BUG-CP11A4-1 (HIGH): ImportSnapshot now rejects when active snapshots
exist. Import overwrites the extent region that non-CoW'd snapshot blocks
read from, which would silently return import data instead of snapshot-time
data. New ErrImportActiveSnapshots error and snapMu-guarded check.
BUG-CP11A4-2 (HIGH): Double import without AllowOverwrite now correctly
rejected. Import bypasses WAL so nextLSN stays at 1; added FlagImported
(Superblock.Flags bit 0) set after successful import and checked alongside
nextLSN in the non-empty gate.
BUG-CP11A4-3 (MED): Replaced fixed exportTempSnapID (0xFFFFFFFE) with
atomic sequence counter (exportTempSnapBase + exportTempSnapSeq). Each
auto-export gets a unique temp snapshot ID, preventing concurrent export
races and user snapshot ID collisions.
Also added beginOp()/endOp() lifecycle guards to both ExportSnapshot and
ImportSnapshot, and documented the non-atomic import failure semantics.
5 new regression tests + QA-EX-3 rewritten for rejection behavior.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add PressureState() and writer wait tracking to WALAdmission, WALStatus
snapshot API on BlockVol, WAL sizing guidance pure functions, Prometheus
histogram/gauge/counter exports, and admin /status WAL fields. 23 new
tests (7 admission, 10 guidance, 6 QA adversarial).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Finding 1: IOBackend=io_uring was accepted and logged as resolved but
had no runtime effect. Now rejected by Validate() until actually wired,
preventing user confusion.
Finding 2: wal_admit_wait_seconds_total was exported as GaugeFunc but
is monotonically increasing. Changed to CounterFunc to match _total
naming convention.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add counters (total, soft, hard, timeout) and wait-time histogram to
WALAdmission, wired through EngineMetrics and exported as Prometheus
metrics. Six new tests verify all code paths. Nil-safe for backwards
compatibility.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Replace UseIOUring bool with IOBackend IOBackendMode (tri-state):
- "standard" (default): sequential pread/pwrite/fdatasync
- "auto": try io_uring, fall back to standard with warning log
- "io_uring": require io_uring, fail startup if unavailable
NewIOUring now returns ErrIOUringUnavailable instead of silently
falling back — callers decide whether to fail or fall back based
on the requested mode. All mode transitions are logged:
io backend: requested=auto selected=standard reason=...
io backend: requested=io_uring selected=io_uring
CLI: --io-backend=standard|auto|io_uring added to iscsi-target.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add ALUA (Asymmetric Logical Unit Access) support to the iSCSI target,
enabling dm-multipath on Linux to automatically detect path state changes
and reroute I/O during HA failover without initiator-side intervention.
- ALUAProvider interface with implicit ALUA (TPGS=0x01)
- INQUIRY byte 5 TPGS bits, VPD 0x83 with NAA+TPG+RTP descriptors
- REPORT TARGET PORT GROUPS handler (MAINTENANCE IN SA=0x0A)
- MAINTENANCE OUT rejection (implicit-only, no SET TPG)
- Standby write rejection (NOT_READY ASC=04h ASCQ=0Bh)
- RoleNone maps to Active/Optimized (standalone single-node compatibility)
- NAA-6 device identifier derived from volume UUID
- -tpg-id flag with [1,65535] validation
- dm-multipath config + setup script (group_by_tpg, ALUA prio)
- 12 unit tests + 16 QA adversarial tests + 4 integration tests
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add SimulatedMaster test helper + 20 assignment sequence tests (8 sequence,
5 failover, 5 adversarial, 2 status). Add BlockVolumeStatus struct and
Status() method. Includes QA test files for CP1-CP4a. 940 total unit tests.
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>
