fix extract_scsi_context() and Error::scsi_sense() to handle Error::DiscRead
in addition to Error::ScsiError, so is_marginal_read() works for DiscRead
errors and disc::copy() can properly route MEDIUM ERROR as a marginal
(bad sector) instead of bailing.
Closes: (internal)#20260427
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).
Pre-0.13.16 the rip API leaked internal mapfile concepts (pos,
bytes_good, work_done, bytes_pending, Finished/NonTrimmed) into per-pass
positional callbacks Fn(u64, u64, u64). Consumers reinvented the math
each time, and v0.13.15's UI bug surfaced exactly because of this —
autorip's web JS computed pct from bytes_good while the backend
computed from pos, silent drift, frozen UI bar.
This release replaces both Disc::copy::on_progress and
Disc::patch::on_progress callbacks with a single Progress trait +
PassProgress struct (new progress module).
pub struct PassProgress {
pub kind: PassKind, // Sweep | Trim {reverse} | Scrape {reverse} | Mux
pub work_done: u64,
pub work_total: u64,
pub bytes_good_total: u64,
pub bytes_total_disc: u64,
}
pub trait Progress {
fn report(&self, p: &PassProgress);
}
impl<F: Fn(&PassProgress)> Progress for F { ... } // closures work directly
CopyOptions::on_progress and PatchOptions::on_progress are renamed to
progress: Option<&dyn Progress>. Closure callers update trivially via
the blanket impl; struct callers gain a clean named-field shape with no
positional-arg confusion.
PassKind carries the semantic (sweep vs trim vs scrape vs mux) so
consumers can label phases without reinventing detection logic.
Disc::patch reports Trim {reverse} for retry passes with block_sectors
>= 2 and Scrape {reverse} when block_sectors == 1. Direction comes
through reverse: bool. Mux variant is reserved for v0.13.17 when the
mux pipeline emits progress.
Tests + clippy clean across all 4 crates.
Breaking: CopyOptions::on_progress + PatchOptions::on_progress now take
Fn(bytes_good, pos, total). Consumers display `pos` for "% swept" — the
true Pass 1 progress that advances through skip-forward bad zones, where
bytes_good (Finished sectors only) freezes. v0.13.14 live trace proved
the existing UI was lying for ~14 minutes about Dune 2 being "stuck at
30%" while Pass 1 was actually 83% through the disc via skip-forward.
PatchOptions::reverse: walk bad ranges from highest LBA to lowest. For
drives that wedge after a forward read of a bad sector, approaching the
post-bad-zone NonTrimmed range from end-of-disc reads good sectors before
the drive sees a bad one. Hypothesis informed by the BU40N + Initio
bridge live data — Pass 2 forward saw zero successful reads in 7 min
while Pass 1's pos walked all the way to end-of-disc.
PatchOptions::wedged_threshold: > 0 → exit early after that many
consecutive failures with zero successes in the same pass. Saves the
wallclock budget for productive grinding when the drive has wedged on
the bad zone for THIS pass; a different direction or block size in the
next pass may still recover. New PatchResult::wedged_exit reports it.
Trace: patch_start (block_sectors, recovery, reverse, wedged_threshold,
num_ranges) and patch_done (blocks_attempted, blocks_read_ok,
blocks_read_failed, wedged_exit, halted, bytes_recovered) at the
freemkv::disc target.
v0.13.12 shipped the async fd_recovery design but a live test on Dune 2
showed Pass 1 sat for 14 minutes with bytes_good=0 — the inner loop iterates
(throttled on_progress log fires every 78s) but each iteration evidently
takes ~60s instead of the microseconds the design promises on fast-fail.
Without trace-level telemetry at the SCSI + Disc::copy boundaries we
can't tell where the time goes.
This release is instrumentation only — no behavior change.
- New dep: tracing 0.1. Per project docs, debug/trace logging is allowed in
libfreemkv (the no-English rule applies to errors). Consumers wire a
tracing subscriber.
- SgIoTransport::execute (Linux): trace at every state transition (entry,
recovery_swap_ok, recovery_pending, write_ok / write_err, poll_done,
timeout_spawn_recovery, scsi_err, read_err, ok). Each event includes
opcode + elapsed timing. The bg recovery thread also traces close_ms +
open_ms so we can see if the kernel really takes 60s to close+open on a
wedged Initio bridge.
- Disc::copy: trace at copy_start, outer_loop, region_enter, every 100
inner-loop iterations (iter_progress with pos/region_end/skip_size/
bytes_good/read_ok_count/read_err_count/last_read_ms/copy_elapsed_ms),
copy_done.
- All trace events use targets `freemkv::scsi` and `freemkv::disc` so
consumers can filter by subsystem (e.g. autorip /api/debug?q=freemkv::scsi).
Next: run the live test on Dune 2 again, read the autorip JSONL log,
diagnose why each iter is slow, fix the actual bug.
The wallclock-based halt timing failed on fast CI runners where a 2 GB
synthetic-disc skip-forward sweep finishes in <100 ms — well under the
200 ms halt fire delay. Reader now signals halt on first read; the
inner-loop halt check on iteration 2 breaks 'outer. No wallclock race.
Fix 1: delete stall guard from Disc::copy. Pass 1 must sweep end-to-end
per ddrescue model (RIP_DESIGN.md §2.1, §3, §9). The v0.13.9 guard at
disc/mod.rs broke Pass 1 at 30% on Dune 2 with 56 GB still NonTried.
Removed stall_secs field, narrative comment in scsi/linux.rs, and the
broken regression test. Replaced with test_disc_copy_completes_full_disc_
with_failing_reader and test_disc_copy_halts_promptly_on_failing_reader.
Fix 2: async SCSI transport recovery. Added Arc<AtomicI32> fd_recovery
on SgIoTransport. On poll timeout: spawn close + spawn open in
background, return Err immediately. Top of execute() swaps fd from
recovery atomic. Main thread never blocked beyond ~1.5s poll budget
(was up to ~60s per timeout because kernel serialized main-thread
open() against in-flight close()). Drop drains pending recovery fd.
§15.1 cross-platform parity: Windows + macOS now have the same
observable recovery contract. SptiTransport gets try_recover()
(synchronous CloseHandle + CreateFileW; Windows close is fast, no
in-flight CDB drain like Linux). MacScsiTransport gets try_recover()
(release IOKit interface + reacquire via new acquire_device_iface()
helper); stores bsd_name for re-resolution. Drop guards null'd-out
interfaces. Stripped English error strings ("try as root" / "run as
administrator") on Linux + Windows. Fixed Windows TimeOutValue
ms→s ceiling so 1500ms gets 2s (was 1s; broke Drive::read fast path).
Fix 4: instrument Disc::patch arms. PatchResult exposes
blocks_attempted, blocks_read_ok, blocks_read_failed so the v0.13.11
mystery (Dune 2 Pass 2 recovered 0 bytes in 100 min) is diagnosable
from the live device log without re-instrumenting from outside.
Cleanup: honor PatchOptions::full_recovery (was read into _ and
ignored; now routed to read_sectors recovery arg). Updated
CopyOptions::batch_sectors doc to describe the actual production
path (sysfs detect_max_batch_sectors, typically 60 sectors / ~120 KB
on BU40N) rather than the test-only 32-sector internal default.
All four crates clippy-clean and tests green on the host targets
(macOS native + cargo check on Linux). Cross-platform CI watches
Linux + Windows + macOS builds + tests.
v0.13.10's 'fd=-1 on first poll timeout' was too aggressive: a single
transient killed the entire transport, Pass 1 finished in 45ms with
0 GB good on Dune 2.
Revert to spawn-close + main-thread-reopen (the v0.13.5/8 pattern).
Per-timeout cost is up to ~60s while the kernel completes the
abandoned command, but the v0.13.9 Disc::copy stall guard caps
catastrophic stalls at 120s of bytes_good non-advance. Pass 1 bails
cleanly with NonTrimmed ranges; Pass 2 has a working Drive for
retries with recovery=true + 30s timeouts.
Fixes the silent Pass 1 hang observed on Dune 2 with v0.13.8 (drive
grinding through bad sectors at 0 KB/s, errs=0, no error surfaced).
Root cause: SgIoTransport::execute's reopen-after-poll-timeout opened
a fresh /dev/sg* fd on the main thread, which serialized against the
spawned close() of the old fd via the kernel's per-device state lock.
The userspace 1.5s timeout still fired, but the abandon-and-reopen
recovery itself blocked the main thread for as long as close() took.
Net: reads returned slowly, skip-forward fired on every iteration,
bytes_good never advanced.
- SgIoTransport::execute: on poll timeout, spawn close, set fd=-1,
return Err. No reopen on the main thread. The transport is now
invalidated until the consumer creates a fresh Drive.
- Disc::copy: add stall guard. CopyOptions.stall_secs (default 120s).
If bytes_good doesn't advance for the threshold, break 'outer
cleanly with complete=false, bytes_pending > 0 so Pass 2 retries
pick up the NonTrimmed ranges with recovery=true 30s timeouts.
- New regression test: test_disc_copy_stall_detection_triggers_
skip_forward in tests/integration_progress_and_halt.rs.
Follow-up to the rip-recovery + drive-access updates: aligns the
remaining docs with the v0.13.6 single-shot read model and the
three-layer recovery architecture.
- architecture.md: module map says single-shot read; new paragraph on
layered recovery with postmortem pointer.
- api-design.md: EventKind enum example expanded; emission notes
document that BytesRead now fires from DiscStream::fill_extents and
Retry/SectorRecovered are no longer emitted in 0.13.6+.
- disc-to-rip.md: Step 10 of the pipeline diagram + module table
reflect single-shot read.
- docs/README.md: added rip-recovery.md to the TOC.
Updates docs/ to reflect the recovery-loop strip:
- rip-recovery.md: drops Phase 1/2/3 description, replaces with three-layer
model (Disc::patch multi-pass / DiscStream batch halving / Drive::read
single-shot). Notes that no SCSI resets fire from any retry path.
- drive-access.md: removes SG_SCSI_RESET + STOP/START UNIT escalation
references; SgIoTransport::reset is now kernel SG_IO flush + ALLOW
MEDIUM REMOVAL only.
- src/mux/disc.rs + tests/: cargo fmt cleanup.
Drive::read is now single-shot. Phase 1/2/3 retries + scsi::reset+reopen
removed (~80 lines). recovery=true bumps timeout to 30s; recovery=false
stays at 1.5s. On any failure returns Err(DiscRead) immediately — caller
(Disc::patch outer loop, DiscStream batch halver) handles retries.
Inline reset+reopen WAS the wedge primitive on the LG BU40N. Per prior
post-mortem, every USB/SCSI reset path tested fails to recover the
wedged Initio bridge — the inline retry was pure cost.
SgIoTransport::reset (Linux) trimmed to kernel SG_IO state flush +
ALLOW MEDIUM REMOVAL. SG_SCSI_RESET ioctl + STOP/START UNIT escalation
removed. macOS reset removed (no-op). scsi::reset() top-level family
removed (no callers).
EventKind::BytesRead { bytes, total } now actually emitted from
DiscStream::fill_extents after each successful sector read. Was
declared in 0.13.0, never fired. Drives autorip per-device progress
in direct mode.
EventKind::Retry / SectorRecovered no longer emitted (variants kept
for forward compat). SpeedChange still emitted via Drive::set_speed
public path.
Tests: new tests/integration_progress_and_halt.rs (5 tests). 233 unit
tests + 5 integration green.
USB/SCSI recovery escalation in drive_has_disc (0.13.1-0.13.3) tested
on LG BU40N USB BD-RE: USBDEVFS_RESET, authorized toggle, driver
unbind/rebind, SCSI host rescan — all succeed at the USB transport
layer but the drive firmware below the bridge stays locked. Only
physical unplug-replug clears it. Rolled back so consumers can
surface the real failure to the user.
New: list_drives falls back to sysfs-cached vendor/model/rev from
/sys/class/scsi_generic/sgN/device/ when live INQUIRY returns empty,
so wedged drives still show their identity in UIs.
Removed: scsi::usb_reset, usb_reset_with_timeout, per-platform
usb_reset methods, recover_then_probe, is_wedge_signature. Breadcrumb
comment in scsi/linux.rs::drive_has_disc points at v0.13.3 tag for
the full implementation if future hardware needs it back.
Linux/macOS/Windows pass-through symmetric; 233 tests passing.
0.13.2's is_wedge_signature gated on opcode=SCSI_INQUIRY (0x12), but
drive_has_disc issues TEST UNIT READY (0x00). Production wedge errors
(E4000: 0x00/0xff/0x00) never matched → SCSI reset + USB reset
escalation never fired.
Drop the opcode gate. Status byte 0xFF is synthesised by our own
execute() path on poll() timeout — it's the ground-truth wedge
marker for any opcode.
Linux-only; macOS/Windows use sense-key-based wedge detection.
Architectural cleanup. autorip + freemkv CLI were reimplementing drive
discovery (sysfs walking, type-5 filtering, sg-path construction) and
calling SCSI reset primitives directly. All of that hardware-aware code
moves into libfreemkv with two cheap public probes:
- DriveInfo + list_drives() — multi-OS enumeration (Linux/macOS/Windows)
with peripheral-type-5 filtering and INQUIRY identity. Cheap.
- drive_has_disc(path) — single TUR with internal wedge recovery
escalation (SCSI reset → USB reset → retry) hidden from callers.
USB-layer reset (USBDEVFS_RESET / IOUSBDeviceInterface::ResetDevice /
storport's combined reset) wired across all three platforms.
Visibility tightening — scsi::reset, scsi::usb_reset, and the timeout
constants are now pub(crate). Compile-time guarantee that no consumer
crate can issue SCSI commands directly.
233 lib tests pass; clippy clean.
Production incident: autorip's poll loop called scsi::reset() on a
wedged BU40N USB drive. The Linux SG_SCSI_RESET ioctl blocked
indefinitely (kernel SCSI subsystem waiting for a bus-wedged device to
ack a reset that will never come). Caller's poll loop hung for 60+
seconds before manual intervention.
scsi::reset() now spawns a detached worker for the platform-specific
reset and bounds the caller's wait via mpsc::recv_timeout. Default
30 s (DEFAULT_RESET_TIMEOUT_SECS); reset_with_timeout(device, dur)
exposes the bound for callers that want a different value. Returns
DeviceResetFailed on timeout. Worker thread keeps running until the
kernel eventually unblocks — leaks one OS thread per hard wedge, but
the daemon stays responsive instead of hanging forever.
Follow-up flagged for 0.13.2: USB-attached drives wedge at the USB
Mass Storage layer below SCSI; SG_SCSI_RESET doesn't help. A
scsi::usb_reset(path) using USBDEVFS_RESET is the proper escalation.
Audit pass against the project docs "no English text in library code" rule.
Found 9 call sites that violated the contract by stuffing English into
io::Error::new(kind, "…") or by abusing Error::DeviceNotFound { path }
as a free-form description field. Each is now a typed Error variant.
New variants and codes: ScsiInterfaceUnavailable (E1004), DeviceLocked
(E1005), IoKitPluginFailed (E1006), UnsupportedPlatform (E2003),
PlatformNotImplemented (E2004), MapfileInvalid (E6011), DiscUrlNotDirect
(E9009).
labels::apply() previously pushed Commentary/Descriptive/Score/IME and
" (Secondary)" English literals into AudioStream.label, leaking into
MKV titles + autorip UI. AudioStream now exposes structured `purpose:
LabelPurpose`, SubtitleStream `qualifier: LabelQualifier`. Callers
translate to localized text. label keeps codec-formatting only.
API hygiene: 11 mux/* modules dropped from `pub` to `pub(crate)` —
their *types* are still re-exported from lib.rs, but the modules were
leaking low-level EBML/TS/network primitives. Stream trait gets a real
rustdoc explaining read-vs-write split. lib.rs grouped re-exports into
documented sections. ScanOptions::with_keydb() removed (one-method-per-
action rule); use struct literal.
Dead-code sweep: removed lookahead.rs (orphan, never declared as mod),
tsreader.rs (TsDemuxReader unused), ebml::{write_int,read_vint,SEEK_*},
ts::{scan_first/last_pts,scan_duration,SCAN_HEAD/TAIL_SIZE,take/set_
remainder}, MkvMuxer codec_private_slots/filled fields and
fill_codec_private method (deferred-codecPrivate path never used since
the v0.10 PES rewrite). cargo clippy --all-targets -D warnings clean.
Tests: new error::tests for variant codes + Display "no English" guard +
io::ErrorKind mapping. 233 lib tests, all green (was 230).
Breaking: ScanOptions::with_keydb removed; mux/* modules pub(crate);
AudioStream and SubtitleStream gained required fields; UnsupportedDrive
{ product_revision: "Renesas not yet implemented" } no longer produced
(use PlatformNotImplemented).
Drive::read is now halt-check-free in its body. Previously, the halt
flag was checked in 4 places and the sleep logic was scattered across
4 "if halt_aware_sleep { return Halted }" call sites — correct, but
the ugliness invited drift: a new sleep added by someone unfamiliar
with the pattern would silently swallow Stop requests.
Two private primitives now own halt awareness:
checked_sleep(Duration) -> Result<()>
checked_exec(cdb, dir, buf, timeout_ms) -> Result<ScsiResult>
Both return Err(Halted) instead of a bool. The ? operator in read()
then propagates halts for free. The recovery path reads top-to-bottom
with no halt vocabulary.
sleep_until_halted lives as a free function so it's unit-testable
without a live Drive. 4 new tests: completes normally, bails on
pre-set flag within one slice, wakes mid-sleep, zero-duration no-op.
Public API unchanged — halt_flag/halt/clear_halt still exposed, the
refactor is entirely internal.
Stop was waiting up to 30 s to register when the drive hit L-EC
recovery mid-read — the recovery phase does 30 s sleeps between
retries and the halt flag was only checked at the start of each sleep.
UI feels broken ("stop isnt working") even though the halt was set.
halt_aware_sleep breaks each wait into 100 ms slices and returns
early on halt. Applied to all 4 sleeps in the recovery path (both
30 s retry delays, both 5 s reset-phase delays).
Disc::copy fast pass (skip_on_error=true, recovery=false) was giving
the drive 5 s per 64 KB block. On structure-protected / marginal UHD
sectors the drive grinds L-EC for nearly the full budget per block,
pinning throughput at ~13 KB/s even though skip_forward would happily
skip past the region.
1500ms bounds the floor at ~43 KB/s/block. Recoverable sectors that
would have succeeded at 3-5 s get picked up on Disc::patch (pass 2+)
where recovery=true and the per-read budget is 30 s.
- README quick-start gains a multi-pass example using the new
Disc::copy + Disc::patch primitives.
- New docs/rip-recovery.md documents the two-stage rip model: mapfile
format (ddrescue-compatible), CopyOptions/PatchOptions surface, the
pass-1/pass-2 algorithm, and the design decisions (why no MODE
SELECT, why ISO intermediate, why ddrescue mapfile).
No code change.
autorip 0.11.22 ships the full multi-pass UI (live mapfile stats,
bad-range viz, Recovery settings). libfreemkv API is unchanged from
0.11.21. Part of the 0.11.22 ecosystem sync.
New primitives for two-stage rip workflows: fast forward pass with
zero-fill on failures, then targeted retries of bad ranges via a
ddrescue-compatible mapfile.
- Disc::copy now takes &CopyOptions (breaking change from positional
args). Always writes a sidecar .mapfile. Opt-in skip_on_error +
skip_forward give ddrescue-style fast sweep: 64 KB blocks,
exponential skip-forward on failure, zero-fill bad blocks. Defaults
preserve pre-0.11.21 behavior (recovery reads, abort on bad sector).
- Disc::patch is new and idempotent. Reads the mapfile, re-reads every
non-finished range with full drive recovery, patches good bytes back
into the ISO at exact offsets. Call N times for N retry attempts.
- disc::mapfile is a new module. ddrescue text format, crash-safe
(flushed on every record()), greppable, human-editable, tool-compatible.
Status chars match ddrescue: ? / * / / / - / +.
- Re-exports FileSectorReader from the crate root.
- freemkv CLI caller (pipe.rs) updated to the new Disc::copy signature
in lockstep — shipped in the 0.11.21 freemkv CLI release.
Part of the 0.11.21 ecosystem sync (libfreemkv + freemkv + bdemu +
autorip all on 0.11.21).
DiscStream::fill_extents loops internally while the demuxer waits for
enough clean data to emit a PES frame. In a dense bad zone that loop
can run for minutes without returning to the outer read() call, so
the caller's Stop signal never gets serviced until a frame is finally
emitted — which may be very far away.
Add DiscStream::set_halt(Arc<AtomicBool>) — typically wired to
Drive::halt_flag() for unified Stop across drive recovery phases and
stream sector processing. fill_extents checks the flag at the top of
every retry iteration; raising it returns Err(Error::Halted) within
one SCSI round-trip.
No behavior change for callers that don't call set_halt. Unblocks the
architectural fix for the "Stop doesn't stop" bug observed on a
damaged UHD disc.
Replace read_with_binary_search + 3×5s light recovery with an adaptive
sizer that shrinks on failure (halve, 3-aligned ≥6) and probes back up
after 100 MiB (51,200 sectors) of clean reads. Descent cost is paid
once per bad region, not once per bad sector.
Emit BatchSizeChanged { new_size, reason } on shrink and probe-up.
Remove BinarySearch event — no longer produced.
Side fix: scsi/macos.rs one-liner for manual_c_str_literals clippy
lint that surfaced on a newer toolchain.
Fix trailing sectors dropped at extent boundaries when sector_count % 3 != 0.
Add verify_title stop support via progress callback returning bool.
Add O_CLOEXEC on all SCSI fd opens to prevent leak to child processes.
Fix SCSI sense descriptor format detection (0x72/0x73 vs 0x70/0x71).
Replace blocking ioctl(SG_IO) with the sg driver's async interface.
Commands are submitted via write(), waited on via poll() with a hard
wall-clock timeout, and completed via read(). If poll() times out,
the fd is abandoned and a fresh one opened — the kernel can no longer
hold us hostage during USB error recovery.
- write() submits command, returns immediately
- poll() enforces exact timeout (EINTR-safe with deadline tracking)
- read() retrieves result + copies data to caller's buffer
- On timeout: old fd closed in background thread, new fd opened
- No SG_FLAG_DIRECT_IO — kernel buffers for safe timeout abandonment
- Store device_path for fd reopen after timeout
- Drop guards fd=-1 (abandoned fd)
@ -18,7 +18,7 @@ Part of the [freemkv](https://github.com/freemkv) project.
```toml
[dependencies]
libfreemkv = "0.10"
libfreemkv = "0.17"
```
## Quick Start
@ -51,6 +51,31 @@ while let Ok(Some(frame)) = input.read() {
output.finish()?;
```
### Multi-pass recovery rip
For damaged discs, the library offers a two-stage rip model: fast sweep with zero-fill and a ddrescue-format mapfile, then targeted retry of bad ranges. See [`docs/rip-recovery.md`](docs/rip-recovery.md) for the full architecture.
```rust
use libfreemkv::disc::{CopyOptions, PatchOptions};
// Pass 1: disc → ISO. Fast 64 KB reads, skip-forward on failure,
// zero-fill bad blocks, write a sidecar .mapfile.
Streams implement `IOStream` (byte-level) and `pes::Stream` (frame-level). `input()` / `output()` resolve URL strings to PES stream instances.`open_input()` / `open_output()` resolve to byte-level IOStream instances. All URLs use the `scheme://path` format — bare paths are rejected.
Streams implement `pes::Stream` (frame-level). `input()` / `output()` resolve URL strings to PES stream instances. All URLs use the `scheme://path` format — bare paths are rejected.
AACS decryption requires a KEYDB.cfg file. If available at `~/.config/aacs/KEYDB.cfg` or passed via `ScanOptions`, the library handles everything — handshake, key derivation, and per-sector decryption — without the application needing to know anything about encryption.
Common problems and solutions for optical drive ripping with freemkv.
---
## 1. USB-SATA Bridge Issues
This is the single most common source of problems when ripping discs over USB.
### Symptoms
- The drive disappears mid-rip. The ripping tool reports the device is gone, and `ls /dev/sg*` no longer shows it.
- The device re-enumerates under a different name: `sg4` becomes `sg5`, then `sg7`, then `sg11` after each USB port reset.
- `dmesg` shows USB port resets: `usb X-Y: reset high-speed USB device`, `xhci_hcd 0000:00:14.0: Cannot enable. Maybe the USB cable is bad?`, or `usb-storage: device reset failed`.
- The SCSI layer reports `host_status=7` (Linux USB transport error) in sense data.
- The drive works fine for reading data discs or burning, but crashes when hitting damaged sectors during a rip.
- After the crash, the drive is completely invisible until physically unplugged and reconnected.
### Root Cause
USB-SATA bridges translate between the USB Mass Storage protocol (BOT or UAS) and the drive's native SATA interface. When the optical drive encounters an unreadable sector, it returns a SCSI CHECK CONDITION with sense key 0x03 (MEDIUM ERROR). Some bridge chipsets -- particularly the Initio INIC-36xx family -- have buggy firmware that mishandles this error response.
Specific failure modes:
- **Incorrect residue reporting.** The bridge claims a different number of bytes transferred than what actually occurred. The Linux USB storage driver sees this discrepancy as a protocol violation and resets the port to recover. The `US_FL_IGNORE_RESIDUE` quirk exists specifically for this class of bug (see `drivers/usb/storage/transport.c` in the Linux kernel).
- **Bridge firmware crash.** On some Initio bridges, a malformed SCSI error response from the drive causes the bridge MCU to hang entirely. The USB controller sees the device stop responding and initiates a port reset. The bridge recovers (it re-enumerates), but the rip is dead -- all state is lost.
- **Sense data corruption.** The bridge forwards garbled or truncated sense data to the host, which the SCSI midlayer cannot parse, leading to a transport reset.
This is a hardware + firmware problem, not a software bug. The same drive connected via direct SATA does not exhibit these symptoms.
### Known Affected Bridges
| Chipset | USB IDs | Notes |
|---------|---------|-------|
| Initio INIC-3609 | `13fd:3609` | Very common in cheap SATA-to-USB enclosures. Highly problematic. |
| Initio INIC-3619 | `13fd:3940` | Same firmware family as INIC-3609. |
| Initio INIC-3069 | `13fd:0840` | Older variant, same residue bug. |
| ASMedia ASM1051 | `174c:5106` | Early ASM SATA bridge. Residue issues on error paths. |
| JMicron JMB36x | `152d:0561` | Some firmware versions. Not all JMicroon chips are affected. |
If your drive came in a pre-built external enclosure (Vantec, Sabrent, OWC, etc.), it almost certainly uses one of these bridge chips internally.
### The Fix: USB Storage Quirk
Apply the `US_FL_IGNORE_RESIDUE` kernel quirk for your bridge. This tells the Linux USB storage driver to ignore the residue field in SCSI response frames, preventing the port reset on mismatched byte counts.
**Step 1: Identify your bridge's vendor:product ID.**
```bash
lsusb
```
Look for your drive's entry. Example output:
```
Bus 002 Device 005: ID 13fd:0840 Initio Corporation INIC-3609
```
Here the vendor ID is `13fd` and the product ID is `0840`.
Replace `13fd:0840` with your device's actual IDs. The `:i` flag means `US_FL_IGNORE_RESIDUE`.
You can combine multiple flags. Common additions:
- `:i` -- ignore residue (`US_FL_IGNORE_RESIDUE`)
- `:u` -- force BOT mode instead of UAS, for bridges with UAS bugs
**Step 3: Reconnect the drive.** Unplug and replug the USB cable, or bind/unbind the device. The quirk is applied per-module-load, so existing sessions may need the drive reconnected.
### Making It Persistent
Add the quirk to your kernel boot parameters so it survives reboots.
Edit `/etc/default/grub` (GRUB) and add to `GRUB_CMDLINE_LINUX_DEFAULT`:
Avoid any enclosure or adapter listing an Initio chipset.
### Best Solution: Direct SATA
Connect your optical drive directly to a motherboard SATA port. This eliminates the USB-SATA bridge entirely and is the most reliable configuration:
- No USB protocol overhead or translation errors.
- No bridge firmware bugs.
- No port resets or re-enumeration.
- Full SATA error recovery handled natively by the kernel's libata driver.
- Sustained read speeds are limited only by the drive, not the USB bus.
If your machine has a free SATA port, use it.
---
## 2. Damaged Disc Handling
### Symptoms
- SCSI MEDIUM ERROR (sense key 0x03) at specific LBAs. `dmesg` shows `sr X:0:0:0: [srY] Unrecoverable read error` or similar.
- Read speed drops to near zero when approaching a damaged area.
- The drive makes audible retrying noises (laser repositioning, spindle speed changes).
- On USB-connected drives: the bridge crashes (see section 1 above) when the drive returns the error.
### How freemkv Handles This
freemkv uses a three-layer recovery model. See [`docs/rip-recovery.md`](docs/rip-recovery.md) for full details.
- **Pass 1 (Disc::copy):** Fast sweep with 64 KB reads. On failure, zero-fills the block and skips forward. Writes a ddrescue-format mapfile for later retry.
- **Pass 2+ (Disc::patch):** Targeted re-reads of bad ranges with a long 30-second timeout per CDB. The drive firmware performs its own ECC and laser power retries within that window.
- **In-stream (DiscStream):** Adaptive batch halving -- reduces request size on failure to isolate bad sectors within a larger block.
This means a disc with some bad sectors will still produce a usable ISO. The damaged areas are zero-filled in pass 1 and retried in subsequent passes. Structure-protected sectors (deliberate unreadable regions from copy protection) will never yield, which is expected.
### The Drive Taint Issue (LG BU40N)
Some drives, notably the LG BU40N, exhibit a "taint" behavior after encountering MEDIUM ERRORs:
1. The drive hits a damaged sector and returns a MEDIUM ERROR.
2. From that point forward, **all subsequent reads fail** -- even reads to sectors that were previously successful.
3. The only recovery is to physically unplug and reconnect the drive (or power-cycle it).
This is not a freemkv bug. It is a drive firmware behavior triggered by the interaction between the drive's internal error recovery and the USB-SATA bridge's handling of the error response. The drive firmware enters a degraded state that it does not recover from without a power cycle.
Workarounds:
- **Use a direct SATA connection.** This eliminates the bridge interaction that triggers the taint.
- **Use a different bridge.** The ASM1153 and JMS578 are less likely to trigger this behavior.
- **Accept the partial ISO.** freemkv's skip-forward recovery will zero-fill the unreadable blocks and continue. The resulting ISO may be playable with minor glitches in the affected areas.
- **Physical replug between retry passes.** If running multi-pass patch, replug the drive between passes to clear the taint state.
freemkv deliberately does not attempt inline SCSI resets or eject cycles to recover from this state, because those operations were found to make the problem worse on affected hardware (see the design rationale in [`docs/rip-recovery.md`](docs/rip-recovery.md)).
---
## 3. Drive Not Detected
### Check Hardware Visibility
```bash
lsusb
```
Verify the drive appears in the USB device list. If it does not show up, the drive is not visible to the host at all -- check cables, power, and USB port.
```bash
ls /dev/sg*
```
On Linux, optical drives appear as `/dev/sg*` devices (the SCSI Generic interface). freemkv uses `/dev/sg*`, not `/dev/sr*`. If `lsusb` shows the device but no `/dev/sg*` entry exists, the `sg` kernel module may not be loaded:
```bash
sudo modprobe sg
```
### Check Kernel Messages
```bash
dmesg | grep -i usb | tail -30
dmesg | grep -i sg | tail -10
```
Look for:
- USB enumeration errors or failed port resets.
- `sg_add` messages confirming the sg device was registered.
- Permission denied or access errors.
### Permission Issues
On most Linux distributions, `/dev/sg*` devices are owned by `root:disk` or `root:cdrom` with restricted permissions. Running freemkv as an unprivileged user will fail with permission errors.
Options:
- Add your user to the appropriate group:
```bash
sudo usermod -aG disk $USER
```
Then log out and back in for the change to take effect. On some distributions the group is `cdrom` or `optical` instead of `disk`.
- Run with elevated privileges:
```bash
sudo freemkv ...
```
- Install a udev rule for persistent per-device permissions. Create `/etc/udev/rules.d/99-sg-optical.rules`:
sudo udevadm control --reload-rules && sudo udevadm trigger
```
### Spin-Up Delay
Optical drives take 30-60 seconds to spin up and become ready after hot-plug or disc insertion. During this window, SCSI commands may return NOT READY or timeout.
freemkv's `Drive::wait_ready()` handles this automatically by polling with TEST UNIT READY until the drive responds. If you are writing your own code using the library, always call `wait_ready()` before `init()`:
```rust
let mut drive = Drive::open(Path::new("/dev/sg4"))?;
drive.wait_ready()?; // blocks until disc is ready, up to 30s
drive.init()?;
```
If the drive was just plugged in, wait a full minute before concluding it is not detected.
---
## 4. How to Identify Your USB-SATA Bridge
If you are experiencing the issues described in section 1, you need to know which bridge chipset your adapter or enclosure uses.
### Step 1: Find the Device
```bash
lsusb
```
Look for entries matching your drive or enclosure. Bridges may appear under their own manufacturer name or as a generic SATA device. Common examples:
```
Bus 002 Device 005: ID 13fd:0840 Initio Corporation
Bus 002 Device 006: ID 174c:1153 ASMedia Technology Inc. ASM1153
Bus 002 Device 007: ID 152d:0578 JMicron Technology Corp. JMS578
This often reveals the bridge chipset even when `lsusb` shows a generic name.
### Step 4: If the Enclosure Is Sealed
Many external drive enclosures (Vantec NexStar, Sabrent, OWC, etc.) do not advertise the bridge chipset on the packaging. In this case:
1. Check `lsusb` while the enclosure is connected.
2. Search the vendor:product ID online -- there are community-maintained lists of which chipsets popular enclosures use.
3. If you cannot determine the chipset and are experiencing bridge crashes, assume it is an Initio and apply the quirk with its IDs.
4. The definitive test: connect the bare drive to a motherboard SATA port. If the problems disappear, the bridge was the cause.
---
## 5. General Debugging Checklist
When something goes wrong during a rip, gather this information before filing an issue:
1. **freemkv version:**`freemkv --version` or the crate version in `Cargo.toml`.
2. **Drive model:** from the drive label, or from `freemkv info`.
3. **Connection type:** USB (with bridge chipset if known) or direct SATA.
4. **Operating system and kernel:**`uname -a`.
5. **Kernel messages during the failure:**`dmesg | tail -50` immediately after the crash.
6. **SCSI device:** which `/dev/sg*` the drive was on, and whether it changed after the failure.
7. **The disc:** title, format (BD/DVD/UHD), condition.
Include all of the above in bug reports. SCSI transport errors that resolve with the `US_FL_IGNORE_RESIDUE` quirk or by switching to direct SATA are bridge firmware bugs, not freemkv bugs.
`libfreemkv` supports a multi-stage rip model for damaged or protection-bearing
discs: a fast forward sweep that tolerates read failures, in-loop request-size
adaptation that survives transient drive trouble without bailing, and targeted
retry passes against a persistent bad-range map. The stream pipeline
(`DiscStream` + `input`/`output`) operates against the resulting ISO image, so
the mux stage never touches the drive.
Recovery is layered cleanly. Each layer has one responsibility and does not
reach into the others.
| Layer | Where it lives | What it does |
|-------|---------------|--------------|
| 1 — Bad-range retry | `Disc::patch` (multi-pass over the mapfile) | Re-reads non-`+` ranges with the long timeout. Idempotent; call N times. |
| 2 — Single-shot primitive | `Drive::read` in `src/drive/mod.rs` | One CDB, one timeout, one result. No inline retries, no SCSI reset. |
| 3 — In-loop request adaptation | `DiscStream::fill_extents` adaptive batch sizer | Halves the batch on failure, retries at the same LBA, walks back up on a clean-read streak. |
The caller orchestrates layer 1. Autorip's `rip_disc` loops `copy` then
N ×`patch` per the `MAX_RETRIES` config, then hands the ISO off to the
existing mux pipeline. Layer 3 runs inside any consumer of `DiscStream`
(direct PES pipeline, ISO playback, etc.) without caller involvement.