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.
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.
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.
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.
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.
Three changes targeting 0.20.9's "muxer never read-stalls on NFS read
latency" invariant:
A. FileSectorSource gets a 32 MiB internal read-ahead buffer
(READAHEAD_BUF_BYTES). Splits out from src/sector/file.rs into
src/io/file_sector_source/ with per-OS open hints (Linux
posix_fadvise(SEQUENTIAL), macOS fcntl(F_RDADVISE) with 64 MiB
cap, Windows TODO stub, BSD/illumos no-op). Backward seeks
rebuffer; partial reads at EOF return only the bytes that exist;
oversize-request bypass for count > BUF_SECTORS.
B. WritebackFile inline #[cfg(target_os = "linux")] blocks split
into per-OS files under src/io/writeback_file/. Linux unchanged
(fallocate KEEP_SIZE, fsync via bounded_syscall). macOS gets a
real F_PREALLOCATE + F_FULLFSYNC impl (was a "skipped (non-linux)"
debug log before). Windows is a stub (FlushFileBuffers via
std sync_all; TODO for SetFileValidData). BSDs/illumos fall back
to std sync_all.
C. New byte_channel module — byte-bounded producer/consumer wrapping
std sync_channel with Mutex/Condvar byte accounting. Sender blocks
when used_bytes + item.byte_size() > capacity. HasByteSize impl
for PesFrame. Default cap BYTE_CHANNEL_DEFAULT_CAPACITY = 64 MiB,
sized to absorb worst-case NFS read p99 (~2 s × UHD peak compressed
~15 MB/s). The mux call site lives in autorip (out of scope here);
this lands the primitive in libfreemkv for autorip to adopt.
Test counts: byte_channel +6, file_sector_source +5, sector::file
round-trip suite (3) preserved. passn_handler_ab.rs A/B fixture
(8 profiles) still green.
precommit.sh libfreemkv: fmt + clippy + test all green on Rust 1.86.
No version bump; no Cargo.lock changes; no forbidden-file edits
(disc/patch.rs, disc/read_error.rs, io/pipeline.rs,
tests/passn_handler_ab.rs).
Matthew Jackson