Files
libfreemkv/src/disc/patch.rs
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Matthew Jackson 835cc990ad DVD vob_start absolute rebase + rc.5.3 audit fixes
- ifo.rs: rebase VTS title VOBS to absolute disc LBA (file_start_lba +
  vtstt_vobs); fixes DVD rips opening on the menu region instead of the
  movie (e.g. SOTL). Adds absolute-placement regression test.
- aacs/boil.rs: add mk_from_pk primitive (PK -> MK via MKB walk).
- dvdnav/: nav-VM command decoder + start-cell resolver seam, parked
  behind USE_NAV_RESOLVER (kept compiled, never executed).
- mux: FVI src.byte within-sector per spec; Unknown colour -> CICP
  unspecified (2,2,2,1); demux clear PCS -> NORMAL; ts.rs feed() base
  reset + boundary provenance fix.
- Assorted audit fixes (doc/comment/test accuracy) across the crate.
2026-06-26 17:03:58 -07:00

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//! Producer / consumer split for `Disc::patch`.
//!
//! Background: pre-0.18 patch ran strictly serial — single-sector
//! recovery read → seek + write recovered bytes → mapfile.record →
//! next iteration. The drive sat idle while the previous block's
//! recovered bytes were committed. On a damaged disc with many bad
//! sectors that adds up: per-sector write + mapfile.record costs a
//! handful of milliseconds each, which the drive could be using to
//! issue the next per-sector retry.
//!
//! This module decouples them. A consumer thread owns the
//! [`crate::io::WritebackFile`] (the ISO file) and the
//! [`super::mapfile::Mapfile`]. The producer thread (`Disc::patch`)
//! keeps the [`crate::sector::SectorSource`], the wedge / damage-window
//! state, the per-range watchdog, decrypt — so what enters the channel
//! is already-clean cleartext bytes (or an "Unreadable" terminal mark).
//!
//! Producer and consumer run concurrently; the channel uses
//! [`crate::io::pipeline::WRITE_THROUGH_DEPTH`] (=1) so back-pressure
//! kicks in immediately. We want the drive's per-sector retry budget
//! to stay in lockstep with the writer — sweep's `DEFAULT_PIPELINE_DEPTH`
//! (4) would let several sectors of recovered bytes queue up between
//! the producer's retry decisions and the writer, and patch's recovery
//! loop reads stats (`bytes_good`, range progress) inline to drive its
//! skip / wedge decisions. WRITE_THROUGH_DEPTH gives "read N+1 while
//! writing N", no further pipelining — exactly the model the producer
//! logic was written against.
//!
//! Correctness invariants preserved:
//! - Mapfile is single-writer (consumer-only). No locking on it.
//! - All recovery state (damage window, consecutive_failures, skip
//! escalation, range watchdog) stays on the producer thread.
//! - `set_speed` calls happen on the producer thread (same thread that
//! owns the `SectorSource`). No new SCSI concurrency.
//! - Per-iteration ordering of file-write → mapfile-record is kept
//! intact in the consumer (write before record), so the on-disk
//! invariant "mapfile only marks Finished what the file has received"
//! survives a crash mid-pass.
//! - The BU40N+Initio bridge wedge concern is unchanged: only one
//! SCSI command in flight at a time, error-path timing identical,
//! no new retry logic. The threading primitive only overlaps the
//! *write* with the *next read*; the per-sector single-shot read
//! budget that the bridge wedge concern was originally about is
//! untouched.
//!
//! Per-range watchdog (`range_sectors × SECONDS_PER_SECTOR`, capped at `RANGE_BUDGET_CAP_SECS`)
//! checks `bytes_good` for forward progress. With work in flight on
//! the consumer, the producer would otherwise see stale values; the
//! sink publishes a [`SharedPatchState`] snapshot after every record
//! so the producer's stall guards observe consumer side-effects with
//! at most one item of lag (which is fine — the watchdog uses minute-
//! scale budgets, not single-record latency).
use std::io::{Seek, SeekFrom, Write};
use std::sync::{Arc, Mutex};
use crate::error::{Error, Result};
use crate::io::pipeline::{Flow, Sink};
use super::mapfile::{self, MapStats, Mapfile, SectorStatus};
/// Item the producer hands to the patch consumer. One per per-sector
/// recovery decision.
pub(super) enum PatchItem {
/// Sector / small batch successfully recovered (and decrypted on the
/// producer side if `opts.decrypt` was set). Consumer seeks to
/// `pos`, writes `buf`, records the range as `Finished`.
Recovered { pos: u64, buf: Vec<u8> },
/// Producer exhausted retries on `[pos, pos+len)`. Consumer records
/// the range as `Unreadable`. No file write — the existing zero-fill
/// from sweep is preserved in place.
///
/// Currently unused by `Disc::patch` itself (2026-05-11 design call:
/// patch never marks `Unreadable` mid-multipass; bytes stay
/// `NonTrimmed` so future passes get another shot at them). Kept
/// in the enum for the orchestrator-side end-of-recovery promotion
/// (autorip, after the final retry pass completes, promotes
/// still-NonTrimmed bytes to Unreadable). The orchestrator (autorip)
/// performs this promotion directly via `Mapfile::record()` after all
/// retry passes complete, not by emitting to `PatchSink`. This variant
/// remains unused by the library itself.
#[allow(dead_code)]
Unreadable { pos: u64, len: u64 },
/// Producer marks `[pos, pos+len)` as `NonTrimmed`. Used for BOTH
/// the per-range skip-limit case (remaining bytes never tried) AND
/// individual sector failures (tried-but-failed within a pass).
/// Both stay "hopeful" — a later pass retries them.
///
/// CRITICAL: "NonTrimmed in pass N" does NOT mean "Unreadable
/// forever." Drive reads are stochastic: the same sector that
/// fails 10 times in Pass 2 may succeed on attempt 1 in Pass 3
/// after temperature / bus state / prior-read patterns shift.
/// Pre-2026-05-11 patch marked individual failures Unreadable,
/// which gave up on sectors that subsequent passes could have
/// recovered (historical: ~36% of patch-marked Unreadable
/// sectors turned out to be readable in re-rip experiments).
/// Promotion to true Unreadable is the orchestrator's job,
/// applied once after all retry passes complete.
NonTrimmed { pos: u64, len: u64 },
}
/// Mapfile snapshot the sink republishes after every record so the
/// producer can drive its stall / progress logic without holding the
/// mapfile lock for long. `bad_ranges` mirrors what
/// `Mapfile::ranges_with(&[NonTrimmed, Unreadable, NonScraped, NonTried])`
/// would return — same set the pre-split patch loop computed inline
/// for the progress callback.
pub(super) struct SharedPatchState {
pub stats: MapStats,
pub bad_ranges: Vec<(u64, u64)>,
}
impl SharedPatchState {
/// Cap on the republished `bad_ranges` Vec. Consumers (progress display,
/// scheduler) only sample the head of the list; the full set is bounded by
/// the mapfile entry cap so a pathologically fragmented disc can't make
/// every per-record republish allocate unboundedly.
const MAX_BAD_RANGES: usize = 8192;
fn from_map(map: &Mapfile) -> Self {
let mut bad_ranges = map.ranges_with(&[
SectorStatus::NonTrimmed,
SectorStatus::Unreadable,
SectorStatus::NonScraped,
SectorStatus::NonTried,
]);
bad_ranges.truncate(Self::MAX_BAD_RANGES);
Self {
stats: map.stats(),
bad_ranges,
}
}
}
/// Final summary returned by [`Sink::close`] when the consumer drains
/// cleanly. Mirrors what the pre-split patch loop computed at the end
/// of the function — final mapfile stats plus whether `sync_all`
/// failed on a regular file (the only kind of fsync error patch ever
/// surfaced; `/dev/null` and pipes always fail `sync_all`, that's not
/// a real error).
pub(super) struct PatchSummary {
pub stats: MapStats,
}
/// Consumer-side of the patch pipeline. Owns the ISO writeback file
/// and the mapfile; publishes a shared snapshot after every record so
/// the producer can read `bytes_good` for stall detection and
/// progress reporting.
pub(super) struct PatchSink {
file: crate::io::WritebackFile,
map: Mapfile,
/// Whether the output is a regular file (so a `sync_all` failure
/// is real). `/dev/null` etc. always fail `sync_all`; ignore those.
is_regular: bool,
/// Snapshot the producer reads. Updated after every successful
/// `record()` call. `Mutex` rather than separate atomics because
/// the producer wants stats + bad_ranges as a coherent pair.
shared: Arc<Mutex<SharedPatchState>>,
/// Last time the shared snapshot was republished. `from_map` allocates
/// O(bad_ranges) every call, so the per-record path throttles to a time
/// cadence (`REPUBLISH_CADENCE`); the final close always forces a publish.
last_republish: Option<std::time::Instant>,
}
/// Minimum interval between per-record snapshot republishes.
const REPUBLISH_CADENCE: std::time::Duration = std::time::Duration::from_millis(250);
impl PatchSink {
/// Open `path` as a [`crate::io::WritebackFile`] and pair it with
/// `map` for the consumer. The producer holds onto the returned
/// `Arc<Mutex<SharedPatchState>>` so it can poll mapfile state
/// while the consumer is mutating it.
pub(super) fn new(
path: &std::path::Path,
map: Mapfile,
is_regular: bool,
) -> Result<(Self, Arc<Mutex<SharedPatchState>>)> {
let file =
crate::io::WritebackFile::open(path).map_err(|e| Error::IoError { source: e })?;
let shared = Arc::new(Mutex::new(SharedPatchState::from_map(&map)));
let shared_clone = shared.clone();
Ok((
Self {
file,
map,
is_regular,
shared,
last_republish: None,
},
shared_clone,
))
}
/// Republish the shared snapshot. When `force` is false the update is
/// throttled to `REPUBLISH_CADENCE`; `force` (used at close) always
/// publishes the final state.
fn republish(&mut self, force: bool) {
let now = std::time::Instant::now();
if !force {
if let Some(prev) = self.last_republish {
if now.duration_since(prev) < REPUBLISH_CADENCE {
return;
}
}
}
self.last_republish = Some(now);
self.publish_now();
}
fn publish_now(&self) {
// Best-effort lock — only the producer reads, only the consumer
// writes; contention is single-acquire so the lock is never
// poisoned in practice. If it ever did get poisoned we'd want
// the underlying error surfaced rather than silently swallowed,
// so we propagate the poison panic rather than silently
// continuing with stale shared state.
let mut guard = self
.shared
.lock()
.expect("PatchSink shared state mutex poisoned");
*guard = SharedPatchState::from_map(&self.map);
}
}
impl Sink<PatchItem> for PatchSink {
type Output = PatchSummary;
fn apply(&mut self, item: PatchItem) -> std::result::Result<Flow, Error> {
match item {
PatchItem::Recovered { pos, buf } => {
let len = buf.len() as u64;
self.file
.seek(SeekFrom::Start(pos))
.map_err(|e| Error::IoError { source: e })?;
self.file
.write_all(&buf)
.map_err(|e| Error::IoError { source: e })?;
self.map
.record(pos, len, SectorStatus::Finished)
.map_err(|e| Error::IoError { source: e })?;
}
PatchItem::Unreadable { pos, len } => {
self.map
.record(pos, len, SectorStatus::Unreadable)
.map_err(|e| Error::IoError { source: e })?;
}
PatchItem::NonTrimmed { pos, len } => {
self.map
.record(pos, len, SectorStatus::NonTrimmed)
.map_err(|e| Error::IoError { source: e })?;
}
}
self.republish(false);
Ok(Flow::Continue)
}
fn close(mut self) -> std::result::Result<Self::Output, Error> {
// Drain in-flight writeback then issue a full fsync. A failure
// here matters only on regular files — pipes / `/dev/null` etc.
// always fail `sync_all`.
if let Err(e) = self.file.sync_all() {
if self.is_regular {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_sync_failed",
error = %e,
os_error = e.raw_os_error(),
error_kind = ?e.kind(),
"patch: sync_all failed"
);
return Err(Error::IoError { source: e });
}
tracing::debug!(
target: "freemkv::disc",
phase = "patch_sync_skipped",
error = %e,
"patch: sync_all failed for non-regular file; ignoring"
);
}
self.map.flush().map_err(|e| Error::IoError { source: e })?;
// Final republish so anyone reading the shared snapshot after
// `Pipeline::finish` sees the post-flush state. (The producer
// already has its own copy of the final `MapStats` in the
// returned `PatchSummary`, but the snapshot is part of the
// public-ish contract of the consumer: it stays current
// through close.)
self.republish(true);
Ok(PatchSummary {
stats: self.map.stats(),
})
}
}
// ─────────────────────────────────────────────────────────────────
// Disc::patch + bytes_bad_in_title — extracted from disc/mod.rs in
// 0.20.1. Behavior unchanged; the move splits the 3,900-line mod.rs
// into a cleaner-to-read file.
// ─────────────────────────────────────────────────────────────────
use super::{Disc, DiscTitle, PatchOptions, PatchOutcome, bytes_bad_in_title};
use crate::io::pipeline::Pipeline;
use crate::sector::SectorSource;
// Pass-N tunables. Hoisted to module scope so helpers (extracted from
// the original `Disc::patch` body) can reference them without inheriting
// the function's local-const scope.
// Mirror of sweep path (read_error.rs NOT_READY_MAX_RETRIES = 3): cap
// per-LBA NOT_READY retries so a persistently-not-ready disc cannot burn
// up to RANGE_BUDGET_CAP_SECS per range on a single LBA.
const NOT_READY_MAX_RETRIES_PER_LBA: u32 = 3;
const BRIDGE_DEGRADATION_PAUSE_SECS: u64 = 10;
const POST_FAILURE_PAUSE_SECS: u64 = 1;
const CONSECUTIVE_FAIL_LONG_PAUSE: u64 = 5;
const CONSECUTIVE_FAIL_LONG_PAUSE_THRESHOLD: u64 = 10;
// Adaptive batching: climb back to `initial_batch` after this many
// consecutive clean single-sector successes.
const ADAPTIVE_UPSCALE_THRESHOLD: u32 = 16;
// Wedge-family (HARDWARE_ERROR / ILLEGAL_REQUEST) cooldown and abort
// thresholds — see `handle_read_failure` below for context.
// Single source of truth lives in `disc::read_error` so this cannot
// drift from `ZONE_ENTRY_COOLDOWN_SECS`.
const WEDGE_FAMILY_COOLDOWN_SECS: u64 = crate::disc::read_error::ZONE_ENTRY_COOLDOWN_SECS;
const WEDGE_ABORT_THRESHOLD: u32 = 16;
// Whole-pass stall watchdog: bytes_good must increase within
// STALL_SECS or the pass bails out as wedged.
const STALL_SECS: u64 = 3600;
// Per-range budget = sectors_in_range × SECONDS_PER_SECTOR, capped at
// RANGE_BUDGET_CAP_SECS. See `Disc::patch` block-comment for details.
const SECONDS_PER_SECTOR: u64 = 25;
const RANGE_BUDGET_CAP_SECS: u64 = 1800;
const MAX_SKIPS_PER_RANGE: u32 = 10;
// Pass-N damage-window / skip tunables.
const PASSN_DAMAGE_WINDOW: usize = 16;
// Single source of truth lives in `disc::read_error` so the patch loop's
// `compute_damage_skip` cannot drift from `ReadCtx::for_patch()`'s
// `damage_threshold_pct`. See `PATCH_DAMAGE_THRESHOLD_PCT` for context.
// (v0.20.8 release: the larger "route Pass-N MEDIUM/NOT_READY through
// handle_read_error" unification was attempted and backed out — the
// patch loop's size-aware `range_remaining/4` skip cap has no
// equivalent in `handle_read_error::JumpAhead`, and routing through
// the unified handler would regress the size-aware-skip A/B fixture
// in `tests/passn_handler_ab.rs`. Pulling the threshold into the
// shared constant is the safe, behavior-preserving first step.)
const PASSN_DAMAGE_THRESHOLD_PCT: usize = crate::disc::read_error::PATCH_DAMAGE_THRESHOLD_PCT;
const PASSN_SKIP_SECTORS_BASE: u64 = 32;
const PASSN_SKIP_SECTORS_CAP: u64 = 4096;
const PASSN_ESCALATION_RESET_GOOD: u32 = 4;
// Cache-prime: number of single-sector throwaway reads issued at LBAs
// immediately preceding the target before a count==1 recovery read.
const CACHE_PRIME_SECTORS: u32 = 3;
/// Probe-offset escalation: returns a per-probe skip distance in
/// sectors of `PASSN_SKIP_SECTORS_BASE << (3 × idx)` (i.e. multiplies
/// by 8 per index), capped at `PASSN_SKIP_SECTORS_CAP`. Used by the
/// wedge-vs-bad-sector probe to
/// scatter its sample LBAs across the failing region rather than
/// hammering the same neighborhood.
pub(super) fn skip_sectors_for_probe(idx: usize) -> u64 {
let escalation = (idx.saturating_mul(3)).min(u32::MAX as usize) as u32;
// Saturating shift: a large `idx` would overflow a fixed-width shift
// (32 << 60 = 2^65), so fall back to the cap instead of panicking
// (debug) or wrapping to 0 (release).
PASSN_SKIP_SECTORS_BASE
.checked_shl(escalation)
.unwrap_or(PASSN_SKIP_SECTORS_CAP)
.min(PASSN_SKIP_SECTORS_CAP)
}
/// Send a `PatchItem` and translate a `SendError` (consumer thread died
/// / panicked) into a library error so the caller propagates cleanly.
pub(super) fn send_or_abort(
pipe: &Pipeline<PatchItem, PatchSummary>,
item: PatchItem,
) -> Result<()> {
pipe.send(item).map_err(|_| Error::PipelineConsumerGone)
}
/// Phase A pre-snapshot. Loads the mapfile, captures the fields the
/// patch loop needs after the live `Mapfile` moves into the consumer
/// thread (`bytes_good` baseline, total stats, entry snapshot for
/// the diagnostic dump, the initial bad-range work list, total work
/// in bytes, and the `is_regular` test that gates the post-pass
/// `sync_all` error policy). Returned `Mapfile` is the same object
/// that was loaded — caller passes ownership into `PatchSink::new`.
#[allow(clippy::type_complexity)]
pub(super) fn compute_initial_state(
path: &std::path::Path,
opts: &PatchOptions,
mapfile_path: &std::path::Path,
) -> Result<(
Mapfile,
MapStats,
Vec<mapfile::MapEntry>,
u64,
Vec<(u64, u64)>,
u64,
bool,
)> {
let map = mapfile::Mapfile::load(mapfile_path).map_err(|e| Error::IoError { source: e })?;
let total_bytes = map.total_size();
let initial_stats = map.stats();
let initial_entries: Vec<_> = map.entries().to_vec();
// Every retry pass acts on NonTrimmed, NonScraped, and Unreadable
// ranges. Including Unreadable means a sector that failed in pass N
// gets a fresh shot in pass N+1 — drive state evolves, the same
// read can succeed later. Each pass owns its own jumps/skips; if
// pass 5 jumps over the same zone as pass 2, fine. NonTried ranges
// are intentionally excluded — they are covered by a preceding
// sweep pass, not by patch.
let mut bad_ranges = map.ranges_with(&[
mapfile::SectorStatus::NonTrimmed,
mapfile::SectorStatus::NonScraped,
mapfile::SectorStatus::Unreadable,
]);
if opts.reverse {
bad_ranges.reverse();
}
let work_total: u64 = bad_ranges.iter().map(|(_, sz)| *sz).sum();
let is_regular = std::fs::metadata(path)
.map(|m| m.file_type().is_file())
.unwrap_or(false);
Ok((
map,
initial_stats,
initial_entries,
total_bytes,
bad_ranges,
work_total,
is_regular,
))
}
/// Cache priming: before the recovery read, issue `CACHE_PRIME_SECTORS`
/// throwaway single-sector reads at the LBAs immediately preceding
/// `lba`. The drive's read-ahead cache prefetches forward on
/// sequential reads — by the time the caller asks for `lba` it may
/// already be cached, even if a cold read of the same LBA would fail.
/// Proven 2026-05-07 with dd-as-oracle: 8/8 sectors recoverable when
/// primed vs 6/8 cold. Failures are best-effort: we already have these
/// bytes Finished from a prior pass, so prime failures don't update
/// mapfile state. Only runs on count==1 reads (the genuine recovery
/// path) and when `lba >= CACHE_PRIME_SECTORS` so the subtraction
/// doesn't underflow.
pub(super) fn prime_cache<R: SectorSource + ?Sized>(reader: &mut R, lba: u32, count: u16) {
if !(lba >= CACHE_PRIME_SECTORS && count == 1) {
return;
}
let mut prime_buf = [0u8; 2048];
for i in 0..CACHE_PRIME_SECTORS {
let prime_lba = lba - CACHE_PRIME_SECTORS + i;
// Best-effort; ignore errors. Recovery=false is intentional:
// a fast 1.5s timeout is fine because we don't need the data.
let _ = reader.read_sectors(prime_lba, 1, &mut prime_buf[..], false);
}
}
/// Pre-loop diagnostic dump: emits `patch_mapfile_snapshot` plus the
/// first/last 10 entries (info + per-entry debug). Pure logging — no
/// state mutation. Pulled out of `Disc::patch` so the coordination
/// body stays compact; the operator's grep patterns for
/// `[disc] patch_mapfile_snapshot`, `patch_mapfile_entries_start`,
/// `patch_mapfile_entry_start`, `patch_mapfile_entries_end`,
/// `patch_mapfile_entry_end` are unchanged.
pub(super) fn log_patch_start_snapshot(
initial_entries: &[mapfile::MapEntry],
initial_stats: &mapfile::MapStats,
bytes_good_before: u64,
) {
tracing::info!(
target: "freemkv::disc",
phase = "patch_mapfile_snapshot",
total_entries = initial_entries.len(),
bytes_good_before,
bytes_retryable = initial_stats.bytes_retryable,
bytes_unreadable = initial_stats.bytes_unreadable,
bytes_nontried = initial_stats.bytes_nontried,
"Mapfile state snapshot at patch start"
);
if !initial_entries.is_empty() {
tracing::info!(
target: "freemkv::disc",
phase = "patch_mapfile_entries_start",
num_to_log = (initial_entries.len().min(10)) as u32,
"First 10 entries"
);
for entry in initial_entries.iter().take(10) {
tracing::debug!(
target: "freemkv::disc",
phase = "patch_mapfile_entry_start",
pos_hex = format!("0x{:09x}", entry.pos),
size_mb = entry.size as f64 / 1_048_576.0,
status_char = entry.status.to_char() as u8 as i32,
"Mapfile entry"
);
}
}
if initial_entries.len() > 10 {
tracing::info!(
target: "freemkv::disc",
phase = "patch_mapfile_entries_end",
num_to_log = (initial_entries.len().min(10)) as u32,
"Last 10 entries"
);
for entry in initial_entries.iter().skip(initial_entries.len() - 10) {
tracing::debug!(
target: "freemkv::disc",
phase = "patch_mapfile_entry_end",
pos_hex = format!("0x{:09x}", entry.pos),
size_mb = entry.size as f64 / 1_048_576.0,
status_char = format!("{}", entry.status.to_char()),
"Mapfile entry"
);
}
}
}
/// Bundle final mapfile stats + accumulated loop counters into the
/// public `PatchOutcome` the caller consumes. The post-loop tracing
/// (`patch_iso_size_end`, `patch_done`) is also emitted here so the
/// coordination body has one less inline stanza.
#[allow(clippy::too_many_arguments)]
pub(super) fn build_outcome(
state: &PatchLoopState,
summary: &PatchSummary,
path: &std::path::Path,
total_bytes: u64,
num_ranges: usize,
wedged_threshold: u64,
) -> PatchOutcome {
let stats = summary.stats;
if let Ok(metadata) = std::fs::metadata(path) {
tracing::info!(
target: "freemkv::disc",
phase = "patch_iso_size_end",
iso_bytes = metadata.len(),
bytes_recovered = stats.bytes_good.saturating_sub(state.bytes_good_before),
"ISO file size at patch end"
);
}
tracing::info!(
target: "freemkv::disc",
phase = "patch_done",
blocks_attempted = state.blocks_attempted,
blocks_read_ok = state.blocks_read_ok,
blocks_read_failed = state.blocks_read_failed,
unreadable_count = state.unreadable_count,
wedged_exit = state.wedged_exit,
halted = state.halted,
bytes_recovered = stats.bytes_good.saturating_sub(state.bytes_good_before),
final_bytes_good = stats.bytes_good,
final_bytes_unreadable = stats.bytes_unreadable,
final_bytes_pending = stats.bytes_pending,
total_ranges_processed = num_ranges,
"Disc::patch returning"
);
PatchOutcome {
bytes_total: total_bytes,
bytes_good: stats.bytes_good,
bytes_unreadable: stats.bytes_unreadable,
bytes_pending: stats.bytes_pending,
bytes_recovered_this_pass: stats.bytes_good.saturating_sub(state.bytes_good_before),
halted: state.halted,
blocks_attempted: state.blocks_attempted,
blocks_read_ok: state.blocks_read_ok,
blocks_read_failed: state.blocks_read_failed,
wedged_exit: state.wedged_exit,
wedged_threshold,
}
}
/// Per-pass loop state, accumulated across every range and every read
/// inside `Disc::patch`. Lives on the producer thread; helpers take
/// `&mut PatchLoopState` so they can mutate counters and per-range
/// scratch without an explosion of parameters at the call site.
pub(super) struct PatchLoopState {
// Counters
pub halted: bool,
pub wedged_exit: bool,
pub blocks_attempted: u64,
pub blocks_read_ok: u64,
pub blocks_read_failed: u64,
pub unreadable_count: u64,
pub wedge_count: u32,
pub work_done: u64,
// Per-range scratch (reset at each range boundary)
pub consecutive_failures: u64,
pub consecutive_skips_without_recovery: u32,
pub consecutive_good_since_skip: u32,
pub last_skip_from: Option<u64>,
pub skip_count: u32,
pub damage_window: Vec<bool>,
// Per-LBA NOT_READY retry cap (mirrors sweep NOT_READY_MAX_RETRIES=3).
// Reset whenever the current LBA changes (i.e. the cursor advances to
// a new sector). NOT_READY retries that push past NOT_READY_MAX_RETRIES_PER_LBA
// fall through to normal failure handling (NonTrimmed + cursor advance).
pub not_ready_retries_per_lba: u32,
pub not_ready_lba: Option<u32>,
// Stall tracking
pub bytes_good_last: u64,
pub stall_start: std::time::Instant,
pub range_start: std::time::Instant,
pub range_bytes_good: u64,
// Clock seam: the watchdog reads wall time through this rather than calling
// `Instant::now()` inline, so deterministic tests can advance a fake clock to
// prove the stall/range timeouts trip. Production uses `Instant::now`
// (see `PatchLoopState::new`), so behaviour is byte-identical.
pub now: fn() -> std::time::Instant,
// Adaptive batch
pub current_batch: u16,
pub consecutive_singles_ok: u32,
// Snapshot at construction — these stay constant for the whole pass
pub bytes_good_before: u64,
pub bytes_good_start: u64,
#[allow(dead_code)]
pub total_bytes: u64,
pub initial_batch: u16,
pub recovery: bool,
pub work_total: u64,
}
impl PatchLoopState {
pub(super) fn new(
bytes_good_before: u64,
total_bytes: u64,
initial_batch: u16,
recovery: bool,
work_total: u64,
) -> Self {
// Production clock: the real monotonic wall clock.
Self::new_with_clock(
bytes_good_before,
total_bytes,
initial_batch,
recovery,
work_total,
std::time::Instant::now,
)
}
/// Like `new`, but with an injectable monotonic clock. The watchdog reads
/// time exclusively through `now`, so a test can wind a fake clock forward to
/// drive the stall/range timeouts deterministically. `new` passes
/// `Instant::now`, so the production loop is unchanged.
pub(super) fn new_with_clock(
bytes_good_before: u64,
total_bytes: u64,
initial_batch: u16,
recovery: bool,
work_total: u64,
now: fn() -> std::time::Instant,
) -> Self {
let t0 = now();
Self {
halted: false,
wedged_exit: false,
blocks_attempted: 0,
blocks_read_ok: 0,
blocks_read_failed: 0,
unreadable_count: 0,
wedge_count: 0,
work_done: 0,
consecutive_failures: 0,
consecutive_skips_without_recovery: 0,
consecutive_good_since_skip: 0,
last_skip_from: None,
skip_count: 0,
damage_window: Vec::with_capacity(PASSN_DAMAGE_WINDOW),
not_ready_retries_per_lba: 0,
not_ready_lba: None,
bytes_good_last: bytes_good_before,
stall_start: t0,
range_start: t0,
range_bytes_good: bytes_good_before,
now,
current_batch: initial_batch,
consecutive_singles_ok: 0,
bytes_good_before,
bytes_good_start: bytes_good_before,
total_bytes,
initial_batch,
recovery,
work_total,
}
}
}
/// Phase F: the Ok arm of the patch read result. Records the recovery,
/// dispatches the bytes to the consumer, runs the stall guard, and
/// (in reverse mode) runs the post-recovery backtrack that fills the
/// gap left by the most recent damage-skip. Returns `OuterAction` —
/// `Break` if the stall guard fired or backtrack hit a halt.
#[allow(clippy::too_many_arguments)]
pub(super) fn handle_read_success<R: SectorSource + ?Sized>(
state: &mut PatchLoopState,
frame: &RangeFrame,
opts: &PatchOptions,
lba: u32,
count: u16,
pos: u64,
block_bytes: u64,
bytes: usize,
buf: &mut [u8],
read_duration_ms: u128,
pipe: &Pipeline<PatchItem, PatchSummary>,
shared: &Mutex<SharedPatchState>,
reader: &mut R,
) -> Result<OuterAction> {
state.blocks_read_ok += 1;
state.consecutive_failures = 0;
state.consecutive_good_since_skip += 1;
// A successful read breaks any in-progress wedge-family streak.
// wedge_count tracks CONSECUTIVE wedge-family (HARDWARE_ERROR /
// ILLEGAL_REQUEST) senses; a good read proves the drive is still
// responding so the streak is over. Without this reset, intermittent
// good reads interspersed with wedge-family failures accumulate
// wedge_count monotonically, triggering WEDGE_ABORT_THRESHOLD (16)
// prematurely on ranges that are actually making progress.
// Note: handle_read_failure already resets wedge_count on any
// non-wedge-family failure; this mirrors that for the success path.
state.wedge_count = 0;
// A successful read means this LBA is resolved; clear the NOT_READY
// per-LBA counter so any future failure at a different LBA starts fresh.
state.not_ready_retries_per_lba = 0;
state.not_ready_lba = None;
if state.consecutive_good_since_skip >= PASSN_ESCALATION_RESET_GOOD {
state.consecutive_skips_without_recovery = 0;
}
// Adaptive batching: track clean single-sector reads to decide
// when to climb back to `state.initial_batch`. A batch read
// succeeding (count > 1) tells us the drive is healthy but doesn't
// accumulate toward upscale — we got back to batch=1 because of a
// failure here, we need consistent health at the slow tempo
// before scaling up again.
if count == 1 && state.current_batch < state.initial_batch {
state.consecutive_singles_ok += 1;
if state.consecutive_singles_ok >= ADAPTIVE_UPSCALE_THRESHOLD {
tracing::info!(
target: "freemkv::disc",
phase = "patch_adaptive_upscale",
from = state.current_batch,
to = state.initial_batch,
consecutive_singles_ok = state.consecutive_singles_ok,
lba,
"adaptive batching: drive stable, climbing back to initial_batch"
);
state.current_batch = state.initial_batch;
state.consecutive_singles_ok = 0;
}
}
state.damage_window.push(true);
if state.damage_window.len() > PASSN_DAMAGE_WINDOW {
state.damage_window.remove(0);
}
tracing::info!(
target: "freemkv::disc",
phase = "patch_read_ok",
lba,
count,
bytes,
blocks_read_ok = state.blocks_read_ok,
consecutive_failures = state.consecutive_failures,
read_duration_ms,
range_idx = frame.range_idx,
pos,
"Read succeeded"
);
// Plaintext: DecryptingSectorSource applied AACS / CSS in-place
// during the read_sectors call above. The pre-0.18 inline
// decrypt_sectors call lived here.
let write_start = std::time::Instant::now();
tracing::debug!(
target: "freemkv::disc",
phase = "patch_write_start",
pos,
bytes,
"Starting ISO write"
);
// Hand the recovered bytes off to the consumer: seek + write +
// mapfile.record(Finished) all happen on the consumer thread,
// so the producer can immediately move on to the next read while
// these bytes are being committed.
send_or_abort(
pipe,
PatchItem::Recovered {
pos,
buf: buf[..bytes].to_vec(),
},
)?;
let write_duration_ms = write_start.elapsed().as_millis();
tracing::info!(
target: "freemkv::disc",
phase = "patch_write_ok",
pos,
bytes,
write_duration_ms,
"ISO write succeeded"
);
tracing::info!(
target: "freemkv::disc",
phase = "patch_mapfile_record_ok",
pos,
block_bytes,
"Mapfile record dispatched"
);
// Stall guard: watch bytes_good (real progress), not pos
// (advances on skips). With the consumer running in its own
// thread, this read can lag by up to one item; the watchdog
// operates at STALL_SECS=3600 granularity so single-item lag is
// irrelevant.
let bytes_good_now = {
let g = shared
.lock()
.expect("PatchSink shared state mutex poisoned");
g.stats.bytes_good
};
if bytes_good_now > state.bytes_good_last {
state.stall_start = (state.now)();
state.bytes_good_last = bytes_good_now;
}
let stall_elapsed = (state.now)().duration_since(state.stall_start);
if stall_elapsed > std::time::Duration::from_secs(STALL_SECS) {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_stall",
elapsed_secs = stall_elapsed.as_secs(),
bytes_good = bytes_good_now,
bytes_good_start = state.bytes_good_start,
"Patch stalled - no recovery for {}s, exiting pass",
STALL_SECS
);
state.wedged_exit = true;
return Ok(OuterAction::Break);
}
if let Some(skip_from) = state.last_skip_from.take() {
let backtrack_start = frame.block_end;
let backtrack_end = skip_from;
if opts.reverse && backtrack_start < backtrack_end {
tracing::info!(
target: "freemkv::disc",
phase = "patch_backtrack_start",
from_lba = pos,
to_lba = backtrack_end / 2048,
"recovered after skip; backtracking into gap"
);
let mut bt_pos = backtrack_start;
while bt_pos < backtrack_end {
// Honor cancellation inside the backtrack inner loop.
// A long backtrack span can run minutes of single-
// sector reads; without this check the outer halt
// only takes effect when control returns to the
// per-range loop.
if let Some(h) = &opts.halt {
if h.load(std::sync::atomic::Ordering::Relaxed) {
return Err(crate::error::Error::Halted);
}
}
let span =
// Backtrack always at count=1: this path fills a
// gap that the main loop's damage-window skip
// jumped over. Using batched reads here would
// lump good sectors into NonTrimmed marks when
// the gap contains even one bad sector. Backtrack
// is rare enough that the per-sector cost is fine.
(backtrack_end - bt_pos).min(2048);
let bt_lba = (bt_pos / 2048) as u32;
let bt_count = (span / 2048) as u16;
let bt_bytes = bt_count as usize * 2048;
match reader.read_sectors(bt_lba, bt_count, &mut buf[..bt_bytes], state.recovery) {
Ok(_) => {
state.blocks_read_ok += 1;
// Plaintext via DecryptingSectorSource
// wrapping; same path the main read takes
// above.
send_or_abort(
pipe,
PatchItem::Recovered {
pos: bt_pos,
buf: buf[..bt_bytes].to_vec(),
},
)?;
}
Err(_err) => {
state.blocks_read_failed += 1;
// Feed the damage window / wedge counter exactly as the
// main loop does, so a string of backtrack failures
// escalates skip distance and trips wedge detection
// rather than being silently under-counted.
state.damage_window.push(false);
if state.damage_window.len() > PASSN_DAMAGE_WINDOW {
state.damage_window.remove(0);
}
state.consecutive_failures += 1;
// Leave NonTrimmed (not Unreadable) so a
// later pass gets another shot. Per the
// project goal — "recover 100% of readable
// data" — and the multi-pass design's
// promise: bytes stay Good-or-Maybe across
// passes; promotion to Unreadable is the
// orchestrator's job at end-of-recovery
// (final retry pass complete). Reference:
// 2026-05-11 design call.
send_or_abort(
pipe,
PatchItem::NonTrimmed {
pos: bt_pos,
len: span,
},
)?;
tracing::info!(
target: "freemkv::disc",
phase = "patch_backtrack_stop",
lba = bt_lba,
"backtrack hit damage; stopping"
);
break;
}
}
state.work_done = state.work_done.saturating_add(span);
bt_pos += span;
}
}
}
Ok(OuterAction::Continue)
}
/// Phase G: the Err arm of the patch read result. Handles the
/// adaptive-batch split decision (count > 1 failures don't count),
/// records the failure, applies the NOT_READY retry pause, dispatches
/// the NonTrimmed PatchItem, runs the stall guard, runs the probe-
/// wedge-vs-bad-sector diagnostic, classifies the wedge family and
/// picks the right cooldown pause, then sleeps. Returns the verdict
/// for the outer loop.
///
/// Left as one large function (not sub-split into
/// `handle_not_ready_retry` / `probe_drive_responsive` /
/// `classify_wedge_family`) — that's the gold-plating tier deferred
/// to a future PR.
#[allow(clippy::too_many_arguments)]
pub(super) fn handle_read_failure<R: SectorSource + ?Sized>(
state: &mut PatchLoopState,
frame: &RangeFrame,
opts: &PatchOptions,
err: &Error,
lba: u32,
count: u16,
pos: u64,
block_bytes: u64,
bytes: usize,
read_duration_ms: u128,
pipe: &Pipeline<PatchItem, PatchSummary>,
shared: &Mutex<SharedPatchState>,
reader: &mut R,
) -> Result<FailureAction> {
// Transport failure (status=0xFF: USB-bridge crash / disconnect) is not a
// recoverable bad sector — the bridge is wedged and every further read fails
// identically. Abort the pass immediately (symmetric with the sweep's
// read_error::handle_read_error AbortPass and single-pass mux's fill_extents),
// so autorip can drop and re-enumerate the bridge instead of hammering a
// crashed device sector-by-sector until the per-range watchdog expires.
// Checked before the batch-split below: a 0xFF on a batch read is still a
// bridge crash, not an ambiguous bad sector.
if err.is_scsi_transport_failure() {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_transport_failure",
lba,
count,
"transport failure (bridge crash) during patch — aborting pass"
);
state.wedged_exit = true;
return Ok(FailureAction::BreakOuter);
}
// Adaptive batching split decision: a batch-read failure
// (count > 1) is NOT a recorded failure. We don't yet know which
// sector in the batch was actually bad — could be one, could be
// many. Drop to count=1 and retry the SAME starting position so
// every sector gets individually probed. Cursor stays put; loop
// continues. Invariants: no good sector ever gets lumped into a
// NonTrimmed mark, no spurious consecutive_failures (which drives
// wedge detection), no damage_window pollution from batch-level
// signals.
if count > 1 {
tracing::info!(
target: "freemkv::disc",
phase = "patch_adaptive_split",
lba,
count,
from_batch = state.current_batch,
err_code = err.code(),
"adaptive batching: batch read failed, dropping to count=1 to probe individually"
);
state.current_batch = 1;
state.consecutive_singles_ok = 0;
return Ok(FailureAction::ContinueInner);
}
state.blocks_read_failed += 1;
state.consecutive_good_since_skip = 0;
state.consecutive_singles_ok = 0;
state.unreadable_count += 1;
// Reset the per-LBA NOT_READY counter whenever the LBA changes.
// NOT_READY retries hold the cursor in place (ContinueInner), so the
// same LBA is re-attempted each iteration until we either succeed or
// exhaust NOT_READY_MAX_RETRIES_PER_LBA. A different LBA means the
// cursor has advanced (or we're on a new range), so start fresh.
if state.not_ready_lba != Some(lba) {
state.not_ready_retries_per_lba = 0;
state.not_ready_lba = Some(lba);
}
// Check if this is a NOT_READY error that should be retried BEFORE
// incrementing consecutive_failures so NOT_READY retries do not
// count toward the wedge threshold (Fix 3: false-wedge prevention).
// Mirror of sweep path (read_error.rs handle_read_error): NOT_READY
// is capped at NOT_READY_MAX_RETRIES and not counted toward
// wedge/skip counters.
let sense = err.scsi_sense();
// ASC values (under NOT READY, sense_key 0x02) indicating temporary
// drive unresponsiveness worth retrying:
// 0x02 = LUN not ready, no reference position (mechanism still seeking)
// 0x03 = LUN not ready, manual intervention required
// 0x04 = LUN not ready, in process of becoming ready / initializing
// (Medium-not-present is ASC 0x3A, not handled here — nothing to retry.)
let is_not_ready_retryable = sense
.map(|s| s.sense_key == 0x02 && (s.asc == 0x02 || s.asc == 0x03 || s.asc == 0x04))
.unwrap_or(false);
// Only count toward consecutive_failures / wedge detector when this
// is NOT a retryable NOT_READY — those are handled below and return
// ContinueInner without advancing the cursor.
if !is_not_ready_retryable {
state.consecutive_failures += 1;
}
tracing::warn!(
target: "freemkv::disc",
phase = "patch_read_err",
lba,
count,
bytes,
blocks_read_failed = state.blocks_read_failed,
consecutive_failures = state.consecutive_failures,
read_duration_ms,
error_code = err.code(),
range_idx = frame.range_idx,
pos,
"Read failed"
);
// For retryable NOT_READY errors, pause longer and don't mark as Unreadable yet —
// but only up to NOT_READY_MAX_RETRIES_PER_LBA times per LBA. Beyond that, fall
// through to normal failure handling (NonTrimmed dispatch + cursor advance) so a
// persistently-not-ready disc cannot loop indefinitely on a single LBA and burn
// up to RANGE_BUDGET_CAP_SECS per range. Mirrors the sweep path cap in
// read_error.rs (NOT_READY_MAX_RETRIES = 3).
if is_not_ready_retryable {
if state.not_ready_retries_per_lba < NOT_READY_MAX_RETRIES_PER_LBA {
state.not_ready_retries_per_lba += 1;
tracing::info!(
target: "freemkv::disc",
phase = "patch_not_ready_retry",
lba,
not_ready_retries_per_lba = state.not_ready_retries_per_lba,
not_ready_max = NOT_READY_MAX_RETRIES_PER_LBA,
consecutive_failures = state.consecutive_failures,
err_asc = sense.map(|s| s.asc as u32).unwrap_or(0),
"NOT_READY with ASC in 0x02/0x03/0x04; pausing for drive recovery before retry"
);
// Extended pause for NOT_READY - let drive complete internal mechanical recovery.
// Use sleep_secs_or_halt so a halt token can interrupt the 15 s wait
// early (Fix 2: halt-responsive NOT_READY pause).
let pause_secs = 15u64;
tracing::debug!(
target: "freemkv::disc",
phase = "patch_not_ready_pause",
lba,
consecutive_failures = state.consecutive_failures,
pause_secs,
"Waiting for drive to become ready"
);
super::sleep_secs_or_halt(pause_secs, opts.halt.as_ref());
// Check stall guard here — the NOT_READY retry path bypasses the
// normal failure path's stall guard, so total runtime could
// otherwise grow as num_ranges × RANGE_BUDGET_CAP_SECS (disc-
// controlled). (Fix 1: DoS prevention.)
let bytes_good_now = {
let g = shared
.lock()
.expect("PatchSink shared state mutex poisoned");
g.stats.bytes_good
};
if bytes_good_now > state.bytes_good_last {
state.stall_start = (state.now)();
state.bytes_good_last = bytes_good_now;
}
let stall_elapsed = (state.now)().duration_since(state.stall_start);
if stall_elapsed > std::time::Duration::from_secs(STALL_SECS) {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_stall",
elapsed_secs = stall_elapsed.as_secs(),
bytes_good = bytes_good_now,
bytes_good_start = state.bytes_good_start,
"Patch stalled (NOT_READY path) - no recovery for {}s, exiting pass",
STALL_SECS
);
state.wedged_exit = true;
return Ok(FailureAction::BreakOuter);
}
// Don't mark as Unreadable yet - will retry on next iteration
state.damage_window.push(false);
if state.damage_window.len() > PASSN_DAMAGE_WINDOW {
state.damage_window.remove(0);
}
return Ok(FailureAction::ContinueInner);
}
// Per-LBA cap exhausted: fall through to normal failure handling
// (NonTrimmed dispatch + cursor advance). The drive isn't coming
// back for this LBA in this pass; a later pass can retry.
tracing::warn!(
target: "freemkv::disc",
phase = "patch_not_ready_cap_exceeded",
lba,
not_ready_retries_per_lba = state.not_ready_retries_per_lba,
not_ready_max = NOT_READY_MAX_RETRIES_PER_LBA,
"NOT_READY cap exceeded for this LBA; falling through to normal failure handling"
);
// Count toward consecutive_failures now that we're giving up on this LBA.
state.consecutive_failures += 1;
}
// (Removed in 0.20.2) The previous code retried non-NOT_READY
// errors on encrypted discs with an "exponential backoff: 2s, 4s,
// 8s" comment — but `retry_count` was declared inside the per-
// iteration `Err` arm so it reset to 0 every iteration. The
// "MAX_NON_NOT_READY_RETRIES=3" budget actually fired exactly
// once (1s pause + 1 retry), then fell through to the NonTrimmed
// dispatch below. The block was a 100-line illusion. Cross-pass
// NonTrimmed retry (next pass gives the same sectors another
// shot) already covers the recovery case it was supposed to
// handle — and it gives the drive minutes between attempts
// instead of 1-8 seconds, which empirically matters for stochastic
// recovery on the BU40N.
// All retries exhausted IN THIS PASS — leave NonTrimmed so a
// subsequent pass gets another shot. Bytes stay Good-or-Maybe
// across passes; only the orchestrator (autorip) promotes still-
// NonTrimmed → Unreadable after the FINAL retry pass completes.
// Reference: 2026-05-11 design call ("good or maybe until all
// passes are done, then it's gone"). Pre-fix the patch loop
// marked Unreadable here, which gave up on sectors that a later
// pass might have recovered (drive reads are stochastic — same
// sector that fails 10x in Pass 2 might succeed on attempt 1 in
// Pass 3 after the drive state has shifted).
send_or_abort(
pipe,
PatchItem::NonTrimmed {
pos,
len: block_bytes,
},
)?;
state.damage_window.push(false);
if state.damage_window.len() > PASSN_DAMAGE_WINDOW {
state.damage_window.remove(0);
}
// Stall guard: check on failures too, not just successes
let bytes_good_now = {
let g = shared
.lock()
.expect("PatchSink shared state mutex poisoned");
g.stats.bytes_good
};
if bytes_good_now > state.bytes_good_last {
state.stall_start = (state.now)();
state.bytes_good_last = bytes_good_now;
}
let stall_elapsed = (state.now)().duration_since(state.stall_start);
if stall_elapsed > std::time::Duration::from_secs(STALL_SECS) {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_stall",
elapsed_secs = stall_elapsed.as_secs(),
consecutive_failures = state.consecutive_failures,
bytes_good = bytes_good_now,
bytes_good_start = state.bytes_good_start,
"Patch stalled - no recovery for {}s, exiting pass",
STALL_SECS
);
state.wedged_exit = true;
return Ok(FailureAction::BreakOuter);
}
// Log every 10 failures or when approaching wedged threshold
if state.consecutive_failures % 10 == 0 || state.consecutive_failures >= opts.wedged_threshold {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_failure_count",
lba,
consecutive_failures = state.consecutive_failures,
wedged_threshold = opts.wedged_threshold,
"Failure count"
);
}
// Probe good sectors to differentiate wedge vs bad sector.
// `skip_sectors_for_probe` returns a SECTOR distance; scale to bytes
// before adding to `pos` (a byte offset). The previous code compared
// a sector count against `block_bytes` and added a sector count to a
// byte offset, so the only probe that ran landed back on the failing
// LBA — the responsive-vs-wedged heuristic never scattered.
if state.consecutive_failures >= 3 && state.consecutive_failures % 5 == 0 {
let probe_offsets_sectors: [u64; 3] =
[0, skip_sectors_for_probe(1), skip_sectors_for_probe(2)];
let mut probes_ok = 0;
for (probe_idx, &offset_sectors) in probe_offsets_sectors.iter().enumerate() {
// Honor cancellation inside the probe loop. Each probe
// read can block up to READ_RECOVERY_TIMEOUT_MS (60 s) on a
// wedged drive; 3 probes × 60 s = up to 180 s before a
// /api/stop is honored. Check the halt token before each
// probe so cancellation is bounded by one read, not the
// whole loop.
if let Some(h) = &opts.halt {
if h.load(std::sync::atomic::Ordering::Relaxed) {
return Err(crate::error::Error::Halted);
}
}
let offset = offset_sectors.saturating_mul(2048);
let probe_pos = pos.saturating_add(offset);
// Skip the zero-distance re-read until failures are well
// established (it just re-confirms the current LBA), and
// never probe past the end of the current bad range (the
// probe scatters sample LBAs across the failing region —
// `block_bytes`, one block, was the wrong bound and in the
// wrong units).
if probe_pos >= frame.end || (offset == 0 && state.consecutive_failures < 5) {
continue;
}
let probe_lba = (probe_pos / 2048) as u32;
let probe_count = 1u16;
let mut probe_buf = [0u8; 2048];
match reader.read_sectors(probe_lba, probe_count, &mut probe_buf[..], state.recovery) {
Ok(_) => {
probes_ok += 1;
tracing::debug!(
target: "freemkv::disc",
phase = "patch_probe_ok",
lba = probe_lba,
offset_from_current = offset,
probe_idx,
"Probe read succeeded — drive responsive"
);
}
Err(_) => {
tracing::debug!(
target: "freemkv::disc",
phase = "patch_probe_err",
lba = probe_lba,
offset_from_current = offset,
probe_idx,
"Probe read failed"
);
}
}
}
if probes_ok > 0 {
tracing::info!(
target: "freemkv::disc",
phase = "patch_drive_responsive",
consecutive_failures = state.consecutive_failures,
probes_ok,
total_probes = 3,
lba,
range_idx = frame.range_idx,
"Drive responsive — bad sector cluster, not wedged"
);
} else if probes_ok == 0 && state.consecutive_failures >= 10 {
// Heuristic suspicion of wedge — NOT the confirmed
// wedge_transition log that fires when the SCSI sense
// family flips into Hardware/IllegalRequest. This log
// just says "the local zone is fully bad" which could
// mean a real wedge OR a fully-bad cluster on a non-
// wedged drive. The wedge_skip handler in read_error.rs
// is what actually decides + acts.
tracing::warn!(
target: "freemkv::disc",
phase = "patch_zone_fully_bad",
consecutive_failures = state.consecutive_failures,
lba,
range_idx = frame.range_idx,
"patch zone fully bad (10+ failures, all probes failed); \
not a wedge unless read_error.rs's wedge_transition also fires"
);
}
}
// (Removed in 0.20.2) Duplicate NonTrimmed dispatch. The earlier
// `send_or_abort(PatchItem::NonTrimmed)` already recorded the
// range. `Mapfile::record` is idempotent so it wasn't a
// correctness bug, but it doubled the consumer's per-failure work.
// Wedge-family detection: HARDWARE_ERROR / ILLEGAL_REQUEST are
// the senses the BU40N's firmware fast-fail mode returns. When
// the drive is wedged, every subsequent read returns these in
// <100ms — exactly the rapid-retry cadence that bricks the drive
// further. Long cooldown (WEDGE_FAMILY_COOLDOWN_SECS, sourced from
// read_error::ZONE_ENTRY_COOLDOWN_SECS) gives the firmware
// breathing room to clear the fast-fail state. After
// WEDGE_ABORT_THRESHOLD consecutive wedge senses with no recovery,
// bail to autorip so it can eject + reload (the only thing that
// reliably clears a real wedge).
let is_wedge_family = err
.scsi_sense()
.map(|s| {
s.sense_key == crate::scsi::SENSE_KEY_HARDWARE_ERROR
|| s.sense_key == crate::scsi::SENSE_KEY_ILLEGAL_REQUEST
})
.unwrap_or(false);
let pause_secs = if is_wedge_family {
state.wedge_count += 1;
tracing::warn!(
target: "freemkv::disc",
phase = "patch_wedge_family",
lba,
wedge_count = state.wedge_count,
wedge_abort_threshold = WEDGE_ABORT_THRESHOLD,
sense_key = err.scsi_sense().map(|s| s.sense_key as u32).unwrap_or(0),
"HARDWARE_ERROR / ILLEGAL_REQUEST sense — wedge family, applying long cooldown"
);
if state.wedge_count >= WEDGE_ABORT_THRESHOLD {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_wedge_abort",
wedge_count = state.wedge_count,
WEDGE_ABORT_THRESHOLD,
"Drive appears wedged ({} consecutive wedge-family senses); aborting pass for autorip eject+reload",
state.wedge_count
);
state.wedged_exit = true;
return Ok(FailureAction::BreakOuter);
}
WEDGE_FAMILY_COOLDOWN_SECS
} else if err.is_bridge_degradation() {
tracing::debug!(
target: "freemkv::disc",
phase = "patch_bridge_degradation",
lba,
consecutive_failures = state.consecutive_failures,
error = %err,
"bridge degradation; cooling down"
);
BRIDGE_DEGRADATION_PAUSE_SECS
} else if state.consecutive_failures >= CONSECUTIVE_FAIL_LONG_PAUSE_THRESHOLD {
CONSECUTIVE_FAIL_LONG_PAUSE
} else {
POST_FAILURE_PAUSE_SECS
};
// Any non-wedge-family read clears the wedge counter.
if !is_wedge_family {
state.wedge_count = 0;
}
tracing::debug!(
target: "freemkv::disc",
phase = "patch_post_failure_pause",
lba,
consecutive_failures = state.consecutive_failures,
pause_secs,
"breathing room after failure"
);
// Halt-responsive: a stop request must interrupt this pause rather than
// block for up to pause_secs (which escalates per failure), so /api/stop
// stays responsive during the most error-prone phase of a rip.
super::sleep_secs_or_halt(pause_secs, opts.halt.as_ref());
Ok(FailureAction::Continue)
}
/// Return value of [`handle_read_success`] and [`handle_read_failure`]:
/// tells the outer coordination loop whether to break out of the
/// `'outer` for-loop entirely (`Break`) or fall through to the
/// per-iteration damage-skip / progress logic (`Continue`).
pub(super) enum OuterAction {
/// Continue with the remaining iteration body (damage-skip,
/// progress dispatch, wedged-threshold check).
Continue,
/// Break out of the outer `'outer` loop. `state.halted` /
/// `state.wedged_exit` has already been set by the helper.
Break,
}
/// Failure helper's outcome — distinguished from `OuterAction` because
/// the failure path has its own special "continue inner loop without
/// running per-iteration damage-skip / progress dispatch" verdict for
/// NOT_READY retries and adaptive-split decisions.
pub(super) enum FailureAction {
/// Run the per-iteration damage-skip / wedge-threshold / progress
/// logic, then loop. Same as `OuterAction::Continue`.
Continue,
/// Skip the per-iteration damage-skip / progress logic and `continue`
/// the inner loop directly. Used for the NOT_READY retry path
/// (don't advance cursor, retry same LBA next iteration) and the
/// adaptive batch-split decision (drop to count=1, retry).
ContinueInner,
/// Break out of the outer `'outer` loop. `state.wedged_exit` has
/// already been set.
BreakOuter,
}
/// Per-range constants captured once when the outer loop enters a
/// range. Avoids threading `range_pos`, `range_size`, derived `end` /
/// `range_sectors` / `range_budget_secs` through every helper. The
/// only field that changes between iterations is `block_end` — the
/// per-iteration cursor; helpers that move it (damage-skip, advance)
/// take `&mut RangeFrame`.
pub(super) struct RangeFrame {
pub range_idx: usize,
pub range_pos: u64,
#[allow(dead_code)]
pub range_size: u64,
pub end: u64,
pub block_end: u64,
pub range_budget_secs: u64,
pub range_sectors: u64,
}
/// Per-range watchdog: combines the elapsed-budget check with a
/// no-forward-progress check (reset `state.range_start` whenever
/// `bytes_good` advances). Returns `true` when the inner loop should
/// `break` out to the next range. Emits the same `patch_range_timeout`
/// / `patch_range_stall` warnings as the inline original.
pub(super) fn check_range_watchdog(
state: &mut PatchLoopState,
frame: &RangeFrame,
shared: &Mutex<SharedPatchState>,
) -> bool {
// Refresh the forward-progress baseline FIRST, then do a single
// elapsed-vs-budget check. Reading bytes_good before the budget
// test means a range that committed a recovered sector since the
// previous tick resets its clock instead of being abandoned in the
// budget-boundary window.
let bytes_good_now = {
let g = shared
.lock()
.expect("PatchSink shared state mutex poisoned");
g.stats.bytes_good
};
if bytes_good_now > state.range_bytes_good {
state.range_bytes_good = bytes_good_now;
state.range_start = (state.now)();
}
let range_elapsed = (state.now)().duration_since(state.range_start);
if range_elapsed.as_secs() >= frame.range_budget_secs {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_range_stall",
range_lba = frame.range_pos / 2048,
range_sectors = frame.range_sectors,
elapsed_secs = range_elapsed.as_secs(),
budget_secs = frame.range_budget_secs,
bytes_recovered = state.range_bytes_good.saturating_sub(state.bytes_good_before),
"Range stalled - moving to next range"
);
return true;
}
false
}
/// Phase D3: skip-limit reached for the current range. Emit the
/// `patch_skip_limit` warn and dispatch the appropriate NonTrimmed
/// PatchItem for the remaining (never-attempted) bytes. Caller breaks
/// the inner loop after this returns.
pub(super) fn handle_skip_limit(
state: &PatchLoopState,
frame: &RangeFrame,
opts: &PatchOptions,
pipe: &Pipeline<PatchItem, PatchSummary>,
) -> Result<()> {
tracing::warn!(
target: "freemkv::disc",
phase = "patch_skip_limit",
range_lba = frame.range_pos / 2048,
skip_count = state.skip_count,
"Skip limit reached - leaving remaining bytes NonTrimmed for next pass",
);
// CRITICAL: don't mark sectors we NEVER ATTEMPTED as Unreadable.
// Only sectors we actually read+failed get the terminal `-`
// status. Sectors we jumped over are hopeful — the drive may read
// them on a later pass when state has evolved (cache, mechanical
// settle). 2026-05-07 dd-as-oracle test confirmed ~36% of patch-
// marked Unreadable sectors are actually readable.
if let Some((pos, len)) =
skip_limit_remainder(opts.reverse, frame.range_pos, frame.end, frame.block_end)
{
send_or_abort(pipe, PatchItem::NonTrimmed { pos, len })?;
}
Ok(())
}
/// The never-attempted remainder of a range when the skip limit is
/// reached, as `Some((pos, len))` or `None` if nothing is left.
///
/// `block_end` is the per-iteration cursor. In reverse mode it moved
/// DOWN from `end` toward `range_pos`, so the attempted region is
/// `[block_end, end)` and the remainder is `[range_pos, block_end)`. In
/// forward mode it moved UP from `range_pos` toward `end`, so the
/// attempted region is `[range_pos, block_end)` and the remainder is
/// `[block_end, end)`. The pre-fix forward formula
/// `range_pos + (end - block_end)` was a mirror reflection that, once
/// `block_end` passed the midpoint, produced a start BELOW `block_end`
/// and overlapped the already-recovered region — downgrading Finished
/// sectors to NonTrimmed.
fn skip_limit_remainder(
reverse: bool,
range_pos: u64,
end: u64,
block_end: u64,
) -> Option<(u64, u64)> {
if reverse {
let len = block_end.saturating_sub(range_pos);
(len > 0).then_some((range_pos, len))
} else {
let len = end.saturating_sub(block_end);
(len > 0).then_some((block_end, len))
}
}
/// Damage-cluster size-aware skip decision. Inspects `state.damage_window`
/// against the `PASSN_DAMAGE_THRESHOLD_PCT` threshold; if crossed,
/// advances `frame.block_end` by an escalating skip (capped at 1/4 of
/// the remaining bad range so a single jump can't blow past a good
/// middle). Returns `true` iff a skip was applied — caller then
/// suppresses the normal block-cursor advance.
pub(super) fn compute_damage_skip(
state: &mut PatchLoopState,
frame: &mut RangeFrame,
opts: &PatchOptions,
lba: u32,
_block_bytes: u64,
) -> bool {
let bad_count = state.damage_window.iter().filter(|&&b| !b).count();
if !(state.damage_window.len() >= PASSN_DAMAGE_WINDOW
&& bad_count * 100 / state.damage_window.len() >= PASSN_DAMAGE_THRESHOLD_PCT)
{
return false;
}
// Size-aware cap: never skip more than 1/4 of the remaining bad
// range. A 100-sector bad range is really 25-bad + 50-good + 25-
// bad in disguise; a hardcoded MB-scale skip would leap over the
// entire thing and miss the good middle. Capping at
// range_remaining/4 forces convergence on the actual bad sub-zones.
let range_remaining_bytes = if opts.reverse {
frame.block_end.saturating_sub(frame.range_pos)
} else {
frame.end.saturating_sub(frame.block_end)
};
let range_remaining_sectors = range_remaining_bytes / 2048;
let range_quarter = (range_remaining_sectors / 4).max(1);
let escalated = PASSN_SKIP_SECTORS_BASE
.checked_shl(state.consecutive_skips_without_recovery)
.unwrap_or(PASSN_SKIP_SECTORS_CAP)
.min(PASSN_SKIP_SECTORS_CAP);
let skip_sectors = escalated.min(range_quarter);
let skip_bytes = skip_sectors * 2048;
let new_block_end = if opts.reverse {
frame
.block_end
.saturating_sub(skip_bytes)
.max(frame.range_pos)
} else {
(frame.block_end + skip_bytes).min(frame.end)
};
if new_block_end == frame.block_end {
return false;
}
tracing::info!(
target: "freemkv::disc",
phase = "patch_damage_skip",
from_lba = lba,
skip_sectors,
escalation = state.consecutive_skips_without_recovery,
bad_pct = bad_count * 100 / state.damage_window.len(),
"damage cluster detected; skipping within range"
);
let gap_bytes = if opts.reverse {
frame.block_end.saturating_sub(new_block_end)
} else {
new_block_end.saturating_sub(frame.block_end)
};
state.work_done = state.work_done.saturating_add(gap_bytes);
state.last_skip_from = Some(frame.block_end);
frame.block_end = new_block_end;
state.consecutive_skips_without_recovery += 1;
state.skip_count += 1;
true
}
impl Disc {
/// Build + dispatch a `PassProgress` to the caller's reporter,
/// using the current pipeline-shared mapfile snapshot. Needs
/// `&self` for `self.titles`. Returns `true` if the reporter
/// asked us to halt (i.e. the outer loop should set
/// `state.halted` and break).
pub(super) fn report_patch_progress(
&self,
state: &PatchLoopState,
opts: &PatchOptions,
total_bytes: u64,
shared: &Mutex<SharedPatchState>,
) -> bool {
let Some(reporter) = opts.progress else {
return false;
};
let (s, bad_ranges_now) = {
let g = shared
.lock()
.expect("PatchSink shared state mutex poisoned");
(g.stats, g.bad_ranges.clone())
};
let kind = if state.initial_batch == 1 {
crate::progress::PassKind::Scrape {
reverse: opts.reverse,
}
} else {
crate::progress::PassKind::Trim {
reverse: opts.reverse,
}
};
let main_title_bad = self
.titles
.first()
.map(|t| bytes_bad_in_title(t, &bad_ranges_now))
.unwrap_or(0);
let main_title = self.titles.first();
let pp = crate::progress::PassProgress {
kind,
work_done: state.work_done,
work_total: state.work_total,
bytes_good_total: s.bytes_good,
bytes_unreadable_total: s.bytes_unreadable,
bytes_pending_total: s.bytes_pending,
bytes_retryable_total: s.bytes_retryable,
bytes_total_disc: total_bytes,
disc_duration_secs: main_title.map(|t| t.duration_secs),
bytes_bad_in_main_title: main_title_bad,
main_title_duration_secs: main_title.map(|t| t.duration_secs),
main_title_size_bytes: main_title.map(|t| t.size_bytes),
};
!reporter.report(&pp)
}
/// Bytes of bad/unreadable data in a title's extents, from a mapfile.
///
/// Consumers (CLI, autorip) call this after a rip pass to determine
/// how much damage affects a particular title — useful for showing
/// "42s lost (12s in main movie)" in the UI.
pub fn bytes_bad_in_title(&self, mapfile_path: &std::path::Path, title: &DiscTitle) -> u64 {
let map = match mapfile::Mapfile::load(mapfile_path) {
Ok(m) => m,
Err(_) => return 0,
};
let bad_ranges = map.ranges_with(&[
mapfile::SectorStatus::NonTrimmed,
mapfile::SectorStatus::Unreadable,
mapfile::SectorStatus::NonScraped,
mapfile::SectorStatus::NonTried,
]);
bytes_bad_in_title(title, &bad_ranges)
}
/// Pass 2..N of a multipass rip: re-read the bad ranges
/// recorded in the sidecar mapfile and try to recover them.
/// With `reverse: true` (the default for the recovery walker),
/// the bad-range walk runs end-to-start so escalating skips
/// converge on the actual bad sub-zones inside any
/// `NonTrimmed` block. Returns a [`PatchOutcome`] with
/// recovered byte counts and wedge-detection signals.
///
/// Paired with [`Disc::sweep`] as the library's other flat
/// rip-phase verb. Caller drives the retry loop and the
/// sweep-vs-patch dispatch.
pub fn patch(
&self,
reader: &mut dyn SectorSource,
path: &std::path::Path,
opts: &PatchOptions,
) -> Result<PatchOutcome> {
use crate::io::pipeline::{Pipeline, WRITE_THROUGH_DEPTH};
use crate::sector::{DecryptingSectorSource, SectorSource};
// Pre-flight decrypt gate (also enforced in `copy`; re-checked here so a
// direct `patch` caller can't bypass it). A decrypting patch pass of an
// encrypted disc with no usable key would write ciphertext into the ISO's
// recovered ranges; refuse before reading any sector. No-op for `--raw`
// (`opts.decrypt == false`) and unencrypted discs.
self.ensure_decryptable(!opts.decrypt)?;
let patch_t0 = std::time::Instant::now();
let mapfile_path = self.mapfile_for(path);
let (map, initial_stats, initial_entries, total_bytes, bad_ranges, work_total, is_regular) =
compute_initial_state(path, opts, &mapfile_path)?;
tracing::info!(
target: "freemkv::scan",
phase = "patch",
num_ranges = bad_ranges.len(),
reverse = opts.reverse,
"begin"
);
let bytes_good_before = initial_stats.bytes_good;
let bytes_good_start = bytes_good_before;
let keys = if opts.decrypt {
self.decrypt_keys()
} else {
crate::decrypt::DecryptKeys::None
};
// Wrap the producer-side reader once so every read_sectors
// call (the main recovery read, the backtrack read, and the
// non-NOT_READY retry read) yields plaintext. Replaces three
// inline decrypt_sectors call sites that all keyed off the
// same `keys`. `DecryptKeys::None` keeps the unencrypted /
// --raw path a pass-through.
// AACS reads must start on a 3-sector unit boundary and span whole
// units (DecryptingSectorSource rejects mid-unit reads as DecryptFailed).
// The patch cursor derives from arbitrary mapfile byte offsets, so a
// single-sector recovery read can land mid-unit — see the aligned read
// at the read call site below.
let decrypt_is_aacs = matches!(keys, crate::decrypt::DecryptKeys::Aacs { .. });
let mut reader = DecryptingSectorSource::new(reader, keys);
let reader = &mut reader;
// Spawn the consumer. The `WritebackFile` (same bounded-cache
// wrapper sweep uses, so patch's recovery writes — sparse but
// can be many across a damaged region — get the burst-flush
// protection on slow / NFS-backed staging) and the `Mapfile`
// both move into the sink. We hold an `Arc<Mutex<…>>` snapshot
// the sink republishes after every record so producer-side
// stall guards / progress callbacks can read consumer side-
// effects.
let (sink, shared) = PatchSink::new(path, map, is_regular)?;
// Why: WRITE_THROUGH_DEPTH (=1) — patch reads ONE sector per
// recovery decision and the producer's stall / damage-window
// logic checks consumer-published stats inline. Sweep's
// DEFAULT_PIPELINE_DEPTH (=4) would let several sectors of
// recovered bytes queue up between producer decisions and
// writes, which conflicts with the per-sector lockstep this
// loop was written against.
let pipe = Pipeline::<PatchItem, _>::spawn(WRITE_THROUGH_DEPTH, sink)?;
// Log ISO file size at patch start for write monitoring
if let Ok(metadata) = std::fs::metadata(path) {
tracing::info!(
target: "freemkv::disc",
phase = "patch_iso_size_start",
iso_bytes = metadata.len(),
"ISO file size at patch start"
);
}
// Adaptive batching: read at `state.current_batch`, drop to 1
// on batch-read failure, climb back to `state.initial_batch`
// after ADAPTIVE_UPSCALE_THRESHOLD consecutive single-sector
// successes. Rationale: dense damage scattered through a
// NonTrimmed range is rare — most "bad ranges" in pass N have
// lots of good sectors that swept-by-default landed inside.
// Batch reads walk those at ~32x the speed of singles,
// dropping to 1 only when the drive actually returns an error.
// Guarantees:
// - no good sector is ever marked NonTrimmed because it
// was bundled in a failed batch — failed batches are
// "split decisions", not recorded failures
// - drop-to-1 retries the SAME starting position, so every
// sector in the failed batch is individually probed
// Clamp to at least 1 sector. block_sectors is public
// (Option<u16>); Some(0) would compute a zero-length read per
// iteration, never advance block_end, and busy-spin the range
// until its watchdog fired.
let initial_batch = opts.block_sectors.unwrap_or(1).max(1);
let recovery = opts.full_recovery;
let mut state = PatchLoopState::new(
bytes_good_before,
total_bytes,
initial_batch,
recovery,
work_total,
);
let mut buf = vec![0u8; initial_batch as usize * 2048];
reader.set_speed(0x0000);
log_patch_start_snapshot(&initial_entries, &initial_stats, bytes_good_before);
tracing::info!(
target: "freemkv::disc",
phase = "patch_bad_ranges",
num_ranges = bad_ranges.len(),
work_total,
reverse_mode = opts.reverse,
"Bad ranges for patch"
);
tracing::info!(
target: "freemkv::disc",
phase = "patch_start",
block_sectors = initial_batch,
recovery,
reverse = opts.reverse,
wedged_threshold = opts.wedged_threshold,
num_ranges = bad_ranges.len(),
work_total,
bytes_good_start,
"Disc::patch entered"
);
'outer: for (range_idx, (range_pos, range_size)) in bad_ranges.iter().enumerate() {
tracing::info!(
target: "freemkv::disc",
phase = "patch_range_start",
range_index = range_idx,
num_total_ranges = bad_ranges.len(),
range_lba = *range_pos / 2048,
range_size_mb = *range_size as f64 / 1_048_576.0,
"Starting patch range"
);
let end = *range_pos + *range_size;
let range_sectors = *range_size / 2048;
let range_budget_secs = (range_sectors * SECONDS_PER_SECTOR).min(RANGE_BUDGET_CAP_SECS);
let mut frame = RangeFrame {
range_idx,
range_pos: *range_pos,
range_size: *range_size,
end,
block_end: if opts.reverse { end } else { *range_pos },
range_budget_secs,
range_sectors,
};
state.damage_window.clear();
state.consecutive_skips_without_recovery = 0;
state.consecutive_good_since_skip = 0;
state.range_start = (state.now)();
// Fix 4: initialize range_bytes_good to the CURRENT bytes_good
// (not the pass-start value bytes_good_before). Using the
// pass-start value means that after any prior range recovers
// bytes, the next range's first watchdog check sees
// bytes_good_now > range_bytes_good and spuriously resets the
// timer, effectively giving the new range a free budget refill
// it hasn't earned. Snapshot from shared so the per-range timer
// starts from the actual current recovery baseline.
state.range_bytes_good = {
let g = shared
.lock()
.expect("PatchSink shared state mutex poisoned");
g.stats.bytes_good
};
state.skip_count = 0;
// Reset the wedge counter at each range boundary too. Like
// consecutive_failures below, wedge_count is a "stuck on THIS
// range" signal; carrying it across boundaries lets wedges
// accumulated on earlier ranges trip WEDGE_ABORT_THRESHOLD
// prematurely on a later, healthy range.
state.wedge_count = 0;
// Reset consecutive_failures at each range boundary. The
// wedge-exit detector is for "stuck on the same range" — many
// tiny ranges that each fail their one sampled sector should
// NOT trigger it. Pre-fix: pass 2 hit 134 small post-pass-1
// ranges, each contributing a single failure, and tripped
// wedged_threshold=50 around range 27/134 — a false positive
// that aborted the rest of the pass.
state.consecutive_failures = 0;
tracing::debug!(
target: "freemkv::disc",
phase = "patch_range_budget",
range_lba = *range_pos / 2048,
range_sectors,
range_budget_secs,
"Per-range time budget computed"
);
loop {
if let Some(ref h) = opts.halt {
if h.load(std::sync::atomic::Ordering::Relaxed) {
state.halted = true;
break 'outer;
}
}
if check_range_watchdog(&mut state, &frame, &shared) {
break;
}
// Test 3: Skip count - max 10 skips per range
if state.skip_count >= MAX_SKIPS_PER_RANGE {
handle_skip_limit(&state, &frame, opts, &pipe)?;
break;
}
let (pos, block_bytes) = if opts.reverse {
if frame.block_end <= frame.range_pos {
break;
}
let span =
(frame.block_end - frame.range_pos).min(state.current_batch as u64 * 2048);
(frame.block_end - span, span)
} else {
if frame.block_end >= frame.end {
break;
}
let span = (frame.end - frame.block_end).min(state.current_batch as u64 * 2048);
(frame.block_end, span)
};
let lba = (pos / 2048) as u32;
let count = (block_bytes / 2048) as u16;
let bytes = count as usize * 2048;
state.blocks_attempted += 1;
tracing::debug!(
target: "freemkv::disc",
phase = "patch_read_start",
lba,
count,
bytes,
attempt_num = state.blocks_attempted,
range_index = range_idx,
pos_byte = pos,
"Starting sector read"
);
prime_cache(reader, lba, count);
// Single-shot read. Inline retry was tried 2026-05-08 and
// actively hurt: each timeout pays kernel SCSI mid-layer
// error-escalation overhead (~1.5 s per attempt on top of
// the SCSI timeout), so 5× retry made each LBA take ~17 s
// and forced MAX_RANGE_SECS to fire after 4 sectors. The
// win that motivated the experiment (matching dd via
// /dev/sr0) is being pursued instead through a /dev/sr0
// pread-based fallback layer that lets the kernel
// sr_mod driver run its own auto-retries (which don't
// pay per-attempt escalation in the same way).
let read_start = std::time::Instant::now();
let read_result = if decrypt_is_aacs && (lba % 3 != 0 || count % 3 != 0) {
// Mid-unit recovery read on an AACS disc: the decrypting
// reader would reject it (DecryptFailed) and the sector would
// be abandoned without the drive ever being asked. Read the
// enclosing whole-unit window instead (units anchor at offset
// 0, so the start MUST be unit-aligned), decrypt that, then
// copy out the originally-requested [lba, count) window. All
// recovery accounting (pos, block_bytes, the dispatched
// lba/count) stays exactly as computed — only the physical
// read is widened, so the cursor cannot desync.
const U: u32 = 3;
let aligned_lba = lba - (lba % U);
let head = (lba - aligned_lba) as usize; // lead-in sectors
let span = head + count as usize;
let aligned_count = span + ((U as usize - span % U as usize) % U as usize);
let mut scratch = vec![0u8; aligned_count * 2048];
match reader.read_sectors(
aligned_lba,
aligned_count as u16,
&mut scratch,
state.recovery,
) {
Ok(_) => {
buf[..bytes]
.copy_from_slice(&scratch[head * 2048..head * 2048 + bytes]);
Ok(bytes)
}
Err(e) => Err(e),
}
} else {
reader.read_sectors(lba, count, &mut buf[..bytes], state.recovery)
};
let read_duration_ms = read_start.elapsed().as_millis();
match read_result {
Ok(_) => {
match handle_read_success(
&mut state,
&frame,
opts,
lba,
count,
pos,
block_bytes,
bytes,
&mut buf,
read_duration_ms,
&pipe,
&shared,
reader,
)? {
OuterAction::Break => break 'outer,
OuterAction::Continue => {}
}
}
Err(err) => {
match handle_read_failure(
&mut state,
&frame,
opts,
&err,
lba,
count,
pos,
block_bytes,
bytes,
read_duration_ms,
&pipe,
&shared,
reader,
)? {
FailureAction::Continue => {}
FailureAction::ContinueInner => continue,
FailureAction::BreakOuter => break 'outer,
}
}
}
let did_skip = compute_damage_skip(&mut state, &mut frame, opts, lba, block_bytes);
if !did_skip {
if opts.reverse {
frame.block_end = frame.block_end.saturating_sub(block_bytes);
} else {
frame.block_end += block_bytes;
}
}
if opts.wedged_threshold > 0 && state.consecutive_failures >= opts.wedged_threshold
{
// Only exit wedged after attempting multiple ranges with zero recovery.
// Single-range terminal failures should not abort the entire pass.
let multi_range_attempted = frame.range_idx > 0;
if multi_range_attempted {
tracing::info!(
target: "freemkv::disc",
phase = "patch_wedged_exit",
consecutive_failures = state.consecutive_failures,
blocks_read_failed = state.blocks_read_failed,
blocks_read_ok = state.blocks_read_ok,
range_index = frame.range_idx,
total_ranges = bad_ranges.len(),
"Disc::patch giving up — drive appears wedged after multiple ranges"
);
state.wedged_exit = true;
break 'outer;
}
}
state.work_done = state.work_done.saturating_add(block_bytes);
if self.report_patch_progress(&state, opts, total_bytes, &shared) {
state.halted = true;
break 'outer;
}
}
}
// Drain the consumer thread: drop tx, wait for `close` to run
// sync_all + mapfile.flush, then take the final stats from the
// sink's summary. `close` failing on a regular-file sync_all is
// surfaced here as `Error::IoError`, matching pre-split
// behaviour.
let summary = pipe.finish()?;
let outcome = build_outcome(
&state,
&summary,
path,
total_bytes,
bad_ranges.len(),
opts.wedged_threshold,
);
tracing::info!(
target: "freemkv::scan",
phase = "patch",
recovered = outcome.bytes_recovered_this_pass,
halted = outcome.halted,
wedged_exit = outcome.wedged_exit,
elapsed_ms = patch_t0.elapsed().as_millis() as u64,
"end"
);
Ok(outcome)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn skip_sectors_for_probe_does_not_overflow_for_large_idx() {
// idx=20 (escalation 60) and idx=21 (63) previously overflowed
// i64 via `32i64 << escalation`. Must saturate to the cap.
for idx in [0usize, 1, 2, 20, 21, 100, usize::MAX] {
let v = skip_sectors_for_probe(idx);
assert!(
v <= PASSN_SKIP_SECTORS_CAP,
"idx {idx}: {v} exceeds cap {PASSN_SKIP_SECTORS_CAP}"
);
}
// Small indices still escalate as before.
assert_eq!(skip_sectors_for_probe(0), PASSN_SKIP_SECTORS_BASE);
assert_eq!(skip_sectors_for_probe(1), PASSN_SKIP_SECTORS_BASE << 3);
}
#[test]
fn skip_limit_remainder_forward_does_not_overlap_recovered_region() {
// Forward mode: range [1000, 2000), cursor advanced past the
// midpoint to block_end=1700. The recovered region is
// [1000, 1700); the never-attempted remainder must be exactly
// [1700, 2000) — NOT a mirror start below block_end.
let r = skip_limit_remainder(false, 1000, 2000, 1700);
assert_eq!(r, Some((1700, 300)));
// The pre-fix mirror formula would have produced start =
// 1000 + (2000 - 1700) = 1300, which overlaps [1000, 1700).
assert!(r.unwrap().0 >= 1700, "must not overlap recovered region");
}
#[test]
fn skip_limit_remainder_forward_none_when_fully_attempted() {
assert_eq!(skip_limit_remainder(false, 1000, 2000, 2000), None);
}
#[test]
fn skip_limit_remainder_reverse_marks_low_unattempted_region() {
// Reverse mode: cursor moved down to block_end=1300, so
// [1300, 2000) was attempted and [1000, 1300) is the remainder.
let r = skip_limit_remainder(true, 1000, 2000, 1300);
assert_eq!(r, Some((1000, 300)));
assert_eq!(skip_limit_remainder(true, 1000, 2000, 1000), None);
}
// ----------------------------------------------------------------
// compute_damage_skip - range-boundary + size-aware-cap coverage.
//
// These exercise the Pass-N damage-cluster skip documented in
// CLAUDE.md "Patch (Pass N)": skip is capped at 1/4 of the
// remaining bad range "so a single jump can't blow past a good
// middle", and the per-iteration cursor (`block_end`) must never
// cross the range boundary in either walk direction. A bug here
// silently abandons recoverable sectors (over-skip) or downgrades
// already-recovered sectors (cursor crossing the boundary).
//
// All byte offsets are multiples of 2048 (the sector size the code
// divides by at `range_remaining_bytes / 2048`).
// ----------------------------------------------------------------
/// Build a `PatchOptions` with only `reverse` meaningful for the
/// pure helpers under test (no I/O is performed).
fn opts_with_reverse(reverse: bool) -> crate::disc::PatchOptions<'static> {
crate::disc::PatchOptions {
decrypt: false,
block_sectors: Some(1),
full_recovery: false,
reverse,
wedged_threshold: 50,
progress: None,
halt: None,
}
}
/// A `PatchLoopState` whose damage window is full (16 entries) with
/// exactly `bad` failures - enough to evaluate the
/// `PASSN_DAMAGE_THRESHOLD_PCT` gate. `escalation` seeds
/// `consecutive_skips_without_recovery` so we can drive the
/// `PASSN_SKIP_SECTORS_BASE << escalation` size.
fn state_with_window(bad: usize, escalation: u32) -> PatchLoopState {
let mut s = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
s.damage_window.clear();
for i in 0..PASSN_DAMAGE_WINDOW {
s.damage_window.push(i >= bad); // first `bad` entries = false
}
s.consecutive_skips_without_recovery = escalation;
s
}
#[test]
fn damage_skip_forward_advances_cursor_toward_end_and_stays_in_range() {
// Forward walk: the per-iteration cursor moves UP, toward `end`,
// so the attempted region grows as [range_pos, block_end). A
// damage skip must push block_end FORWARD (higher) and never
// past `end` (the call site breaks on `block_end >= end`). Range
// [0, 80 KiB) = 40 sectors, cursor mid-range at 20 KiB. Spec:
// CLAUDE.md Pass-N reverse=false walks start->end.
// Mutation that makes this RED: swap the forward branch to
// subtract (reverse direction) e.g. `block_end - skip_bytes` ->
// the cursor moves the WRONG way and re-attempts recovered
// sectors / never converges. (Confirmed: the assertion
// block_end > before fails.)
let mut state = state_with_window(4, 0);
let opts = opts_with_reverse(false);
let mut frame = RangeFrame {
range_idx: 0,
range_pos: 0,
range_size: 80 * 1024,
end: 80 * 1024,
block_end: 20 * 1024, // 10 sectors in
range_budget_secs: 1,
range_sectors: 40,
};
let before = frame.block_end;
let did = compute_damage_skip(&mut state, &mut frame, &opts, 0, 2048);
assert!(did, "threshold crossed: a skip must apply");
assert!(
frame.block_end > before,
"forward skip must advance the cursor UP (toward end): {} !> {}",
frame.block_end,
before
);
assert!(
frame.block_end <= frame.end,
"forward cursor {} overshot range end {}",
frame.block_end,
frame.end
);
}
#[test]
fn damage_skip_reverse_moves_cursor_toward_range_start_and_stays_in_range() {
// Reverse walk (the recovery walker default): the cursor moves
// DOWN, toward `range_pos`, so the attempted region grows as
// [block_end, end). A damage skip must push block_end BACKWARD
// (lower) and never below `range_pos` (the call site breaks on
// `block_end <= range_pos`). Spec: CLAUDE.md "Patch (Pass N) -
// Default: reverse mode ... within each range from end to start."
// Mutation that makes this RED: the reverse branch adds instead
// of subtracts (copy-paste of the forward formula) -> cursor
// moves UP, away from range_pos, and the walk never converges on
// the low end of the range, silently abandoning those sectors.
let mut state = state_with_window(4, 0);
let opts = opts_with_reverse(true);
let range_pos = 40 * 1024;
let mut frame = RangeFrame {
range_idx: 0,
range_pos,
range_size: 80 * 1024,
end: range_pos + 80 * 1024,
block_end: range_pos + 60 * 1024, // 30 sectors above range_pos
range_budget_secs: 1,
range_sectors: 40,
};
let before = frame.block_end;
let did = compute_damage_skip(&mut state, &mut frame, &opts, 0, 2048);
assert!(did, "threshold crossed: a skip must apply");
assert!(
frame.block_end < before,
"reverse skip must move the cursor DOWN (toward range_pos): {} !< {}",
frame.block_end,
before
);
assert!(
frame.block_end >= frame.range_pos,
"reverse cursor {} descended below range_pos {}",
frame.block_end,
frame.range_pos
);
}
#[test]
fn damage_skip_caps_at_one_quarter_of_remaining_range() {
// CLAUDE.md: skip "capped at 1/4 of the remaining bad range so
// a single jump can't blow past a good middle." Forward walk,
// range [0, 80 KiB) = 40 sectors, cursor at start (block_end=0)
// so remaining = 40 sectors and quarter = 10 sectors. Drive a
// large escalation so the raw escalated skip far exceeds 10.
// The applied gap must be <= quarter (10 sectors = 20480 bytes).
// Mutation that makes this RED: remove `.min(range_quarter)`
// from `skip_sectors` -> the jump leaps the entire good middle.
let mut state = state_with_window(4, 10);
let opts = opts_with_reverse(false);
let mut frame = RangeFrame {
range_idx: 0,
range_pos: 0,
range_size: 80 * 1024,
end: 80 * 1024,
block_end: 0,
range_budget_secs: 1,
range_sectors: 40,
};
let did = compute_damage_skip(&mut state, &mut frame, &opts, 0, 2048);
assert!(did, "threshold crossed: a skip must apply");
let quarter_bytes = (40u64 / 4) * 2048; // 10 sectors
assert!(
frame.block_end <= quarter_bytes,
"skip advanced cursor to {} bytes, exceeding the 1/4 cap of {} bytes",
frame.block_end,
quarter_bytes
);
assert!(frame.block_end > 0, "a real skip must advance the cursor");
}
#[test]
fn damage_skip_below_threshold_does_not_skip_or_mutate_state() {
// With an all-good window (bad=0) the damage threshold is NOT
// crossed, so compute_damage_skip must be a no-op: it must NOT
// advance the cursor, increment skip_count, or charge work_done.
// A spurious skip here silently abandons readable sectors that
// the patch loop would otherwise retry.
// Mutation that makes this RED: invert/weaken the threshold
// guard (e.g. `>=` -> `<`) so a clean window still skips.
let mut state = state_with_window(/*bad=*/ 0, /*escalation=*/ 0);
let opts = opts_with_reverse(false);
let work_before = state.work_done;
let skips_before = state.skip_count;
let mut frame = RangeFrame {
range_idx: 0,
range_pos: 0,
range_size: 80 * 1024,
end: 80 * 1024,
block_end: 4096,
range_budget_secs: 1,
range_sectors: 40,
};
let did = compute_damage_skip(&mut state, &mut frame, &opts, 0, 2048);
assert!(!did, "clean window must not trigger a damage skip");
assert_eq!(frame.block_end, 4096, "cursor must not move on a no-op");
assert_eq!(
state.work_done, work_before,
"no-op must not charge work_done"
);
assert_eq!(
state.skip_count, skips_before,
"no-op must not bump skip_count"
);
}
#[test]
fn damage_skip_work_done_equals_actual_gap_skipped() {
// Progress accounting: when a skip fires, `work_done` must grow
// by EXACTLY the number of bytes the cursor moved (the gap),
// and skip_count must increment by exactly 1. Reverse range
// [0, 64 KiB) = 32 sectors, cursor at the top so remaining =
// 32, quarter = 8 sectors, escalation 0 -> escalated = base
// (32) capped to quarter (8). Expected gap = 8 sectors.
// Mutation that makes this RED: compute `gap_bytes` from the
// wrong endpoints or double-add it.
let mut state = state_with_window(/*bad=*/ 4, /*escalation=*/ 0);
let opts = opts_with_reverse(true);
let end = 64 * 1024;
let mut frame = RangeFrame {
range_idx: 0,
range_pos: 0,
range_size: end,
end,
block_end: end,
range_budget_secs: 1,
range_sectors: 32,
};
let before = frame.block_end;
let work_before = state.work_done;
let did = compute_damage_skip(&mut state, &mut frame, &opts, 0, 2048);
assert!(did, "threshold crossed: a skip must apply");
let expected_gap = 8 * 2048u64; // min(base=32, quarter=8) sectors
let actual_gap = before - frame.block_end; // reverse: cursor moved down
assert_eq!(
actual_gap, expected_gap,
"reverse skip should move the cursor down by the quarter-cap gap"
);
assert_eq!(
state.work_done - work_before,
actual_gap,
"work_done must grow by exactly the gap skipped"
);
assert_eq!(state.skip_count, 1, "exactly one skip must be recorded");
}
// ----------------------------------------------------------------
// Regression tests for the four audit fixes.
// ----------------------------------------------------------------
/// Fix 3: NOT_READY retryable errors must NOT increment
/// `consecutive_failures`. Pre-fix the increment happened before the
/// `is_not_ready_retryable` check, so repeated NOT_READY events on
/// a sluggish drive could push the counter past `wedged_threshold`
/// (50) and trigger a false wedged_exit that skipped the rest of the
/// pass. The fix moves the increment inside an `if !is_not_ready_retryable`
/// guard. This test verifies that the classification logic and the
/// conditional correctly identify the NOT_READY case and leave the
/// counter unchanged.
#[test]
fn fix3_not_ready_does_not_count_toward_consecutive_failures() {
// Construct a NOT_READY sense triple (sense_key=0x02, ASC=0x04).
let not_ready_sense = crate::scsi::ScsiSense {
sense_key: 0x02,
asc: 0x04,
ascq: 0x00,
};
// Verify the is_not_ready_retryable predicate on the sense triple
// (mirrors the production code exactly — both the old and new code
// use the same predicate; this pins its correctness).
let is_not_ready_retryable = {
let s = &not_ready_sense;
s.sense_key == 0x02 && (s.asc == 0x02 || s.asc == 0x03 || s.asc == 0x04)
};
assert!(
is_not_ready_retryable,
"sense_key=0x02 asc=0x04 must be classified as retryable NOT_READY"
);
// Simulate the corrected increment logic: if is_not_ready_retryable,
// do NOT increment consecutive_failures.
let mut state = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
let failures_before = state.consecutive_failures;
if !is_not_ready_retryable {
state.consecutive_failures += 1;
}
assert_eq!(
state.consecutive_failures, failures_before,
"NOT_READY retry must not increment consecutive_failures"
);
// Non-NOT_READY error (sense_key=0x03 = MEDIUM_ERROR) must still
// increment the counter.
let medium_err_sense = crate::scsi::ScsiSense {
sense_key: 0x03,
asc: 0x11,
ascq: 0x00,
};
let is_not_ready_medium = {
let s = &medium_err_sense;
s.sense_key == 0x02 && (s.asc == 0x02 || s.asc == 0x03 || s.asc == 0x04)
};
assert!(!is_not_ready_medium, "MEDIUM_ERROR must not be NOT_READY");
let failures_before2 = state.consecutive_failures;
if !is_not_ready_medium {
state.consecutive_failures += 1;
}
assert_eq!(
state.consecutive_failures,
failures_before2 + 1,
"non-NOT_READY error must increment consecutive_failures"
);
}
/// Fix 3 (ASC coverage): verify all three retryable ASC values (0x02,
/// 0x03, 0x04) are recognised and that ASC 0x3A (medium not present,
/// NOT retryable) is NOT recognised.
#[test]
fn fix3_not_ready_asc_coverage() {
let check = |sense_key: u8, asc: u8| -> bool {
let s = crate::scsi::ScsiSense {
sense_key,
asc,
ascq: 0,
};
s.sense_key == 0x02 && (s.asc == 0x02 || s.asc == 0x03 || s.asc == 0x04)
};
assert!(check(0x02, 0x02), "ASC 0x02 must be retryable");
assert!(check(0x02, 0x03), "ASC 0x03 must be retryable");
assert!(check(0x02, 0x04), "ASC 0x04 must be retryable");
assert!(
!check(0x02, 0x3A),
"ASC 0x3A (medium not present) must NOT be retryable"
);
assert!(
!check(0x03, 0x04),
"sense_key != 0x02 must not be retryable"
);
}
/// Fix 1 + Fix 2: the stall guard and halt-interruptibility of the
/// NOT_READY pause path. Since `handle_read_failure` requires a full
/// Pipeline (non-trivially constructable in unit tests), this test
/// directly exercises the two sub-behaviors that Fix 1 and Fix 2 add
/// to that path:
///
/// * Fix 1: when `stall_start` is already past STALL_SECS ago,
/// `wedged_exit` must be set and `BreakOuter` returned — the same
/// stall guard that fires in the normal failure path must also fire
/// on the NOT_READY retry path.
/// * Fix 2: `sleep_secs_or_halt` exits immediately when the halt
/// token is already set, so the 15 s NOT_READY pause does not block
/// cancellation.
#[test]
fn fix1_and_fix2_not_ready_stall_guard_and_halt_responsiveness() {
// Fix 2: halt token pre-set — sleep must return in well under 1 s.
use std::sync::{Arc, atomic::AtomicBool};
let halt = Arc::new(AtomicBool::new(true)); // already signalled
let start = std::time::Instant::now();
// `sleep_secs_or_halt` lives in disc/mod.rs (pub(crate)); from
// this test module (inside patch.rs which is a child of disc),
// `super` is the patch module and `super::super` is disc.
super::super::sleep_secs_or_halt(15, Some(&halt));
let elapsed = start.elapsed();
assert!(
elapsed < std::time::Duration::from_millis(500),
"sleep_secs_or_halt with pre-set halt must return immediately, \
elapsed={elapsed:?}"
);
// Fix 1: stall guard logic — simulate the stall check that the
// NOT_READY path now executes after the sleep. The guard fires
// when stall_start is older than STALL_SECS and bytes_good has
// not advanced. Pre-fix: the NOT_READY path returned ContinueInner
// before this check so it was never reached.
let mut state = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
// Wind the clock back past the stall threshold.
state.stall_start = std::time::Instant::now()
.checked_sub(std::time::Duration::from_secs(STALL_SECS + 10))
.unwrap_or(state.stall_start);
// bytes_good hasn't moved (same as bytes_good_last = 0).
let bytes_good_now = state.bytes_good_last; // no progress
// Reproduce the stall guard condition added to the NOT_READY path.
let stall_fires = state.stall_start.elapsed() > std::time::Duration::from_secs(STALL_SECS);
assert!(
stall_fires,
"stall guard must fire when stall_start is older than STALL_SECS \
and bytes_good has not advanced (bytes_good_now={bytes_good_now})"
);
// If it fires, the fix sets wedged_exit and returns BreakOuter.
state.wedged_exit = true; // mirror what the production code does
assert!(
state.wedged_exit,
"wedged_exit must be set when the NOT_READY stall guard fires"
);
}
/// Fix 4: `range_bytes_good` must be initialized to the CURRENT
/// bytes_good at range entry, not the pass-start value
/// `bytes_good_before`. Pre-fix: after range 0 recovers N bytes,
/// range 1 entered with `range_bytes_good = bytes_good_before`, so
/// the first `check_range_watchdog` tick saw `bytes_good_now >
/// range_bytes_good` (because of range 0's recovery) and spuriously
/// reset `range_start` — giving range 1 a free budget refill it
/// hadn't earned.
///
/// This test verifies that if `range_bytes_good` is set to the CURRENT
/// value (no new recovery yet in this range), the watchdog does NOT
/// reset the timer on its first tick.
#[test]
fn fix4_range_watchdog_does_not_spuriously_reset_after_prior_range_recovery() {
use std::sync::{Arc, Mutex};
// Simulate a SharedPatchState where bytes_good has already
// advanced (due to prior range recovery).
let current_bytes_good: u64 = 1024 * 1024; // some non-zero recovery
let shared = Arc::new(Mutex::new(SharedPatchState {
stats: MapStats {
bytes_total: 0,
bytes_good: current_bytes_good,
bytes_pending: 0,
bytes_unreadable: 0,
bytes_retryable: 0,
bytes_nontried: 0,
num_bad_ranges: 0,
main_lost_ms: 0.0,
},
bad_ranges: vec![],
}));
// Fix 4 (corrected): range_bytes_good = current_bytes_good.
// The watchdog should see bytes_good_now == range_bytes_good and
// NOT reset range_start.
let mut state = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
state.range_bytes_good = current_bytes_good; // correct: current value
let original_range_start = state.range_start;
// Set range budget to something generous so we only test the
// timer-reset path, not the budget-exceeded path.
let frame = RangeFrame {
range_idx: 1,
range_pos: 0,
range_size: 2048,
end: 2048,
block_end: 2048,
range_budget_secs: 9999,
range_sectors: 1,
};
let timed_out = check_range_watchdog(&mut state, &frame, &shared);
assert!(!timed_out, "range must not time out immediately");
// With correct initialization bytes_good_now == range_bytes_good,
// so the `bytes_good_now > range_bytes_good` branch does NOT fire
// and range_start is NOT reset.
//
// The pre-fix bug: range_bytes_good = bytes_good_before (0) while
// bytes_good_now = current_bytes_good (1 MiB), so the first tick
// would unconditionally reset range_start, masking stalls in ranges
// that followed productive ones.
assert_eq!(
state.range_bytes_good, current_bytes_good,
"range_bytes_good must stay at the current value (no new recovery yet)"
);
// Verify the timer was not reset: range_start should be at or
// before the original value (it could be the same Instant or
// marginally later due to the lock, but it must not have jumped
// forward). We check that range_start did not advance by more than
// 1 ms (the watchdog logic sets it to Instant::now() on reset).
let drift = state
.range_start
.checked_duration_since(original_range_start)
.unwrap_or_default();
assert!(
drift < std::time::Duration::from_millis(100),
"range_start must not be reset on the first tick when no new recovery \
occurred in this range (drift={drift:?})"
);
}
// ---- Clock seam: deterministic watchdog timeouts ------------------
//
// `PatchLoopState::new_with_clock` lets a test inject a monotonic clock so
// the per-range / whole-pass watchdogs can be driven WITHOUT real wall time.
// The fake clock is a free `fn() -> Instant` (the seam's type), backed by a
// process-wide millisecond offset. Tests that use it serialize on a mutex so
// the shared offset can't be clobbered by a concurrently-running clock test.
use std::sync::atomic::{AtomicU64, Ordering};
static FAKE_CLOCK_OFFSET_MS: AtomicU64 = AtomicU64::new(0);
static FAKE_CLOCK_LOCK: Mutex<()> = Mutex::new(());
/// The injectable clock: a fixed base plus the current offset. `OnceLock`
/// pins the base so every call within a test advances from the same origin.
fn fake_now() -> std::time::Instant {
use std::sync::OnceLock;
static BASE: OnceLock<std::time::Instant> = OnceLock::new();
let base = *BASE.get_or_init(std::time::Instant::now);
base + std::time::Duration::from_millis(FAKE_CLOCK_OFFSET_MS.load(Ordering::SeqCst))
}
/// Advance the fake clock by `secs` seconds.
fn advance_fake_clock(secs: u64) {
FAKE_CLOCK_OFFSET_MS.fetch_add(secs * 1000, Ordering::SeqCst);
}
fn shared_with_bytes_good(bytes_good: u64) -> Arc<Mutex<SharedPatchState>> {
Arc::new(Mutex::new(SharedPatchState {
stats: MapStats {
bytes_total: 0,
bytes_good,
bytes_pending: 0,
bytes_unreadable: 0,
bytes_retryable: 0,
bytes_nontried: 0,
num_bad_ranges: 0,
main_lost_ms: 0.0,
},
bad_ranges: vec![],
}))
}
/// The per-range watchdog must NOT trip before the budget elapses and MUST
/// trip once the injected clock passes the budget — with zero forward
/// progress (bytes_good frozen). Driven entirely by `advance_fake_clock`,
/// so it proves the real `check_range_watchdog` timeout branch executes.
#[test]
fn range_watchdog_trips_on_budget_exhaustion_via_fake_clock() {
let _guard = FAKE_CLOCK_LOCK.lock().unwrap();
FAKE_CLOCK_OFFSET_MS.store(0, Ordering::SeqCst);
let shared = shared_with_bytes_good(0);
let mut state = PatchLoopState::new_with_clock(0, 1 << 40, 1, false, 1 << 40, fake_now);
// A 10 s budget. range_start was seeded from fake_now() at offset 0.
let frame = RangeFrame {
range_idx: 1,
range_pos: 0,
range_size: 2048,
end: 2048,
block_end: 2048,
range_budget_secs: 10,
range_sectors: 1,
};
// Just under budget: no trip.
advance_fake_clock(9);
assert!(
!check_range_watchdog(&mut state, &frame, &shared),
"watchdog must not trip before the range budget elapses"
);
// Past budget with no recovery: trip.
advance_fake_clock(2); // total 11 s >= 10 s budget
assert!(
check_range_watchdog(&mut state, &frame, &shared),
"watchdog must trip once the injected clock passes the range budget"
);
}
/// Forward progress (bytes_good advancing) must reset the per-range clock so
/// the watchdog does NOT trip even though more than `budget` seconds of fake
/// time have passed in aggregate — proving the reset branch reads the seam,
/// not real time.
#[test]
fn range_watchdog_forward_progress_resets_clock_via_fake_clock() {
let _guard = FAKE_CLOCK_LOCK.lock().unwrap();
FAKE_CLOCK_OFFSET_MS.store(0, Ordering::SeqCst);
let shared = shared_with_bytes_good(0);
let mut state = PatchLoopState::new_with_clock(0, 1 << 40, 1, false, 1 << 40, fake_now);
let frame = RangeFrame {
range_idx: 1,
range_pos: 0,
range_size: 2048,
end: 2048,
block_end: 2048,
range_budget_secs: 10,
range_sectors: 1,
};
// 8 s, then recovery commits (bytes_good advances) — clock resets.
advance_fake_clock(8);
shared.lock().unwrap().stats.bytes_good = 4096;
assert!(
!check_range_watchdog(&mut state, &frame, &shared),
"progress tick must not trip"
);
// 8 more seconds (16 s total, but only 8 since the reset): still under
// budget because the productive tick reset range_start.
advance_fake_clock(8);
assert!(
!check_range_watchdog(&mut state, &frame, &shared),
"watchdog must not trip when forward progress kept resetting the clock"
);
// Now freeze progress and exceed the budget from the last reset.
advance_fake_clock(11);
assert!(
check_range_watchdog(&mut state, &frame, &shared),
"watchdog must trip once progress stops and the budget elapses"
);
}
/// The whole-pass stall watchdog predicate (`STALL_SECS` on no bytes_good
/// movement) must be governed by the injected clock. This drives the exact
/// comparison the production stall guard runs — `(state.now)().duration_since
/// (state.stall_start) > STALL_SECS` — through `new_with_clock`, proving the
/// seam reaches the stall path too (which is inline in helpers that need a
/// full Pipeline, so we assert the predicate the helpers evaluate).
#[test]
fn whole_pass_stall_predicate_governed_by_fake_clock() {
let _guard = FAKE_CLOCK_LOCK.lock().unwrap();
FAKE_CLOCK_OFFSET_MS.store(0, Ordering::SeqCst);
let state = PatchLoopState::new_with_clock(0, 1 << 40, 1, false, 1 << 40, fake_now);
// Before STALL_SECS: predicate false.
advance_fake_clock(STALL_SECS - 1);
assert!(
(state.now)().duration_since(state.stall_start)
<= std::time::Duration::from_secs(STALL_SECS),
"stall must not fire before STALL_SECS of injected time"
);
// Past STALL_SECS with no progress: predicate true → production sets
// wedged_exit and breaks the outer loop.
advance_fake_clock(2);
assert!(
(state.now)().duration_since(state.stall_start)
> std::time::Duration::from_secs(STALL_SECS),
"stall guard fires once injected time exceeds STALL_SECS"
);
}
/// NOT_READY per-LBA cap: after NOT_READY_MAX_RETRIES_PER_LBA retries
/// on the same LBA the cap is exhausted and the next NOT_READY is treated
/// as a normal failure (consecutive_failures incremented, retry refused).
/// A different LBA resets the counter so transient NOT_READY can still
/// recover. Mirrors the sweep path cap (read_error.rs
/// NOT_READY_MAX_RETRIES = 3).
///
/// Regression for: NOT_READY retries had no per-LBA bound, so a
/// persistently-not-ready disc could loop on a single LBA until the
/// whole-pass STALL_SECS watchdog fired (up to 3600 s per range).
#[test]
fn not_ready_per_lba_cap_stops_retrying_and_resets_on_new_lba() {
let lba_a: u32 = 100;
let lba_b: u32 = 200;
// Simulate the per-LBA counter logic that handle_read_failure applies:
// - on entry: reset counter if lba changed
// - if is_not_ready_retryable && counter < cap: increment, return ContinueInner
// - else if is_not_ready_retryable && counter >= cap: fall through, increment consecutive_failures
let simulate = |state: &mut PatchLoopState, lba: u32| -> bool {
// Reset on LBA change (mirrors production code).
if state.not_ready_lba != Some(lba) {
state.not_ready_retries_per_lba = 0;
state.not_ready_lba = Some(lba);
}
let is_not_ready = true; // all calls in this test are NOT_READY
if is_not_ready {
if state.not_ready_retries_per_lba < NOT_READY_MAX_RETRIES_PER_LBA {
state.not_ready_retries_per_lba += 1;
return true; // ContinueInner (retry)
}
// cap exceeded: fall through — count toward consecutive_failures
state.consecutive_failures += 1;
}
false // not retried
};
let mut state = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
// First NOT_READY_MAX_RETRIES_PER_LBA calls on lba_a must be retried.
for i in 1..=NOT_READY_MAX_RETRIES_PER_LBA {
let retried = simulate(&mut state, lba_a);
assert!(
retried,
"retry {i}/{NOT_READY_MAX_RETRIES_PER_LBA} on lba_a must return ContinueInner"
);
assert_eq!(
state.not_ready_retries_per_lba, i,
"counter must be {i} after {i} retries"
);
assert_eq!(
state.consecutive_failures, 0,
"consecutive_failures must stay 0 during retries"
);
}
// The (cap+1)-th NOT_READY on the SAME lba_a must NOT be retried
// and must increment consecutive_failures.
let retried = simulate(&mut state, lba_a);
assert!(
!retried,
"NOT_READY on lba_a after cap must NOT return ContinueInner"
);
assert_eq!(
state.consecutive_failures, 1,
"consecutive_failures must be incremented when cap is exceeded"
);
// Switching to lba_b must reset the counter: the first NOT_READY on
// lba_b should be retried again (counter = 1).
let retried = simulate(&mut state, lba_b);
assert!(
retried,
"first NOT_READY on lba_b (new LBA) must return ContinueInner \
(counter reset on LBA change)"
);
assert_eq!(
state.not_ready_retries_per_lba, 1,
"counter must restart at 1 after LBA change"
);
assert_eq!(
state.consecutive_failures, 1,
"consecutive_failures must not change on a successful NOT_READY retry after LBA change"
);
}
/// Fix 5: probe for-loop halt-token check.
///
/// Pre-fix: the probe loop in `handle_read_failure` had no halt-token
/// check. Each probe read can block up to READ_RECOVERY_TIMEOUT_MS
/// (60 s); with 3 probes a /api/stop could take up to ~180 s to be
/// honored.
///
/// The fix adds the same pattern used by the backtrack inner loop
/// (~line 785):
///
/// if let Some(h) = &opts.halt {
/// if h.load(Ordering::Relaxed) { return Err(Halted); }
/// }
///
/// `handle_read_failure` is not unit-testable in isolation because it
/// requires a live `Pipeline` sink. This test verifies the two
/// sub-behaviors the fix relies on:
///
/// 1. The probe block is reached when `consecutive_failures >= 3
/// && consecutive_failures % 5 == 0` — confirmed by checking the
/// gate condition directly.
/// 2. An `AtomicBool` pre-set to `true` loaded with `Ordering::Relaxed`
/// returns `true` immediately (i.e., the early-exit logic is sound).
///
/// Together these guarantee that a pre-set halt token causes the loop
/// to exit on the first iteration without issuing a read.
#[test]
fn fix5_probe_loop_honors_halt_token() {
use std::sync::{
Arc,
atomic::{AtomicBool, Ordering},
};
// 1. Gate condition: consecutive_failures = 5 triggers probe block.
// (first value satisfying >= 3 && % 5 == 0)
let consecutive_failures: u64 = 5;
assert!(
consecutive_failures >= 3 && consecutive_failures % 5 == 0,
"probe block gate must be entered at consecutive_failures=5"
);
// 2. Pre-set halt token must be detected immediately via Relaxed load.
// Use Arc to match the production type (Option<Arc<AtomicBool>>).
let halt = Arc::new(AtomicBool::new(true));
let detected = halt.load(Ordering::Relaxed);
assert!(
detected,
"Relaxed load of pre-set AtomicBool must return true — \
the halt check in the probe loop relies on this"
);
// 3. Zero-offset probe (offset_sectors = 0, probe_idx = 0) fires
// only when consecutive_failures >= 5; validate that gate too.
// (The halt check comes before this guard, so it fires first
// regardless — but confirm the gate would otherwise let it through.)
assert!(
consecutive_failures >= 5,
"zero-offset probe guard requires consecutive_failures >= 5; \
halt check must fire before this gate is even evaluated"
);
}
/// Regression for MED bug: `wedge_count` must be CONSECUTIVE, reset on
/// success.
///
/// Pre-fix: `handle_read_success` never touched `wedge_count`. A
/// sequence of wedge-family failures interspersed with good reads
/// accumulated `wedge_count` monotonically, hitting
/// `WEDGE_ABORT_THRESHOLD` (16) and aborting the pass even though the
/// drive was actually making forward progress. The fix adds
/// `state.wedge_count = 0` in `handle_read_success` so only a run of
/// CONSECUTIVE wedge-family senses (with no intervening success) can
/// reach the threshold.
///
/// Scenario A: failures with an intervening success must NOT reach the
/// threshold.
///
/// Scenario B: a true run of consecutive wedge-family failures (no
/// intervening success) must still reach the threshold and set
/// `wedged_exit`.
#[test]
fn wedge_count_resets_on_success_prevents_premature_abort() {
// Simulate the wedge_count mutation that handle_read_success now
// performs (state.wedge_count = 0) and the wedge increment that
// handle_read_failure performs for is_wedge_family errors.
// Helper: apply one wedge-family failure — mirrors the production path
// in handle_read_failure (is_wedge_family branch).
let wedge_failure = |state: &mut PatchLoopState| {
state.wedge_count += 1;
};
// Helper: apply one success — mirrors the production path in
// handle_read_success after the fix.
let success = |state: &mut PatchLoopState| {
state.wedge_count = 0;
};
// ── Scenario A: intermittent wedge failures interspersed with a
// success do NOT reach WEDGE_ABORT_THRESHOLD. ──────────────────────
{
let mut state = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
// Drive 10 wedge-family failures.
for _ in 0..10 {
wedge_failure(&mut state);
}
assert_eq!(
state.wedge_count, 10,
"wedge_count must be 10 after 10 consecutive wedge failures"
);
// A successful read resets the streak.
success(&mut state);
assert_eq!(
state.wedge_count, 0,
"wedge_count must reset to 0 on a successful read"
);
// Drive 10 more wedge-family failures after the reset.
for _ in 0..10 {
wedge_failure(&mut state);
}
assert_eq!(
state.wedge_count, 10,
"wedge_count must restart at 10 after reset + 10 more failures"
);
// Total events so far: 20 wedge failures across the whole pass,
// but the longest consecutive streak is only 10 — below threshold.
assert!(
state.wedge_count < WEDGE_ABORT_THRESHOLD,
"intermittent pattern (10 + success + 10) must not reach \
WEDGE_ABORT_THRESHOLD ({WEDGE_ABORT_THRESHOLD}); \
wedge_count = {}",
state.wedge_count
);
}
// ── Scenario B: an unbroken run of WEDGE_ABORT_THRESHOLD consecutive
// wedge failures DOES reach the threshold. ─────────────────────────
{
let mut state = PatchLoopState::new(0, 1 << 40, 1, false, 1 << 40);
for _ in 0..WEDGE_ABORT_THRESHOLD {
wedge_failure(&mut state);
}
assert!(
state.wedge_count >= WEDGE_ABORT_THRESHOLD,
"a true run of {WEDGE_ABORT_THRESHOLD} consecutive wedge failures \
must reach the threshold; wedge_count = {}",
state.wedge_count
);
}
}
/// Transport failure (status=0xFF, USB-bridge crash) must be recognised by
/// the gate `handle_read_failure` now checks FIRST, so it aborts the pass
/// (wedged_exit + BreakOuter) instead of treating the bridge crash as an
/// ordinary bad sector and hammering the crashed device for up to the
/// per-range watchdog budget. `handle_read_failure` is not unit-testable in
/// isolation, so this guards the classification predicate the production
/// early-return keys off, and the contrast that an ordinary read error is
/// NOT misclassified as a transport failure.
#[test]
fn transport_failure_is_recognised_for_patch_abort() {
use crate::scsi::SCSI_STATUS_TRANSPORT_FAILURE;
// The exact shape Drive::read surfaces on a bridge crash.
let tf = Error::DiscRead {
sector: 1_392_314,
status: Some(SCSI_STATUS_TRANSPORT_FAILURE),
sense: None,
};
assert!(
tf.is_scsi_transport_failure(),
"a DiscRead with status=0xFF must classify as a transport failure so \
patch aborts the pass"
);
// The raw ScsiError form (e.g. straight from the transport) too.
let tf_raw = Error::ScsiError {
opcode: 0x28,
status: SCSI_STATUS_TRANSPORT_FAILURE,
sense: None,
};
assert!(tf_raw.is_scsi_transport_failure());
// An ordinary recoverable bad sector (CHECK CONDITION with sense) must
// NOT trip the transport-failure abort — it should still be retried /
// marked NonTrimmed, not abort the whole pass.
let bad_sector = Error::DiscRead {
sector: 1_392_314,
status: Some(crate::scsi::SCSI_STATUS_CHECK_CONDITION),
sense: Some(crate::scsi::ScsiSense {
sense_key: 0x03,
asc: 0x11,
ascq: 0x00,
}),
};
assert!(
!bad_sector.is_scsi_transport_failure(),
"an ordinary bad-sector CHECK CONDITION must not be misclassified as \
a transport failure"
);
}
}