TQ: Support for ZFS Key Rotation by plaidfinch · Pull Request #9737 · oxidecomputer/omicron

plaidfinch · 2026-01-28T22:22:51Z

When Trust Quorum commits a new epoch, all U.2 crypt datasets must have their encryption keys rotated to use the new epoch's derived key. This change implements the key rotation flow triggered by epoch commits.

Trust Quorum Integration

Add watch channel to NodeTaskHandle for epoch change notifications
Initialize channel with current committed epoch on startup
Notify subscribers via send_if_modified() when epoch changes

Config Reconciler Integration

Accept committed_epoch_rx watch channel from trust quorum
Trigger reconciliation when epoch changes
Track per-disk encryption epoch in ExternalDisks
Add rekey_for_epoch() to coordinate key rotation:
- Filter disks needing rekey (cached epoch < target OR unknown)
- Derive keys for each disk via StorageKeyRequester
- Send batch request to dataset task
- Update cached epochs on success
- Retry on failure via normal reconciliation retry logic

Dataset Task Changes

Add RekeyRequest/RekeyResult types for batch rekey operations
Add datasets_rekey() with idempotency check (skip if already at target)
Use Zfs::change_key() for atomic key + epoch property update

ZFS Utilities

Add Zfs::change_key() using zfs_atomic_change_key crate
Add Zfs::load_key(), unload_key(), dataset_exists()
Add epoch field to DatasetProperties
Add structured error types for key operations

Crash Recovery

Add trial decryption recovery in sled-storage for datasets with missing epoch property (e.g., crash during initial creation)
Unload key before each trial attempt to handle crash-after-load-key
Set epoch property after successful recovery

key-manager/src/lib.rs

sled-agent/config-reconciler/src/reconciler_task/external_disks.rs

This commit adds a 3 phase mechanism for sled expungement. The first phase is to remove the sled from the latest trust quorum configuration via omdb. The second phase is to reboot the sled after polling for commit the trust quorum removal. The third phase is to issue the existing omdb expunge command, which changes the sled policy as before. The first and second phases remove the need to physically remove the sled before expungement. They act as a software mechanism that gates the sled-agent from restarting on the sled and doing work when it should be treated as "absent". We've discussed this numerous times in the update huddle and it is finally arriving! The third phase is what informs reconfigurator that the sled is gone and remains the same except for an extra sanity check that that the last committed trust quorum configuration does not contain the sled that is to be expunged. The removed sled may be added back to this rack or another after being clean slated. I tested this by deleting the files in the internal "cluster" and "config" directories and rebooting the removed sled in a4x2 and it worked. This PR is marked draft because it changes the current sled-expunge pathway to depend on real trust quorum. We cannot safely merge it in until the key-rotation work from #9737 is merged in. This also builds on #9741 and should merge after that PR.

When Trust Quorum commits a new epoch, all U.2 crypt datasets must have their encryption keys rotated to use the new epoch's derived key. This change implements the key rotation flow triggered by epoch commits. ## Trust Quorum Integration - Add watch channel to `NodeTaskHandle` for epoch change notifications - Initialize channel with current committed epoch on startup - Notify subscribers via `send_if_modified()` when epoch changes ## Config Reconciler Integration - Accept `committed_epoch_rx` watch channel from trust quorum - Trigger reconciliation when epoch changes - Track per-disk encryption epoch in `ExternalDisks` - Add `rekey_for_epoch()` to coordinate key rotation: - Filter disks needing rekey (cached epoch < target OR unknown) - Derive keys for each disk via `StorageKeyRequester` - Send batch request to dataset task - Update cached epochs on success - Retry on failure via normal reconciliation retry logic ## Dataset Task Changes - Add `RekeyRequest`/`RekeyResult` types for batch rekey operations - Add `datasets_rekey()` with idempotency check (skip if already at target) - Use `Zfs::change_key()` for atomic key + epoch property update ## ZFS Utilities - Add `Zfs::change_key()` using `zfs_atomic_change_key` crate - Add `Zfs::load_key()`, `unload_key()`, `dataset_exists()` - Add `epoch` field to `DatasetProperties` - Add structured error types for key operations ## Crash Recovery - Add trial decryption recovery in `sled-storage` for datasets with missing epoch property (e.g., crash during initial creation) - Unload key before each trial attempt to handle crash-after-load-key - Set epoch property after successful recovery ## Safety Properties - Atomic: Key and epoch property set together via `zfs_atomic_change_key` - Idempotent: Skip rekey if dataset already at target epoch - Crash-safe: Epoch read from ZFS on restart rebuilds cache correctly - Conservative: Unknown epochs (None) trigger rekey attempt

Create a new key-manager-types crate containing the disk encryption key types (Aes256GcmDiskEncryptionKey and VersionedAes256GcmDiskEncryptionKey) that were previously defined in key-manager. This breaks the dependency from illumos-utils to key-manager, allowing illumos-utils to depend only on the minimal types crate. The key-manager crate re-exports VersionedAes256GcmDiskEncryptionKey for backwards compatibility.

illumos-utils/src/zfs.rs

sled-agent/config-reconciler/src/reconciler_task/external_disks.rs

sled-agent/config-reconciler/src/reconciler_task.rs

illumos-utils/src/zfs.rs

andrewjstone

This looks fantastic @plaidfinch.

We'll need to test this and possibly coordinate merging it in case it relies on trust quorum being enabled / lrtq upgrade, etc...

illumos-utils/Cargo.toml

illumos-utils/src/zfs.rs

sled-agent/config-reconciler/src/dataset_serialization_task.rs

sled-agent/config-reconciler/src/reconciler_task.rs

sled-storage/src/dataset.rs

illumos-utils/src/zfs.rs

sled-agent/config-reconciler/src/dataset_serialization_task.rs

sled-agent/config-reconciler/src/reconciler_task.rs

sled-storage/src/dataset.rs

andrewjstone · 2026-02-04T20:43:31Z

We tested this on a4x2 with TQ enabled and keys were created correctly during RSS. We then added a sled and rotation completed correctly. We're going to relaunch with trust quorum disabled and see if we can upgrade out of lrtq successfully and then add a sled in our next experiment.

illumos-utils/src/zfs.rs

sled-agent/config-reconciler/src/dataset_serialization_task.rs

sled-agent/config-reconciler/src/reconciler_task.rs

andrewjstone · 2026-02-05T06:26:34Z

Woohoo. Tested on hardware. LRTQ upgrade succeeded. This required a small patch, which we should pull into this branch: 494d49a

I think it's probably good to go in once the comments are resolved and this patch is pulled in. Will re-assess when fresh tomorrow.

- Format ZFS_GET_PROPS const with concat! and clarify epoch field docs - Preserve error source chain with anyhow::Error::from instead of formatting - Convert KeyRotationError from enum to struct (single variant) - Log current and new epochs in key rotation success and failure paths - Change rekey_for_epoch to return ReconciliationResult instead of bool - Add error log for unexpected epoch-ahead-of-target condition - Simplify epoch filter using Option<Epoch> ordering - Move dataset_name allocation into Ok branch to minimize scope - Upgrade all-key-derivations-failed log from info to warn - Inline dataset_exists helper, calling Zfs::dataset_exists directly - Log warning on best-effort unload_key failure

…ectations

The mark_unchanged() call before the reconciler loop was a no-op: borrow_and_update() inside do_reconcilation() already reads and processes the current epoch unconditionally, marking it as seen. Also remove a stale comment about copying epoch out of the Ref, which was informational and no longer adds clarity.

sled-agent/src/http_entrypoints.rs

This reverts commit 8062384.

…etriever

andrewjstone · 2026-02-06T16:41:01Z

Out of an abundance of caution, we'll hold off merging this until the R18 branch has been cut. I don't think there's any real risk here, but it also isn't necessary to merge. We'll be testing the latest changes today.

andrewjstone · 2026-02-06T20:15:00Z

I was able to add, expunge, add with a4x2 and it all worked. We ended up at epoch 4.

plaidfinch commented Jan 28, 2026

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andrewjstone mentioned this pull request Jan 31, 2026

Trust Quorum Tracking #8262

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andrewjstone mentioned this pull request Jan 31, 2026

TQ: Support sled expunge via trust quorum pathway #9765

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plaidfinch force-pushed the tq-zfs-key-rotation branch from eb41801 to c070803 Compare February 4, 2026 02:38

plaidfinch force-pushed the tq-zfs-key-rotation branch from c070803 to e45b10d Compare February 4, 2026 02:43

plaidfinch linked an issue Feb 4, 2026 that may be closed by this pull request

TQ: Support for ZFS Key Rotation #9587

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plaidfinch force-pushed the tq-zfs-key-rotation branch from 1a9b8cf to 291e41e Compare February 4, 2026 03:10

plaidfinch marked this pull request as ready for review February 4, 2026 03:11

plaidfinch force-pushed the tq-zfs-key-rotation branch from 291e41e to ad6274e Compare February 4, 2026 03:12

plaidfinch requested review from andrewjstone and jgallagher February 4, 2026 03:12

plaidfinch commented Feb 4, 2026

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hawkw reviewed Feb 4, 2026

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andrewjstone and others added 4 commits February 5, 2026 16:34

remove stale check

6c4b60b

Fix log messages during trial decryption to be more precise about exp…

963d9da

…ectations

plaidfinch commented Feb 5, 2026

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plaidfinch added 3 commits February 5, 2026 17:58

Add 2-minute timeout around get_key in the config reconciler

8062384

Revert "Add 2-minute timeout around get_key in the config reconciler"

912f6f5

This reverts commit 8062384.

Add 2-minute timeout around loading rack secrets inside the TqSecretR…

a70594e

…etriever

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Trust Quorum Integration

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