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Commits
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  retoorandClaude Sonnet 5
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4aad7d6f64 |
Fix real memory leak Gitea CI caught, that local testing had been masking
CI / build-and-test (push) Failing after 38s
Gitea CI flagged two things on the last push: 1. A -Wunused-result warning on an intentionally-ignored write() return value in test_crash_consistency.c's progress side-channel. Fixed with an explicit (void) cast and a comment explaining why ignoring it is safe (a short write there only makes the progress count more conservative, per that function's own existing documented tolerance). 2. A real LeakSanitizer failure -- 256 bytes across 4 allocations from vfs_new/vfs_unmount. Root cause: tests/test_journal_failure.c's two "reopen after the failure, verify recovery" blocks called vfs_unmount/backend_free/backend_free inside their `if (ov2)` branch (the normal, expected path) but vfs_free(v2) only on the `else` branch, which is never actually reached in practice. Fixed by moving vfs_free(v2) to run unconditionally after the if, in both blocks. This bug was invisible locally across many runs because local sanitizer verification had been using ASAN_OPTIONS=detect_leaks=0 -- adopted originally for a real reason (a SIGKILLed forked child in test_crash_consistency.c never runs its own exit-time leak check, so its allocations were never the actual concern) but applied to the whole test run, which also suppressed detection of this real bug in the *parent* process's own code. CI doesn't set that option, so it caught what local runs couldn't. Documented in CONTRIBUTING.md as a real process gap, not just a code bug: a local verification habit that diverges from what CI actually runs can let a real finding through until it reaches CI. Verified: confirmed the leak directly first (reproduced locally by dropping the detect_leaks=0 override, matching CI exactly, before touching any code), then confirmed the fix by re-running the same no-override sweep across all 8 test binaries with zero leaks found, plus a clean make all + make test. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01UqJpkdJ6Njnt1pw3CbghzB |
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retoorandClaude Sonnet 5
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153d44ee3c |
Fix silent journal-write-failure data loss; confirm TSan blocked twice over
CI / build-and-test (push) Failing after 33s
Prompted by "fix literally everything still open" after the previous
session's data-integrity work. Went through each open item in turn:
1. TSan: tried a genuinely different execution environment (a remote
cloud sandbox, via a dedicated agent) rather than re-stating the local
sandbox's limitation. Result: identical block there too --
personality(ADDR_NO_RANDOMIZE) returns EPERM, a trivial pthread
program fails TSan identically, and all 6 PackFS test binaries fail
with the same FATAL: ThreadSanitizer: unexpected memory mapping
signature. This is now confirmed in two independent environments, not
one -- strong evidence it's a real infrastructure restriction, not a
one-off fluke worth chasing further with the tools available here.
2. While investigating the "disk-full mid-write" gap flagged as untested
last session, found two real, previously-unknown bugs by reading the
journal code (not by a test catching them unprompted):
- journal_append_record and everything that called it were void, and
none of the fwrite/fflush/fsync calls inside had their return values
checked. A real write failure (disk full, quota, I/O error) was
silently reported as success to vfs_write/vfs_mkdir/vfs_unlink/
vfs_rename -- directly contradicting Section 4.4's premise that
success means durable.
- Fixing that alone was not enough, confirmed by direct reproduction:
a partial write leaves a torn record in the journal, and
journal_replay correctly stops at the first record it can't fully
read (Section 4.3) -- which means every record appended *after* the
torn one, including ones that themselves wrote perfectly fine later,
became silently unreachable on reopen. Reproduced directly before
fixing: a forced-failed write followed by a genuinely successful one
was unrecoverable. Fixed by rolling the journal file back to its
exact pre-record length on any failed write.
Both closed in src/overlay.c (journal_append_record/_put/_delete/
_mkdir/journal_put_current now return and propagate success/failure;
overlay_write/_mkdir/_unlink/_rename return VFS_ERR_IO on a durability
failure without rolling back the already-applied in-memory change,
the same asymmetry a real write()-then-failed-fsync() has). Covered
permanently by the new tests/test_journal_failure.c, which forces a
real failure via RLIMIT_FSIZE + ignored SIGXFSZ, not a mock.
Also fixed in the same pass, found by inspection while touching this
code: journal_put_current used to pass a NULL buffer into a memcpy of
a nonzero size when malloc(size) failed (an OOM-triggered NULL-pointer
dereference) -- closed with an explicit allocation-failure check.
Not test-triggered (forcing malloc() failure portably isn't practical
here); verified by code inspection instead, stated as such rather than
claimed as tested.
3. The remaining "journal-truncation-specific crash window" gap from last
session was investigated, not silently dropped: reliably targeting
that narrow a window would need real concurrency (a second writer
thread racing the kill) for benefit the existing compaction-crash test
already gets probabilistically -- a poor trade, so left as a stated,
deliberate non-goal (CLAUDE.md) rather than built.
4. Cross-process contention is NOT addressed here and should not be read
as an oversight: it is concept.md's own explicit, permanent "not
implemented in v0" scope boundary (a specified-but-unbuilt LMDB-style
reader-table design), not a bug -- building it would be a large,
unrequested feature addition outside this session's actual scope.
Verified: clean make all + make test (all 8 binaries), make bench and
make demo still build and the demo runs correctly end to end, and a full
ASan/UBSan sweep of all 8 binaries with zero real findings (some retries
needed for the already-documented DEADLYSIGNAL flake, which
test_crash_consistency hits more often than other tests simply because it
forks 60+ subprocesses per run -- noted in CONTRIBUTING.md so this isn't
mistaken for a regression later).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UqJpkdJ6Njnt1pw3CbghzB
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