Add master-driven lifecycle operations: promotion, demotion, rebuild,
and split-brain prevention. All testable on Windows with mock TCP.
New files:
- promotion.go: HandleAssignment (single entry point for role changes),
promote (Replica/None -> Primary with durable epoch), demote
(Primary -> Draining -> Stale with drain timeout)
- rebuild.go: RebuildServer (WAL catch-up + full extent streaming),
StartRebuild client (WAL catch-up with full extent fallback,
two-phase rebuild with second catch-up for concurrent writes)
Modified:
- wal_writer.go: ScanFrom() method, ErrWALRecycled sentinel
- repl_proto.go: rebuild message types + RebuildRequest encode/decode
- blockvol.go: assignMu, drainTimeout, rebuildServer fields;
HandleAssignment/StartRebuildServer/StopRebuildServer methods;
rebuild server stop in Close()
- dirty_map.go: Clear() method for full extent rebuild
32 new tests covering WAL scan, promotion/demotion, rebuild server,
rebuild client, split-brain prevention, and full lifecycle scenarios.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Primary ships WAL entries to replica over TCP (data channel), confirms
durability via barrier RPC (control channel). SyncCache runs local fsync
and replica barrier in parallel via MakeDistributedSync. When replica is
unreachable, shipper enters permanent degraded mode and falls back to
local-only sync (Phase 3 behavior).
Key design: two separate TCP ports (data+control), contiguous LSN
enforcement, epoch equality check, WAL-full retry on replica,
cond.Wait-based barrier with configurable timeout, BarrierFsyncFailed
status code. Close lifecycle: shipper → receiver → drain → committer →
flusher → fd.
New files: repl_proto.go, wal_shipper.go, replica_apply.go,
replica_barrier.go, dist_group_commit.go
Modified: blockvol.go, blockvol_test.go
27 dev tests + 21 QA tests = 48 new tests; 889 total (609 engine + 280
iSCSI), all passing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
9 categories: PDU, Params, Login, Discovery, SCSI, DataIO, Session,
Target, Integration. 2,183 lines. All 229 tests pass (164 dev + 55 QA).
No new production bugs found.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
1. Discovery session nil handler crash: reject SCSI commands with
Reject PDU when s.scsi is nil (discovery sessions have no target).
2. CmdSN window enforcement: validate incoming CmdSN against
[ExpCmdSN, MaxCmdSN] using serial arithmetic. Drop out-of-window
commands per RFC 7143 section 4.2.2.1.
3. Data-Out buffer offset validation: enforce BufferOffset == received
for ordered data (DataPDUInOrder=Yes). Prevents silent corruption
from out-of-order or overlapping data.
4. ImmediateData enforcement: reject immediate data in SCSI command
PDU when negotiated ImmediateData=No.
5. UNMAP descriptor length alignment: reject blockDescLen not a
multiple of 16 bytes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The Linux kernel iSCSI initiator pipelines multiple SCSI commands on
the same TCP connection (command queuing). When a write needs R2T for
data beyond the immediate portion, collectDataOut may read a pipelined
SCSI command instead of the expected Data-Out PDU.
Fix: queue non-Data-Out PDUs received during collectDataOut into a
pending buffer. The main dispatch loop drains pending PDUs before
reading from the connection. This correctly handles interleaved
commands during multi-PDU write transfers.
Bug found during WSL2 smoke test: mkfs.ext4 hangs at "Writing
superblocks" because inode table zeroing sends large writes that
exceed FirstBurstLength, triggering R2T while the kernel has already
queued the next command.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Skip InitiatorAlias in negotiation (was returning NotUnderstood)
- Capture TargetName in StageLoginOp direct-jump path (iscsiadm skips
security stage, sends CSG=LoginOp directly -- nil SCSIHandler crash)
- Add portalAddr to TargetServer for discovery responses (listener on
[::] is not routable from WSL2 clients)
- Add -portal flag to iscsi-target binary
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
