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.
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.
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.
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.
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.
MattJackson