Commit Graph
95 Commits
Author SHA1 Message Date
Matthew Jackson d50a7173ad Expose error_code so consumers can read a code instead of parsing one
io_error_code was private, so the predicates built on it (is_halt,
is_skippable_title_stub, is_disc_level_no_key) were the only way to ask
anything about an io::Error's origin. A consumer that needs the code
itself — to report WHY a title failed rather than to branch on one of
three known cases — had no route to it: mux_stream returns an io::Error,
the typed Error is gone by then, and only the E<code> string prefix
survives.

That left every front-end to re-implement the prefix parse by hand,
which is precisely the string-matching 1.5.x spent its time removing.
One parser, exported.

No behaviour change: the function is unchanged and the three predicates
still call it.
2026-07-31 14:46:39 -07:00
Matthew Jackson 2efe1425d6 refactor(decrypt): one orchestrator owns the no-key decision
There were TWO top-level decrypt paths: decrypt_sectors_impl for CSS and
clear media, whose AACS arm was a bare `return Err` stub, and a wholly
separate decrypt_sectors_mapped for AACS. Each scheme therefore decided
its own answer to "there is no key for these bytes", and nothing held
them to the same one.

They drifted, in opposite directions, within a single release:

  css::descramble_region descrambled with a key the sector's own crib had
  just proven stale — garbage behind an intact clear header, reported Ok.

  the mapped path returned early for any LBA outside every range, before
  ever asking whether those bytes were ciphertext, so an unkeyable
  encrypted unit passed through and extract counted it as good.

Both were fixed individually earlier today. This removes the shape that
allowed them.

decrypt_span is now the single orchestrator: it owns the loop, the
refusal, and the loss count, and each scheme supplies only what
genuinely differs. apply_aacs_map is a scheme step that reports what it
could not open; it no longer decides what that means. The public
wrappers (decrypt_sectors, _in_content, _mapped) are unchanged in
signature and all funnel through it.

Adding a scheme now means adding an arm here, which means answering the
refusal question. That is the point.

The new test asserts ONE verdict across all three schemes — AACS with no
map, AACS with an encrypted unit outside every range, and CSS whose
re-crack failed — plus that clear media is NOT a refusal. A per-scheme
test cannot hold this: each would keep passing while the two disagreed.
Flipping the AACS arm back to pass-through reds it.

Also removes the last of the tracing-capture scaffolding. Serialising
those captures crate-wide did not fix the 1-in-10 flake, and asserting
the predicates directly made the helper, both capture subscribers and
an unrelated dead OrderSink unused. Deleted rather than left behind.
2026-07-30 21:35:33 -07:00
Matthew Jackson 72bcc371fb fix(io): a halted fsync is recognisable as a halt, not a hard failure
The three bounded-fsync failures returned bare io::ErrorKind values —
TimedOut, Interrupted, Other/EIO. `is_halt()` matches on
`io_error_code(e) == Some(E_HALTED)`, i.e. the "E<code>" prefix that
`From<Error> for io::Error` mints, and that is documented as the ONLY
recognised shape. A bare ErrorKind carries no prefix.

So cancelling a rip while sync_all / finish was inside the bounded fsync
made `is_halt()` return false, and the CLI reported a clean user cancel
as a hard I/O failure at the end of an otherwise complete mux.

All three were also mutually unclassifiable, which is the same
information-loss the numeric-code scheme exists to prevent: a caller
could not tell "cancelled" from "NFS wedged" from "worker died", and
should not retry the third the way it retries the first. And their
Display text is std English — "timed out", "operation interrupted" —
reaching a user from library code, which this crate does not do.

Now Error::Halted, Error::SyncTimeout (E_SYNC_TIMEOUT 9056) and
Error::SyncWorkerLost (E_SYNC_WORKER_LOST 9057), on both platforms.

E_HALTED also now maps to ErrorKind::Interrupted rather than falling into
the 6000..=6999 InvalidData bucket. A stop is an interruption, not
invalid data. Nothing branched on the old kind — every consumer uses
is_halt() — so this is safe as well as more accurate.

Two things worth recording. I first placed the E_HALTED arm AFTER the
6000..=6999 range arm and wrote a comment claiming it preceded it; match
arms are ordered, so the range won and the comment was simply false. The
test caught it. And the macOS test asserted only that each arm was
non-Ok with a particular ErrorKind — it passed throughout the period the
three were indistinguishable. It now asserts they can be TOLD APART,
which is the property that actually matters.

Found by the round-9 opus escalation over the API contract.
2026-07-30 20:04:08 -07:00
Matthew Jackson 944e6a8b09 fix: align the Linux fsync error with macOS, and clear three stale docs
Round 9 findings, triaged and verified against the pinned tree.

writeback_file: a bounded-fsync WorkerLost returned bare ErrorKind::Other
on Linux where macOS returns EIO. Round 8 fixed the Linux arm to return
Err at all — the right fix — but stopped short of matching the value, so
a consumer distinguishing timeout / halt / lost-worker had nothing to
branch on for the third case on one platform. Now EIO on both.

Three doc comments described the pre-fix behaviour, one of them for
longer than the bug existed:

  linux.rs durable_sync still said "all three fallbacks return Ok(())"
  mod.rs sync_all still said Linux silently swallows fsync failures and
    callers must not treat Ok(()) as a durability barrier
  mod.rs SequentialSink::finish repeated the same caveat

All three now say what the code does: a bounded-fsync failure is an Err
on every platform, so Ok(()) IS a durability barrier. A doc that
describes a fixed bug is worse than no doc — it tells a caller to write
a workaround for something that no longer exists.

au_assembly: discard_gap_before duplicated drop_marks_before's
mark-retirement body verbatim and added one statement. Mine, from
earlier today. It now calls it. Two copies of the same retirement loop
is exactly how the two call sites would drift back together.

clpi: ClpiStream's audio_format / audio_rate / video_format / video_rate
are decoded from untrusted on-disc bytes on every parse and read by
nothing. The identically-named fields consumed in disc/bluray.rs belong
to mpls::StreamEntry, not to this struct — checked, because an earlier
round wrongly called a live function dead. Deleted, along with the seven
test assertions that pinned them; the tests that pin pid, coding_type
and language remain. Also removed a section-header comment orphaned by
the get_extents deletion, describing a fixture that no longer exists.
2026-07-30 18:39:47 -07:00
Matthew Jackson 5360f8d309 test: salvage the orphaned labels/disc triage, and extract build_labels
Thirteen agents triaging src/labels and src/disc died on a saturated
machine, leaving 5,836 insertions across 28 files uncommitted in a
worktree. Recovered by 3-way apply onto twelve commits of drift; zero
conflicts. The diff was archived to freemkv-private first, because a
worktree is not a backup and this one had already nearly been lost.

One production change, and it is the right one: mpls_universal::parse
read every playlist off the disc AND converted the entries to labels in
a single function, so the conversion — stream-type mapping, dedup key,
the dense global counters — could only be reached through a synthetic
UDF image. Extracted to build_labels(&[Playlist]), which unit tests can
drive from already-parsed values. Behaviour-preserving: same iteration
order, same skip-on-error.

Two collisions resolved by hand:

A second mod pass_progress_tests, written independently against the
same survivors as the one committed in c610285. Kept mine — it covers
the distinct-counters case and the Progress blanket impl, which theirs
does not — but theirs had three clamp tests mine lacked: good_pct,
bad_pct and pending_pct also clamp an overshoot, and I had only tested
that for work_pct. Merged those in as one test and proved each of the
three clamps load-bearing by removing them individually.

An unused_parens warning in a new fixture.

Method note, recorded because it cost real time: git apply --3way
STAGES its result, so `git diff` reads empty and the tree looks
untouched. I nearly concluded the patch had silently failed. Worse, the
first attempt piped through `head -20`, so `echo exit=$?` reported
head's status rather than git's — the same mistake this audit has
already documented once. Check the real exit status, and check
--cached, not just the working tree.
2026-07-30 16:36:13 -07:00
Matthew Jackson 18f8b285c4 Bound the BD-J label parsers, and stop a crafted disc hanging the scan
Ten defects in code no previous round had ever scoped. `src/labels/`
identifies a disc's studio by parsing jar archives and JVM class files off
untrusted media, so every byte here is attacker-controllable — and 813 of
its lines were executed by no test at all.

The worst is a non-terminating loop. A fallback stream-number scan
advanced with `saturating_add`, and the comment says why: a crafted XML
"must not overflow (panic in debug, wrap-to-0 in release)". Once the
counter pins at u16::MAX and that number is taken, the loop cannot exit.
So a fix for an overflow panic produced an unbounded hang, which is
strictly worse — a panic is observable and catchable, and catch_unwind
cannot interrupt a live loop. Reachable from about 8 MB of XML.

Where the same overflow appears in the deluxe decoder the fix is
checked_add and stop, NOT saturation — twice wrong there, because
saturating would peg every stream past the ceiling at one number and
apply_labels binds on (type, number), silently mislabelling tracks. A
correctness bug wearing the costume of success.

Round 7 capped the ldc-string retention per class; nothing capped the
aggregate, so a 64 MiB jar held that budget for every class at once. Same
defect one level up, which is the shape that keeps recurring in this
directory. Four other amplifications are bounded the same way, each with a
stated headroom and a paired test proving real media passes untouched —
the tightest is 5x on a label length, the loosest 2000x on the stream
numbering space, against BD's 32-per-type STN_table limit.

Two are not caps at all: a quadratic membership scan became a set, and an
attacker-derived length added to a cursor without saturation now cannot
wrap. Nothing is excluded by either.

A `#[cfg(test)]` hand-copy of a shipping parser was the ninth bad test
this audit has found, and the first proven by mutation rather than
inspection: deleting the guard from the REAL function left all 26 tests
green, including the one named for that guard. Pointed at the real
function, the same mutation fails.

Separately, all three failure arms of the bounded fsync returned Ok(()) on
both macOS and Linux, so sync_all reported success for a durability
barrier that never ran. Only macOS was in scope; the Linux twin is fixed
here too, because a platform disagreeing with its sibling about whether a
failed sync is an error is the class that already produced an over-length
SCSI CDB macOS rejected and the other two truncated. Note the behaviour
change: a mux whose final sync times out on a wedged mount now fails
rather than exiting 0.

Three of the caps are proven by wall-clock deadline rather than an
operation count, with 18-80x margin on the passing side. On a heavily
oversubscribed machine those could flake.
2026-07-30 11:30:24 -07:00
Matthew Jackson 327087c70e Make five tests capable of failing, and stop the presence probe unmounting the disc
The worst of the five was a regression suite that never touched the code
it guarded: nine batch-count tests called `safe_batch_count` and
`buggy_batch_count`, both defined in the test file itself. The u16
truncation they exist to prevent could be reintroduced in
sector/prefetched.rs with every one of them green. They now drive the real
producer through the public API, and reinstating the truncation fails five
of the nine. Worth recording that the symptom has changed since the
original fix: the unit-alignment clamp below floors a zero batch at three
sectors, so the bug is now a twenty-fold throughput cliff rather than the
stall it once was.

The MP4 reserve test's only numeric case was dominated by the floor and
the buffer, so BYTES_PER_SAMPLE could be zeroed without failing it. It now
has a case where the per-sample term dominates. The zero-count guard in
FileSectorSource was likewise unfalsifiable — seek-past-EOF and a
zero-length read both succeed — so the test now observes the file cursor.
The AACS media-key ambiguity guard had no test at all; the pool scan is
extracted so the verifier can be injected, because a genuine two-key
collision needs one ciphertext decrypting under two AES-128 keys to
plaintexts sharing a 64-bit magic, which is a 2^64 search and not a
fixture.

macOS implemented the documented cheap, side-effect-free presence probe by
building a full exclusive transport — which force-unmounts the disc. Linux
and Windows issue one TEST UNIT READY with no unmount; macOS was the
outlier. It now walks the IOKit registry for the media object instead.

The C shim's registry reads assumed CoreFoundation types the registry does
not guarantee, so a driver publishing a CFNumber where a CFString was
expected aborted the process from inside public API. Types are checked and
a wrong type treated as absent. The unbounded waitpid on the unmount child
is now a polled deadline, and the last-resort match gained the NULL check
its two siblings already had.

The empty-CDB guard existed only on Linux while a shared helper's comment
claimed all three backends had it. Moved into the helper, so the comment
is now true and macOS and Windows are covered.

One finding was REJECTED with evidence rather than fixed. The TrueHD
buffer-cap test was indeed bogus, but MAX_TRUEHD_BUF turns out to be
unreachable by any input: the parser only retains data when the buffer is
shorter than the declared AU, and that declaration is twelve bits, so the
worst case is 8189 bytes against a 256 KiB cap. An exhaustive sweep over
all 65536 AU headers confirmed it. The fixture now sits at the reachable
ceiling and asserts that instead. The cap itself is left in place as
defence, unreachable by construction, matching how the AC-3 resync guard
was handled earlier in this audit.

Two behaviour changes worth naming: Linux's empty-CDB error becomes
InvalidCdbLength rather than a transport failure, and an unknown device
now reports absent media rather than a not-found error, because the
registry cannot tell an empty drive from a missing one. The latter is a
conflation of the kind this audit has fixed three times; it is recorded
for the next round rather than left silent.
2026-07-30 09:26:56 -07:00
Matthew Jackson d444afbdfc Turn a release-only slice panic into an error, and stop calling 32 kHz 48 kHz
Four round-6 findings.

FileSectorSource::read_sectors guarded its output buffer with a
debug_assert, which is compiled out in release — so an undersized buffer
panicked with 'range end index out of range' instead of returning an
error, out of a public SectorSource impl where the length is caller input.
Drive::read_fua already carries this exact guard, with a comment recording
the same panic being fixed there, and PrefetchedSectorSource has a
regression test for the same case; this impl had been given neither. The
new test is red in release for precisely the predicted reason: 'range end
index 8192 out of range for slice of length 2049'.

parse_track's sample-rate ladder ended in an unconditional S48, so any
SamplingFrequency below 44100 was recorded as 48 kHz. A 32000 Hz AC-3 or
DTS track is legal and common in broadcast-sourced content, and the wrong
rate then propagated into the reconstructed AudioStream. Anything below
the lowest mapped rate is now Unknown, which is what the crate's canonical
SampleRate::from_hz already returned — the ladder disagreed with it. The
ladder itself stays, because the MKV element is a float and wants
tolerance rather than exact equality.

shim_open_exclusive used the mach port from IOMainPort without checking
the return; on failure the port is left untouched and every IOKit call
below ran against an uninitialised value. shim_list_drives in the same
file does check it.

build.rs treated cc and ar as successful if the process merely SPAWNED, so
a genuine compile error in the macOS C shim produced no object file and
surfaced later as an unexplained link failure against a missing symbol.
The shim is macOS-only and is neither linted nor compiled on the other two
platforms, so a mistake in it has exactly one chance to be noticed.

The last two have no test: one needs IOMainPort to fail, the other needs a
deliberately broken C shim, and neither is reachable from the test
harness. Both mirror a correct sibling in the same file, which is the
evidence available.
2026-07-29 22:56:33 -07:00
Matthew Jackson 921404d135 Fix five clippy errors that only appear on the target CI lints
CI's clippy job runs on ubuntu-latest, so cfg(target_os = "linux") code is
what the gate actually compiles — and none of it is built by clippy on a
Mac. Five `-D warnings` errors were sitting in drive/linux.rs,
scsi/linux.rs, io/writeback/linux.rs and the Linux arm of drive/mod.rs:
four collapsible let-chains and one manual `% n == 0`. CI was red on the
lint job while the local gate reported all green.

Collapsed into let-chains, which the declared toolchain supports, and
folded drive/mod.rs's length precondition into its chain so the body no
longer needs a nested block.

Found because an agent working on the SCSI backends reported the lints in
passing while checking that a Windows-only file compiled. Worth noting how
it stayed hidden: every one of these files is cfg-gated to a platform this
machine is not, so no amount of local gating would have surfaced them. The
companion change to the precommit script closes that hole.
2026-07-29 22:37:47 -07:00
Matthew Jackson 0bbceed985 Round 4: fix 26 defects across crypto, resource use and codec paths
Twenty-six confirmed findings from the fourth audit round, landed as one
cluster because they were found by agents working over disjoint file sets.

The one worth calling out is a pair of AACS tests that could not fail.
Both asserted CBC behaviour against a hand-rolled expectation that
happened to be IV-independent, so replacing AACS_IV with sixteen zero
bytes left them passing — they were pinning the code's own arithmetic,
not the published constant. Replaced with a literal witness of the
published IV plus the NIST SP 800-38A F.2.2 CBC-AES128 vector, and
verified the other way round: zeroing AACS_IV now fails three tests.

The rest are allocation and correctness work on hot paths: the Annex-B
writer in demux_sink allocated and freed a whole-frame Vec per frame,
which for a UHD title is ~200,000 allocations over the mmap threshold
plus the page faults to first-touch each one; it now reuses a buffer on
the writer, and still takes the NAL prefix width from the configuration
record rather than assuming four.

Six findings whose real fix lives in a consumer crate are recorded for
re-filing rather than patched here.
2026-07-29 22:09:52 -07:00
Matthew Jackson 5f8dc392c0 Sweep the pinned toolchain to Rust 1.97
The Windows UI needs current winsafe, whose real minimum is 1.89 (its manifest
under-declares 1.87 while it uses NonNull::from_ref). Rather than stop at the
minimum, this goes to current stable and fixes what that costs.

The counter-intuitive result: 1.97 is CHEAPER than 1.89. libfreemkv had 54
clippy errors at 1.89 and 6 at 1.97, because clippy tightened the noisy
collapsible_if lint in between. Stopping at the minimum would have been the most
expensive choice available.

Roughly 47 lints across the eight repos, the large majority auto-fixed:
libfreemkv 6, freemkv-engine 14, bdemu 8, freemkv-keysources 7, autorip 6,
freemkv-unlock 3, freemkv-i18n 3. The hand-fixed ones are a descending sort to
sort_by_key(Reverse), four manual checked-division sites, a loop counter replaced
by enumerate, and a loop whose first let-else became a while-let.

Worth recording for whoever bumps next: clippy is MSRV-AWARE. Those 54 lints only
appear once the crate DECLARES 1.89 or later, because let-chains become
available. A bare `cargo +1.89 clippy` against a manifest still pinned at 1.87
reports clean and is meaningless — gate with the real precommit script, which is
also the only thing that covers build scripts.

The pin still sits below the Mac default, so it keeps doing its job: catching
lint drift locally before CI sees it.
2026-07-29 21:00:55 -07:00
Matthew Jackson a32373ff40 Fix fifteen defects across perf, resource, panics and key hygiene
All 21 findings held up under verification; 15 fixed here, 6 deferred to files
another agent held this round, 0 rejected.

**A defect in my own round-2 probe fix.** CHUNK_SECTORS was 1024, and
1024 % 3 == 1 — verified — so every chunk after the first was misaligned against
the 6144-byte AACS aligned unit and would be REJECTED by
DecryptingSectorSource's alignment gate. On an encrypted disc the forced-subtitle
probe I added last round would have read almost nothing past its first chunk.
Now 1023 sectors (341 aligned units) with a const assertion that fails the build
if it stops dividing, plus set_unit_base per extent so the source's gate is
anchored where the extent actually starts.

**The same probe skipped sectors on a short read**, advancing by the REQUESTED
count rather than the bytes actually returned, so a partial read silently left a
gap in the middle of the evidence. It now advances by n/SECTOR_BYTES and clamps n
to the buffer.

**Its cache key omitted the PGS PID set**, so a playlist declaring an extra
subtitle PID got another playlist's verdict for a track that had never been
probed. And the key was the whole extent list, so partial clip sharing missed
entirely. Both fixed by keying (start_lba, sector_count, pid) — and per-extent
keying was shown SOUND rather than assumed: ForcedTracker is two monotone
booleans, so per-extent evidence composes by field-wise OR, order- and
grouping-independently. Making that honest required per-extent demux state, so an
extent's evidence comes only from its own bytes, and memoising only extents whose
read reached a designed stop.

**A reachable panic in the timeline.** mkvstream::parse_block accepts a
TimestampScale up to i64::MAX, so a video frame can set high_ns = i64::MAX and the
next passive frame panicked adding the backstep. In release it wrapped negative
instead, firing the straggler clamp for essentially every passive frame — audio
and subtitles rewritten onto the wrong point of the output timeline. All four
sites saturate.

**A public constructor divided by zero**: PrefetchedSectorSource::new_with_events
with unit_align == 0. Now InvalidInput, matching its batch_sectors sibling.

**Two Debug impls printed key material.** DiscInputs (volume_id, mkb, unit_key_ro,
samples) and UnitKeyFile both derived Debug. Nothing logs them today — fixed as
prevention, because the next tracing::debug! someone adds is the leak. A doc claim
that DiscInputs "contains no secrets" was false and is corrected.

**An env-var multiply could overflow** in file_sector_source; now bounded at 64 GiB
like its writeback sibling, with the parse split out so the bound is testable
without touching process env.

**The mp4 demuxer allowed one sample per file byte** — ~64x RAM amplification.
Now file_len/16, since only vide/soun tracks are indexed and the shortest legal
AC-3 frame is 128 bytes.

**Two pipeline concurrency defects**: a consumer apply() error was invisible to the
producer, and abandon/finalise had a TOCTOU where a caller could report an
unfinalised output. Both fixed with compare-exchange state rather than a bool.

**Two per-frame copies removed**, both MEASURED rather than reasoned: the AU
assembler now hands its allocation to the frame (same pointer, unchanged capacity,
proven by asserting the pointer) and tsmux reuses one Annex-B buffer across
frames. Both keep capacity deliberately — a naive split_off would have cost more
than it saved.

**A comment pointed at the wrong file** for a mirrored constant; the mirror is now
compiler-enforced with a const assertion converting 90 kHz ticks to ns, so drift
fails the build.

Deferred to another agent's files, all confirmed: detect_rate's fractional-twin
snap, the mp4 reserve's u32 truncation, round_up_grain's overflow, the quadratic
base-key gap fill, and MkvStream's frame cap counting frames rather than bytes.

Every fix verified red by reverting it. Also noted for later:
DecodeSampleSet still derives Debug over multi-MB of on-disc ciphertext.
2026-07-29 20:47:31 -07:00
Matthew Jackson 94a876664b Correct six stale comments and doc claims
All six describe code that does something different from what they say, which
is the class of defect that gets a maintainer to write a bug on purpose.

docs/clpi.md presented the CLPI stream-PID entry as byte-aligned 2/2/2/4/4-byte
fields with a 32-bit fine-entry count. It is one 80-bit packed block —
reserved(10) + EP_stream_type(4) + num_EP_coarse(16) + num_EP_fine(18) +
EP_map_start_address(32) — and num_EP_fine is 18 bits. Anyone parsing to the
doc's offsets would read garbage. Replaced with the real bit layout.

docs/udf.md said read_directory()'s recursion cap is 3; MAX_DIR_DEPTH is 8.

TROUBLESHOOTING.md called Pass 1 `recovery::copy`. The engine's `sweep` is
documented as "Pass 1 of a multipass rip"; `copy` is the dispatch verb that
chooses between sweep and patch. This inconsistency was mine, introduced in the
1.6.0 doc rewrite. docs/drive-access.md already said `sweep` and was right — a
round-2 finding claimed the opposite on the grounds that `recovery::sweep`
appears nowhere else in this crate, which it cannot, being in another crate.

io/pipeline.rs cited `disc::patch` as WRITE_THROUGH_DEPTH's caller; that moved
to freemkv-engine in 1.6.0 and no `patch` exists here.

truehd.rs's doc on mlp_major_sync_crc_ok said the trailer is compared
big-endian while the body compares u16::from_le_bytes — and a big-endian
compare was the bug the function was fixed for, so the comment described the
defect rather than the code.

sector/decrypting.rs claimed the decorator owns "the only mutable state (its
call-count cap and spent flag)". DecryptingSectorSource has no such fields and
no KeyFetch field at all in this revision.
2026-07-29 18:50:53 -07:00
Matthew Jackson d8e5b97c86 1.6.0: remove recovery strategy (moved to freemkv-engine) + trim dead surface
The sweep/patch recovery strategy, mapfile, retry-decision state machine,
section-recover, and damage classification move out of libfreemkv into the
new freemkv-engine crate. libfreemkv keeps the raw single-shot read and
SCSI-fact translation (SenseFamily stays in scsi).

- Delete disc/{sweep,patch,mapfile,read_error,section_recover}.rs, the
  Disc::copy/sweep/patch methods, the Copy/Sweep/Patch option+result types,
  classify_damage/DamageSeverity, progress_snapshot_from_mapfile, and the
  three recovery integration tests.
- Trim public surface the recovery deletion orphaned: delete the dead
  READ_PIPELINE_DEPTH const, the write-side SectorSink/FileSectorSink (no
  consumer), and the DriveSpeed enum (its one live use — set max drive
  speed — becomes Drive::SPEED_MAX_KBPS). Make mapfile_path_for,
  decrypt_sectors_mapped pub(crate); gate NoopEvents to test.
- Version 1.6.0.
2026-07-28 15:35:19 -07:00
MattJackson ca0daaea07 io: promote WritebackFile to pub
Bounded-cache buffered File replacement used across mux/extract/sweep/patch
-- general I/O infrastructure, not recovery policy. freemkv-engine's
relocated sweep/patch need to construct it directly once those methods
leave this crate. No behavior change.
2026-07-28 11:36:43 -07:00
Matthew Jackson 830d1e360c Mux decrypt/verify redesign, HD DVD first-class, MVC 3D
decrypt:
- decrypt_sectors is now a pure decrypt (apply key, leave plaintext, report
  unverified bytes); TS-structure is a separate primitive (is_clean_ts/ps) used
  only for key selection and read-verify. The mux passes decrypted bytes through
  (the demuxer drops non-conforming packets), ending the NULL-TS conceal loop and
  the per-unit key-server refetch storm. Key-proof floor replaces the 75%
  supermajority.

recovery:
- Removed the post-read decrypt-verify gate (verify.rs) that mis-aligned the
  disc-absolute unit grid against clip-anchored AACS units and false-failed good
  clips (e.g. Dunkirk's orphan-CPS clip). Bad sectors are marked by physical read
  result; decryptability is proven at scan + mux time.

HD DVD (first-class AACS):
- Role-based candidate-list file sourcing so an HD DVD's /ANY!/ files
  (MKBROM.AACS, VTKF000.AACS, CONTENT_CERT.AACS) are found with no disc-type
  branch. parse_vtkf parses VTKF000.AACS into the same UnitKeyFile as a BD
  Unit_Key_RO.inf, so the shared VUK unwrap applies unchanged. set_unit_base
  clip-anchoring. Two decrypt-axis assumptions remain UNVERIFIED-HDDVD-DECRYPT
  (no encrypted disc to test).

mux:
- MVC (Blu-ray 3D) track signals unified into one MVCDecoderConfigurationRecord;
  release-safe track_vint (3-byte VINT) and pid_index (i32) guards.

hardening:
- Container-aware is_clean / encryption detection; bytes_bad_in_title fail-safe
  on a corrupt mapfile; CSS crack gated on DiscFormat::Dvd (HD DVD excluded);
  non-vacuous CSS tests; patch NOT_READY/HARDWARE/ILLEGAL_REQUEST/ABORTED
  sense-path tests.
2026-07-15 19:35:12 -07:00
Matthew Jackson 0d587d1154 fix: assorted correctness fixes and dead-code cleanup
- aacs/resolve: a media-keys-only provider missing the VID classifies as
  VidUnavailable, not NoMaterial (an MK derives the VUK once the VID
  arrives).
- disc/bluray: mark a clip seen only after its .clpi parses, so a
  transient parse failure on the first PlayItem cannot suppress the
  clip's extents for a later PlayItem referencing it that succeeds.
- disc/patch: log rather than swallow mapfile record/flush failures on a
  reverify downgrade, so a failed persist cannot silently mismark a bad
  unit good on resume.
- mux/ts: flag a discontinuity when a partial PES is dropped, matching
  the other partial-drop paths.
- mux/demux_thread: the no-demuxer branch forwards an empty batch for
  early consumer-disconnect detection instead of reading the whole disc.
- io/pipeline: correct the send-timing log (as_secs_f64, not as_micros
  printed as ms).
- aacs/derive, aacs/variant, disc/read_error, keysource: comment/doc
  accuracy. sector/prefetched, udf: remove dead fields/functions.
- mux/disc: assert unit-aligned read counts in the test.
2026-07-08 14:44:15 -07:00
Matthew Jackson d8c323bf9f Magic-number/taxonomy pass: central wire-format + sector + unit consts
- libfreemkv::consts: coding_type::* (ES coding-type bytes), pes_stream_id::*
  + PAYLOAD_RANGE, SECTOR_BYTES (usize) + SECTOR_BYTES_U64 (offset math)
- replace bare wire-code/sector literals across disc, mpls, clpi, labels,
  m2ts_mux, ps, tsmux, file_sector_source, extract
- remove two unreachable secondary-stream match arms in mpls parse_stream_entry
2026-06-26 13:20:21 -07:00
Matthew Jackson decb87a250 AACS pipeline reshape + TrueHD metadata + central consts + clippy/fmt clean
- AACS: delete in-lib keydb parser (Step 3); boil-down primitives
  (mk_from_dk/vuk_from_mk/uk_from_vuk) + newtypes; KeySource->get_uk(ctx)+
  ResolveCtx; Unlocker->unlock()->Result<Vid,UnlockError> + AacsCertUnlocker;
  OEM bus-key gate (AacsBusKeyUnavailable); structured ResolutionTrace (Step 4).
- TrueHD: sample-rate from major-sync, Atmos label, 44.1k AU duration.
- consts: central media/format constants module; 17 duplicate const-defs
  centralized (sector/TS-packet/source-packet); mpls stream-entry + category
  codes named.
- clippy --all-targets -D warnings clean (1.86); fmt clean; 2199 lib tests.
2026-06-26 12:19:24 -07:00
Matthew Jackson 05729f5dfe fix(libfreemkv): rc6 hardening pass — mux timeline/colour/PCR, demux panic sentinel, parser robustness + doc accuracy
Surgical fixes (each with a regression test that fails without the change):

mux/mkv.rs, mux/demux_sink.rs: drive the clip-boundary timeline epoch
off the resolved PRIMARY VIDEO track, not the literal stream index 0.
An M2TS/PMT title can list an audio ES before video, so streams[0] may
be audio; a non-video epoch driver ratchets the frontier and inflates
the timeline. mkv cluster-opening falls back to track 0 for audio-only
titles so they still open clusters.

mux/codec/ac3.rs: correct ACMOD_CHANNELS — acmod=5 (3/1) is 4 channels,
not 3 (was undercounting a 3/1 stream); fix the A/52 Table 5.8 doc.

disc/mod.rs: HDMV coding_type 0x91 (Interactive Graphics / menus) no
longer maps to PGS subtitle — it falls through to Unknown so the PMT/STN
walker drops it instead of surfacing a bogus subtitle track.

mux/videomap.rs + mux/mkv.rs: FVI colour now mirrors the MKV muxer's CICP
precedence (measured CICP authoritative; HDR-driven PQ/HLG transfer
override) via a shared cicp_for_video helper, so the two sinks can't
disagree (HDR10 BT.2020 no longer emits SDR transfer 14).

mux/mkvstream.rs: saturating_add on cluster_ts + rel_ts so an adversarial
CLUSTER_TIMESTAMP near i64::MAX can't overflow/panic before the existing
saturating_mul.

mux/timeline.rs: tighten the tail-straggler clamp so a normal new-epoch
non-video frame leading the sparse video frontier by >3s is not demoted
into the previous clip's epoch.

mux/m2ts_mux/mod.rs: re-stamp PCR per video TS packet (mid-PES), not only
at PES boundaries, so a large UHD I-frame can't open a multi-second PCR
gap; modular 33-bit PTS rebasing so a real 90 kHz clock wrap is not
collapsed to PTS 0 (pre-base frames still floor to 0).

io/byte_prefetcher.rs, sector/prefetched.rs: wrap the producer feed loop
in catch_unwind and emit a typed error sentinel on panic, so a mid-stream
producer panic is not read as a clean EOF at the demux boundary (which
would silently truncate the mux).

mux/codec/h264.rs: extend HIGH_PROFILES to the full ISO/IEC 14496-15 set
that mandates the avcC chroma/bit-depth extension (adds 244 et al.).

Doc/comment accuracy: css/mod.rs (50000 sectors, not scrambled-sectors),
aacs/decrypt.rs (decrypt_unit already-clear path), ifo.rs (TT_SRPT at
0xC4), css/lfsr.rs (LFSR0 24-bit; TAB1-then-XOR cipher; real scramble-flag
predicate), disc/read_error.rs (for_sweep does bounded transient retries).

Skipped: keydb.rs SSRF guard (low/latent, no live caller) — a hard
loopback block breaks an existing behavioral test that exercises the
header-EOF path over a loopback server; a clean fix needs a resolver test
seam beyond this surgical pass. The sibling keydb_fetch.rs comment fix is
out of scope (freemkv crate).
2026-06-25 23:39:03 -07:00
Matthew Jackson 6592f2a590 libfreemkv: rc.5.1 DVD correctness fixes
- CSS: unlock scrambled-sector reads on enforcing drives via bus-auth
  only; classify sense 6F/03 as CSS-locked; early-bail on a fully locked
  scan; gate the AACS handshake off DVD discs.
- DVD first-play menu no longer prepended to the feature: read the title
  VOBS base from vtstt_vobs (0xC4), not the menu VOBS vtsm_vobs (0xC0).
- Interlaced field-duration (DefaultDecodedFieldDuration) written as a
  direct TrackEntry child rather than inside Video, so Windows reports
  the correct frame rate.
- Audio channel count read from the AC-3 bitstream; FieldOrder set to
  TFF; per-track BPS tags.
- Structured disc diagnostics at --log-level 3; reduced per-operation
  log spam.
2026-06-24 14:34:55 -07:00
Matthew Jackson 8b8ada7802 fix: drop BytePrefetcher channel endpoints before join to prevent deadlock
Drop rx and recycle_tx (now Option fields) before joining the producer
thread in BytePrefetcher::Drop. Without this, a non-EOF source fills the
depth-2 forward channel then spins in send_timeout(POLL_INTERVAL) forever
because rx is never drained; join() deadlocks. Adds a regression test
(drop_endless_prefetcher_joins_cleanly) that directly exercises the path.
2026-06-24 05:50:58 -07:00
Matthew Jackson b82075b41a Fix rc5 audit findings: keydb doc, pipeline ordering, hot-loop Arc, tests
- keydb.rs: separate default_path()/no_home_dir() doc blocks; correct the
  false XDG lock-step claim (Linux write path uses $HOME, ignores
  XDG_CONFIG_HOME; read-side search also checks XDG_CONFIG_HOME).
- io/pipeline.rs: use Release/Acquire on the abandoned flag so a leaked
  consumer reliably skips close() on weak memory models (ARM64/POWER),
  not just x86 TSO.
- mux/disc.rs: cache the decrypt-loss Arc at construction; lost_bytes()
  no longer clones an Arc per frame on the mux hot path.
- disc/dvd.rs: assert display_aspect mapping for both 16:9 (PAL test) and
  4:3 (NTSC test).
- mux/resolve.rs: extract css_error_aborts() helper and unit-test the
  scrambled-but-uncracked CSS guard (Fix 6) incl. the --raw exemption.
- aacs/keys.rs: add unit tests for mkb_type_raw/mkb_type/mkb_is_uhd and
  MkbType (Category C 2.0 UHD, prerecorded 1.0, no-0x10-record None).
- release.yml: publish job needs [verify, test] so a failing test suite
  blocks crates.io publication.
2026-06-23 19:11:09 -07:00
Matthew Jackson d5afeb6088 io: add platform-aware fsync helpers (dir + durable file sync)
Add an io::fsync module with a per-OS split (posix/windows) mirroring the
writeback_file convention, replacing two duplicated dir-fsync copies:

- dir(): POSIX directory fsync; a no-op on Windows, where std cannot open
  a directory as a File and the failed open logged a spurious warning on
  every mapfile write.
- file_durable(): opens the target read+write before sync_all so the flush
  succeeds on Windows, where FlushFileBuffers rejects a read-only handle
  with ERROR_ACCESS_DENIED.

Point the mapfile writer at the shared dir() helper.
2026-06-23 12:38:02 -07:00
Matthew Jackson c3c5259f84 pipeline: leaked consumer must not finalise an abandoned output
When finish_with_halt's grace period expires it detaches from the
consumer thread and returns an error to the caller, but the leaked
consumer kept running to completion: once its wedged write syscall
returned it would fall through to sink.close(). For the mux writer
close() finalises the MKV (Cues block + segment-header patch), so a
leaked consumer could finalise — and keep writing to — an output file
the caller had already reported as failed, racing a fresh rip for the
same device over the same path.

Add a shared abandonment flag the consumer polls in its drain loop and
again before close(). finish_with_grace sets it before dropping the
JoinHandle, so the moment the wedged syscall returns the consumer skips
any further apply and skips close() entirely, then exits. This does not
interrupt the in-flight syscall (only its return or process exit can),
but it bounds the damage to the write already in flight instead of a
full finalise of an abandoned file.

Regression tests cover both sides: a consumer leaked past the grace
period skips close(), while one that finishes inside the grace window
still calls close() and finalises normally.
2026-06-22 23:22:57 -07:00
Matthew Jackson 337e77951c rc2: macOS cross-compile fix + security/recovery hardening
- build.rs: pass target -arch to cc so macos_shim cross-compiles (x86_64-apple-darwin)
- AACS/CSS: unit-aligned decrypting sweep; per-VTS CSS title keys (hard-fail on wrong VTS);
  reject truncated Unit_Key_RO; AACS 2.0 sig-verify skip; CSS bus-auth random nonce
- recovery: gap-filling mapfile load; sweep/copy resume reconciliation; stale-mapfile abort;
  patch wedge/damage-window range reset
- mux: TS continuity + PSI CC desync guards; HEVC numTemporalLayers clamp; MPEG-2 pending
  byte-cap; PS parse_pts marker-bit validation; HdrFormat strict parse; Unknown-variant metadata
- net/keydb: network:// SSRF parity (IPv4-mapped, CGNAT, 0.0.0.0/8, Class-E); bounded keydb
  header read + size cap + error context
- io: durable mapfile fsync; NFS writeback degrade; sync_file_range error capture;
  Windows SCSI u32 transfer guard
2026-06-22 08:58:10 -07:00
Matthew Jackson 5941c059c6 v1.0.0-rc.1
CSS keyless decrypt (Stevenson), AACS 1.0/2.0/2.1, MPEG-2 DVD, multi-OS SCSI, multipass recovery, mux highway, audit hardening
2026-06-21 21:06:07 -07:00
Matthew Jackson f79c2a0aa9 libfreemkv 0.31.4: prune 144 vacuous tests (keep spec-grounded subset) 2026-06-08 07:28:55 -07:00
Matthew Jackson 8000bae177 libfreemkv 0.31.2: comprehensive spec-grounded test suite (~950 tests)
Test-hardening release, no runtime changes. Adds spec-grounded unit tests
across the silent-corruption surfaces — UDF/MPLS/CLPI/IFO parsing, BD/DVD
title + extent assembly, AACS/CSS key handling, TS/PS demux + codec parsers,
MKV/EBML container output, the mux pipeline, sector prefetch + decrypt
decorator, drive/SCSI sense decoding, label extraction, and core I/O. Each
test is grounded in the format spec or real on-disc behavior and verified to
fail under a targeted source mutation. No behavior changed.
2026-06-07 22:28:29 -07:00
Matthew Jackson 061f68594a 0.31.0: hardening and correctness pass across mux, codec, AACS/CSS, UDF/MPLS/CLPI, recovery, drive/SCSI, labels, and I/O
Library-wide review-and-fix pass: tightened AACS keydb/handshake/variant
handling and trailing-partial-unit policy, corrected MPLS mark offset and
added UDF allocation bounds, hardened the mux/codec framing and M2TS paths,
guarded SCSI READ CAPACITY short transfers and unified error mapping, added
overflow guards on untrusted disc input, and made prefetch shutdown
deterministic. Release profile now builds with thin LTO + single codegen unit.
2026-06-07 17:37:38 -07:00
MattJackson 1565da610a chore: scrub non-shippable references from tests/comments 2026-06-01 21:36:57 -07:00
MattJackson c51b3181f2 mux: pipelined PES highway — read+decrypt → demux → parse on 3 threads
Introduces the freemkv mux throughput highway: a three-stage thread
pipeline that replaces the inline single-thread read path for any
file-backed source (ISO and m2ts file URLs both route through it).

  Thread A: read + decrypt  (PrefetchedSectorSource / BytePrefetcher)
  Thread B: M2TS demux      (DemuxThread)
  Thread C: codec parse     (PipelinedPesStream, on caller thread)

Each handoff uses a bounded crossbeam channel with a recycled buffer
pool — no allocations or memcpys in the steady-state hot loop.

Component map:

* io/byte_prefetcher.rs (new) — std::io::Read producer thread with
  recycled Vec<u8> pool. Pairs with PrefetchedSectorSource (sector
  side) so demux_thread::spawn_zero_copy can wire either upstream.
* sector/prefetched.rs — recycled buffer pool added; into_channels()
  peels off the rx/recycle_tx/shell triple for zero-copy demux.
* mux/demux_thread.rs (new) — owns the TsDemuxer/PsDemuxer, runs
  feed() on its thread, ships Vec<PesPacket> batches.
* mux/pipelined_stream.rs (new) — the read-side Stream impl. Pulls
  packets from the demux thread and runs codec parse on the caller.
* mux/resolve.rs — build_iso_pipeline (public) / build_m2ts_pipeline
  (private) assemble the three stages; iso:// and m2ts:// both
  return PipelinedPesStream.
* mux/m2ts.rs — collapsed to a write-only sink (Mode::Read deleted;
  the read direction lives on the highway now).
* mux/codec/h264.rs — find_start_code uses memchr SIMD memmem::find.
* mux/codec/hevc.rs — tightened frame_data initial capacity.
* mux/ts.rs — boundary-packet handling avoids the per-batch 16 MiB
  remainder copy; PesAssembler starts at 16 KiB to dodge the 64-page
  first-touch fault tax that the previous 256 KiB pre-alloc paid on
  every PES boundary.
* mux/disc.rs — gains DiscStream::new_pipeline + read_pipeline as
  the legacy autorip ingress (drive + multipass paths still need
  on_event / skip_errors before they migrate to the highway).
* io/file_sector_source/* — per-OS prefetch() syscall hook
  (Linux readahead, macOS F_RDADVISE, Windows/other no-op).
* decrypt.rs — FREEMKV_DECRYPT_THREADS renamed to FREEMKV_THREADS;
  pool sized to all cores by default.

Measured on rip1 testbed (Civil War UHD, 62 GiB ISO → null://):

  60 → 322 MB/s warm cache (old new_pipeline path)
  60 → 660 MB/s warm cache (highway path, this commit)
  60 → 126 MB/s sustained disk-bound

The IsoSectorReader baseline reader was deleted in favour of
FileSectorSource so the freemkv CLI and autorip exercise the same
read path.
2026-05-19 13:35:32 -07:00
MattJackson b08662f95c Revert "iter14: re-engage FileSectorSource 4 MiB readahead buffer"
This reverts commit 4594196b6e.
2026-05-17 10:50:00 -07:00
MattJackson 4594196b6e iter14: re-engage FileSectorSource 4 MiB readahead buffer
iter13 strace finding: producer thread (mux ISO reader) spends 80%
of wall-clock in state D (NFS RPC wait), doing 207 preads/sec at
103 us each. Pipe is 78 MB/s isolated read; we use ~25 MB/s.

FileSectorSource was using direct per-sector pread (0.21.3 bypass).
That bypass was justified under Phase 2.5 + 0.21.7 producer-poll cap
("32 MiB refill bursts the TCP connection enough to starve the
writer thread"). Both of those conditions are gone now (iter8
baseline: no Phase 2.5, no producer poll cap).

The 4 MiB buffer infrastructure was preserved with #[allow(dead_code)]
in case re-engagement was ever wanted. iter14 just routes the hot
path through buffer_covers + refill + memcpy. Net diff: ~10 LOC of
business logic, 5 unit tests already cover the contract.

Expected: producer's effective read rate jumps from 25 → 60+ MB/s
(matches dd ceiling for 1+ MiB block reads). If consumer side keeps
up, mean mux climbs from 28.7 → 35-50 MB/s. If consumer is now the
cap, we see a clear ceiling around 30-35 and we know where to look
next.

Critically: this change ONLY affects mux-from-ISO. Disc→ISO sweep,
Pass N bad-sector retry, AACS, drive ops, mapfile, recovery — all
untouched (they use DriveSectorSource which is a separate impl).
2026-05-17 10:36:04 -07:00
MattJackson 9d6974df3e iter13 base: lock chunk back to 32 MiB after iter12 revert
iter12 revert restored chunk to 128 (iter11 value) by way of the
revert chain. Setting it back explicitly to 32 for iter13. We're
back to iter8 baseline config (no Phase 2.5, 32 MiB chunks,
DONTNEED, no app-level FileSectorSource buffer, channel depth 32).

iter13 is instrumentation: strace the mux thread during a known-dip
to see where time is actually going.
2026-05-17 09:49:03 -07:00
MattJackson 3394a5b3fe Revert "iter12: fallocate without KEEP_SIZE + truncate_at_sync; chunk back to 32 MiB"
This reverts commit e2c7e20329.
2026-05-17 09:48:35 -07:00
MattJackson e2c7e20329 iter12: fallocate without KEEP_SIZE + truncate_at_sync; chunk back to 32 MiB
iter11 (128 MiB) crashed to 16.6 mean — chunk-size sweet spot is
firmly 32 MiB. Locking in.

iter12 hypothesis: each NFS write past the file's EOF triggers a
server-side SETATTR (metadata commit) to update the file length.
With ~62 GiB of MKV output and writes at chunk boundaries, that's
thousands of SETATTRs per rip. By using plain fallocate (mode 0)
the file is pre-extended to size_bytes up front; subsequent writes
overwrite the pre-extended region with no metadata ops.

Adds high_water tracking + truncate_at_sync so we ftruncate down
to actual content size if the size hint was an overestimate.
2026-05-17 09:35:07 -07:00
MattJackson ff22385a61 iter11: WRITEBACK_CHUNK_BYTES 32 -> 128 MiB
Prediction: ~26-27 mean (regression from iter8). Confirms chunk-size
sweet spot at 32 MiB. Then move off chunk-size as a lever entirely.
2026-05-17 09:21:00 -07:00
MattJackson d39d3933f5 Revert "Reapply "io/writeback: medium-agnostic by construction, no DONTNEED, single detection point""
This reverts commit f7165a2020.
2026-05-17 09:19:44 -07:00
MattJackson 31dc3d35c3 iter10: chunk back to 32 MiB
iter9 (64 MiB on top of no-P2.5) regressed -1.2 from iter8. 32 MiB
remains best on the no-P2.5 path. Net iter10 = iter8 minus DONTNEED
(via the prior commit re-applying f4a881b).
2026-05-17 09:06:34 -07:00
MattJackson f7165a2020 Reapply "io/writeback: medium-agnostic by construction, no DONTNEED, single detection point"
This reverts commit 8ec767339e.
2026-05-17 09:06:14 -07:00
MattJackson d836f8b1e7 iter9: 64 MiB chunks on top of iter8 (Phase 2.5 disabled)
iter8 (Phase 2.5 disabled, 32 MiB chunks) hit 28.7 MB/s mean
— 1.3 MB/s below R2 floor. Without Phase 2.5, WAIT_AFTER blocks the
mux thread directly once per chunk. Halving the WAIT_AFTER frequency
(32 → 64 MiB chunks) should raise the mean without changing the
underlying architecture.
2026-05-17 08:52:51 -07:00
MattJackson 8919de5b03 iter8: chunk back to 32 MiB on top of Phase-2.5 revert
iter7's 64 MiB chunks didn't help (23.1 vs iter4's 24.0). Reverting
to 32 MiB so iter8 differs from iter4 by exactly one variable:
Phase 2.5 disabled / direct passthrough mux thread.

Test question: is Phase 2.5 helping at all? If iter8 mean > iter4,
Phase 2.5 has been a net negative on this rig the whole time. If
iter8 mean < iter4, Phase 2.5 is doing what it claimed.
2026-05-17 08:39:27 -07:00
MattJackson 0dc1f12108 Revert "Reapply "io/writeback_file: restore Phase 2.5 (writer thread + bounded ring)""
This reverts commit 335e8b68cc.
2026-05-17 08:39:06 -07:00
MattJackson 6abc25a7e8 iter7: WRITEBACK_CHUNK_BYTES 32 -> 64 MiB
iter6 (8 MiB chunks) regressed mean -8.2 MB/s vs iter4 (32 MiB).
Trend: bigger = better in this workload, against the page-age
theory. Try 64 MiB to see if fewer/larger syncs raise mean further.
0.21.14 went to 128 MiB and was reverted; 64 is between.
2026-05-17 08:25:44 -07:00
MattJackson 611ad77586 iter6: revert depth bump + WRITEBACK_CHUNK_BYTES 32->8 MiB
iter5 (256-frame channel) regressed -1.8 MB/s vs iter4. Reverting to
32 frames.

iter4 sample pattern shows clear ~30 s oscillation (peak 45 MB/s →
dip 3 MB/s → recovery). Matches Linux vm.dirty_expire_centisecs
default (30 s). 32 MiB chunks at 25 MB/s issue WAIT_AFTER every
~1.3 s, which can't outrun the kernel's own page-age limit, so
pages buildup then flush in bursts. Smaller 8 MiB chunks
(WAIT_AFTER every ~0.33 s) should keep the dirty-page set young
and eliminate the periodic flush-burst dip.
2026-05-17 08:09:57 -07:00
MattJackson 60590193e3 iter5: READ_PIPELINE_DEPTH 32 -> 256 frames
iter4 measurement (Phase 2.5 + DONTNEED, no FileSectorSource buffer)
showed mean 24.0 MB/s but with dips to 2.8 MB/s. Channel at 32 frames
(~1.6 MiB at 50 KB/frame avg) drains in <100 ms on any producer pause,
starving the consumer.

256 frames = ~12 MiB ≈ 3-4 sec of consumer drain at the rolling-avg
floor we want to hit. Should coast through producer micro-stalls
without idle gaps.
2026-05-17 07:53:41 -07:00
MattJackson 5f24843d3c Revert "iter2: restore FileSectorSource readahead buffer (32 MiB)"
This reverts commit ecf9a4d01e.
2026-05-17 07:38:34 -07:00
MattJackson ecf9a4d01e iter2: restore FileSectorSource readahead buffer (32 MiB)
iter1 baseline (Phase 2.5 + DONTNEED restored) measured at 18.4 MB/s
mean on Civil War remux — well below the rig's 37 MB/s concurrent-r+w
ceiling. Per-sector pread is the producer-side bottleneck: ~50us per
pread on NFS = ~19k preads/sec = effective ceiling near what we see.

The 0.21.3 bypass commit cited an A/B test showing the buffer hurt
throughput on NFS bidirectional workloads. That test was taken under
the 0.21.7 producer polling cap; once the cap is gone, the cap was
the bottleneck, not the buffer. Same invalidation pattern as the
0.21.5 Phase 2.5 revert.

Restored the buffered path. DONTNEED page-cache eviction from 0.21.6
stays intact.
2026-05-16 22:46:22 -07:00
MattJackson 8ec767339e Revert "io/writeback: medium-agnostic by construction, no DONTNEED, single detection point"
This reverts commit f4a881b25d.
2026-05-16 17:02:20 -07:00