ctx->reply.u is a single untagged union shared across opcodes (debugmsg /
get(dataset_t*) / jobid / clusterconf / ctrlstatus alias the same 8 bytes).
Commit 61e1391 added speculative free-guards
`if (ctx->reply.u.ctrlstatus) free_CtrlStatus_ptr(...)` (and the clusterconf
twin). A non-NULL slot does NOT imply a CtrlStatus*: a failover-aborted
reslist/joblist leaves ctx->reply.u.get == &getreply (a dead STACK pointer)
because xce_get_with_condition/xce_resval only cleared the slot on the success
path, not the xce_get_req<0 / cbuf_get<0 early returns. The next ctrlstatus
reply (worker thread) freed that foreign pointer as a CtrlStatus -> ASan
SEGV / stack-use-after-return in free_CtrlStatus (controller.capnp.c:11638).
Fix (root cause, both layers):
- Revert the unsafe free-guards in xce_handle_reply: MOVE_PTR overwrite only,
never free/deref an untagged union slot by type.
- Clear ctx->reply.u.get = NULL on ALL exit paths of xce_get_with_condition
and xce_resval via a single `goto done` cleanup (forget-proof; the bug was
one forgotten failover path). Also drops the now-unused controller.capnp.h.
- Defense-in-depth: handle_get_reply drops a reply when the slot is NULL.
Regression: expose xce_handle_reply and add
test_handle_reply_ctrlstatus_does_not_free_foreign_slot, which poisons the
shared slot with a foreign heap value and proves the ctrlstatus reply handler
does not free it (RED reproduced the exact free_CtrlStatus_ptr double-free;
GREEN after fix). xcelib_test 244/0, controller_unit_test 166/0, all binaries
build clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MSxwb2Xt5F84ATgiAZnH8V
bug-918 resolved (c-capnproto flake repin); clean controller build passes full
suite (Ok:1 Fail:0). Earlier wal_catchup failures were a stale incremental-build
artifact, not fsync/regression. Validation gate reliable for remaining tasks.
WAL-byte decode proves REAL data loss (not commit-index): committed prefix
entries physically absent from live nodes (ctrl-2 WAL starts LSN 16, ctrl-3 LSN
13), present only on the down node. Mechanism: empty-rejoin catch-up streams
[watermark..committed] not [1..], no snapshot to backfill the prefix -> permanent
gap. Predates libxce-failover. Full findings + open forks + xce_test waldump
tooling plan in INVESTIGATION-failover-job-loss.md. Not yet fixed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
xce_failover_rotate reconnected with endpoint_fini+endpoint_init+endpoint_connect
but never re-bound ep->iomgr (reset by endpoint_init) nor re-armed the owner/
msg/err handlers + iomgr_monitor. endpoint_connect then dereferenced a NULL
iomgr (->ssl_ctx) → SEGV at netio.c:672 during live master failover. Added
xce_ctx_reconnect() in xcectx.c that mirrors xcecli_start's establishment
(without restarting iomgr/vtaskmgr or touching ctx->state); rotate delegates to
it. Found via live 3-node E2E. bug-610.
fsync_worker slept the full wal_sync_ms in one uninterruptible nanosleep()
before re-checking fsync_stop. persist_stop sets the flag and immediately
pthread_join()s, so the join blocked until the in-flight sleep returned —
up to a full wal_sync_ms per teardown. Tests set wal_sync_ms=5000 ("slow
fsync — no races"), so each persist_stop cost ~5s; across the ~7 suites
that use it the cumulative teardown time blew past the 300s controller-test
meson cap, killing the suite with SIGTERM.
Replace the nanosleep with pthread_cond_timedwait on a new fsync_mutex/
fsync_cond (added to persist_t, init in persist_init, destroyed in
persist_fini). persist_stop now sets fsync_stop and signals fsync_cond
under fsync_mutex before joining, so the worker wakes immediately. fdatasync
still runs under p->lock, released before re-acquiring fsync_mutex — no lock
nesting. The "commit: WAIT deadline expired" log lines were unrelated
intentional negative tests (50-300ms), not the cause.
Full controller suite now completes in ~10s (was >300s TIMEOUT); 0 failures.
Logged as bug-604.
configAck branch: per-push majority (acked_config_lsn >= push_tag,
1+count > n_peers/2 over r->ce->n_peers, n_peers<=1 immediate,
ce==NULL -EINVAL); legacy >0 counting and n_active==0 shortcut dead.
push_config_to_standbys returns the barrier result; upgrade failure ->
send_upgrade_error (rc forwarded), no success ACK, no restart,
committed_config_tag success-only.
Remediation r1 (two CRITICAL review findings):
- F1: wire production config-ACK ingestion — replconfigpushreplymsg
decode branch in repl_ack_decode_and_dispatch -> repl_on_config_ack
on the promoted-vote ep; + defensive cluster.c OPCode_reply case.
Closes the unlanded half of ha-config-bootstrap 8.1; without this the
barrier would brick every multi-member config upgrade. No schema change.
- F2: keep the barrier off the iomgr thread — export
push_config_transport_only (non-blocking) for the 5 ha.c + join.c
streaming sites; barrier path now vtask-only (do_upgrade_config).
Wire-path test drives real capnp ACK bytes through the production decode
branch. 30/30 rollout, 6/6 repl_majority, 46/46 config_repl; census 0
FAIL; pre-existing fixture leak only (less than baseline).
Green integration proof: 4 facts driven during total quorum loss append
RETAIN with rc 0 in <1000ms (vs 5000ms timeout — wrongly-applied WAIT
tripwire), pending with retained-depth=4 logged, present exactly once
on disk (real WAL header scan); reconnect + one covering ACK commits
the suffix with current_lsn unchanged (no redelivery). Completes the
bug-396 fix evidence (umbrella Req 2.8). Census 495/495.
4 green pins: handle_jobdispatch replies receipt-only with zero WAL
appends through a real 2-alloc dispatch cycle (notify outcomes intact,
reply-precedes-processing); set/clr_preason and do_update_op rusage
stay receipt-style with RETAIN-pending fact appends ACK-committed.
Umbrella Reply-Ordering Contract cited per pin. DISCOVERY bug-451
(reviewer-verified): RUSAGE hook va_list type confusion — 4-byte OOB
read + garbage state in WAL_JOB_RUSAGE payloads; fix deferred to 7.1.
Census 488; zero failures.
Fixed the 3 bug-411 baseline failures honestly: stale timeout
expectation updated to the reject-on-timeout contract (engine-wired
fixture, killing power retained); two healthy-primary gate fixtures
populated with standby_endpoints (gate logic untouched). Census: 46
groups / 467 tests / 0 failures standalone under default ASAN.
Audit (reviewer-confirmed, recorded in tasks.md): no production walAck
path reaches the deprecated acked_lsn>0 counting or n_active==0
short-circuit except the documented LSN-0 first entry. Leak inventory
for 6 groups documented as follow-up.
Replace no-send stub with real WAL entry transmission via
xce_wal_batch_req_raw. For each non-catch-up registered standby,
serialize the entry header+payload into a wal_catchup_entry_t
and enqueue. Keep the MAX_PENDING_ACKS eviction guard.
5 new tests: no-standbys, one-standby-send, skip-catch-up,
evict-overloaded, send-failure-continues. Controller suite green.
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
Appended "Gap Analysis — Validation Pass (2026-06-09)" to each spec's
research.md with requirement-to-asset maps, status tags, and effort/risk.
Key outcomes:
- ha-repl-hardening: REOPENED with task series 7.1-7.7 — replication
payload data plane is missing (snapshot chunks and WAL catch-up ship
header-only; standbys converge on LSN without holding entity state)
- worker-join-refactor, resval-id-decoupling: marked implemented
(all criteria re-verified, full test suite green)
- buglog: 335/336 (scheduler dequeue, open), 337/338/339 (fixed in
previous commit); cerebrum Decision Log corrected (term-only vote
deny was recorded as intentional but was a regression)
