disc/patch: leave failed reads NonTrimmed mid-multipass, not Unreadable

User design call after watching Pass 2 mark ~20 KB as "Cosmetic"
(permanently Unreadable) after just 10 retries within a single pass:
"i think it's good or maybe until all passes are done. then it's
gone."

That contradicts what the multi-pass design promises a user. The
project goal in project docs is "recover 100% of readable data from any
optical disc, automatically." Marking sectors Unreadable after a
SINGLE pass's per-range retry budget gives up on sectors that
subsequent passes might recover — drive reads are stochastic, the
sector that fails 10 times in Pass 2 may succeed on attempt 1 in
Pass 3 after temperature / bus state / prior-read patterns shift.
The patch.rs doc comment already noted ~36% of patch-marked
Unreadable sectors turned out to be readable in re-rip experiments.

Three sites in `Disc::patch` were emitting `PatchItem::Unreadable`
mid-pass:
  - backtrack hit damage (line ~2659)
  - all-retries-exhausted on a single LBA (line ~2846)
  - redundant second mark after the wedge-suspicion log (line ~2970)

All three now emit `PatchItem::NonTrimmed` instead. Failed bytes
stay "maybe" (NonTrimmed) so the next pass gets another shot. The
per-range skip-limit (10) and per-pass wedge-threshold (50) still
bound time-per-pass; they just no longer turn the bytes terminal.

The `PatchItem::Unreadable` variant stays in the enum (with
#[allow(dead_code)]) because the orchestrator-side end-of-recovery
promotion will use it: autorip, after the final retry pass
completes, scans the mapfile and promotes still-NonTrimmed →
Unreadable. That promotion lands in a follow-up commit on the
autorip side — separable from this libfreemkv change.

Loss accounting unchanged: `bytes_pending + bytes_unreadable` is
the "lost or pending" total that `abort_on_lost_secs` consults
(disc/mod.rs:1327). Moving bytes from one bucket to the other
mid-pass doesn't affect whether the rip would abort; it only
affects display (UI shows "Maybe" vs "Cosmetic") and whether
subsequent passes retry the bytes (the actual fix).

Test update: `test_pass_progress_separates_unreadable_from_pending`
was renamed to `test_pass2_leaves_failed_reads_as_pending_not_unreadable`
and rewritten to assert the new invariant — Pass 2 leaves all
failed bytes as bytes_pending (no mid-pass Unreadable promotion).
Original assertions were checking the pre-design-call behavior.

Precommit (cargo +1.86 fmt + clippy + test) green.
This commit is contained in:
MattJackson
2026-05-10 18:47:05 -07:00
parent 0bca7a11bd
commit 72f2224efe
3 changed files with 79 additions and 32 deletions
+29 -11
View File
@@ -2654,9 +2654,17 @@ impl Disc {
} }
Err(_err) => { Err(_err) => {
blocks_read_failed += 1; blocks_read_failed += 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( send_or_abort(
&pipe, &pipe,
PatchItem::Unreadable { PatchItem::NonTrimmed {
pos: bt_pos, pos: bt_pos,
len: span, len: span,
}, },
@@ -2840,10 +2848,21 @@ impl Disc {
} }
} }
// All retries exhausted - mark as Unreadable // 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( send_or_abort(
&pipe, &pipe,
PatchItem::Unreadable { PatchItem::NonTrimmed {
pos, pos,
len: block_bytes, len: block_bytes,
}, },
@@ -2960,25 +2979,24 @@ impl Disc {
} }
} }
// Redundant second Unreadable mark — preserved // Pair with the earlier NonTrimmed dispatch — same
// bit-for-bit from the pre-split loop (`record` // bytes, same state. Pre-2026-05-11 this was a
// is idempotent for same-status replacement of // second Unreadable mark; now it's NonTrimmed for
// the same range). Routes through the consumer // the same reason: cross-pass retry survival.
// like every other state change.
send_or_abort( send_or_abort(
&pipe, &pipe,
PatchItem::Unreadable { PatchItem::NonTrimmed {
pos, pos,
len: block_bytes, len: block_bytes,
}, },
)?; )?;
tracing::info!( tracing::info!(
target: "freemkv::disc", target: "freemkv::disc",
phase = "patch_mapfile_record_unreadable", phase = "patch_mapfile_record_nontrimmed",
pos, pos,
block_bytes, block_bytes,
consecutive_failures, consecutive_failures,
"Mapfile record dispatched as Unreadable" "Mapfile record dispatched as NonTrimmed (retry next pass)"
); );
let pause_secs = if err.is_bridge_degradation() { let pause_secs = if err.is_bridge_degradation() {
+25 -6
View File
@@ -70,14 +70,33 @@ pub(super) enum PatchItem {
/// Producer exhausted retries on `[pos, pos+len)`. Consumer records /// Producer exhausted retries on `[pos, pos+len)`. Consumer records
/// the range as `Unreadable`. No file write — the existing zero-fill /// the range as `Unreadable`. No file write — the existing zero-fill
/// from sweep is preserved in place. /// 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). When that ships, this
/// becomes the variant the orchestrator emits to the same
/// PatchSink.
#[allow(dead_code)]
Unreadable { pos: u64, len: u64 }, Unreadable { pos: u64, len: u64 },
/// Producer hit the per-range skip limit and is leaving the /// Producer marks `[pos, pos+len)` as `NonTrimmed`. Used for BOTH
/// remaining bytes as `NonTrimmed` for a future pass. CRITICAL: /// the per-range skip-limit case (remaining bytes never tried) AND
/// this is not the same as `Unreadable` — sectors we never tried /// individual sector failures (tried-but-failed within a pass).
/// stay hopeful. (See the comment at the skip-limit branch in /// Both stay "hopeful" — a later pass retries them.
/// `Disc::patch`: ~36% of patch-marked Unreadable sectors are ///
/// actually readable on a later pass.) No file write. /// 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 }, NonTrimmed { pos: u64, len: u64 },
} }
+25 -15
View File
@@ -655,12 +655,16 @@ fn test_disc_copy_marks_failed_ecc_blocks_as_nontrimmed() {
// ── 9. PassProgress carries separate unreadable vs pending byte counts ───── // ── 9. PassProgress carries separate unreadable vs pending byte counts ─────
// //
// The video-damage-time display needs bytes_unreadable_total (confirmed dead) // 2026-05-11 design call: Pass N never marks bytes as `Unreadable` mid-multipass —
// separate from bytes_pending_total (might still recover). This test verifies // failed reads stay `NonTrimmed` so the next pass can retry them. The orchestrator
// that a Pass 2 with some confirmed failures produces correct field values. // (autorip) promotes still-NonTrimmed bytes to Unreadable after the FINAL retry
// pass completes. This test was rewritten from its pre-design-call shape (which
// asserted Pass 2 produced bytes_unreadable > 0) to verify the new invariant:
// pass-level retries keep failed bytes in `bytes_pending` so subsequent passes
// get more shots at them.
#[test] #[test]
fn test_pass_progress_separates_unreadable_from_pending() { fn test_pass2_leaves_failed_reads_as_pending_not_unreadable() {
let capacity_sectors: u32 = 128; let capacity_sectors: u32 = 128;
let total_bytes: u64 = capacity_sectors as u64 * SECTOR_SIZE as u64; let total_bytes: u64 = capacity_sectors as u64 * SECTOR_SIZE as u64;
@@ -734,24 +738,30 @@ fn test_pass_progress_separates_unreadable_from_pending() {
pass2.bytes_good, 0, pass2.bytes_good, 0,
"pass2: still no good sectors (reader always fails)" "pass2: still no good sectors (reader always fails)"
); );
assert!( // 2026-05-11 design: pass-level retries do NOT promote failed bytes
pass2.bytes_unreadable > 0, // to Unreadable. Failed bytes stay NonTrimmed (pending) so a later
"pass2: some sectors confirmed unreadable" // pass can retry. End-of-recovery promotion is an orchestrator
// concern (autorip), not the patch loop's.
assert_eq!(
pass2.bytes_unreadable, 0,
"pass2: Disc::patch never marks Unreadable mid-multipass — orchestrator promotes after final pass"
); );
assert!( // bytes_pending stays at total_bytes because everything still
pass2.bytes_pending < pass1.bytes_pending, // failed and nothing got recovered or promoted out of pending.
"pass2: fewer pending sectors than pass1" assert_eq!(
pass2.bytes_pending, total_bytes,
"pass2: failed bytes remain NonTrimmed for the next pass to retry"
); );
let observed_unreadable = last_unreadable.load(Ordering::Relaxed); let observed_unreadable = last_unreadable.load(Ordering::Relaxed);
let observed_pending = last_pending.load(Ordering::Relaxed); let observed_pending = last_pending.load(Ordering::Relaxed);
assert!( assert_eq!(
observed_unreadable > 0, observed_unreadable, 0,
"progress should report confirmed unreadable bytes" "progress should report zero confirmed-unreadable mid-pass under the new design"
); );
assert!( assert!(
observed_pending == 0 || observed_pending < total_bytes, observed_pending > 0,
"pending should shrink as sectors are confirmed unreadable" "progress should report pending bytes as the reader keeps failing"
); );
// Video damage time: unreadable / total * duration // Video damage time: unreadable / total * duration