Merge pull request #6116 from filecoin-project/release/v1.8.0

Lotus v1.8.0
Lotus version 1.8.0
2021-04-27 09:01:34 +02:00 · 2021-04-27 02:02:49 -04:00 · 2021-04-27 02:02:44 -04:00 · 2021-04-05 15:30:28 -04:00 · 2021-04-05 15:27:43 -04:00 · 2021-04-05 15:24:05 -04:00
282 changed files with 14160 additions and 3002 deletions
@@ -2,6 +2,7 @@ version: 2.1
 orbs:
  go: gotest/tools@0.0.13
  aws-cli: circleci/aws-cli@1.3.2
+  packer: salaxander/packer@0.0.3

 executors:
  golang:
@@ -129,6 +130,9 @@ jobs:
      winpost-test:
        type: string
        default: "0"
+      deadline-test:
+        type: string
+        default: "0"
      test-suite-name:
        type: string
        default: unit
@@ -162,6 +166,7 @@ jobs:
          name: go test
          environment:
            LOTUS_TEST_WINDOW_POST: << parameters.winpost-test >>
+            LOTUS_TEST_DEADLINE_TOGGLING: << parameters.deadline-test >>
            SKIP_CONFORMANCE: "1"
          command: |
            mkdir -p /tmp/test-reports/<< parameters.test-suite-name >>
@@ -203,6 +208,8 @@ jobs:
    <<: *test
  test-window-post-dispute:
    <<: *test
+  test-deadline-toggling:
+    <<: *test
  test-terminate:
    <<: *test
  test-conformance:
@@ -277,6 +284,11 @@ jobs:
      - install-deps
      - prepare
      - run: make calibnet
+      - run: mkdir linux-calibnet && mv lotus lotus-miner lotus-worker linux-calibnet
+      - persist_to_workspace:
+          root: "."
+          paths:
+            - linux-calibnet
  build-lotus-soup:
    description: |
      Compile `lotus-soup` Testground test plan
@@ -289,7 +301,7 @@ jobs:
      - run: cd extern/filecoin-ffi && make
      - run:
          name: "go get lotus@master"
-          command: cd testplans/lotus-soup && go get github.com/filecoin-project/lotus@master
+          command: cd testplans/lotus-soup && go mod edit -replace=github.com/filecoin-project/lotus=../..
      - run:
          name: "build lotus-soup testplan"
          command: pushd testplans/lotus-soup && go build -tags=testground .
@@ -583,6 +595,22 @@ jobs:
              docker push $<<parameters.account-url>>/<<parameters.repo>>:${tag}
            done

+  publish-packer:
+    description: build and push AWS IAM and DigitalOcean droplet.
+    executor:
+      name: packer/default
+      packer-version: 1.6.6
+    steps:
+      - checkout
+      - attach_workspace:
+          at: "."
+      - packer/build:
+          template: tools/packer/lotus.pkr.hcl
+          args: "-var ci_workspace_bins=./linux -var lotus_network=mainnet -var git_tag=$CIRCLE_TAG"
+      - packer/build:
+          template: tools/packer/lotus.pkr.hcl
+          args: "-var ci_workspace_bins=./linux-calibnet -var lotus_network=calibrationnet -var git_tag=$CIRCLE_TAG"
+
 workflows:
  version: 2.1
  ci:
@@ -627,6 +655,11 @@ workflows:
          go-test-flags: "-run=TestTerminate"
          winpost-test: "1"
          test-suite-name: terminate
+      - test-deadline-toggling:
+          codecov-upload: true
+          go-test-flags: "-run=TestDeadlineToggling"
+          deadline-test: "1"
+          test-suite-name: deadline-toggling
      - test-short:
          go-test-flags: "--timeout 10m --short"
          test-suite-name: short
@@ -683,3 +716,15 @@ workflows:
          path: .
          repo: lotus-dev
          tag: '${CIRCLE_SHA1:0:8}'
+      - publish-packer:
+          requires:
+            - build-all
+            - build-ntwk-calibration
+          filters:
+            branches:
+              ignore:
+                - /.*/
+            tags:
+              only:
+                - /^v\d+\.\d+\.\d+$/
+         
@@ -0,0 +1,33 @@
+---
+name: Bug Report
+about: Create a report to help us improve
+title: "[BUG] "
+labels: hint/needs-triaging, kind/bug
+assignees: ''
+
+---
+
+> Note: For security-related bugs/issues, please follow the [security policy](https://github.com/filecoin-project/lotus/security/policy).
+
+**Describe the bug**
+A clear and concise description of what the bug is. 
+(If you are not sure what the bug is, try to figure it out via a [discussion](https://github.com/filecoin-project/lotus/discussions/new) first!
+
+**Version (run `lotus version`):**
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Run '...'
+2. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Logs**
+Provide daemon/miner/worker logs, and goroutines(if available) for troubleshooting.
+ 
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Additional context**
+Add any other context about the problem here.
@@ -1,27 +0,0 @@
---
-name: Bug report
-about: Create a report to help us improve
-title: ''
-labels: ''
-assignees: ''
-
---
-
-**Describe the bug**
-A clear and concise description of what the bug is.
-
-**To Reproduce**
-Steps to reproduce the behavior:
-1. Run '...'
-2. See error
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**Version (run `lotus version`):**
-
-**Additional context**
-Add any other context about the problem here.
@@ -0,0 +1,49 @@
+---
+name: Deal Making Issues
+about: Create a report for help with deal making failures.
+title: "[Deal Making Issue]"
+labels: hint/needs-triaging, area/markets
+assignees: ''
+
+---
+
+> Note: For security-related bugs/issues, please follow the [security policy](https://github.com/filecoin-project/lotus/security/policy).
+
+Please provide all the information requested here to help us troubleshoot "deal making failed" issues.
+If the information requested is missing, we will probably have to just ask you to provide it anyway,
+before we can help debug.
+
+**Basic Information**
+Including information like, Are you the client or the miner? Is this a storage deal or a retrieval deal? Is it an offline deal?
+
+**Describe the problem**
+
+A brief description of the problem you encountered while trying to make a deal. 
+
+**Version**
+
+The output of `lotus --version`.
+
+**Setup**
+
+You miner(if applicable) and daemon setup, i.e: What hardware do you use, how much ram and etc.
+
+**To Reproduce**
+ Steps to reproduce the behavior:
+ 1. Run '...'
+ 2. See error
+
+**Deal status**
+
+The output of `lotus client list-deals -v` and/or `lotus-miner storage-deals|retrieval-deals|data-transfers list [-v]` commands for the deal(s) in question.
+
+**Lotus daemon and miner logs**
+
+Please go through the logs of your daemon and miner(if applicable), and include screenshots of any error/warning-like messages you find.
+
+Alternatively please upload full log files and share a link here
+
+** Code modifications **
+
+If you have modified parts of lotus, please describe which areas were modified,
+and the scope of those modifications
@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: "[Feature Request]"
+labels: hint/needs-triaging
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.
@@ -0,0 +1,35 @@
+---
+name: Mining Issues
+about: Create a report for help with mining failures.
+title: "[Mining Issue]"
+labels: hint/needs-triaging, area/mining
+assignees: ''
+
+---
+
+> Note: For security-related bugs/issues, please follow the [security policy](https://github.com/filecoin-project/lotus/security/policy).
+
+Please provide all the information requested here to help us troubleshoot "mining/WinningPoSt failed" issues.
+If the information requested is missing, you may be asked you to provide it.
+
+**Describe the problem**
+A brief description of the problem you encountered while mining new blocks.
+
+**Version**
+
+The output of `lotus --version`.
+
+**Setup**
+
+You miner and daemon setup, including what hardware do you use, your environment variable settings, how do you run your miner and worker, do you use GPU and etc.
+
+**Lotus daemon and miner logs**
+
+Please go through the logs of your daemon and miner, and include screenshots of any error/warning-like messages you find, highlighting the one has "winning post" in it.
+
+Alternatively please upload full log files and share a link here
+
+** Code modifications **
+
+If you have modified parts of lotus, please describe which areas were modified,
+and the scope of those modifications
@@ -0,0 +1,46 @@
+---
+name: Proving Issues
+about: Create a report for help with proving failures.
+title: "[Proving Issue]"
+labels: area/proving, hint/needs-triaging
+assignees: ''
+
+---
+
+> Note: For security-related bugs/issues, please follow the [security policy](https://github.com/filecoin-project/lotus/security/policy).
+
+Please provide all the information requested here to help us troubleshoot "proving/window PoSt failed" issues.
+If the information requested is missing, we will probably have to just ask you to provide it anyway,
+before we can help debug.
+
+**Describe the problem**
+A brief description of the problem you encountered while proving the storage.
+
+**Version**
+
+The output of `lotus --version`.
+
+**Setup**
+
+You miner and daemon setup, including what hardware do you use, your environment variable settings, how do you run your miner and worker, do you use GPU and etc.
+
+**Proving status**
+
+The output of `lotus-miner proving` info.
+
+**Lotus miner logs**
+
+Please go through the logs of your miner, and include screenshots of any error-like messages you find, highlighting the one has "window post" in it.
+
+Alternatively please upload full log files and share a link here
+
+**Lotus miner diagnostic info**
+
+Please collect the following diagnostic information, and share a link here
+
+* lotus-miner diagnostic info `lotus-miner info all > allinfo.txt`
+
+** Code modifications **
+
+If you have modified parts of lotus, please describe which areas were modified,
+and the scope of those modifications
@@ -1,21 +1,32 @@
 ---
 name: Sealing Issues
 about: Create a report for help with sealing (commit) failures.
-title: ''
-labels: 'sealing'
+title: "[Sealing Issue]"
+labels: hint/needs-triaging, area/sealing
 assignees: ''

 ---

+> Note: For security-related bugs/issues, please follow the [security policy](https://github.com/filecoin-project/lotus/security/policy).
+
 Please provide all the information requested here to help us troubleshoot "commit failed" issues.
 If the information requested is missing, we will probably have to just ask you to provide it anyway,
 before we can help debug.

 **Describe the problem**
+A brief description of the problem you encountered while sealing a sector.

-A brief description of the problem you encountered while proving (sealing) a sector.
+**Version**

-Including what commands you ran, and a description of your setup, is very helpful.
+The output of `lotus --version`.
+
+**Setup**
+
+You miner and daemon setup, including what hardware do you use, your environment variable settings, how do you run your miner and worker, do you use GPU and etc.
+
+**Commands**
+
+Commands you ran.

 **Sectors status**

@@ -37,7 +48,3 @@ Please collect the following diagnostic information, and share a link here

 If you have modified parts of lotus, please describe which areas were modified,
 and the scope of those modifications
-
-**Version**
-
-The output of `lotus --version`.
@@ -1,11 +1,153 @@
 # Lotus changelog

+# 1.8.0 / 2021-04-05
+
+This is a mandatory release of Lotus that upgrades the network to version 12, which introduces various performance improvements to the cron processing of the power actor. The network will upgrade at height 712320, which is 2021-04-29T06:00:00Z.
+
+## Changes 
+
+- v4 specs-actors integration, nv12 migration (https://github.com/filecoin-project/lotus/pull/6116)
+
+# 1.6.0 / 2021-04-05
+
+This is a mandatory release of Lotus that upgrades the network to version 11, which implements [FIP-0014](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0014.md). The network will upgrade at height 665280, which is 2021-04-12T22:00:00Z.
+
+## v1 sector extension CLI
+
+This release also expands the `lotus-miner sectors extend` CLI, with a new option that automatically extends all extensible v1 sectors. The option can be run using `lotus-miner sectors extend --v1-sectors`.
+
+- The `tolerance` flag can be passed to indicate what durations aren't "worth" extending. It defaults to one week, which means that sectors whose current lifetime's are within one week of the maximum possible lifetime will not be extended.
+
+- The `expiration-cutoff` flag can be passed to skip sectors whose expiration is past a certain point from the current head. It defaults to infinity (no cutoff), but if, say, 28800 was specified, then only sectors expiring in the next 10 days would be extended (2880 epochs in 1 day).
+
+## Changes 
+
+- Util for miners to extend all v1 sectors (https://github.com/filecoin-project/lotus/pull/5924)
+- Upgrade the butterfly network (https://github.com/filecoin-project/lotus/pull/5929)
+- Introduce the v11 network upgrade (https://github.com/filecoin-project/lotus/pull/5904)
+- Debug mode: Make upgrade heights controllable by an envvar (https://github.com/filecoin-project/lotus/pull/5919)
+
+# 1.5.3 / 2021-03-24
+
+This is a patch release of Lotus that introduces small fixes to the Storage FSM.
+
+## Changes 
+
+- storagefsm: Fix double unlock with ready WaitDeals sectors (https://github.com/filecoin-project/lotus/pull/5783)
+- backupds: Allow larger values in write log (https://github.com/filecoin-project/lotus/pull/5776)
+- storagefsm: Don't log the SectorRestart event (https://github.com/filecoin-project/lotus/pull/5779)
+
+# 1.5.2 / 2021-03-11
+
+This is an hotfix release of Lotus that fixes a critical bug introduced in v1.5.1 in the miner windowPoSt logic. This upgrade is only affecting miner nodes.
+
+## Changes
+- fix window post rand check (https://github.com/filecoin-project/lotus/pull/5773)
+- wdpost: Always use head tipset to get randomness (https://github.com/filecoin-project/lotus/pull/5774)
+
+# 1.5.1 / 2021-03-10
+
+This is an optional release of Lotus that introduces an important fix to the WindowPoSt computation process. The change is to wait for some confidence before drawing beacon randomness for the proof. Without this, invalid proofs might be generated as the result of a null tipset. 
+
+## Splitstore
+
+This release also introduces the splitstore, a new optional blockstore that segregates the monolithic blockstore into cold and hot regions. The hot region contains objects from the last 4-5 finalities plus all reachable objects from two finalities away. All other objects are moved to the cold region using a compaction process that executes every finality, once 5 finalities have elapsed.
+
+The splitstore allows us to separate the two regions quite effectively, using two separate badger blockstores. The separation
+means that the live working set is much smaller, which results in potentially significant performance improvements. In addition, it means that the coldstore can be moved to a separate (bigger, slower, cheaper) disk without loss of performance.
+
+The design also allows us to use different implementations for the two blockstores; for example, an append-only blockstore could be used for coldstore and a faster memory mapped blockstore could be used for the hotstore (eg LMDB). We plan to experiment with these options in the future.
+
+Once the splitstore has been enabled, the existing monolithic blockstore becomes the coldstore. On the first head change notification, the splitstore will warm up the hotstore by copying all reachable objects from the current tipset into the hotstore.  All new writes go into the hotstore, with the splitstore tracking the write epoch. Once 5 finalities have elapsed, and every finality thereafter, the splitstore compacts by moving cold objects into the coldstore. There is also experimental support for garbage collection, whereby nunreachable objects are simply discarded.
+
+To enable the splitstore, add the following to config.toml:
+
+```
+[Chainstore]
+  EnableSplitstore = true
+```
+
+## Highlights
+
+Other highlights include:
+
+- Improved deal data handling - now multiple deals can be adding to sectors in parallel
+- Rewriten sector pledging - it now actually cares about max sealing sector limits
+- Better handling for sectors stuck in the RecoverDealIDs state
+- lotus-miner sectors extend command
+- Optional configurable storage path size limit
+- Config to disable owner/worker fallback from control addresses (useful when owner is a key on a hardware wallet)
+- A write log for node metadata, which can be restored as a backup when the metadata leveldb becomes corrupted (e.g. when you run out of disk space / system crashes in some bad way)
+
+## Changes
+
+- avoid use mp.cfg directly to avoid race (https://github.com/filecoin-project/lotus/pull/5350)
+- Show replacing message CID is state search-msg cli (https://github.com/filecoin-project/lotus/pull/5656)
+- Fix riceing by importing the main package (https://github.com/filecoin-project/lotus/pull/5675)
+- Remove sectors with all deals expired in RecoverDealIDs (https://github.com/filecoin-project/lotus/pull/5658)
+- storagefsm: Rewrite input handling (https://github.com/filecoin-project/lotus/pull/5375)
+- reintroduce Refactor send command for better testability (https://github.com/filecoin-project/lotus/pull/5668)
+- Improve error message with importing a chain (https://github.com/filecoin-project/lotus/pull/5669)
+- storagefsm: Cleanup CC sector creation (https://github.com/filecoin-project/lotus/pull/5612)
+- chain list --gas-stats display capacity (https://github.com/filecoin-project/lotus/pull/5676)
+- Correct some logs (https://github.com/filecoin-project/lotus/pull/5694)
+- refactor blockstores (https://github.com/filecoin-project/lotus/pull/5484)
+- Add idle to sync stage's String() (https://github.com/filecoin-project/lotus/pull/5702)
+- packer provisioner (https://github.com/filecoin-project/lotus/pull/5604)
+- add DeleteMany to Blockstore interface (https://github.com/filecoin-project/lotus/pull/5703)
+- segregate chain and state blockstores (https://github.com/filecoin-project/lotus/pull/5695)
+- fix(multisig): The format of the amount is not correct in msigLockApp (https://github.com/filecoin-project/lotus/pull/5718)
+- Update butterfly network (https://github.com/filecoin-project/lotus/pull/5627)
+- Collect worker task metrics (https://github.com/filecoin-project/lotus/pull/5648)
+- Correctly format disputer log (https://github.com/filecoin-project/lotus/pull/5716)
+- Log block CID in the large delay warning (https://github.com/filecoin-project/lotus/pull/5704)
+- Move api client builders to a cliutil package (https://github.com/filecoin-project/lotus/pull/5728)
+- Implement net peers --extended (https://github.com/filecoin-project/lotus/pull/5734)
+- Command to extend sector expiration (https://github.com/filecoin-project/lotus/pull/5666)
+- garbage collect hotstore after compaction (https://github.com/filecoin-project/lotus/pull/5744)
+- tune badger gc to repeatedly gc the value log until there is no rewrite (https://github.com/filecoin-project/lotus/pull/5745)
+- Add configuration option for pubsub IPColocationWhitelist subnets (https://github.com/filecoin-project/lotus/pull/5735)
+- hot/cold blockstore segregation (aka. splitstore) (https://github.com/filecoin-project/lotus/pull/4992)
+- Customize verifreg root key and remainder account when making genesis (https://github.com/filecoin-project/lotus/pull/5730)
+- chore: update go-graphsync to 0.6.0 (https://github.com/filecoin-project/lotus/pull/5746)
+- Add connmgr metadata to NetPeerInfo (https://github.com/filecoin-project/lotus/pull/5749)
+- test: attempt to make the splitstore test deterministic (https://github.com/filecoin-project/lotus/pull/5750)
+- Feat/api no dep build (https://github.com/filecoin-project/lotus/pull/5729)
+- Fix bootstrapper profile setting (https://github.com/filecoin-project/lotus/pull/5756)
+- Check liveness of sectors when processing termination batches (https://github.com/filecoin-project/lotus/pull/5759)
+- Configurable storage path storage limit (https://github.com/filecoin-project/lotus/pull/5624)
+- miner: Config to disable owner/worker address fallback (https://github.com/filecoin-project/lotus/pull/5620)
+- Fix TestUnpadReader on Go 1.16 (https://github.com/filecoin-project/lotus/pull/5761)
+- Metadata datastore log (https://github.com/filecoin-project/lotus/pull/5755)
+- Remove the SR2 stats, leave just the network totals (https://github.com/filecoin-project/lotus/pull/5757)
+- fix: wait a bit before starting to compute window post proofs (https://github.com/filecoin-project/lotus/pull/5764)
+- fix: retry proof when randomness changes (https://github.com/filecoin-project/lotus/pull/5768)
+
+
+# 1.5.0 / 2021-02-23
+
+This is a mandatory release of Lotus that introduces the fifth upgrade to the Filecoin network. The network upgrade occurs at height 550321, before which time all nodes must have updated to this release (or later). At this height, [v3 specs-actors](https://github.com/filecoin-project/specs-actors/releases/tag/v3.0.0) will take effect, which in turn implements the following two FIPs:
+
+- [FIP-0007 h/amt-v3](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0007.md) which improves the performance of the Filecoin HAMT and AMT.
+- [FIP-0010 off-chain Window PoSt Verification](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0010.md) which reduces the gas consumption of `SubmitWindowedPoSt` messages significantly by optimistically accepting Window PoSt proofs without verification, and allowing them to be disputed later by off-chain verifiers.
+
+Note that the integration of v3 actors was already completed in 1.4.2, this upgrade simply sets the epoch for the upgrade to occur.
+
+## Disputer
+
+FIP-0010 introduces the ability to dispute bad Window PoSts. Node operators are encouraged to run the new Lotus disputer alongside their Lotus daemons. For more information, see the announcement [here](https://github.com/filecoin-project/lotus/discussions/5617#discussioncomment-387333).
+
+## Changes
+
+- [#5341](https://github.com/filecoin-project/lotus/pull/5341)  Add a  `LOTUS_DISABLE_V3_ACTOR_MIGRATION` envvar
+    - Setting this envvar to 1 disables the v3 actor migration, should only be used in the event of a failed migration
+
 # 1.4.2 / 2021-02-17

 This is a large, and highly recommended, optional release with new features and improvements for lotus miner and deal-making UX. The release also integrates [v3 specs-actors](https://github.com/filecoin-project/specs-actors/releases/tag/v3.0.0), which implements two FIPs:

 - [FIP-0007 h/amt-v3](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0007.md) which improves the performance of the Filecoin HAMT and AMT.
- [FIP-0010 off-chain Window PoSt Verification](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0010.md) which reduces the gas consumption of `SubmitedWindowedPost` messages significantly by optimistically accepting Window PoSt proofs without verification, and allowing them to be disputed later by off-chain verifiers.
+- [FIP-0010 off-chain Window PoSt Verification](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0010.md) which reduces the gas consumption of `SubmitWindowedPoSt` messages significantly by optimistically accepting Window PoSt proofs without verification, and allowing them to be disputed later by off-chain verifiers.
 
 Note that this release does NOT set an upgrade epoch for v3 actors to take effect. That will be done in the upcoming 1.5.0 release.
 
@@ -63,17 +63,23 @@ CLEAN+=build/.update-modules
 deps: $(BUILD_DEPS)
 .PHONY: deps

+build-devnets: build lotus-seed lotus-shed lotus-wallet lotus-gateway
+.PHONY: build-devnets
+
 debug: GOFLAGS+=-tags=debug
-debug: lotus lotus-miner lotus-worker lotus-seed
+debug: build-devnets

 2k: GOFLAGS+=-tags=2k
-2k: lotus lotus-miner lotus-worker lotus-seed
+2k: build-devnets

 calibnet: GOFLAGS+=-tags=calibnet
-calibnet: lotus lotus-miner lotus-worker lotus-seed
+calibnet: build-devnets

 nerpanet: GOFLAGS+=-tags=nerpanet
-nerpanet: lotus lotus-miner lotus-worker lotus-seed
+nerpanet: build-devnets
+
+butterflynet: GOFLAGS+=-tags=butterflynet
+butterflynet: build-devnets

 lotus: $(BUILD_DEPS)
 	rm -f lotus
@@ -11,8 +11,6 @@ import (
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 	protocol "github.com/libp2p/go-libp2p-core/protocol"
-
-	"github.com/filecoin-project/lotus/build"
 )

 type Common interface {
@@ -33,6 +31,7 @@ type Common interface {
 	NetPubsubScores(context.Context) ([]PubsubScore, error)
 	NetAutoNatStatus(context.Context) (NatInfo, error)
 	NetAgentVersion(ctx context.Context, p peer.ID) (string, error)
+	NetPeerInfo(context.Context, peer.ID) (*ExtendedPeerInfo, error)

 	// NetBandwidthStats returns statistics about the nodes total bandwidth
 	// usage and current rate across all peers and protocols.
@@ -57,7 +56,7 @@ type Common interface {
 	ID(context.Context) (peer.ID, error)

 	// Version provides information about API provider
-	Version(context.Context) (Version, error)
+	Version(context.Context) (APIVersion, error)

 	LogList(context.Context) ([]string, error)
 	LogSetLevel(context.Context, string, string) error
@@ -71,15 +70,15 @@ type Common interface {
 	Closing(context.Context) (<-chan struct{}, error)
 }

-// Version provides various build-time information
-type Version struct {
+// APIVersion provides various build-time information
+type APIVersion struct {
 	Version string

 	// APIVersion is a binary encoded semver version of the remote implementing
 	// this api
 	//
 	// See APIVersion in build/version.go
-	APIVersion build.Version
+	APIVersion Version

 	// TODO: git commit / os / genesis cid?

@@ -87,7 +86,7 @@ type Version struct {
 	BlockDelay uint64
 }

-func (v Version) String() string {
+func (v APIVersion) String() string {
 	return fmt.Sprintf("%s+api%s", v.Version, v.APIVersion.String())
 }

@@ -32,6 +32,14 @@ import (
 	"github.com/filecoin-project/lotus/node/modules/dtypes"
 )

+//go:generate go run github.com/golang/mock/mockgen -destination=mocks/mock_full.go -package=mocks . FullNode
+
+// ChainIO abstracts operations for accessing raw IPLD objects.
+type ChainIO interface {
+	ChainReadObj(context.Context, cid.Cid) ([]byte, error)
+	ChainHasObj(context.Context, cid.Cid) (bool, error)
+}
+
 // FullNode API is a low-level interface to the Filecoin network full node
 type FullNode interface {
 	Common
@@ -862,6 +870,8 @@ const (

 func (v SyncStateStage) String() string {
 	switch v {
+	case StageIdle:
+		return "idle"
 	case StageHeaders:
 		return "header sync"
 	case StagePersistHeaders:
@@ -36,7 +36,7 @@ type StorageMiner interface {
 	MiningBase(context.Context) (*types.TipSet, error)

 	// Temp api for testing
-	PledgeSector(context.Context) error
+	PledgeSector(context.Context) (abi.SectorID, error)

 	// Get the status of a given sector by ID
 	SectorsStatus(ctx context.Context, sid abi.SectorNumber, showOnChainInfo bool) (SectorInfo, error)
@@ -238,6 +238,9 @@ type AddressConfig struct {
 	PreCommitControl []address.Address
 	CommitControl    []address.Address
 	TerminateControl []address.Address
+
+	DisableOwnerFallback  bool
+	DisableWorkerFallback bool
 }

 // PendingDealInfo has info about pending deals and when they are due to be
@@ -9,12 +9,10 @@ import (
 	"github.com/filecoin-project/lotus/extern/sector-storage/sealtasks"
 	"github.com/filecoin-project/lotus/extern/sector-storage/stores"
 	"github.com/filecoin-project/lotus/extern/sector-storage/storiface"
-
-	"github.com/filecoin-project/lotus/build"
 )

 type WorkerAPI interface {
-	Version(context.Context) (build.Version, error)
+	Version(context.Context) (Version, error)
 	// TODO: Info() (name, ...) ?

 	TaskTypes(context.Context) (map[sealtasks.TaskType]struct{}, error) // TaskType -> Weight
@@ -1,68 +0,0 @@
-package apibstore
-
-import (
-	"context"
-
-	blocks "github.com/ipfs/go-block-format"
-	"github.com/ipfs/go-cid"
-	"golang.org/x/xerrors"
-
-	"github.com/filecoin-project/lotus/lib/blockstore"
-)
-
-type ChainIO interface {
-	ChainReadObj(context.Context, cid.Cid) ([]byte, error)
-	ChainHasObj(context.Context, cid.Cid) (bool, error)
-}
-
-type apiBStore struct {
-	api ChainIO
-}
-
-func NewAPIBlockstore(cio ChainIO) blockstore.Blockstore {
-	return &apiBStore{
-		api: cio,
-	}
-}
-
-func (a *apiBStore) DeleteBlock(cid.Cid) error {
-	return xerrors.New("not supported")
-}
-
-func (a *apiBStore) Has(c cid.Cid) (bool, error) {
-	return a.api.ChainHasObj(context.TODO(), c)
-}
-
-func (a *apiBStore) Get(c cid.Cid) (blocks.Block, error) {
-	bb, err := a.api.ChainReadObj(context.TODO(), c)
-	if err != nil {
-		return nil, err
-	}
-	return blocks.NewBlockWithCid(bb, c)
-}
-
-func (a *apiBStore) GetSize(c cid.Cid) (int, error) {
-	bb, err := a.api.ChainReadObj(context.TODO(), c)
-	if err != nil {
-		return 0, err
-	}
-	return len(bb), nil
-}
-
-func (a *apiBStore) Put(blocks.Block) error {
-	return xerrors.New("not supported")
-}
-
-func (a *apiBStore) PutMany([]blocks.Block) error {
-	return xerrors.New("not supported")
-}
-
-func (a *apiBStore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
-	return nil, xerrors.New("not supported")
-}
-
-func (a *apiBStore) HashOnRead(enabled bool) {
-	return
-}
-
-var _ blockstore.Blockstore = &apiBStore{}
@@ -33,7 +33,6 @@ import (
 	"github.com/filecoin-project/specs-storage/storage"

 	"github.com/filecoin-project/lotus/api"
-	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/actors/builtin/miner"
 	"github.com/filecoin-project/lotus/chain/actors/builtin/paych"
 	"github.com/filecoin-project/lotus/chain/types"
@@ -60,12 +59,13 @@ type CommonStruct struct {
 		NetBandwidthStatsByPeer     func(ctx context.Context) (map[string]metrics.Stats, error)      `perm:"read"`
 		NetBandwidthStatsByProtocol func(ctx context.Context) (map[protocol.ID]metrics.Stats, error) `perm:"read"`
 		NetAgentVersion             func(ctx context.Context, p peer.ID) (string, error)             `perm:"read"`
+		NetPeerInfo                 func(context.Context, peer.ID) (*api.ExtendedPeerInfo, error)    `perm:"read"`
 		NetBlockAdd                 func(ctx context.Context, acl api.NetBlockList) error            `perm:"admin"`
 		NetBlockRemove              func(ctx context.Context, acl api.NetBlockList) error            `perm:"admin"`
 		NetBlockList                func(ctx context.Context) (api.NetBlockList, error)              `perm:"read"`

-		ID      func(context.Context) (peer.ID, error)     `perm:"read"`
-		Version func(context.Context) (api.Version, error) `perm:"read"`
+		ID      func(context.Context) (peer.ID, error)        `perm:"read"`
+		Version func(context.Context) (api.APIVersion, error) `perm:"read"`

 		LogList     func(context.Context) ([]string, error)     `perm:"write"`
 		LogSetLevel func(context.Context, string, string) error `perm:"write"`
@@ -304,7 +304,7 @@ type StorageMinerStruct struct {
 		MarketPendingDeals        func(ctx context.Context) (api.PendingDealInfo, error)                                                                                                                       `perm:"write"`
 		MarketPublishPendingDeals func(ctx context.Context) error                                                                                                                                              `perm:"admin"`

-		PledgeSector func(context.Context) error `perm:"write"`
+		PledgeSector func(context.Context) (abi.SectorID, error) `perm:"write"`

 		SectorsStatus                 func(ctx context.Context, sid abi.SectorNumber, showOnChainInfo bool) (api.SectorInfo, error) `perm:"read"`
 		SectorsList                   func(context.Context) ([]abi.SectorNumber, error)                                             `perm:"read"`
@@ -389,7 +389,7 @@ type WorkerStruct struct {
 	Internal struct {
 		// TODO: lower perms

-		Version func(context.Context) (build.Version, error) `perm:"admin"`
+		Version func(context.Context) (api.Version, error) `perm:"admin"`

 		TaskTypes func(context.Context) (map[sealtasks.TaskType]struct{}, error) `perm:"admin"`
 		Paths     func(context.Context) ([]stores.StoragePath, error)            `perm:"admin"`
@@ -540,13 +540,17 @@ func (c *CommonStruct) NetAgentVersion(ctx context.Context, p peer.ID) (string,
 	return c.Internal.NetAgentVersion(ctx, p)
 }

+func (c *CommonStruct) NetPeerInfo(ctx context.Context, p peer.ID) (*api.ExtendedPeerInfo, error) {
+	return c.Internal.NetPeerInfo(ctx, p)
+}
+
 // ID implements API.ID
 func (c *CommonStruct) ID(ctx context.Context) (peer.ID, error) {
 	return c.Internal.ID(ctx)
 }

 // Version implements API.Version
-func (c *CommonStruct) Version(ctx context.Context) (api.Version, error) {
+func (c *CommonStruct) Version(ctx context.Context) (api.APIVersion, error) {
 	return c.Internal.Version(ctx)
 }

@@ -1274,7 +1278,7 @@ func (c *StorageMinerStruct) ActorAddressConfig(ctx context.Context) (api.Addres
 	return c.Internal.ActorAddressConfig(ctx)
 }

-func (c *StorageMinerStruct) PledgeSector(ctx context.Context) error {
+func (c *StorageMinerStruct) PledgeSector(ctx context.Context) (abi.SectorID, error) {
 	return c.Internal.PledgeSector(ctx)
 }

@@ -1610,7 +1614,7 @@ func (c *StorageMinerStruct) CheckProvable(ctx context.Context, pp abi.Registere

 // WorkerStruct

-func (w *WorkerStruct) Version(ctx context.Context) (build.Version, error) {
+func (w *WorkerStruct) Version(ctx context.Context) (api.Version, error) {
 	return w.Internal.Version(ctx)
 }

@@ -5,14 +5,18 @@ package api
 import (
 	"fmt"
 	"io"
+	"sort"

 	abi "github.com/filecoin-project/go-state-types/abi"
 	paych "github.com/filecoin-project/specs-actors/actors/builtin/paych"
+	cid "github.com/ipfs/go-cid"
 	cbg "github.com/whyrusleeping/cbor-gen"
 	xerrors "golang.org/x/xerrors"
 )

 var _ = xerrors.Errorf
+var _ = cid.Undef
+var _ = sort.Sort

 func (t *PaymentInfo) MarshalCBOR(w io.Writer) error {
 	if t == nil {
@@ -171,7 +175,8 @@ func (t *PaymentInfo) UnmarshalCBOR(r io.Reader) error {
 			}

 		default:
-			return fmt.Errorf("unknown struct field %d: '%s'", i, name)
+			// Field doesn't exist on this type, so ignore it
+			cbg.ScanForLinks(r, func(cid.Cid) {})
 		}
 	}

@@ -319,7 +324,8 @@ func (t *SealedRef) UnmarshalCBOR(r io.Reader) error {
 			}

 		default:
-			return fmt.Errorf("unknown struct field %d: '%s'", i, name)
+			// Field doesn't exist on this type, so ignore it
+			cbg.ScanForLinks(r, func(cid.Cid) {})
 		}
 	}

@@ -427,7 +433,8 @@ func (t *SealedRefs) UnmarshalCBOR(r io.Reader) error {
 			}

 		default:
-			return fmt.Errorf("unknown struct field %d: '%s'", i, name)
+			// Field doesn't exist on this type, so ignore it
+			cbg.ScanForLinks(r, func(cid.Cid) {})
 		}
 	}

@@ -575,7 +582,8 @@ func (t *SealTicket) UnmarshalCBOR(r io.Reader) error {
 			}

 		default:
-			return fmt.Errorf("unknown struct field %d: '%s'", i, name)
+			// Field doesn't exist on this type, so ignore it
+			cbg.ScanForLinks(r, func(cid.Cid) {})
 		}
 	}

@@ -723,7 +731,8 @@ func (t *SealSeed) UnmarshalCBOR(r io.Reader) error {
 			}

 		default:
-			return fmt.Errorf("unknown struct field %d: '%s'", i, name)
+			// Field doesn't exist on this type, so ignore it
+			cbg.ScanForLinks(r, func(cid.Cid) {})
 		}
 	}

@@ -113,7 +113,7 @@ func init() {
 	addExample(network.Connected)
 	addExample(dtypes.NetworkName("lotus"))
 	addExample(api.SyncStateStage(1))
-	addExample(build.FullAPIVersion)
+	addExample(api.FullAPIVersion)
 	addExample(api.PCHInbound)
 	addExample(time.Minute)
 	addExample(datatransfer.TransferID(3))
@@ -123,6 +123,8 @@ func init() {
 	addExample(retrievalmarket.DealStatusNew)
 	addExample(network.ReachabilityPublic)
 	addExample(build.NewestNetworkVersion)
+	addExample(map[string]int{"name": 42})
+	addExample(map[string]time.Time{"name": time.Unix(1615243938, 0).UTC()})
 	addExample(&types.ExecutionTrace{
 		Msg:    exampleValue("init", reflect.TypeOf(&types.Message{}), nil).(*types.Message),
 		MsgRct: exampleValue("init", reflect.TypeOf(&types.MessageReceipt{}), nil).(*types.MessageReceipt),
@@ -17,7 +17,7 @@ import (

 func TestCCUpgrade(t *testing.T, b APIBuilder, blocktime time.Duration) {
 	for _, height := range []abi.ChainEpoch{
-		2,    // before
+		-1,   // before
 		162,  // while sealing
 		530,  // after upgrade deal
 		5000, // after
@@ -31,7 +31,7 @@ func TestCCUpgrade(t *testing.T, b APIBuilder, blocktime time.Duration) {

 func testCCUpgrade(t *testing.T, b APIBuilder, blocktime time.Duration, upgradeHeight abi.ChainEpoch) {
 	ctx := context.Background()
-	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV3At(upgradeHeight)}, OneMiner)
+	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV4At(upgradeHeight)}, OneMiner)
 	client := n[0].FullNode.(*impl.FullNodeAPI)
 	miner := sn[0]

@@ -0,0 +1,350 @@
+package test
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-bitfield"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/big"
+	"github.com/filecoin-project/go-state-types/exitcode"
+	"github.com/filecoin-project/go-state-types/network"
+	miner2 "github.com/filecoin-project/specs-actors/v2/actors/builtin/miner"
+	"github.com/ipfs/go-cid"
+	cbor "github.com/ipfs/go-ipld-cbor"
+
+	"github.com/filecoin-project/lotus/blockstore"
+	"github.com/filecoin-project/lotus/build"
+	"github.com/filecoin-project/lotus/chain/actors"
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+	"github.com/filecoin-project/lotus/chain/actors/builtin/miner"
+	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/filecoin-project/lotus/extern/sector-storage/mock"
+	"github.com/filecoin-project/lotus/node/impl"
+)
+
+// TestDeadlineToggling:
+// * spins up a v3 network (miner A)
+// * creates an inactive miner (miner B)
+// * creates another miner, pledges a sector, waits for power (miner C)
+//
+// * goes through v4 upgrade
+// * goes through PP
+// * creates minerD, minerE
+// * makes sure that miner B/D are inactive, A/C still are
+// * pledges sectors on miner B/D
+// * precommits a sector on minerE
+// * disables post on miner C
+// * goes through PP 0.5PP
+// * asserts that minerE is active
+// * goes through rest of PP (1.5)
+// * asserts that miner C loses power
+// * asserts that miner B/D is active and has power
+// * asserts that minerE is inactive
+// * disables post on miner B
+// * terminates sectors on miner D
+// * goes through another PP
+// * asserts that miner B loses power
+// * asserts that miner D loses power, is inactive
+func TestDeadlineToggling(t *testing.T, b APIBuilder, blocktime time.Duration) {
+	var upgradeH abi.ChainEpoch = 4000
+	var provingPeriod abi.ChainEpoch = 2880
+
+	const sectorsC, sectorsD, sectersB = 10, 9, 8
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV4At(upgradeH)}, OneMiner)
+
+	client := n[0].FullNode.(*impl.FullNodeAPI)
+	minerA := sn[0]
+
+	{
+		addrinfo, err := client.NetAddrsListen(ctx)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if err := minerA.NetConnect(ctx, addrinfo); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	defaultFrom, err := client.WalletDefaultAddress(ctx)
+	require.NoError(t, err)
+
+	maddrA, err := minerA.ActorAddress(ctx)
+	require.NoError(t, err)
+
+	build.Clock.Sleep(time.Second)
+
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		for ctx.Err() == nil {
+			build.Clock.Sleep(blocktime)
+			if err := minerA.MineOne(ctx, MineNext); err != nil {
+				if ctx.Err() != nil {
+					// context was canceled, ignore the error.
+					return
+				}
+				t.Error(err)
+			}
+		}
+	}()
+	defer func() {
+		cancel()
+		<-done
+	}()
+
+	minerB := n[0].Stb(ctx, t, TestSpt, defaultFrom)
+	minerC := n[0].Stb(ctx, t, TestSpt, defaultFrom)
+
+	maddrB, err := minerB.ActorAddress(ctx)
+	require.NoError(t, err)
+	maddrC, err := minerC.ActorAddress(ctx)
+	require.NoError(t, err)
+
+	ssz, err := minerC.ActorSectorSize(ctx, maddrC)
+	require.NoError(t, err)
+
+	// pledge sectors on C, go through a PP, check for power
+	{
+		pledgeSectors(t, ctx, minerC, sectorsC, 0, nil)
+
+		di, err := client.StateMinerProvingDeadline(ctx, maddrC, types.EmptyTSK)
+		require.NoError(t, err)
+
+		fmt.Printf("Running one proving period (miner C)\n")
+		fmt.Printf("End for head.Height > %d\n", di.PeriodStart+di.WPoStProvingPeriod*2)
+
+		for {
+			head, err := client.ChainHead(ctx)
+			require.NoError(t, err)
+
+			if head.Height() > di.PeriodStart+provingPeriod*2 {
+				fmt.Printf("Now head.Height = %d\n", head.Height())
+				break
+			}
+			build.Clock.Sleep(blocktime)
+		}
+
+		expectedPower := types.NewInt(uint64(ssz) * sectorsC)
+
+		p, err := client.StateMinerPower(ctx, maddrC, types.EmptyTSK)
+		require.NoError(t, err)
+
+		// make sure it has gained power.
+		require.Equal(t, p.MinerPower.RawBytePower, expectedPower)
+	}
+
+	// go through upgrade + PP
+	for {
+		head, err := client.ChainHead(ctx)
+		require.NoError(t, err)
+
+		if head.Height() > upgradeH+provingPeriod {
+			fmt.Printf("Now head.Height = %d\n", head.Height())
+			break
+		}
+		build.Clock.Sleep(blocktime)
+	}
+
+	checkMiner := func(ma address.Address, power abi.StoragePower, active bool, tsk types.TipSetKey) {
+		p, err := client.StateMinerPower(ctx, ma, tsk)
+		require.NoError(t, err)
+
+		// make sure it has the expected power.
+		require.Equal(t, p.MinerPower.RawBytePower, power)
+
+		mact, err := client.StateGetActor(ctx, ma, tsk)
+		require.NoError(t, err)
+
+		mst, err := miner.Load(adt.WrapStore(ctx, cbor.NewCborStore(blockstore.NewAPIBlockstore(client))), mact)
+		require.NoError(t, err)
+
+		act, err := mst.DeadlineCronActive()
+		require.NoError(t, err)
+		require.Equal(t, active, act)
+	}
+
+	// check that just after the upgrade minerB was still active
+	{
+		uts, err := client.ChainGetTipSetByHeight(ctx, upgradeH+2, types.EmptyTSK)
+		require.NoError(t, err)
+		checkMiner(maddrB, types.NewInt(0), true, uts.Key())
+	}
+
+	nv, err := client.StateNetworkVersion(ctx, types.EmptyTSK)
+	require.NoError(t, err)
+	require.GreaterOrEqual(t, nv, network.Version12)
+
+	minerD := n[0].Stb(ctx, t, TestSpt, defaultFrom)
+	minerE := n[0].Stb(ctx, t, TestSpt, defaultFrom)
+
+	maddrD, err := minerD.ActorAddress(ctx)
+	require.NoError(t, err)
+	maddrE, err := minerE.ActorAddress(ctx)
+	require.NoError(t, err)
+
+	// first round of miner checks
+	checkMiner(maddrA, types.NewInt(uint64(ssz)*GenesisPreseals), true, types.EmptyTSK)
+	checkMiner(maddrC, types.NewInt(uint64(ssz)*sectorsC), true, types.EmptyTSK)
+
+	checkMiner(maddrB, types.NewInt(0), false, types.EmptyTSK)
+	checkMiner(maddrD, types.NewInt(0), false, types.EmptyTSK)
+	checkMiner(maddrE, types.NewInt(0), false, types.EmptyTSK)
+
+	// pledge sectors on minerB/minerD, stop post on minerC
+	pledgeSectors(t, ctx, minerB, sectersB, 0, nil)
+	checkMiner(maddrB, types.NewInt(0), true, types.EmptyTSK)
+
+	pledgeSectors(t, ctx, minerD, sectorsD, 0, nil)
+	checkMiner(maddrD, types.NewInt(0), true, types.EmptyTSK)
+
+	minerC.StorageMiner.(*impl.StorageMinerAPI).IStorageMgr.(*mock.SectorMgr).Fail()
+
+	// precommit a sector on minerE
+	{
+		head, err := client.ChainHead(ctx)
+		require.NoError(t, err)
+
+		cr, err := cid.Parse("bagboea4b5abcatlxechwbp7kjpjguna6r6q7ejrhe6mdp3lf34pmswn27pkkiekz")
+		require.NoError(t, err)
+
+		params := &miner.SectorPreCommitInfo{
+			Expiration:   2880 * 300,
+			SectorNumber: 22,
+			SealProof:    TestSpt,
+
+			SealedCID:     cr,
+			SealRandEpoch: head.Height() - 200,
+		}
+
+		enc := new(bytes.Buffer)
+		require.NoError(t, params.MarshalCBOR(enc))
+
+		m, err := client.MpoolPushMessage(ctx, &types.Message{
+			To:     maddrE,
+			From:   defaultFrom,
+			Value:  types.FromFil(1),
+			Method: miner.Methods.PreCommitSector,
+			Params: enc.Bytes(),
+		}, nil)
+		require.NoError(t, err)
+
+		r, err := client.StateWaitMsg(ctx, m.Cid(), 2)
+		require.NoError(t, err)
+		require.Equal(t, exitcode.Ok, r.Receipt.ExitCode)
+	}
+
+	// go through 0.5 PP
+	for {
+		head, err := client.ChainHead(ctx)
+		require.NoError(t, err)
+
+		if head.Height() > upgradeH+provingPeriod+(provingPeriod/2) {
+			fmt.Printf("Now head.Height = %d\n", head.Height())
+			break
+		}
+		build.Clock.Sleep(blocktime)
+	}
+
+	checkMiner(maddrE, types.NewInt(0), true, types.EmptyTSK)
+
+	// go through rest of the PP
+	for {
+		head, err := client.ChainHead(ctx)
+		require.NoError(t, err)
+
+		if head.Height() > upgradeH+(provingPeriod*3) {
+			fmt.Printf("Now head.Height = %d\n", head.Height())
+			break
+		}
+		build.Clock.Sleep(blocktime)
+	}
+
+	// second round of miner checks
+	checkMiner(maddrA, types.NewInt(uint64(ssz)*GenesisPreseals), true, types.EmptyTSK)
+	checkMiner(maddrC, types.NewInt(0), true, types.EmptyTSK)
+	checkMiner(maddrB, types.NewInt(uint64(ssz)*sectersB), true, types.EmptyTSK)
+	checkMiner(maddrD, types.NewInt(uint64(ssz)*sectorsD), true, types.EmptyTSK)
+	checkMiner(maddrE, types.NewInt(0), false, types.EmptyTSK)
+
+	// disable post on minerB
+	minerB.StorageMiner.(*impl.StorageMinerAPI).IStorageMgr.(*mock.SectorMgr).Fail()
+
+	// terminate sectors on minerD
+	{
+		var terminationDeclarationParams []miner2.TerminationDeclaration
+		secs, err := minerD.SectorsList(ctx)
+		require.NoError(t, err)
+		require.Len(t, secs, sectorsD)
+
+		for _, sectorNum := range secs {
+			sectorbit := bitfield.New()
+			sectorbit.Set(uint64(sectorNum))
+
+			loca, err := client.StateSectorPartition(ctx, maddrD, sectorNum, types.EmptyTSK)
+			require.NoError(t, err)
+
+			para := miner2.TerminationDeclaration{
+				Deadline:  loca.Deadline,
+				Partition: loca.Partition,
+				Sectors:   sectorbit,
+			}
+
+			terminationDeclarationParams = append(terminationDeclarationParams, para)
+		}
+
+		terminateSectorParams := &miner2.TerminateSectorsParams{
+			Terminations: terminationDeclarationParams,
+		}
+
+		sp, aerr := actors.SerializeParams(terminateSectorParams)
+		require.NoError(t, aerr)
+
+		smsg, err := client.MpoolPushMessage(ctx, &types.Message{
+			From:   defaultFrom,
+			To:     maddrD,
+			Method: miner.Methods.TerminateSectors,
+
+			Value:  big.Zero(),
+			Params: sp,
+		}, nil)
+		require.NoError(t, err)
+
+		fmt.Println("sent termination message:", smsg.Cid())
+
+		r, err := client.StateWaitMsg(ctx, smsg.Cid(), 2)
+		require.NoError(t, err)
+		require.Equal(t, exitcode.Ok, r.Receipt.ExitCode)
+
+		checkMiner(maddrD, types.NewInt(0), true, r.TipSet)
+	}
+
+	// go through another PP
+	for {
+		head, err := client.ChainHead(ctx)
+		require.NoError(t, err)
+
+		if head.Height() > upgradeH+(provingPeriod*5) {
+			fmt.Printf("Now head.Height = %d\n", head.Height())
+			break
+		}
+		build.Clock.Sleep(blocktime)
+	}
+
+	// third round of miner checks
+	checkMiner(maddrA, types.NewInt(uint64(ssz)*GenesisPreseals), true, types.EmptyTSK)
+	checkMiner(maddrC, types.NewInt(0), true, types.EmptyTSK)
+	checkMiner(maddrB, types.NewInt(0), true, types.EmptyTSK)
+	checkMiner(maddrD, types.NewInt(0), false, types.EmptyTSK)
+}
@@ -11,10 +11,13 @@ import (

 	logging "github.com/ipfs/go-log/v2"

-	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/stretchr/testify/require"

+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+
 	"github.com/filecoin-project/lotus/build"
+	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/miner"
 	"github.com/filecoin-project/lotus/node/impl"
 )
@@ -199,3 +202,39 @@ func TestDealMining(t *testing.T, b APIBuilder, blocktime time.Duration, carExpo
 	fmt.Println("shutting down mining")
 	<-done
 }
+
+func (ts *testSuite) testNonGenesisMiner(t *testing.T) {
+	ctx := context.Background()
+	n, sn := ts.makeNodes(t, []FullNodeOpts{
+		FullNodeWithActorsV4At(-1),
+	}, []StorageMiner{
+		{Full: 0, Preseal: PresealGenesis},
+	})
+
+	full, ok := n[0].FullNode.(*impl.FullNodeAPI)
+	if !ok {
+		t.Skip("not testing with a full node")
+		return
+	}
+	genesisMiner := sn[0]
+
+	bm := NewBlockMiner(ctx, t, genesisMiner, 4*time.Millisecond)
+	bm.MineBlocks()
+	t.Cleanup(bm.Stop)
+
+	gaa, err := genesisMiner.ActorAddress(ctx)
+	require.NoError(t, err)
+
+	gmi, err := full.StateMinerInfo(ctx, gaa, types.EmptyTSK)
+	require.NoError(t, err)
+
+	testm := n[0].Stb(ctx, t, TestSpt, gmi.Owner)
+
+	ta, err := testm.ActorAddress(ctx)
+	require.NoError(t, err)
+
+	tid, err := address.IDFromAddress(ta)
+	require.NoError(t, err)
+
+	require.Equal(t, uint64(1001), tid)
+}
@@ -15,7 +15,7 @@ import (
 	cbor "github.com/ipfs/go-ipld-cbor"

 	"github.com/filecoin-project/lotus/api"
-	"github.com/filecoin-project/lotus/api/apibstore"
+	"github.com/filecoin-project/lotus/blockstore"
 	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors/builtin"
@@ -132,7 +132,7 @@ func TestPaymentChannels(t *testing.T, b APIBuilder, blocktime time.Duration) {
 		t.Fatal("Unable to settle payment channel")
 	}

-	creatorStore := adt.WrapStore(ctx, cbor.NewCborStore(apibstore.NewAPIBlockstore(paymentCreator)))
+	creatorStore := adt.WrapStore(ctx, cbor.NewCborStore(blockstore.NewAPIBlockstore(paymentCreator)))

 	// wait for the receiver to submit their vouchers
 	ev := events.NewEvents(ctx, paymentCreator)
@@ -6,7 +6,6 @@ import (
 	"testing"
 	"time"

-	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/filecoin-project/go-state-types/network"
 	"github.com/filecoin-project/lotus/api"
 	"github.com/filecoin-project/lotus/build"
@@ -18,7 +17,9 @@ import (
 )

 func TestTapeFix(t *testing.T, b APIBuilder, blocktime time.Duration) {
-	t.Run("before", func(t *testing.T) { testTapeFix(t, b, blocktime, false) })
+	// The "before" case is disabled, because we need the builder to mock 32 GiB sectors to accurately repro this case
+	// TODO: Make the mock sector size configurable and reenable this
+	//t.Run("before", func(t *testing.T) { testTapeFix(t, b, blocktime, false) })
 	t.Run("after", func(t *testing.T) { testTapeFix(t, b, blocktime, true) })
 }
 func testTapeFix(t *testing.T, b APIBuilder, blocktime time.Duration, after bool) {
@@ -73,23 +74,9 @@ func testTapeFix(t *testing.T, b APIBuilder, blocktime time.Duration, after bool
 		<-done
 	}()

-	err = miner.PledgeSector(ctx)
+	sid, err := miner.PledgeSector(ctx)
 	require.NoError(t, err)

-	// Wait till done.
-	var sectorNo abi.SectorNumber
-	for {
-		s, err := miner.SectorsList(ctx) // Note - the test builder doesn't import genesis sectors into FSM
-		require.NoError(t, err)
-		fmt.Printf("Sectors: %d\n", len(s))
-		if len(s) == 1 {
-			sectorNo = s[0]
-			break
-		}
-
-		build.Clock.Sleep(100 * time.Millisecond)
-	}
-
 	fmt.Printf("All sectors is fsm\n")

 	// If before, we expect the precommit to fail
@@ -101,7 +88,7 @@ func testTapeFix(t *testing.T, b APIBuilder, blocktime time.Duration, after bool
 	}

 	for {
-		st, err := miner.SectorsStatus(ctx, sectorNo, false)
+		st, err := miner.SectorsStatus(ctx, sid.Number, false)
 		require.NoError(t, err)
 		if st.State == successState {
 			break
@@ -8,20 +8,21 @@ import (
 	"testing"
 	"time"

-	"github.com/filecoin-project/lotus/chain/stmgr"
-	"github.com/filecoin-project/lotus/chain/types"
-
 	logging "github.com/ipfs/go-log/v2"
 	"github.com/multiformats/go-multiaddr"

 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"

+	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/filecoin-project/go-state-types/big"
 	"github.com/filecoin-project/go-state-types/network"
+
 	"github.com/filecoin-project/lotus/api"
 	"github.com/filecoin-project/lotus/build"
+	"github.com/filecoin-project/lotus/chain/stmgr"
+	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/miner"
 	"github.com/filecoin-project/lotus/node"
 )
@@ -35,11 +36,15 @@ func init() {
 	build.InsecurePoStValidation = true
 }

+type StorageBuilder func(context.Context, *testing.T, abi.RegisteredSealProof, address.Address) TestStorageNode
+
 type TestNode struct {
 	api.FullNode
 	// ListenAddr is the address on which an API server is listening, if an
 	// API server is created for this Node
 	ListenAddr multiaddr.Multiaddr
+
+	Stb StorageBuilder
 }

 type TestStorageNode struct {
@@ -56,6 +61,8 @@ var PresealGenesis = -1

 const GenesisPreseals = 2

+const TestSpt = abi.RegisteredSealProof_StackedDrg2KiBV1_1
+
 // Options for setting up a mock storage miner
 type StorageMiner struct {
 	Full    int
@@ -94,6 +101,7 @@ func TestApis(t *testing.T, b APIBuilder) {
 	t.Run("testMining", ts.testMining)
 	t.Run("testMiningReal", ts.testMiningReal)
 	t.Run("testSearchMsg", ts.testSearchMsg)
+	t.Run("testNonGenesisMiner", ts.testNonGenesisMiner)
 }

 func DefaultFullOpts(nFull int) []FullNodeOpts {
@@ -112,7 +120,11 @@ var OneMiner = []StorageMiner{{Full: 0, Preseal: PresealGenesis}}
 var OneFull = DefaultFullOpts(1)
 var TwoFull = DefaultFullOpts(2)

-var FullNodeWithActorsV3At = func(upgradeHeight abi.ChainEpoch) FullNodeOpts {
+var FullNodeWithActorsV4At = func(upgradeHeight abi.ChainEpoch) FullNodeOpts {
+	if upgradeHeight == -1 {
+		upgradeHeight = 3
+	}
+
 	return FullNodeOpts{
 		Opts: func(nodes []TestNode) node.Option {
 			return node.Override(new(stmgr.UpgradeSchedule), stmgr.UpgradeSchedule{{
@@ -121,10 +133,13 @@ var FullNodeWithActorsV3At = func(upgradeHeight abi.ChainEpoch) FullNodeOpts {
 				Height:    1,
 				Migration: stmgr.UpgradeActorsV2,
 			}, {
-				// Skip directly to tape height so precommits work.
 				Network:   network.Version10,
-				Height:    upgradeHeight,
+				Height:    2,
 				Migration: stmgr.UpgradeActorsV3,
+			}, {
+				Network:   network.Version12,
+				Height:    upgradeHeight,
+				Migration: stmgr.UpgradeActorsV4,
 			}})
 		},
 	}
@@ -155,13 +170,16 @@ var MineNext = miner.MineReq{
 }

 func (ts *testSuite) testVersion(t *testing.T) {
-	build.RunningNodeType = build.NodeFull
+	api.RunningNodeType = api.NodeFull
+	t.Cleanup(func() {
+		api.RunningNodeType = api.NodeUnknown
+	})

 	ctx := context.Background()
 	apis, _ := ts.makeNodes(t, OneFull, OneMiner)
-	api := apis[0]
+	napi := apis[0]

-	v, err := api.Version(ctx)
+	v, err := napi.Version(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -162,7 +162,7 @@ func pledgeSectors(t *testing.T, ctx context.Context, miner TestStorageNode, n,
 			log.Errorf("WAIT")
 		}
 		log.Errorf("PLEDGING %d", i)
-		err := miner.PledgeSector(ctx)
+		_, err := miner.PledgeSector(ctx)
 		require.NoError(t, err)
 	}

@@ -206,7 +206,7 @@ func pledgeSectors(t *testing.T, ctx context.Context, miner TestStorageNode, n,

 func TestWindowPost(t *testing.T, b APIBuilder, blocktime time.Duration, nSectors int) {
 	for _, height := range []abi.ChainEpoch{
-		2,    // before
+		-1,   // before
 		162,  // while sealing
 		5000, // while proving
 	} {
@@ -223,7 +223,7 @@ func testWindowPostUpgrade(t *testing.T, b APIBuilder, blocktime time.Duration,
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()

-	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV3At(upgradeHeight)}, OneMiner)
+	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV4At(upgradeHeight)}, OneMiner)

 	client := n[0].FullNode.(*impl.FullNodeAPI)
 	miner := sn[0]
@@ -442,7 +442,7 @@ func TestTerminate(t *testing.T, b APIBuilder, blocktime time.Duration) {

 	nSectors := uint64(2)

-	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV3At(2)}, []StorageMiner{{Full: 0, Preseal: int(nSectors)}})
+	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV4At(-1)}, []StorageMiner{{Full: 0, Preseal: int(nSectors)}})

 	client := n[0].FullNode.(*impl.FullNodeAPI)
 	miner := sn[0]
@@ -617,7 +617,7 @@ func TestWindowPostDispute(t *testing.T, b APIBuilder, blocktime time.Duration)
 	///
 	// Then we're going to manually submit bad proofs.
 	n, sn := b(t, []FullNodeOpts{
-		FullNodeWithActorsV3At(2),
+		FullNodeWithActorsV4At(-1),
 	}, []StorageMiner{
 		{Full: 0, Preseal: PresealGenesis},
 		{Full: 0},
@@ -900,7 +900,7 @@ func TestWindowPostDisputeFails(t *testing.T, b APIBuilder, blocktime time.Durat
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()

-	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV3At(2)}, OneMiner)
+	n, sn := b(t, []FullNodeOpts{FullNodeWithActorsV4At(-1)}, OneMiner)

 	client := n[0].FullNode.(*impl.FullNodeAPI)
 	miner := sn[0]
@@ -3,6 +3,7 @@ package api
 import (
 	"encoding/json"
 	"fmt"
+	"time"

 	datatransfer "github.com/filecoin-project/go-data-transfer"
 	"github.com/filecoin-project/go-state-types/abi"
@@ -99,3 +100,18 @@ type NetBlockList struct {
 	IPAddrs   []string
 	IPSubnets []string
 }
+
+type ExtendedPeerInfo struct {
+	ID          peer.ID
+	Agent       string
+	Addrs       []string
+	Protocols   []string
+	ConnMgrMeta *ConnMgrInfo
+}
+
+type ConnMgrInfo struct {
+	FirstSeen time.Time
+	Value     int
+	Tags      map[string]int
+	Conns     map[string]time.Time
+}
@@ -0,0 +1,71 @@
+package api
+
+import (
+	"fmt"
+
+	xerrors "golang.org/x/xerrors"
+)
+
+type Version uint32
+
+func newVer(major, minor, patch uint8) Version {
+	return Version(uint32(major)<<16 | uint32(minor)<<8 | uint32(patch))
+}
+
+// Ints returns (major, minor, patch) versions
+func (ve Version) Ints() (uint32, uint32, uint32) {
+	v := uint32(ve)
+	return (v & majorOnlyMask) >> 16, (v & minorOnlyMask) >> 8, v & patchOnlyMask
+}
+
+func (ve Version) String() string {
+	vmj, vmi, vp := ve.Ints()
+	return fmt.Sprintf("%d.%d.%d", vmj, vmi, vp)
+}
+
+func (ve Version) EqMajorMinor(v2 Version) bool {
+	return ve&minorMask == v2&minorMask
+}
+
+type NodeType int
+
+const (
+	NodeUnknown NodeType = iota
+
+	NodeFull
+	NodeMiner
+	NodeWorker
+)
+
+var RunningNodeType NodeType
+
+func VersionForType(nodeType NodeType) (Version, error) {
+	switch nodeType {
+	case NodeFull:
+		return FullAPIVersion, nil
+	case NodeMiner:
+		return MinerAPIVersion, nil
+	case NodeWorker:
+		return WorkerAPIVersion, nil
+	default:
+		return Version(0), xerrors.Errorf("unknown node type %d", nodeType)
+	}
+}
+
+// semver versions of the rpc api exposed
+var (
+	FullAPIVersion   = newVer(1, 2, 0)
+	MinerAPIVersion  = newVer(1, 0, 1)
+	WorkerAPIVersion = newVer(1, 0, 0)
+)
+
+//nolint:varcheck,deadcode
+const (
+	majorMask = 0xff0000
+	minorMask = 0xffff00
+	patchMask = 0xffffff
+
+	majorOnlyMask = 0xff0000
+	minorOnlyMask = 0x00ff00
+	patchOnlyMask = 0x0000ff
+)
@@ -0,0 +1,66 @@
+package blockstore
+
+import (
+	"context"
+
+	blocks "github.com/ipfs/go-block-format"
+	"github.com/ipfs/go-cid"
+	"golang.org/x/xerrors"
+)
+
+type ChainIO interface {
+	ChainReadObj(context.Context, cid.Cid) ([]byte, error)
+	ChainHasObj(context.Context, cid.Cid) (bool, error)
+}
+
+type apiBlockstore struct {
+	api ChainIO
+}
+
+// This blockstore is adapted in the constructor.
+var _ BasicBlockstore = (*apiBlockstore)(nil)
+
+func NewAPIBlockstore(cio ChainIO) Blockstore {
+	bs := &apiBlockstore{api: cio}
+	return Adapt(bs) // return an adapted blockstore.
+}
+
+func (a *apiBlockstore) DeleteBlock(cid.Cid) error {
+	return xerrors.New("not supported")
+}
+
+func (a *apiBlockstore) Has(c cid.Cid) (bool, error) {
+	return a.api.ChainHasObj(context.TODO(), c)
+}
+
+func (a *apiBlockstore) Get(c cid.Cid) (blocks.Block, error) {
+	bb, err := a.api.ChainReadObj(context.TODO(), c)
+	if err != nil {
+		return nil, err
+	}
+	return blocks.NewBlockWithCid(bb, c)
+}
+
+func (a *apiBlockstore) GetSize(c cid.Cid) (int, error) {
+	bb, err := a.api.ChainReadObj(context.TODO(), c)
+	if err != nil {
+		return 0, err
+	}
+	return len(bb), nil
+}
+
+func (a *apiBlockstore) Put(blocks.Block) error {
+	return xerrors.New("not supported")
+}
+
+func (a *apiBlockstore) PutMany([]blocks.Block) error {
+	return xerrors.New("not supported")
+}
+
+func (a *apiBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+	return nil, xerrors.New("not supported")
+}
+
+func (a *apiBlockstore) HashOnRead(enabled bool) {
+	return
+}
@@ -16,7 +16,7 @@ import (
 	logger "github.com/ipfs/go-log/v2"
 	pool "github.com/libp2p/go-buffer-pool"

-	"github.com/filecoin-project/lotus/lib/blockstore"
+	"github.com/filecoin-project/lotus/blockstore"
 )

 var (
@@ -110,10 +110,7 @@ func Open(opts Options) (*Blockstore, error) {
 		return nil, fmt.Errorf("failed to open badger blockstore: %w", err)
 	}

-	bs := &Blockstore{
-		DB: db,
-	}
-
+	bs := &Blockstore{DB: db}
 	if p := opts.Prefix; p != "" {
 		bs.prefixing = true
 		bs.prefix = []byte(p)
@@ -134,6 +131,25 @@ func (b *Blockstore) Close() error {
 	return b.DB.Close()
 }

+// CollectGarbage runs garbage collection on the value log
+func (b *Blockstore) CollectGarbage() error {
+	if atomic.LoadInt64(&b.state) != stateOpen {
+		return ErrBlockstoreClosed
+	}
+
+	var err error
+	for err == nil {
+		err = b.DB.RunValueLogGC(0.125)
+	}
+
+	if err == badger.ErrNoRewrite {
+		// not really an error in this case
+		return nil
+	}
+
+	return err
+}
+
 // View implements blockstore.Viewer, which leverages zero-copy read-only
 // access to values.
 func (b *Blockstore) View(cid cid.Cid, fn func([]byte) error) error {
@@ -321,6 +337,44 @@ func (b *Blockstore) DeleteBlock(cid cid.Cid) error {
 	})
 }

+func (b *Blockstore) DeleteMany(cids []cid.Cid) error {
+	if atomic.LoadInt64(&b.state) != stateOpen {
+		return ErrBlockstoreClosed
+	}
+
+	batch := b.DB.NewWriteBatch()
+	defer batch.Cancel()
+
+	// toReturn tracks the byte slices to return to the pool, if we're using key
+	// prefixing. we can't return each slice to the pool after each Set, because
+	// badger holds on to the slice.
+	var toReturn [][]byte
+	if b.prefixing {
+		toReturn = make([][]byte, 0, len(cids))
+		defer func() {
+			for _, b := range toReturn {
+				KeyPool.Put(b)
+			}
+		}()
+	}
+
+	for _, cid := range cids {
+		k, pooled := b.PooledStorageKey(cid)
+		if pooled {
+			toReturn = append(toReturn, k)
+		}
+		if err := batch.Delete(k); err != nil {
+			return err
+		}
+	}
+
+	err := batch.Flush()
+	if err != nil {
+		err = fmt.Errorf("failed to delete blocks from badger blockstore: %w", err)
+	}
+	return err
+}
+
 // AllKeysChan implements Blockstore.AllKeysChan.
 func (b *Blockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
 	if atomic.LoadInt64(&b.state) != stateOpen {
@@ -6,8 +6,9 @@ import (
 	"testing"

 	blocks "github.com/ipfs/go-block-format"
-	blockstore "github.com/ipfs/go-ipfs-blockstore"
 	"github.com/stretchr/testify/require"
+
+	"github.com/filecoin-project/lotus/blockstore"
 )

 func TestBadgerBlockstore(t *testing.T) {
@@ -60,8 +61,8 @@ func TestStorageKey(t *testing.T) {
 	require.Equal(t, k3, k2)
 }

-func newBlockstore(optsSupplier func(path string) Options) func(tb testing.TB) (bs blockstore.Blockstore, path string) {
-	return func(tb testing.TB) (bs blockstore.Blockstore, path string) {
+func newBlockstore(optsSupplier func(path string) Options) func(tb testing.TB) (bs blockstore.BasicBlockstore, path string) {
+	return func(tb testing.TB) (bs blockstore.BasicBlockstore, path string) {
 		tb.Helper()

 		path, err := ioutil.TempDir("", "")
@@ -82,8 +83,8 @@ func newBlockstore(optsSupplier func(path string) Options) func(tb testing.TB) (
 	}
 }

-func openBlockstore(optsSupplier func(path string) Options) func(tb testing.TB, path string) (bs blockstore.Blockstore, err error) {
-	return func(tb testing.TB, path string) (bs blockstore.Blockstore, err error) {
+func openBlockstore(optsSupplier func(path string) Options) func(tb testing.TB, path string) (bs blockstore.BasicBlockstore, err error) {
+	return func(tb testing.TB, path string) (bs blockstore.BasicBlockstore, err error) {
 		tb.Helper()
 		return Open(optsSupplier(path))
 	}
@@ -8,18 +8,19 @@ import (
 	"strings"
 	"testing"

-	"github.com/filecoin-project/lotus/lib/blockstore"
 	blocks "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
 	u "github.com/ipfs/go-ipfs-util"

+	"github.com/filecoin-project/lotus/blockstore"
+
 	"github.com/stretchr/testify/require"
 )

 // TODO: move this to go-ipfs-blockstore.
 type Suite struct {
-	NewBlockstore  func(tb testing.TB) (bs blockstore.Blockstore, path string)
-	OpenBlockstore func(tb testing.TB, path string) (bs blockstore.Blockstore, err error)
+	NewBlockstore  func(tb testing.TB) (bs blockstore.BasicBlockstore, path string)
+	OpenBlockstore func(tb testing.TB, path string) (bs blockstore.BasicBlockstore, err error)
 }

 func (s *Suite) RunTests(t *testing.T, prefix string) {
@@ -290,7 +291,7 @@ func (s *Suite) TestDelete(t *testing.T) {

 }

-func insertBlocks(t *testing.T, bs blockstore.Blockstore, count int) []cid.Cid {
+func insertBlocks(t *testing.T, bs blockstore.BasicBlockstore, count int) []cid.Cid {
 	keys := make([]cid.Cid, count)
 	for i := 0; i < count; i++ {
 		block := blocks.NewBlock([]byte(fmt.Sprintf("some data %d", i)))
@@ -0,0 +1,95 @@
+package blockstore
+
+import (
+	cid "github.com/ipfs/go-cid"
+	ds "github.com/ipfs/go-datastore"
+	logging "github.com/ipfs/go-log/v2"
+
+	blockstore "github.com/ipfs/go-ipfs-blockstore"
+)
+
+var log = logging.Logger("blockstore")
+
+var ErrNotFound = blockstore.ErrNotFound
+
+// Blockstore is the blockstore interface used by Lotus. It is the union
+// of the basic go-ipfs blockstore, with other capabilities required by Lotus,
+// e.g. View or Sync.
+type Blockstore interface {
+	blockstore.Blockstore
+	blockstore.Viewer
+	BatchDeleter
+}
+
+// BasicBlockstore is an alias to the original IPFS Blockstore.
+type BasicBlockstore = blockstore.Blockstore
+
+type Viewer = blockstore.Viewer
+
+type BatchDeleter interface {
+	DeleteMany(cids []cid.Cid) error
+}
+
+// WrapIDStore wraps the underlying blockstore in an "identity" blockstore.
+// The ID store filters out all puts for blocks with CIDs using the "identity"
+// hash function. It also extracts inlined blocks from CIDs using the identity
+// hash function and returns them on get/has, ignoring the contents of the
+// blockstore.
+func WrapIDStore(bstore blockstore.Blockstore) Blockstore {
+	if is, ok := bstore.(*idstore); ok {
+		// already wrapped
+		return is
+	}
+
+	if bs, ok := bstore.(Blockstore); ok {
+		// we need to wrap our own because we don't want to neuter the DeleteMany method
+		// the underlying blockstore has implemented an (efficient) DeleteMany
+		return NewIDStore(bs)
+	}
+
+	// The underlying blockstore does not implement DeleteMany, so we need to shim it.
+	// This is less efficient as it'll iterate and perform single deletes.
+	return NewIDStore(Adapt(bstore))
+}
+
+// FromDatastore creates a new blockstore backed by the given datastore.
+func FromDatastore(dstore ds.Batching) Blockstore {
+	return WrapIDStore(blockstore.NewBlockstore(dstore))
+}
+
+type adaptedBlockstore struct {
+	blockstore.Blockstore
+}
+
+var _ Blockstore = (*adaptedBlockstore)(nil)
+
+func (a *adaptedBlockstore) View(cid cid.Cid, callback func([]byte) error) error {
+	blk, err := a.Get(cid)
+	if err != nil {
+		return err
+	}
+	return callback(blk.RawData())
+}
+
+func (a *adaptedBlockstore) DeleteMany(cids []cid.Cid) error {
+	for _, cid := range cids {
+		err := a.DeleteBlock(cid)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Adapt adapts a standard blockstore to a Lotus blockstore by
+// enriching it with the extra methods that Lotus requires (e.g. View, Sync).
+//
+// View proxies over to Get and calls the callback with the value supplied by Get.
+// Sync noops.
+func Adapt(bs blockstore.Blockstore) Blockstore {
+	if ret, ok := bs.(Blockstore); ok {
+		return ret
+	}
+	return &adaptedBlockstore{bs}
+}
@@ -0,0 +1,174 @@
+package blockstore
+
+import (
+	"context"
+	"os"
+
+	block "github.com/ipfs/go-block-format"
+	"github.com/ipfs/go-cid"
+)
+
+// buflog is a logger for the buffered blockstore. It is subscoped from the
+// blockstore logger.
+var buflog = log.Named("buf")
+
+type BufferedBlockstore struct {
+	read  Blockstore
+	write Blockstore
+}
+
+func NewBuffered(base Blockstore) *BufferedBlockstore {
+	var buf Blockstore
+	if os.Getenv("LOTUS_DISABLE_VM_BUF") == "iknowitsabadidea" {
+		buflog.Warn("VM BLOCKSTORE BUFFERING IS DISABLED")
+		buf = base
+	} else {
+		buf = NewMemory()
+	}
+
+	bs := &BufferedBlockstore{
+		read:  base,
+		write: buf,
+	}
+	return bs
+}
+
+func NewTieredBstore(r Blockstore, w Blockstore) *BufferedBlockstore {
+	return &BufferedBlockstore{
+		read:  r,
+		write: w,
+	}
+}
+
+var (
+	_ Blockstore = (*BufferedBlockstore)(nil)
+	_ Viewer     = (*BufferedBlockstore)(nil)
+)
+
+func (bs *BufferedBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+	a, err := bs.read.AllKeysChan(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	b, err := bs.write.AllKeysChan(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make(chan cid.Cid)
+	go func() {
+		defer close(out)
+		for a != nil || b != nil {
+			select {
+			case val, ok := <-a:
+				if !ok {
+					a = nil
+				} else {
+					select {
+					case out <- val:
+					case <-ctx.Done():
+						return
+					}
+				}
+			case val, ok := <-b:
+				if !ok {
+					b = nil
+				} else {
+					select {
+					case out <- val:
+					case <-ctx.Done():
+						return
+					}
+				}
+			}
+		}
+	}()
+
+	return out, nil
+}
+
+func (bs *BufferedBlockstore) DeleteBlock(c cid.Cid) error {
+	if err := bs.read.DeleteBlock(c); err != nil {
+		return err
+	}
+
+	return bs.write.DeleteBlock(c)
+}
+
+func (bs *BufferedBlockstore) DeleteMany(cids []cid.Cid) error {
+	if err := bs.read.DeleteMany(cids); err != nil {
+		return err
+	}
+
+	return bs.write.DeleteMany(cids)
+}
+
+func (bs *BufferedBlockstore) View(c cid.Cid, callback func([]byte) error) error {
+	// both stores are viewable.
+	if err := bs.write.View(c, callback); err == ErrNotFound {
+		// not found in write blockstore; fall through.
+	} else {
+		return err // propagate errors, or nil, i.e. found.
+	}
+	return bs.read.View(c, callback)
+}
+
+func (bs *BufferedBlockstore) Get(c cid.Cid) (block.Block, error) {
+	if out, err := bs.write.Get(c); err != nil {
+		if err != ErrNotFound {
+			return nil, err
+		}
+	} else {
+		return out, nil
+	}
+
+	return bs.read.Get(c)
+}
+
+func (bs *BufferedBlockstore) GetSize(c cid.Cid) (int, error) {
+	s, err := bs.read.GetSize(c)
+	if err == ErrNotFound || s == 0 {
+		return bs.write.GetSize(c)
+	}
+
+	return s, err
+}
+
+func (bs *BufferedBlockstore) Put(blk block.Block) error {
+	has, err := bs.read.Has(blk.Cid()) // TODO: consider dropping this check
+	if err != nil {
+		return err
+	}
+
+	if has {
+		return nil
+	}
+
+	return bs.write.Put(blk)
+}
+
+func (bs *BufferedBlockstore) Has(c cid.Cid) (bool, error) {
+	has, err := bs.write.Has(c)
+	if err != nil {
+		return false, err
+	}
+	if has {
+		return true, nil
+	}
+
+	return bs.read.Has(c)
+}
+
+func (bs *BufferedBlockstore) HashOnRead(hor bool) {
+	bs.read.HashOnRead(hor)
+	bs.write.HashOnRead(hor)
+}
+
+func (bs *BufferedBlockstore) PutMany(blks []block.Block) error {
+	return bs.write.PutMany(blks)
+}
+
+func (bs *BufferedBlockstore) Read() Blockstore {
+	return bs.read
+}
@@ -0,0 +1,25 @@
+package blockstore
+
+import (
+	"context"
+
+	blockstore "github.com/ipfs/go-ipfs-blockstore"
+)
+
+type CacheOpts = blockstore.CacheOpts
+
+func DefaultCacheOpts() CacheOpts {
+	return CacheOpts{
+		HasBloomFilterSize:   0,
+		HasBloomFilterHashes: 0,
+		HasARCCacheSize:      512 << 10,
+	}
+}
+
+func CachedBlockstore(ctx context.Context, bs Blockstore, opts CacheOpts) (Blockstore, error) {
+	cached, err := blockstore.CachedBlockstore(ctx, bs, opts)
+	if err != nil {
+		return nil, err
+	}
+	return WrapIDStore(cached), nil
+}
@@ -0,0 +1,9 @@
+// Package blockstore and subpackages contain most of the blockstore
+// implementations used by Lotus.
+//
+// Blockstores not ultimately constructed out of the building blocks in this
+// package may not work properly.
+//
+// This package re-exports parts of the go-ipfs-blockstore package such that
+// no other package needs to import it directly, for ergonomics and traceability.
+package blockstore
@@ -9,48 +9,61 @@ import (

 	blocks "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
-	blockstore "github.com/ipfs/go-ipfs-blockstore"
-	logging "github.com/ipfs/go-log"
 )

-var log = logging.Logger("blockstore")
-
-type FallbackStore struct {
-	blockstore.Blockstore
-
-	fallbackGetBlock func(context.Context, cid.Cid) (blocks.Block, error)
-	lk               sync.RWMutex
+// UnwrapFallbackStore takes a blockstore, and returns the underlying blockstore
+// if it was a FallbackStore. Otherwise, it just returns the supplied store
+// unmodified.
+func UnwrapFallbackStore(bs Blockstore) (Blockstore, bool) {
+	if fbs, ok := bs.(*FallbackStore); ok {
+		return fbs.Blockstore, true
+	}
+	return bs, false
 }

-func (fbs *FallbackStore) SetFallback(fg func(context.Context, cid.Cid) (blocks.Block, error)) {
+// FallbackStore is a read-through store that queries another (potentially
+// remote) source if the block is not found locally. If the block is found
+// during the fallback, it stores it in the local store.
+type FallbackStore struct {
+	Blockstore
+
+	lk sync.RWMutex
+	// missFn is the function that will be invoked on a local miss to pull the
+	// block from elsewhere.
+	missFn func(context.Context, cid.Cid) (blocks.Block, error)
+}
+
+var _ Blockstore = (*FallbackStore)(nil)
+
+func (fbs *FallbackStore) SetFallback(missFn func(context.Context, cid.Cid) (blocks.Block, error)) {
 	fbs.lk.Lock()
 	defer fbs.lk.Unlock()

-	fbs.fallbackGetBlock = fg
+	fbs.missFn = missFn
 }

 func (fbs *FallbackStore) getFallback(c cid.Cid) (blocks.Block, error) {
-	log.Errorw("fallbackstore: Block not found locally, fetching from the network", "cid", c)
+	log.Warnf("fallbackstore: block not found locally, fetching from the network; cid: %s", c)
 	fbs.lk.RLock()
 	defer fbs.lk.RUnlock()

-	if fbs.fallbackGetBlock == nil {
+	if fbs.missFn == nil {
 		// FallbackStore wasn't configured yet (chainstore/bitswap aren't up yet)
 		// Wait for a bit and retry
 		fbs.lk.RUnlock()
 		time.Sleep(5 * time.Second)
 		fbs.lk.RLock()

-		if fbs.fallbackGetBlock == nil {
-			log.Errorw("fallbackstore: fallbackGetBlock not configured yet")
-			return nil, blockstore.ErrNotFound
+		if fbs.missFn == nil {
+			log.Errorw("fallbackstore: missFn not configured yet")
+			return nil, ErrNotFound
 		}
 	}

 	ctx, cancel := context.WithTimeout(context.TODO(), 120*time.Second)
 	defer cancel()

-	b, err := fbs.fallbackGetBlock(ctx, c)
+	b, err := fbs.missFn(ctx, c)
 	if err != nil {
 		return nil, err
 	}
@@ -69,7 +82,7 @@ func (fbs *FallbackStore) Get(c cid.Cid) (blocks.Block, error) {
 	switch err {
 	case nil:
 		return b, nil
-	case blockstore.ErrNotFound:
+	case ErrNotFound:
 		return fbs.getFallback(c)
 	default:
 		return b, err
@@ -81,7 +94,7 @@ func (fbs *FallbackStore) GetSize(c cid.Cid) (int, error) {
 	switch err {
 	case nil:
 		return sz, nil
-	case blockstore.ErrNotFound:
+	case ErrNotFound:
 		b, err := fbs.getFallback(c)
 		if err != nil {
 			return 0, err
@@ -91,5 +104,3 @@ func (fbs *FallbackStore) GetSize(c cid.Cid) (int, error) {
 		return sz, err
 	}
 }
-
-var _ blockstore.Blockstore = &FallbackStore{}
@@ -0,0 +1,174 @@
+package blockstore
+
+import (
+	"context"
+	"io"
+
+	"golang.org/x/xerrors"
+
+	blocks "github.com/ipfs/go-block-format"
+	cid "github.com/ipfs/go-cid"
+	mh "github.com/multiformats/go-multihash"
+)
+
+var _ Blockstore = (*idstore)(nil)
+
+type idstore struct {
+	bs Blockstore
+}
+
+func NewIDStore(bs Blockstore) Blockstore {
+	return &idstore{bs: bs}
+}
+
+func decodeCid(cid cid.Cid) (inline bool, data []byte, err error) {
+	if cid.Prefix().MhType != mh.IDENTITY {
+		return false, nil, nil
+	}
+
+	dmh, err := mh.Decode(cid.Hash())
+	if err != nil {
+		return false, nil, err
+	}
+
+	if dmh.Code == mh.IDENTITY {
+		return true, dmh.Digest, nil
+	}
+
+	return false, nil, err
+}
+
+func (b *idstore) Has(cid cid.Cid) (bool, error) {
+	inline, _, err := decodeCid(cid)
+	if err != nil {
+		return false, xerrors.Errorf("error decoding Cid: %w", err)
+	}
+
+	if inline {
+		return true, nil
+	}
+
+	return b.bs.Has(cid)
+}
+
+func (b *idstore) Get(cid cid.Cid) (blocks.Block, error) {
+	inline, data, err := decodeCid(cid)
+	if err != nil {
+		return nil, xerrors.Errorf("error decoding Cid: %w", err)
+	}
+
+	if inline {
+		return blocks.NewBlockWithCid(data, cid)
+	}
+
+	return b.bs.Get(cid)
+}
+
+func (b *idstore) GetSize(cid cid.Cid) (int, error) {
+	inline, data, err := decodeCid(cid)
+	if err != nil {
+		return 0, xerrors.Errorf("error decoding Cid: %w", err)
+	}
+
+	if inline {
+		return len(data), err
+	}
+
+	return b.bs.GetSize(cid)
+}
+
+func (b *idstore) View(cid cid.Cid, cb func([]byte) error) error {
+	inline, data, err := decodeCid(cid)
+	if err != nil {
+		return xerrors.Errorf("error decoding Cid: %w", err)
+	}
+
+	if inline {
+		return cb(data)
+	}
+
+	return b.bs.View(cid, cb)
+}
+
+func (b *idstore) Put(blk blocks.Block) error {
+	inline, _, err := decodeCid(blk.Cid())
+	if err != nil {
+		return xerrors.Errorf("error decoding Cid: %w", err)
+	}
+
+	if inline {
+		return nil
+	}
+
+	return b.bs.Put(blk)
+}
+
+func (b *idstore) PutMany(blks []blocks.Block) error {
+	toPut := make([]blocks.Block, 0, len(blks))
+	for _, blk := range blks {
+		inline, _, err := decodeCid(blk.Cid())
+		if err != nil {
+			return xerrors.Errorf("error decoding Cid: %w", err)
+		}
+
+		if inline {
+			continue
+		}
+		toPut = append(toPut, blk)
+	}
+
+	if len(toPut) > 0 {
+		return b.bs.PutMany(toPut)
+	}
+
+	return nil
+}
+
+func (b *idstore) DeleteBlock(cid cid.Cid) error {
+	inline, _, err := decodeCid(cid)
+	if err != nil {
+		return xerrors.Errorf("error decoding Cid: %w", err)
+	}
+
+	if inline {
+		return nil
+	}
+
+	return b.bs.DeleteBlock(cid)
+}
+
+func (b *idstore) DeleteMany(cids []cid.Cid) error {
+	toDelete := make([]cid.Cid, 0, len(cids))
+	for _, cid := range cids {
+		inline, _, err := decodeCid(cid)
+		if err != nil {
+			return xerrors.Errorf("error decoding Cid: %w", err)
+		}
+
+		if inline {
+			continue
+		}
+		toDelete = append(toDelete, cid)
+	}
+
+	if len(toDelete) > 0 {
+		return b.bs.DeleteMany(toDelete)
+	}
+
+	return nil
+}
+
+func (b *idstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+	return b.bs.AllKeysChan(ctx)
+}
+
+func (b *idstore) HashOnRead(enabled bool) {
+	b.bs.HashOnRead(enabled)
+}
+
+func (b *idstore) Close() error {
+	if c, ok := b.bs.(io.Closer); ok {
+		return c.Close()
+	}
+	return nil
+}
@@ -1,4 +1,4 @@
-package ipfsbstore
+package blockstore

 import (
 	"bytes"
@@ -16,16 +16,16 @@ import (
 	iface "github.com/ipfs/interface-go-ipfs-core"
 	"github.com/ipfs/interface-go-ipfs-core/options"
 	"github.com/ipfs/interface-go-ipfs-core/path"
-
-	"github.com/filecoin-project/lotus/lib/blockstore"
 )

-type IpfsBstore struct {
+type IPFSBlockstore struct {
 	ctx             context.Context
 	api, offlineAPI iface.CoreAPI
 }

-func NewIpfsBstore(ctx context.Context, onlineMode bool) (*IpfsBstore, error) {
+var _ BasicBlockstore = (*IPFSBlockstore)(nil)
+
+func NewLocalIPFSBlockstore(ctx context.Context, onlineMode bool) (Blockstore, error) {
 	localApi, err := httpapi.NewLocalApi()
 	if err != nil {
 		return nil, xerrors.Errorf("getting local ipfs api: %w", err)
@@ -34,6 +34,7 @@ func NewIpfsBstore(ctx context.Context, onlineMode bool) (*IpfsBstore, error) {
 	if err != nil {
 		return nil, xerrors.Errorf("setting offline mode: %s", err)
 	}
+
 	offlineAPI := api
 	if onlineMode {
 		offlineAPI, err = localApi.WithOptions(options.Api.Offline(true))
@@ -42,14 +43,16 @@ func NewIpfsBstore(ctx context.Context, onlineMode bool) (*IpfsBstore, error) {
 		}
 	}

-	return &IpfsBstore{
+	bs := &IPFSBlockstore{
 		ctx:        ctx,
 		api:        api,
 		offlineAPI: offlineAPI,
-	}, nil
+	}
+
+	return Adapt(bs), nil
 }

-func NewRemoteIpfsBstore(ctx context.Context, maddr multiaddr.Multiaddr, onlineMode bool) (*IpfsBstore, error) {
+func NewRemoteIPFSBlockstore(ctx context.Context, maddr multiaddr.Multiaddr, onlineMode bool) (Blockstore, error) {
 	httpApi, err := httpapi.NewApi(maddr)
 	if err != nil {
 		return nil, xerrors.Errorf("setting remote ipfs api: %w", err)
@@ -58,6 +61,7 @@ func NewRemoteIpfsBstore(ctx context.Context, maddr multiaddr.Multiaddr, onlineM
 	if err != nil {
 		return nil, xerrors.Errorf("applying offline mode: %s", err)
 	}
+
 	offlineAPI := api
 	if onlineMode {
 		offlineAPI, err = httpApi.WithOptions(options.Api.Offline(true))
@@ -66,18 +70,20 @@ func NewRemoteIpfsBstore(ctx context.Context, maddr multiaddr.Multiaddr, onlineM
 		}
 	}

-	return &IpfsBstore{
+	bs := &IPFSBlockstore{
 		ctx:        ctx,
 		api:        api,
 		offlineAPI: offlineAPI,
-	}, nil
+	}
+
+	return Adapt(bs), nil
 }

-func (i *IpfsBstore) DeleteBlock(cid cid.Cid) error {
+func (i *IPFSBlockstore) DeleteBlock(cid cid.Cid) error {
 	return xerrors.Errorf("not supported")
 }

-func (i *IpfsBstore) Has(cid cid.Cid) (bool, error) {
+func (i *IPFSBlockstore) Has(cid cid.Cid) (bool, error) {
 	_, err := i.offlineAPI.Block().Stat(i.ctx, path.IpldPath(cid))
 	if err != nil {
 		// The underlying client is running in Offline mode.
@@ -93,7 +99,7 @@ func (i *IpfsBstore) Has(cid cid.Cid) (bool, error) {
 	return true, nil
 }

-func (i *IpfsBstore) Get(cid cid.Cid) (blocks.Block, error) {
+func (i *IPFSBlockstore) Get(cid cid.Cid) (blocks.Block, error) {
 	rd, err := i.api.Block().Get(i.ctx, path.IpldPath(cid))
 	if err != nil {
 		return nil, xerrors.Errorf("getting ipfs block: %w", err)
@@ -107,7 +113,7 @@ func (i *IpfsBstore) Get(cid cid.Cid) (blocks.Block, error) {
 	return blocks.NewBlockWithCid(data, cid)
 }

-func (i *IpfsBstore) GetSize(cid cid.Cid) (int, error) {
+func (i *IPFSBlockstore) GetSize(cid cid.Cid) (int, error) {
 	st, err := i.api.Block().Stat(i.ctx, path.IpldPath(cid))
 	if err != nil {
 		return 0, xerrors.Errorf("getting ipfs block: %w", err)
@@ -116,7 +122,7 @@ func (i *IpfsBstore) GetSize(cid cid.Cid) (int, error) {
 	return st.Size(), nil
 }

-func (i *IpfsBstore) Put(block blocks.Block) error {
+func (i *IPFSBlockstore) Put(block blocks.Block) error {
 	mhd, err := multihash.Decode(block.Cid().Hash())
 	if err != nil {
 		return err
@@ -128,7 +134,7 @@ func (i *IpfsBstore) Put(block blocks.Block) error {
 	return err
 }

-func (i *IpfsBstore) PutMany(blocks []blocks.Block) error {
+func (i *IPFSBlockstore) PutMany(blocks []blocks.Block) error {
 	// TODO: could be done in parallel

 	for _, block := range blocks {
@@ -140,12 +146,10 @@ func (i *IpfsBstore) PutMany(blocks []blocks.Block) error {
 	return nil
 }

-func (i *IpfsBstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+func (i *IPFSBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
 	return nil, xerrors.Errorf("not supported")
 }

-func (i *IpfsBstore) HashOnRead(enabled bool) {
+func (i *IPFSBlockstore) HashOnRead(enabled bool) {
 	return // TODO: We could technically support this, but..
 }
-
-var _ blockstore.Blockstore = &IpfsBstore{}
@@ -7,20 +7,32 @@ import (
 	"github.com/ipfs/go-cid"
 )

-// MemStore is a terminal blockstore that keeps blocks in memory.
-type MemStore map[cid.Cid]blocks.Block
+// NewMemory returns a temporary memory-backed blockstore.
+func NewMemory() MemBlockstore {
+	return make(MemBlockstore)
+}

-func (m MemStore) DeleteBlock(k cid.Cid) error {
+// MemBlockstore is a terminal blockstore that keeps blocks in memory.
+type MemBlockstore map[cid.Cid]blocks.Block
+
+func (m MemBlockstore) DeleteBlock(k cid.Cid) error {
 	delete(m, k)
 	return nil
 }

-func (m MemStore) Has(k cid.Cid) (bool, error) {
+func (m MemBlockstore) DeleteMany(ks []cid.Cid) error {
+	for _, k := range ks {
+		delete(m, k)
+	}
+	return nil
+}
+
+func (m MemBlockstore) Has(k cid.Cid) (bool, error) {
 	_, ok := m[k]
 	return ok, nil
 }

-func (m MemStore) View(k cid.Cid, callback func([]byte) error) error {
+func (m MemBlockstore) View(k cid.Cid, callback func([]byte) error) error {
 	b, ok := m[k]
 	if !ok {
 		return ErrNotFound
@@ -28,7 +40,7 @@ func (m MemStore) View(k cid.Cid, callback func([]byte) error) error {
 	return callback(b.RawData())
 }

-func (m MemStore) Get(k cid.Cid) (blocks.Block, error) {
+func (m MemBlockstore) Get(k cid.Cid) (blocks.Block, error) {
 	b, ok := m[k]
 	if !ok {
 		return nil, ErrNotFound
@@ -37,7 +49,7 @@ func (m MemStore) Get(k cid.Cid) (blocks.Block, error) {
 }

 // GetSize returns the CIDs mapped BlockSize
-func (m MemStore) GetSize(k cid.Cid) (int, error) {
+func (m MemBlockstore) GetSize(k cid.Cid) (int, error) {
 	b, ok := m[k]
 	if !ok {
 		return 0, ErrNotFound
@@ -46,7 +58,7 @@ func (m MemStore) GetSize(k cid.Cid) (int, error) {
 }

 // Put puts a given block to the underlying datastore
-func (m MemStore) Put(b blocks.Block) error {
+func (m MemBlockstore) Put(b blocks.Block) error {
 	// Convert to a basic block for safety, but try to reuse the existing
 	// block if it's already a basic block.
 	k := b.Cid()
@@ -64,7 +76,7 @@ func (m MemStore) Put(b blocks.Block) error {

 // PutMany puts a slice of blocks at the same time using batching
 // capabilities of the underlying datastore whenever possible.
-func (m MemStore) PutMany(bs []blocks.Block) error {
+func (m MemBlockstore) PutMany(bs []blocks.Block) error {
 	for _, b := range bs {
 		_ = m.Put(b) // can't fail
 	}
@@ -74,7 +86,7 @@ func (m MemStore) PutMany(bs []blocks.Block) error {
 // AllKeysChan returns a channel from which
 // the CIDs in the Blockstore can be read. It should respect
 // the given context, closing the channel if it becomes Done.
-func (m MemStore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+func (m MemBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
 	ch := make(chan cid.Cid, len(m))
 	for k := range m {
 		ch <- k
@@ -85,6 +97,6 @@ func (m MemStore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {

 // HashOnRead specifies if every read block should be
 // rehashed to make sure it matches its CID.
-func (m MemStore) HashOnRead(enabled bool) {
+func (m MemBlockstore) HashOnRead(enabled bool) {
 	// no-op
 }
@@ -0,0 +1,154 @@
+package blockstore
+
+import (
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+)
+
+//
+// Currently unused, but kept in repo in case we introduce one of the candidate
+// cache implementations (Freecache, Ristretto), both of which report these
+// metrics.
+//
+
+// CacheMetricsEmitInterval is the interval at which metrics are emitted onto
+// OpenCensus.
+var CacheMetricsEmitInterval = 5 * time.Second
+
+var (
+	CacheName, _ = tag.NewKey("cache_name")
+)
+
+// CacheMeasures groups all metrics emitted by the blockstore caches.
+var CacheMeasures = struct {
+	HitRatio       *stats.Float64Measure
+	Hits           *stats.Int64Measure
+	Misses         *stats.Int64Measure
+	Entries        *stats.Int64Measure
+	QueriesServed  *stats.Int64Measure
+	Adds           *stats.Int64Measure
+	Updates        *stats.Int64Measure
+	Evictions      *stats.Int64Measure
+	CostAdded      *stats.Int64Measure
+	CostEvicted    *stats.Int64Measure
+	SetsDropped    *stats.Int64Measure
+	SetsRejected   *stats.Int64Measure
+	QueriesDropped *stats.Int64Measure
+}{
+	HitRatio:       stats.Float64("blockstore/cache/hit_ratio", "Hit ratio of blockstore cache", stats.UnitDimensionless),
+	Hits:           stats.Int64("blockstore/cache/hits", "Total number of hits at blockstore cache", stats.UnitDimensionless),
+	Misses:         stats.Int64("blockstore/cache/misses", "Total number of misses at blockstore cache", stats.UnitDimensionless),
+	Entries:        stats.Int64("blockstore/cache/entry_count", "Total number of entries currently in the blockstore cache", stats.UnitDimensionless),
+	QueriesServed:  stats.Int64("blockstore/cache/queries_served", "Total number of queries served by the blockstore cache", stats.UnitDimensionless),
+	Adds:           stats.Int64("blockstore/cache/adds", "Total number of adds to blockstore cache", stats.UnitDimensionless),
+	Updates:        stats.Int64("blockstore/cache/updates", "Total number of updates in blockstore cache", stats.UnitDimensionless),
+	Evictions:      stats.Int64("blockstore/cache/evictions", "Total number of evictions from blockstore cache", stats.UnitDimensionless),
+	CostAdded:      stats.Int64("blockstore/cache/cost_added", "Total cost (byte size) of entries added into blockstore cache", stats.UnitBytes),
+	CostEvicted:    stats.Int64("blockstore/cache/cost_evicted", "Total cost (byte size) of entries evicted by blockstore cache", stats.UnitBytes),
+	SetsDropped:    stats.Int64("blockstore/cache/sets_dropped", "Total number of sets dropped by blockstore cache", stats.UnitDimensionless),
+	SetsRejected:   stats.Int64("blockstore/cache/sets_rejected", "Total number of sets rejected by blockstore cache", stats.UnitDimensionless),
+	QueriesDropped: stats.Int64("blockstore/cache/queries_dropped", "Total number of queries dropped by blockstore cache", stats.UnitDimensionless),
+}
+
+// CacheViews groups all cache-related default views.
+var CacheViews = struct {
+	HitRatio       *view.View
+	Hits           *view.View
+	Misses         *view.View
+	Entries        *view.View
+	QueriesServed  *view.View
+	Adds           *view.View
+	Updates        *view.View
+	Evictions      *view.View
+	CostAdded      *view.View
+	CostEvicted    *view.View
+	SetsDropped    *view.View
+	SetsRejected   *view.View
+	QueriesDropped *view.View
+}{
+	HitRatio: &view.View{
+		Measure:     CacheMeasures.HitRatio,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Hits: &view.View{
+		Measure:     CacheMeasures.Hits,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Misses: &view.View{
+		Measure:     CacheMeasures.Misses,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Entries: &view.View{
+		Measure:     CacheMeasures.Entries,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	QueriesServed: &view.View{
+		Measure:     CacheMeasures.QueriesServed,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Adds: &view.View{
+		Measure:     CacheMeasures.Adds,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Updates: &view.View{
+		Measure:     CacheMeasures.Updates,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Evictions: &view.View{
+		Measure:     CacheMeasures.Evictions,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	CostAdded: &view.View{
+		Measure:     CacheMeasures.CostAdded,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	CostEvicted: &view.View{
+		Measure:     CacheMeasures.CostEvicted,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	SetsDropped: &view.View{
+		Measure:     CacheMeasures.SetsDropped,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	SetsRejected: &view.View{
+		Measure:     CacheMeasures.SetsRejected,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	QueriesDropped: &view.View{
+		Measure:     CacheMeasures.QueriesDropped,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+}
+
+// DefaultViews exports all default views for this package.
+var DefaultViews = []*view.View{
+	CacheViews.HitRatio,
+	CacheViews.Hits,
+	CacheViews.Misses,
+	CacheViews.Entries,
+	CacheViews.QueriesServed,
+	CacheViews.Adds,
+	CacheViews.Updates,
+	CacheViews.Evictions,
+	CacheViews.CostAdded,
+	CacheViews.CostEvicted,
+	CacheViews.SetsDropped,
+	CacheViews.SetsRejected,
+	CacheViews.QueriesDropped,
+}
@@ -0,0 +1,38 @@
+package splitstore
+
+import (
+	"path/filepath"
+
+	"golang.org/x/xerrors"
+
+	cid "github.com/ipfs/go-cid"
+)
+
+// MarkSet is a utility to keep track of seen CID, and later query for them.
+//
+// * If the expected dataset is large, it can be backed by a datastore (e.g. bbolt).
+// * If a probabilistic result is acceptable, it can be backed by a bloom filter (default).
+type MarkSet interface {
+	Mark(cid.Cid) error
+	Has(cid.Cid) (bool, error)
+	Close() error
+}
+
+// markBytes is deliberately a non-nil empty byte slice for serialization.
+var markBytes = []byte{}
+
+type MarkSetEnv interface {
+	Create(name string, sizeHint int64) (MarkSet, error)
+	Close() error
+}
+
+func OpenMarkSetEnv(path string, mtype string) (MarkSetEnv, error) {
+	switch mtype {
+	case "", "bloom":
+		return NewBloomMarkSetEnv()
+	case "bolt":
+		return NewBoltMarkSetEnv(filepath.Join(path, "markset.bolt"))
+	default:
+		return nil, xerrors.Errorf("unknown mark set type %s", mtype)
+	}
+}
@@ -0,0 +1,77 @@
+package splitstore
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+
+	"golang.org/x/xerrors"
+
+	bbloom "github.com/ipfs/bbloom"
+	cid "github.com/ipfs/go-cid"
+)
+
+const (
+	BloomFilterMinSize     = 10_000_000
+	BloomFilterProbability = 0.01
+)
+
+type BloomMarkSetEnv struct{}
+
+var _ MarkSetEnv = (*BloomMarkSetEnv)(nil)
+
+type BloomMarkSet struct {
+	salt []byte
+	bf   *bbloom.Bloom
+}
+
+var _ MarkSet = (*BloomMarkSet)(nil)
+
+func NewBloomMarkSetEnv() (*BloomMarkSetEnv, error) {
+	return &BloomMarkSetEnv{}, nil
+}
+
+func (e *BloomMarkSetEnv) Create(name string, sizeHint int64) (MarkSet, error) {
+	size := int64(BloomFilterMinSize)
+	for size < sizeHint {
+		size += BloomFilterMinSize
+	}
+
+	salt := make([]byte, 4)
+	_, err := rand.Read(salt)
+	if err != nil {
+		return nil, xerrors.Errorf("error reading salt: %w", err)
+	}
+
+	bf, err := bbloom.New(float64(size), BloomFilterProbability)
+	if err != nil {
+		return nil, xerrors.Errorf("error creating bloom filter: %w", err)
+	}
+
+	return &BloomMarkSet{salt: salt, bf: bf}, nil
+}
+
+func (e *BloomMarkSetEnv) Close() error {
+	return nil
+}
+
+func (s *BloomMarkSet) saltedKey(cid cid.Cid) []byte {
+	hash := cid.Hash()
+	key := make([]byte, len(s.salt)+len(hash))
+	n := copy(key, s.salt)
+	copy(key[n:], hash)
+	rehash := sha256.Sum256(key)
+	return rehash[:]
+}
+
+func (s *BloomMarkSet) Mark(cid cid.Cid) error {
+	s.bf.Add(s.saltedKey(cid))
+	return nil
+}
+
+func (s *BloomMarkSet) Has(cid cid.Cid) (bool, error) {
+	return s.bf.Has(s.saltedKey(cid)), nil
+}
+
+func (s *BloomMarkSet) Close() error {
+	return nil
+}
@@ -0,0 +1,81 @@
+package splitstore
+
+import (
+	"time"
+
+	"golang.org/x/xerrors"
+
+	cid "github.com/ipfs/go-cid"
+	bolt "go.etcd.io/bbolt"
+)
+
+type BoltMarkSetEnv struct {
+	db *bolt.DB
+}
+
+var _ MarkSetEnv = (*BoltMarkSetEnv)(nil)
+
+type BoltMarkSet struct {
+	db       *bolt.DB
+	bucketId []byte
+}
+
+var _ MarkSet = (*BoltMarkSet)(nil)
+
+func NewBoltMarkSetEnv(path string) (*BoltMarkSetEnv, error) {
+	db, err := bolt.Open(path, 0644,
+		&bolt.Options{
+			Timeout: 1 * time.Second,
+			NoSync:  true,
+		})
+	if err != nil {
+		return nil, err
+	}
+
+	return &BoltMarkSetEnv{db: db}, nil
+}
+
+func (e *BoltMarkSetEnv) Create(name string, hint int64) (MarkSet, error) {
+	bucketId := []byte(name)
+	err := e.db.Update(func(tx *bolt.Tx) error {
+		_, err := tx.CreateBucketIfNotExists(bucketId)
+		if err != nil {
+			return xerrors.Errorf("error creating bolt db bucket %s: %w", name, err)
+		}
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &BoltMarkSet{db: e.db, bucketId: bucketId}, nil
+}
+
+func (e *BoltMarkSetEnv) Close() error {
+	return e.db.Close()
+}
+
+func (s *BoltMarkSet) Mark(cid cid.Cid) error {
+	return s.db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		return b.Put(cid.Hash(), markBytes)
+	})
+}
+
+func (s *BoltMarkSet) Has(cid cid.Cid) (result bool, err error) {
+	err = s.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		v := b.Get(cid.Hash())
+		result = v != nil
+		return nil
+	})
+
+	return result, err
+}
+
+func (s *BoltMarkSet) Close() error {
+	return s.db.Update(func(tx *bolt.Tx) error {
+		return tx.DeleteBucket(s.bucketId)
+	})
+}
@@ -0,0 +1,138 @@
+package splitstore
+
+import (
+	"io/ioutil"
+	"testing"
+
+	cid "github.com/ipfs/go-cid"
+	"github.com/multiformats/go-multihash"
+)
+
+func TestBoltMarkSet(t *testing.T) {
+	testMarkSet(t, "bolt")
+}
+
+func TestBloomMarkSet(t *testing.T) {
+	testMarkSet(t, "bloom")
+}
+
+func testMarkSet(t *testing.T, lsType string) {
+	t.Helper()
+
+	path, err := ioutil.TempDir("", "sweep-test.*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	env, err := OpenMarkSetEnv(path, lsType)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer env.Close() //nolint:errcheck
+
+	hotSet, err := env.Create("hot", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	coldSet, err := env.Create("cold", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	makeCid := func(key string) cid.Cid {
+		h, err := multihash.Sum([]byte(key), multihash.SHA2_256, -1)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		return cid.NewCidV1(cid.Raw, h)
+	}
+
+	mustHave := func(s MarkSet, cid cid.Cid) {
+		has, err := s.Has(cid)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !has {
+			t.Fatal("mark not found")
+		}
+	}
+
+	mustNotHave := func(s MarkSet, cid cid.Cid) {
+		has, err := s.Has(cid)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if has {
+			t.Fatal("unexpected mark")
+		}
+	}
+
+	k1 := makeCid("a")
+	k2 := makeCid("b")
+	k3 := makeCid("c")
+	k4 := makeCid("d")
+
+	hotSet.Mark(k1)  //nolint
+	hotSet.Mark(k2)  //nolint
+	coldSet.Mark(k3) //nolint
+
+	mustHave(hotSet, k1)
+	mustHave(hotSet, k2)
+	mustNotHave(hotSet, k3)
+	mustNotHave(hotSet, k4)
+
+	mustNotHave(coldSet, k1)
+	mustNotHave(coldSet, k2)
+	mustHave(coldSet, k3)
+	mustNotHave(coldSet, k4)
+
+	// close them and reopen to redo the dance
+
+	err = hotSet.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = coldSet.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	hotSet, err = env.Create("hot", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	coldSet, err = env.Create("cold", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	hotSet.Mark(k3)  //nolint
+	hotSet.Mark(k4)  //nolint
+	coldSet.Mark(k1) //nolint
+
+	mustNotHave(hotSet, k1)
+	mustNotHave(hotSet, k2)
+	mustHave(hotSet, k3)
+	mustHave(hotSet, k4)
+
+	mustHave(coldSet, k1)
+	mustNotHave(coldSet, k2)
+	mustNotHave(coldSet, k3)
+	mustNotHave(coldSet, k4)
+
+	err = hotSet.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = coldSet.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+}
@@ -0,0 +1,255 @@
+package splitstore
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/lotus/blockstore"
+	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/filecoin-project/lotus/chain/types/mock"
+
+	cid "github.com/ipfs/go-cid"
+	datastore "github.com/ipfs/go-datastore"
+	dssync "github.com/ipfs/go-datastore/sync"
+	logging "github.com/ipfs/go-log/v2"
+)
+
+func init() {
+	CompactionThreshold = 5
+	CompactionCold = 1
+	CompactionBoundary = 2
+	logging.SetLogLevel("splitstore", "DEBUG")
+}
+
+func testSplitStore(t *testing.T, cfg *Config) {
+	chain := &mockChain{}
+	// genesis
+	genBlock := mock.MkBlock(nil, 0, 0)
+	genTs := mock.TipSet(genBlock)
+	chain.push(genTs)
+
+	// the myriads of stores
+	ds := dssync.MutexWrap(datastore.NewMapDatastore())
+	hot := blockstore.NewMemorySync()
+	cold := blockstore.NewMemorySync()
+
+	// put the genesis block to cold store
+	blk, err := genBlock.ToStorageBlock()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = cold.Put(blk)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// open the splitstore
+	ss, err := Open("", ds, hot, cold, cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer ss.Close() //nolint
+
+	err = ss.Start(chain)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// make some tipsets, but not enough to cause compaction
+	mkBlock := func(curTs *types.TipSet, i int) *types.TipSet {
+		blk := mock.MkBlock(curTs, uint64(i), uint64(i))
+		sblk, err := blk.ToStorageBlock()
+		if err != nil {
+			t.Fatal(err)
+		}
+		err = ss.Put(sblk)
+		if err != nil {
+			t.Fatal(err)
+		}
+		ts := mock.TipSet(blk)
+		chain.push(ts)
+
+		return ts
+	}
+
+	mkGarbageBlock := func(curTs *types.TipSet, i int) {
+		blk := mock.MkBlock(curTs, uint64(i), uint64(i))
+		sblk, err := blk.ToStorageBlock()
+		if err != nil {
+			t.Fatal(err)
+		}
+		err = ss.Put(sblk)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	waitForCompaction := func() {
+		for atomic.LoadInt32(&ss.compacting) == 1 {
+			time.Sleep(100 * time.Millisecond)
+		}
+	}
+
+	curTs := genTs
+	for i := 1; i < 5; i++ {
+		curTs = mkBlock(curTs, i)
+		waitForCompaction()
+	}
+
+	mkGarbageBlock(genTs, 1)
+
+	// count objects in the cold and hot stores
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	countBlocks := func(bs blockstore.Blockstore) int {
+		count := 0
+		ch, err := bs.AllKeysChan(ctx)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for range ch {
+			count++
+		}
+		return count
+	}
+
+	coldCnt := countBlocks(cold)
+	hotCnt := countBlocks(hot)
+
+	if coldCnt != 1 {
+		t.Errorf("expected %d blocks, but got %d", 1, coldCnt)
+	}
+
+	if hotCnt != 5 {
+		t.Errorf("expected %d blocks, but got %d", 5, hotCnt)
+	}
+
+	// trigger a compaction
+	for i := 5; i < 10; i++ {
+		curTs = mkBlock(curTs, i)
+		waitForCompaction()
+	}
+
+	coldCnt = countBlocks(cold)
+	hotCnt = countBlocks(hot)
+
+	if !cfg.EnableFullCompaction {
+		if coldCnt != 5 {
+			t.Errorf("expected %d cold blocks, but got %d", 5, coldCnt)
+		}
+
+		if hotCnt != 5 {
+			t.Errorf("expected %d hot blocks, but got %d", 5, hotCnt)
+		}
+	}
+
+	if cfg.EnableFullCompaction && !cfg.EnableGC {
+		if coldCnt != 3 {
+			t.Errorf("expected %d cold blocks, but got %d", 3, coldCnt)
+		}
+
+		if hotCnt != 7 {
+			t.Errorf("expected %d hot blocks, but got %d", 7, hotCnt)
+		}
+	}
+
+	if cfg.EnableFullCompaction && cfg.EnableGC {
+		if coldCnt != 2 {
+			t.Errorf("expected %d cold blocks, but got %d", 2, coldCnt)
+		}
+
+		if hotCnt != 7 {
+			t.Errorf("expected %d hot blocks, but got %d", 7, hotCnt)
+		}
+	}
+}
+
+func TestSplitStoreSimpleCompaction(t *testing.T) {
+	testSplitStore(t, &Config{TrackingStoreType: "mem"})
+}
+
+func TestSplitStoreFullCompactionWithoutGC(t *testing.T) {
+	testSplitStore(t, &Config{
+		TrackingStoreType:    "mem",
+		EnableFullCompaction: true,
+	})
+}
+
+func TestSplitStoreFullCompactionWithGC(t *testing.T) {
+	testSplitStore(t, &Config{
+		TrackingStoreType:    "mem",
+		EnableFullCompaction: true,
+		EnableGC:             true,
+	})
+}
+
+type mockChain struct {
+	sync.Mutex
+	tipsets  []*types.TipSet
+	listener func(revert []*types.TipSet, apply []*types.TipSet) error
+}
+
+func (c *mockChain) push(ts *types.TipSet) {
+	c.Lock()
+	c.tipsets = append(c.tipsets, ts)
+	c.Unlock()
+
+	if c.listener != nil {
+		err := c.listener(nil, []*types.TipSet{ts})
+		if err != nil {
+			log.Errorf("mockchain: error dispatching listener: %s", err)
+		}
+	}
+}
+
+func (c *mockChain) GetTipsetByHeight(_ context.Context, epoch abi.ChainEpoch, _ *types.TipSet, _ bool) (*types.TipSet, error) {
+	c.Lock()
+	defer c.Unlock()
+
+	iEpoch := int(epoch)
+	if iEpoch > len(c.tipsets) {
+		return nil, fmt.Errorf("bad epoch %d", epoch)
+	}
+
+	return c.tipsets[iEpoch-1], nil
+}
+
+func (c *mockChain) GetHeaviestTipSet() *types.TipSet {
+	c.Lock()
+	defer c.Unlock()
+
+	return c.tipsets[len(c.tipsets)-1]
+}
+
+func (c *mockChain) SubscribeHeadChanges(change func(revert []*types.TipSet, apply []*types.TipSet) error) {
+	c.listener = change
+}
+
+func (c *mockChain) WalkSnapshot(_ context.Context, ts *types.TipSet, epochs abi.ChainEpoch, _ bool, _ bool, f func(cid.Cid) error) error {
+	c.Lock()
+	defer c.Unlock()
+
+	start := int(ts.Height()) - 1
+	end := start - int(epochs)
+	if end < 0 {
+		end = -1
+	}
+	for i := start; i > end; i-- {
+		ts := c.tipsets[i]
+		for _, cid := range ts.Cids() {
+			err := f(cid)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
@@ -0,0 +1,109 @@
+package splitstore
+
+import (
+	"path/filepath"
+	"sync"
+
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/go-state-types/abi"
+	cid "github.com/ipfs/go-cid"
+)
+
+// TrackingStore is a persistent store that tracks blocks that are added
+// to the hotstore, tracking the epoch at which they are written.
+type TrackingStore interface {
+	Put(cid.Cid, abi.ChainEpoch) error
+	PutBatch([]cid.Cid, abi.ChainEpoch) error
+	Get(cid.Cid) (abi.ChainEpoch, error)
+	Delete(cid.Cid) error
+	DeleteBatch([]cid.Cid) error
+	ForEach(func(cid.Cid, abi.ChainEpoch) error) error
+	Sync() error
+	Close() error
+}
+
+// OpenTrackingStore opens a tracking store of the specified type in the
+// specified path.
+func OpenTrackingStore(path string, ttype string) (TrackingStore, error) {
+	switch ttype {
+	case "", "bolt":
+		return OpenBoltTrackingStore(filepath.Join(path, "tracker.bolt"))
+	case "mem":
+		return NewMemTrackingStore(), nil
+	default:
+		return nil, xerrors.Errorf("unknown tracking store type %s", ttype)
+	}
+}
+
+// NewMemTrackingStore creates an in-memory tracking store.
+// This is only useful for test or situations where you don't want to open the
+// real tracking store (eg concurrent read only access on a node's datastore)
+func NewMemTrackingStore() *MemTrackingStore {
+	return &MemTrackingStore{tab: make(map[cid.Cid]abi.ChainEpoch)}
+}
+
+// MemTrackingStore is a simple in-memory tracking store
+type MemTrackingStore struct {
+	sync.Mutex
+	tab map[cid.Cid]abi.ChainEpoch
+}
+
+var _ TrackingStore = (*MemTrackingStore)(nil)
+
+func (s *MemTrackingStore) Put(cid cid.Cid, epoch abi.ChainEpoch) error {
+	s.Lock()
+	defer s.Unlock()
+	s.tab[cid] = epoch
+	return nil
+}
+
+func (s *MemTrackingStore) PutBatch(cids []cid.Cid, epoch abi.ChainEpoch) error {
+	s.Lock()
+	defer s.Unlock()
+	for _, cid := range cids {
+		s.tab[cid] = epoch
+	}
+	return nil
+}
+
+func (s *MemTrackingStore) Get(cid cid.Cid) (abi.ChainEpoch, error) {
+	s.Lock()
+	defer s.Unlock()
+	epoch, ok := s.tab[cid]
+	if ok {
+		return epoch, nil
+	}
+	return 0, xerrors.Errorf("missing tracking epoch for %s", cid)
+}
+
+func (s *MemTrackingStore) Delete(cid cid.Cid) error {
+	s.Lock()
+	defer s.Unlock()
+	delete(s.tab, cid)
+	return nil
+}
+
+func (s *MemTrackingStore) DeleteBatch(cids []cid.Cid) error {
+	s.Lock()
+	defer s.Unlock()
+	for _, cid := range cids {
+		delete(s.tab, cid)
+	}
+	return nil
+}
+
+func (s *MemTrackingStore) ForEach(f func(cid.Cid, abi.ChainEpoch) error) error {
+	s.Lock()
+	defer s.Unlock()
+	for cid, epoch := range s.tab {
+		err := f(cid, epoch)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *MemTrackingStore) Sync() error  { return nil }
+func (s *MemTrackingStore) Close() error { return nil }
@@ -0,0 +1,120 @@
+package splitstore
+
+import (
+	"time"
+
+	"golang.org/x/xerrors"
+
+	cid "github.com/ipfs/go-cid"
+	bolt "go.etcd.io/bbolt"
+
+	"github.com/filecoin-project/go-state-types/abi"
+)
+
+type BoltTrackingStore struct {
+	db       *bolt.DB
+	bucketId []byte
+}
+
+var _ TrackingStore = (*BoltTrackingStore)(nil)
+
+func OpenBoltTrackingStore(path string) (*BoltTrackingStore, error) {
+	opts := &bolt.Options{
+		Timeout: 1 * time.Second,
+		NoSync:  true,
+	}
+	db, err := bolt.Open(path, 0644, opts)
+	if err != nil {
+		return nil, err
+	}
+
+	bucketId := []byte("tracker")
+	err = db.Update(func(tx *bolt.Tx) error {
+		_, err := tx.CreateBucketIfNotExists(bucketId)
+		if err != nil {
+			return xerrors.Errorf("error creating bolt db bucket %s: %w", string(bucketId), err)
+		}
+		return nil
+	})
+
+	if err != nil {
+		_ = db.Close()
+		return nil, err
+	}
+
+	return &BoltTrackingStore{db: db, bucketId: bucketId}, nil
+}
+
+func (s *BoltTrackingStore) Put(cid cid.Cid, epoch abi.ChainEpoch) error {
+	val := epochToBytes(epoch)
+	return s.db.Batch(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		return b.Put(cid.Hash(), val)
+	})
+}
+
+func (s *BoltTrackingStore) PutBatch(cids []cid.Cid, epoch abi.ChainEpoch) error {
+	val := epochToBytes(epoch)
+	return s.db.Batch(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		for _, cid := range cids {
+			err := b.Put(cid.Hash(), val)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}
+
+func (s *BoltTrackingStore) Get(cid cid.Cid) (epoch abi.ChainEpoch, err error) {
+	err = s.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		val := b.Get(cid.Hash())
+		if val == nil {
+			return xerrors.Errorf("missing tracking epoch for %s", cid)
+		}
+		epoch = bytesToEpoch(val)
+		return nil
+	})
+	return epoch, err
+}
+
+func (s *BoltTrackingStore) Delete(cid cid.Cid) error {
+	return s.db.Batch(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		return b.Delete(cid.Hash())
+	})
+}
+
+func (s *BoltTrackingStore) DeleteBatch(cids []cid.Cid) error {
+	return s.db.Batch(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		for _, cid := range cids {
+			err := b.Delete(cid.Hash())
+			if err != nil {
+				return xerrors.Errorf("error deleting %s", cid)
+			}
+		}
+		return nil
+	})
+}
+
+func (s *BoltTrackingStore) ForEach(f func(cid.Cid, abi.ChainEpoch) error) error {
+	return s.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket(s.bucketId)
+		return b.ForEach(func(k, v []byte) error {
+			cid := cid.NewCidV1(cid.Raw, k)
+			epoch := bytesToEpoch(v)
+			return f(cid, epoch)
+		})
+	})
+}
+
+func (s *BoltTrackingStore) Sync() error {
+	return s.db.Sync()
+}
+
+func (s *BoltTrackingStore) Close() error {
+	return s.db.Close()
+}
@@ -0,0 +1,130 @@
+package splitstore
+
+import (
+	"io/ioutil"
+	"testing"
+
+	cid "github.com/ipfs/go-cid"
+	"github.com/multiformats/go-multihash"
+
+	"github.com/filecoin-project/go-state-types/abi"
+)
+
+func TestBoltTrackingStore(t *testing.T) {
+	testTrackingStore(t, "bolt")
+}
+
+func testTrackingStore(t *testing.T, tsType string) {
+	t.Helper()
+
+	makeCid := func(key string) cid.Cid {
+		h, err := multihash.Sum([]byte(key), multihash.SHA2_256, -1)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		return cid.NewCidV1(cid.Raw, h)
+	}
+
+	mustHave := func(s TrackingStore, cid cid.Cid, epoch abi.ChainEpoch) {
+		val, err := s.Get(cid)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if val != epoch {
+			t.Fatal("epoch mismatch")
+		}
+	}
+
+	mustNotHave := func(s TrackingStore, cid cid.Cid) {
+		_, err := s.Get(cid)
+		if err == nil {
+			t.Fatal("expected error")
+		}
+	}
+
+	path, err := ioutil.TempDir("", "snoop-test.*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	s, err := OpenTrackingStore(path, tsType)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	k1 := makeCid("a")
+	k2 := makeCid("b")
+	k3 := makeCid("c")
+	k4 := makeCid("d")
+
+	s.Put(k1, 1) //nolint
+	s.Put(k2, 2) //nolint
+	s.Put(k3, 3) //nolint
+	s.Put(k4, 4) //nolint
+
+	mustHave(s, k1, 1)
+	mustHave(s, k2, 2)
+	mustHave(s, k3, 3)
+	mustHave(s, k4, 4)
+
+	s.Delete(k1) // nolint
+	s.Delete(k2) // nolint
+
+	mustNotHave(s, k1)
+	mustNotHave(s, k2)
+	mustHave(s, k3, 3)
+	mustHave(s, k4, 4)
+
+	s.PutBatch([]cid.Cid{k1}, 1) //nolint
+	s.PutBatch([]cid.Cid{k2}, 2) //nolint
+
+	mustHave(s, k1, 1)
+	mustHave(s, k2, 2)
+	mustHave(s, k3, 3)
+	mustHave(s, k4, 4)
+
+	allKeys := map[string]struct{}{
+		k1.String(): {},
+		k2.String(): {},
+		k3.String(): {},
+		k4.String(): {},
+	}
+
+	err = s.ForEach(func(k cid.Cid, _ abi.ChainEpoch) error {
+		_, ok := allKeys[k.String()]
+		if !ok {
+			t.Fatal("unexpected key")
+		}
+
+		delete(allKeys, k.String())
+		return nil
+	})
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(allKeys) != 0 {
+		t.Fatal("not all keys were returned")
+	}
+
+	// no close and reopen and ensure the keys still exist
+	err = s.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	s, err = OpenTrackingStore(path, tsType)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	mustHave(s, k1, 1)
+	mustHave(s, k2, 2)
+	mustHave(s, k3, 3)
+	mustHave(s, k4, 4)
+
+	s.Close() //nolint:errcheck
+}
@@ -0,0 +1,81 @@
+package blockstore
+
+import (
+	"context"
+	"sync"
+
+	blocks "github.com/ipfs/go-block-format"
+	"github.com/ipfs/go-cid"
+)
+
+// NewMemorySync returns a thread-safe in-memory blockstore.
+func NewMemorySync() *SyncBlockstore {
+	return &SyncBlockstore{bs: make(MemBlockstore)}
+}
+
+// SyncBlockstore is a terminal blockstore that is a synchronized version
+// of MemBlockstore.
+type SyncBlockstore struct {
+	mu sync.RWMutex
+	bs MemBlockstore // specifically use a memStore to save indirection overhead.
+}
+
+func (m *SyncBlockstore) DeleteBlock(k cid.Cid) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.bs.DeleteBlock(k)
+}
+
+func (m *SyncBlockstore) DeleteMany(ks []cid.Cid) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.bs.DeleteMany(ks)
+}
+
+func (m *SyncBlockstore) Has(k cid.Cid) (bool, error) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return m.bs.Has(k)
+}
+
+func (m *SyncBlockstore) View(k cid.Cid, callback func([]byte) error) error {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+
+	return m.bs.View(k, callback)
+}
+
+func (m *SyncBlockstore) Get(k cid.Cid) (blocks.Block, error) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return m.bs.Get(k)
+}
+
+func (m *SyncBlockstore) GetSize(k cid.Cid) (int, error) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return m.bs.GetSize(k)
+}
+
+func (m *SyncBlockstore) Put(b blocks.Block) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.bs.Put(b)
+}
+
+func (m *SyncBlockstore) PutMany(bs []blocks.Block) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.bs.PutMany(bs)
+}
+
+func (m *SyncBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	// this blockstore implementation doesn't do any async work.
+	return m.bs.AllKeysChan(ctx)
+}
+
+func (m *SyncBlockstore) HashOnRead(enabled bool) {
+	// noop
+}
@@ -1,4 +1,4 @@
-package timedbs
+package blockstore

 import (
 	"context"
@@ -10,37 +10,37 @@ import (
 	"github.com/ipfs/go-cid"
 	"github.com/raulk/clock"
 	"go.uber.org/multierr"
-
-	"github.com/filecoin-project/lotus/build"
-	"github.com/filecoin-project/lotus/lib/blockstore"
 )

-// TimedCacheBS is a blockstore that keeps blocks for at least the specified
-// caching interval before discarding them. Garbage collection must be started
-// and stopped by calling Start/Stop.
+// TimedCacheBlockstore is a blockstore that keeps blocks for at least the
+// specified caching interval before discarding them. Garbage collection must
+// be started and stopped by calling Start/Stop.
 //
 // Under the covers, it's implemented with an active and an inactive blockstore
 // that are rotated every cache time interval. This means all blocks will be
 // stored at most 2x the cache interval.
-type TimedCacheBS struct {
+//
+// Create a new instance by calling the NewTimedCacheBlockstore constructor.
+type TimedCacheBlockstore struct {
 	mu               sync.RWMutex
-	active, inactive blockstore.MemStore
+	active, inactive MemBlockstore
 	clock            clock.Clock
 	interval         time.Duration
 	closeCh          chan struct{}
 	doneRotatingCh   chan struct{}
 }

-func NewTimedCacheBS(cacheTime time.Duration) *TimedCacheBS {
-	return &TimedCacheBS{
-		active:   blockstore.NewTemporary(),
-		inactive: blockstore.NewTemporary(),
-		interval: cacheTime,
-		clock:    build.Clock,
+func NewTimedCacheBlockstore(interval time.Duration) *TimedCacheBlockstore {
+	b := &TimedCacheBlockstore{
+		active:   NewMemory(),
+		inactive: NewMemory(),
+		interval: interval,
+		clock:    clock.New(),
 	}
+	return b
 }

-func (t *TimedCacheBS) Start(ctx context.Context) error {
+func (t *TimedCacheBlockstore) Start(_ context.Context) error {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	if t.closeCh != nil {
@@ -65,11 +65,11 @@ func (t *TimedCacheBS) Start(ctx context.Context) error {
 	return nil
 }

-func (t *TimedCacheBS) Stop(ctx context.Context) error {
+func (t *TimedCacheBlockstore) Stop(_ context.Context) error {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	if t.closeCh == nil {
-		return fmt.Errorf("not started started")
+		return fmt.Errorf("not started")
 	}
 	select {
 	case <-t.closeCh:
@@ -80,15 +80,15 @@ func (t *TimedCacheBS) Stop(ctx context.Context) error {
 	return nil
 }

-func (t *TimedCacheBS) rotate() {
-	newBs := blockstore.NewTemporary()
+func (t *TimedCacheBlockstore) rotate() {
+	newBs := NewMemory()

 	t.mu.Lock()
 	t.inactive, t.active = t.active, newBs
 	t.mu.Unlock()
 }

-func (t *TimedCacheBS) Put(b blocks.Block) error {
+func (t *TimedCacheBlockstore) Put(b blocks.Block) error {
 	// Don't check the inactive set here. We want to keep this block for at
 	// least one interval.
 	t.mu.Lock()
@@ -96,33 +96,43 @@ func (t *TimedCacheBS) Put(b blocks.Block) error {
 	return t.active.Put(b)
 }

-func (t *TimedCacheBS) PutMany(bs []blocks.Block) error {
+func (t *TimedCacheBlockstore) PutMany(bs []blocks.Block) error {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	return t.active.PutMany(bs)
 }

-func (t *TimedCacheBS) Get(k cid.Cid) (blocks.Block, error) {
+func (t *TimedCacheBlockstore) View(k cid.Cid, callback func([]byte) error) error {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	err := t.active.View(k, callback)
+	if err == ErrNotFound {
+		err = t.inactive.View(k, callback)
+	}
+	return err
+}
+
+func (t *TimedCacheBlockstore) Get(k cid.Cid) (blocks.Block, error) {
 	t.mu.RLock()
 	defer t.mu.RUnlock()
 	b, err := t.active.Get(k)
-	if err == blockstore.ErrNotFound {
+	if err == ErrNotFound {
 		b, err = t.inactive.Get(k)
 	}
 	return b, err
 }

-func (t *TimedCacheBS) GetSize(k cid.Cid) (int, error) {
+func (t *TimedCacheBlockstore) GetSize(k cid.Cid) (int, error) {
 	t.mu.RLock()
 	defer t.mu.RUnlock()
 	size, err := t.active.GetSize(k)
-	if err == blockstore.ErrNotFound {
+	if err == ErrNotFound {
 		size, err = t.inactive.GetSize(k)
 	}
 	return size, err
 }

-func (t *TimedCacheBS) Has(k cid.Cid) (bool, error) {
+func (t *TimedCacheBlockstore) Has(k cid.Cid) (bool, error) {
 	t.mu.RLock()
 	defer t.mu.RUnlock()
 	if has, err := t.active.Has(k); err != nil {
@@ -133,17 +143,23 @@ func (t *TimedCacheBS) Has(k cid.Cid) (bool, error) {
 	return t.inactive.Has(k)
 }

-func (t *TimedCacheBS) HashOnRead(_ bool) {
+func (t *TimedCacheBlockstore) HashOnRead(_ bool) {
 	// no-op
 }

-func (t *TimedCacheBS) DeleteBlock(k cid.Cid) error {
+func (t *TimedCacheBlockstore) DeleteBlock(k cid.Cid) error {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	return multierr.Combine(t.active.DeleteBlock(k), t.inactive.DeleteBlock(k))
 }

-func (t *TimedCacheBS) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+func (t *TimedCacheBlockstore) DeleteMany(ks []cid.Cid) error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return multierr.Combine(t.active.DeleteMany(ks), t.inactive.DeleteMany(ks))
+}
+
+func (t *TimedCacheBlockstore) AllKeysChan(_ context.Context) (<-chan cid.Cid, error) {
 	t.mu.RLock()
 	defer t.mu.RUnlock()

@@ -1,4 +1,4 @@
-package timedbs
+package blockstore

 import (
 	"context"
@@ -12,8 +12,8 @@ import (
 	"github.com/ipfs/go-cid"
 )

-func TestTimedBSSimple(t *testing.T) {
-	tc := NewTimedCacheBS(10 * time.Millisecond)
+func TestTimedCacheBlockstoreSimple(t *testing.T) {
+	tc := NewTimedCacheBlockstore(10 * time.Millisecond)
 	mClock := clock.NewMock()
 	mClock.Set(time.Now())
 	tc.clock = mClock
@@ -0,0 +1,119 @@
+package blockstore
+
+import (
+	"context"
+
+	blocks "github.com/ipfs/go-block-format"
+	"github.com/ipfs/go-cid"
+)
+
+type unionBlockstore []Blockstore
+
+// Union returns an unioned blockstore.
+//
+// * Reads return from the first blockstore that has the value, querying in the
+//   supplied order.
+// * Writes (puts and deltes) are broadcast to all stores.
+//
+func Union(stores ...Blockstore) Blockstore {
+	return unionBlockstore(stores)
+}
+
+func (m unionBlockstore) Has(cid cid.Cid) (has bool, err error) {
+	for _, bs := range m {
+		if has, err = bs.Has(cid); has || err != nil {
+			break
+		}
+	}
+	return has, err
+}
+
+func (m unionBlockstore) Get(cid cid.Cid) (blk blocks.Block, err error) {
+	for _, bs := range m {
+		if blk, err = bs.Get(cid); err == nil || err != ErrNotFound {
+			break
+		}
+	}
+	return blk, err
+}
+
+func (m unionBlockstore) View(cid cid.Cid, callback func([]byte) error) (err error) {
+	for _, bs := range m {
+		if err = bs.View(cid, callback); err == nil || err != ErrNotFound {
+			break
+		}
+	}
+	return err
+}
+
+func (m unionBlockstore) GetSize(cid cid.Cid) (size int, err error) {
+	for _, bs := range m {
+		if size, err = bs.GetSize(cid); err == nil || err != ErrNotFound {
+			break
+		}
+	}
+	return size, err
+}
+
+func (m unionBlockstore) Put(block blocks.Block) (err error) {
+	for _, bs := range m {
+		if err = bs.Put(block); err != nil {
+			break
+		}
+	}
+	return err
+}
+
+func (m unionBlockstore) PutMany(blks []blocks.Block) (err error) {
+	for _, bs := range m {
+		if err = bs.PutMany(blks); err != nil {
+			break
+		}
+	}
+	return err
+}
+
+func (m unionBlockstore) DeleteBlock(cid cid.Cid) (err error) {
+	for _, bs := range m {
+		if err = bs.DeleteBlock(cid); err != nil {
+			break
+		}
+	}
+	return err
+}
+
+func (m unionBlockstore) DeleteMany(cids []cid.Cid) (err error) {
+	for _, bs := range m {
+		if err = bs.DeleteMany(cids); err != nil {
+			break
+		}
+	}
+	return err
+}
+
+func (m unionBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+	// this does not deduplicate; this interface needs to be revisited.
+	outCh := make(chan cid.Cid)
+
+	go func() {
+		defer close(outCh)
+
+		for _, bs := range m {
+			ch, err := bs.AllKeysChan(ctx)
+			if err != nil {
+				return
+			}
+			for cid := range ch {
+				outCh <- cid
+			}
+		}
+	}()
+
+	return outCh, nil
+}
+
+func (m unionBlockstore) HashOnRead(enabled bool) {
+	for _, bs := range m {
+		bs.HashOnRead(enabled)
+	}
+}
@@ -0,0 +1,102 @@
+package blockstore
+
+import (
+	"context"
+	"testing"
+
+	blocks "github.com/ipfs/go-block-format"
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	b0 = blocks.NewBlock([]byte("abc"))
+	b1 = blocks.NewBlock([]byte("foo"))
+	b2 = blocks.NewBlock([]byte("bar"))
+)
+
+func TestUnionBlockstore_Get(t *testing.T) {
+	m1 := NewMemory()
+	m2 := NewMemory()
+
+	_ = m1.Put(b1)
+	_ = m2.Put(b2)
+
+	u := Union(m1, m2)
+
+	v1, err := u.Get(b1.Cid())
+	require.NoError(t, err)
+	require.Equal(t, b1.RawData(), v1.RawData())
+
+	v2, err := u.Get(b2.Cid())
+	require.NoError(t, err)
+	require.Equal(t, b2.RawData(), v2.RawData())
+}
+
+func TestUnionBlockstore_Put_PutMany_Delete_AllKeysChan(t *testing.T) {
+	m1 := NewMemory()
+	m2 := NewMemory()
+
+	u := Union(m1, m2)
+
+	err := u.Put(b0)
+	require.NoError(t, err)
+
+	var has bool
+
+	// write was broadcasted to all stores.
+	has, _ = m1.Has(b0.Cid())
+	require.True(t, has)
+
+	has, _ = m2.Has(b0.Cid())
+	require.True(t, has)
+
+	has, _ = u.Has(b0.Cid())
+	require.True(t, has)
+
+	// put many.
+	err = u.PutMany([]blocks.Block{b1, b2})
+	require.NoError(t, err)
+
+	// write was broadcasted to all stores.
+	has, _ = m1.Has(b1.Cid())
+	require.True(t, has)
+
+	has, _ = m1.Has(b2.Cid())
+	require.True(t, has)
+
+	has, _ = m2.Has(b1.Cid())
+	require.True(t, has)
+
+	has, _ = m2.Has(b2.Cid())
+	require.True(t, has)
+
+	// also in the union store.
+	has, _ = u.Has(b1.Cid())
+	require.True(t, has)
+
+	has, _ = u.Has(b2.Cid())
+	require.True(t, has)
+
+	// deleted from all stores.
+	err = u.DeleteBlock(b1.Cid())
+	require.NoError(t, err)
+
+	has, _ = u.Has(b1.Cid())
+	require.False(t, has)
+
+	has, _ = m1.Has(b1.Cid())
+	require.False(t, has)
+
+	has, _ = m2.Has(b1.Cid())
+	require.False(t, has)
+
+	// check that AllKeysChan returns b0 and b2, twice (once per backing store)
+	ch, err := u.AllKeysChan(context.Background())
+	require.NoError(t, err)
+
+	var i int
+	for range ch {
+		i++
+	}
+	require.Equal(t, 4, i)
+}
@@ -0,0 +1,2 @@
+/dns4/bootstrap-0.butterfly.fildev.network/tcp/1347/p2p/12D3KooWRkaF18SR3E6qL6dkGrozT8QJUV5VbhE9E7BZtPmHqdWJ
+/dns4/bootstrap-1.butterfly.fildev.network/tcp/1347/p2p/12D3KooWJcJUc23WJjJHGSboGcU3t76z9Lb7CghrH2tiBiDCY4ux
@@ -1,4 +1,4 @@
-/dns4/bootstrap-0.calibration.fildev.network/tcp/1347/p2p/12D3KooWK1QYsm6iqyhgH7vqsbeoNoKHbT368h1JLHS1qYN36oyc
-/dns4/bootstrap-1.calibration.fildev.network/tcp/1347/p2p/12D3KooWKDyJZoPsNak1iYNN1GGmvGnvhyVbWBL6iusYfP3RpgYs
-/dns4/bootstrap-2.calibration.fildev.network/tcp/1347/p2p/12D3KooWJRSTnzABB6MYYEBbSTT52phQntVD1PpRTMh1xt9mh6yH
-/dns4/bootstrap-3.calibration.fildev.network/tcp/1347/p2p/12D3KooWQLi3kY6HnMYLUtwCe26zWMdNhniFgHVNn1DioQc7NiWv
+/dns4/bootstrap-0.calibration.fildev.network/tcp/1347/p2p/12D3KooWRLZAseMo9h7fRD6ojn6YYDXHsBSavX5YmjBZ9ngtAEec
+/dns4/bootstrap-1.calibration.fildev.network/tcp/1347/p2p/12D3KooWJFtDXgZEQMEkjJPSrbfdvh2xfjVKrXeNFG1t8ioJXAzv
+/dns4/bootstrap-2.calibration.fildev.network/tcp/1347/p2p/12D3KooWP1uB9Lo7yCA3S17TD4Y5wStP5Nk7Vqh53m8GsFjkyujD
+/dns4/bootstrap-3.calibration.fildev.network/tcp/1347/p2p/12D3KooWLrPM4WPK1YRGPCUwndWcDX8GCYgms3DiuofUmxwvhMCn
@@ -1,4 +1,4 @@
-/dns4/bootstrap-0.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWNfuGjtzWTVz8eJGZ2C3aJg2xLqorhsagu4LTWw6CwpK9
-/dns4/bootstrap-1.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWDfsxYk7dC6NNsHqZqqyMJCzkjZuXhjsmqBk3TUCBZLga
-/dns4/bootstrap-2.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWRZAGHmCCaa2gkYmnC4Q2TEwHGFSh6Fh1FFJ7RSXak5yN
-/dns4/bootstrap-3.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWBFxEigSKLvxJVdw3JziC9ePHHnyAn5LifWSqg2kttcth
+/dns4/bootstrap-2.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWQcL6ReWmR6ASWx4iT7EiAmxKDQpvgq1MKNTQZp5NPnWW
+/dns4/bootstrap-0.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWGyJCwCm7EfupM15CFPXM4c7zRVHwwwjcuy9umaGeztMX
+/dns4/bootstrap-3.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWNK9RmfksKXSCQj7ZwAM7L6roqbN4kwJteihq7yPvSgPs
+/dns4/bootstrap-1.nerpa.interplanetary.dev/tcp/1347/p2p/12D3KooWCWSaH6iUyXYspYxELjDfzToBsyVGVz3QvC7ysXv7wESo
@@ -3,6 +3,9 @@
 package build

 import (
+	"os"
+	"strconv"
+
 	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/filecoin-project/lotus/chain/actors/policy"
 )
@@ -10,24 +13,29 @@ import (
 const BootstrappersFile = ""
 const GenesisFile = ""

-const UpgradeBreezeHeight = -1
+var UpgradeBreezeHeight = abi.ChainEpoch(-1)
+
 const BreezeGasTampingDuration = 0

-const UpgradeSmokeHeight = -1
-const UpgradeIgnitionHeight = -2
-const UpgradeRefuelHeight = -3
-const UpgradeTapeHeight = -4
+var UpgradeSmokeHeight = abi.ChainEpoch(-1)
+var UpgradeIgnitionHeight = abi.ChainEpoch(-2)
+var UpgradeRefuelHeight = abi.ChainEpoch(-3)
+var UpgradeTapeHeight = abi.ChainEpoch(-4)

-const UpgradeActorsV2Height = 10
-const UpgradeLiftoffHeight = -5
+var UpgradeActorsV2Height = abi.ChainEpoch(10)
+var UpgradeLiftoffHeight = abi.ChainEpoch(-5)

-const UpgradeKumquatHeight = 15
-const UpgradeCalicoHeight = 20
-const UpgradePersianHeight = 25
-const UpgradeOrangeHeight = 27
-const UpgradeClausHeight = 30
+var UpgradeKumquatHeight = abi.ChainEpoch(15)
+var UpgradeCalicoHeight = abi.ChainEpoch(20)
+var UpgradePersianHeight = abi.ChainEpoch(25)
+var UpgradeOrangeHeight = abi.ChainEpoch(27)
+var UpgradeClausHeight = abi.ChainEpoch(30)

-const UpgradeActorsV3Height = 35
+var UpgradeActorsV3Height = abi.ChainEpoch(35)
+
+var UpgradeNorwegianHeight = abi.ChainEpoch(40)
+
+var UpgradeActorsV4Height = abi.ChainEpoch(45)

 var DrandSchedule = map[abi.ChainEpoch]DrandEnum{
 	0: DrandMainnet,
@@ -38,6 +46,36 @@ func init() {
 	policy.SetConsensusMinerMinPower(abi.NewStoragePower(2048))
 	policy.SetMinVerifiedDealSize(abi.NewStoragePower(256))

+	getUpgradeHeight := func(ev string, def abi.ChainEpoch) abi.ChainEpoch {
+		hs, found := os.LookupEnv(ev)
+		if found {
+			h, err := strconv.Atoi(hs)
+			if err != nil {
+				log.Panicf("failed to parse %s env var", ev)
+			}
+
+			return abi.ChainEpoch(h)
+		}
+
+		return def
+	}
+
+	UpgradeBreezeHeight = getUpgradeHeight("LOTUS_BREEZE_HEIGHT", UpgradeBreezeHeight)
+	UpgradeSmokeHeight = getUpgradeHeight("LOTUS_SMOKE_HEIGHT", UpgradeSmokeHeight)
+	UpgradeIgnitionHeight = getUpgradeHeight("LOTUS_IGNITION_HEIGHT", UpgradeIgnitionHeight)
+	UpgradeRefuelHeight = getUpgradeHeight("LOTUS_REFUEL_HEIGHT", UpgradeRefuelHeight)
+	UpgradeTapeHeight = getUpgradeHeight("LOTUS_TAPE_HEIGHT", UpgradeTapeHeight)
+	UpgradeActorsV2Height = getUpgradeHeight("LOTUS_ACTORSV2_HEIGHT", UpgradeActorsV2Height)
+	UpgradeLiftoffHeight = getUpgradeHeight("LOTUS_LIFTOFF_HEIGHT", UpgradeLiftoffHeight)
+	UpgradeKumquatHeight = getUpgradeHeight("LOTUS_KUMQUAT_HEIGHT", UpgradeKumquatHeight)
+	UpgradeCalicoHeight = getUpgradeHeight("LOTUS_CALICO_HEIGHT", UpgradeCalicoHeight)
+	UpgradePersianHeight = getUpgradeHeight("LOTUS_PERSIAN_HEIGHT", UpgradePersianHeight)
+	UpgradeOrangeHeight = getUpgradeHeight("LOTUS_ORANGE_HEIGHT", UpgradeOrangeHeight)
+	UpgradeClausHeight = getUpgradeHeight("LOTUS_CLAUS_HEIGHT", UpgradeClausHeight)
+	UpgradeActorsV3Height = getUpgradeHeight("LOTUS_ACTORSV3_HEIGHT", UpgradeActorsV3Height)
+	UpgradeNorwegianHeight = getUpgradeHeight("LOTUS_NORWEGIAN_HEIGHT", UpgradeNorwegianHeight)
+	UpgradeActorsV4Height = getUpgradeHeight("LOTUS_ACTORSV4_HEIGHT", UpgradeActorsV4Height)
+
 	BuildType |= Build2k
 }

@@ -0,0 +1,54 @@
+// +build butterflynet
+
+package build
+
+import (
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/lotus/chain/actors/policy"
+	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
+)
+
+var DrandSchedule = map[abi.ChainEpoch]DrandEnum{
+	0: DrandMainnet,
+}
+
+const BootstrappersFile = "butterflynet.pi"
+const GenesisFile = "butterflynet.car"
+
+const UpgradeBreezeHeight = -1
+const BreezeGasTampingDuration = 120
+const UpgradeSmokeHeight = -2
+const UpgradeIgnitionHeight = -3
+const UpgradeRefuelHeight = -4
+
+var UpgradeActorsV2Height = abi.ChainEpoch(30)
+
+const UpgradeTapeHeight = 60
+const UpgradeLiftoffHeight = -5
+const UpgradeKumquatHeight = 90
+const UpgradeCalicoHeight = 120
+const UpgradePersianHeight = 150
+const UpgradeClausHeight = 180
+const UpgradeOrangeHeight = 210
+const UpgradeActorsV3Height = 240
+const UpgradeNorwegianHeight = UpgradeActorsV3Height + (builtin2.EpochsInHour * 12)
+const UpgradeActorsV4Height = 8922
+
+func init() {
+	policy.SetConsensusMinerMinPower(abi.NewStoragePower(2 << 30))
+	policy.SetSupportedProofTypes(
+		abi.RegisteredSealProof_StackedDrg512MiBV1,
+	)
+
+	SetAddressNetwork(address.Testnet)
+
+	Devnet = true
+}
+
+const BlockDelaySecs = uint64(builtin2.EpochDurationSeconds)
+
+const PropagationDelaySecs = uint64(6)
+
+// BootstrapPeerThreshold is the minimum number peers we need to track for a sync worker to start
+const BootstrapPeerThreshold = 2
@@ -32,22 +32,21 @@ const UpgradeLiftoffHeight = -5

 const UpgradeKumquatHeight = 90

-const UpgradeCalicoHeight = 92000
-const UpgradePersianHeight = UpgradeCalicoHeight + (builtin2.EpochsInHour * 60)
+const UpgradeCalicoHeight = 100
+const UpgradePersianHeight = UpgradeCalicoHeight + (builtin2.EpochsInHour * 1)

-// 2020-12-17T19:00:00Z
-const UpgradeClausHeight = 161386
+const UpgradeClausHeight = 250

-// 2021-01-17T19:00:00Z
-const UpgradeOrangeHeight = 250666
+const UpgradeOrangeHeight = 300

-// 2021-01-28T21:00:00Z
-const UpgradeActorsV3Height = 282586
+const UpgradeActorsV3Height = 600
+const UpgradeNorwegianHeight = 114000
+
+const UpgradeActorsV4Height = 193789

 func init() {
-	policy.SetConsensusMinerMinPower(abi.NewStoragePower(10 << 30))
+	policy.SetConsensusMinerMinPower(abi.NewStoragePower(32 << 30))
 	policy.SetSupportedProofTypes(
-		abi.RegisteredSealProof_StackedDrg512MiBV1,
 		abi.RegisteredSealProof_StackedDrg32GiBV1,
 		abi.RegisteredSealProof_StackedDrg64GiBV1,
 	)
@@ -3,10 +3,12 @@
 // +build !testground
 // +build !calibnet
 // +build !nerpanet
+// +build !butterflynet

 package build

 import (
+	"math"
 	"os"

 	"github.com/filecoin-project/go-address"
@@ -51,8 +53,14 @@ const UpgradeOrangeHeight = 336458
 // 2020-12-22T02:00:00Z
 const UpgradeClausHeight = 343200

-// TODO
-const UpgradeActorsV3Height = 999999999
+// 2021-03-04T00:00:30Z
+var UpgradeActorsV3Height = abi.ChainEpoch(550321)
+
+// 2021-04-12T22:00:00Z
+const UpgradeNorwegianHeight = 665280
+
+// 2021-04-29T06:00:00Z
+var UpgradeActorsV4Height = abi.ChainEpoch(712320)

 func init() {
 	policy.SetConsensusMinerMinPower(abi.NewStoragePower(10 << 40))
@@ -61,6 +69,14 @@ func init() {
 		SetAddressNetwork(address.Mainnet)
 	}

+	if os.Getenv("LOTUS_DISABLE_V3_ACTOR_MIGRATION") == "1" {
+		UpgradeActorsV3Height = math.MaxInt64
+	}
+
+	if os.Getenv("LOTUS_DISABLE_V4_ACTOR_MIGRATION") == "1" {
+		UpgradeActorsV4Height = math.MaxInt64
+	}
+
 	Devnet = false

 	BuildType = BuildMainnet
@@ -24,21 +24,23 @@ const UpgradeSmokeHeight = -1
 const UpgradeIgnitionHeight = -2
 const UpgradeRefuelHeight = -3

-const UpgradeTapeHeight = -4
-
 const UpgradeLiftoffHeight = -5
-const UpgradeActorsV2Height = 120 // critical: the network can bootstrap from v1 only

-const UpgradeKumquatHeight = -6
+const UpgradeActorsV2Height = 30 // critical: the network can bootstrap from v1 only
+const UpgradeTapeHeight = 60

-const UpgradeCalicoHeight = 306000
-const UpgradePersianHeight = UpgradeCalicoHeight + (builtin2.EpochsInHour * 12)
+const UpgradeKumquatHeight = 90

-const UpgradeOrangeHeight = 307500
+const UpgradeCalicoHeight = 100
+const UpgradePersianHeight = UpgradeCalicoHeight + (builtin2.EpochsInHour * 1)

-const UpgradeClausHeight = 307600
+const UpgradeClausHeight = 250

-const UpgradeActorsV3Height = 308000
+const UpgradeOrangeHeight = 300
+
+const UpgradeActorsV3Height = 600
+const UpgradeNorwegianHeight = 999999
+const UpgradeActorsV4Height = 99999999

 func init() {
 	// Minimum block production power is set to 4 TiB
@@ -81,18 +81,20 @@ var (
 	UpgradeBreezeHeight      abi.ChainEpoch = -1
 	BreezeGasTampingDuration abi.ChainEpoch = 0

-	UpgradeSmokeHeight    abi.ChainEpoch = -1
-	UpgradeIgnitionHeight abi.ChainEpoch = -2
-	UpgradeRefuelHeight   abi.ChainEpoch = -3
-	UpgradeTapeHeight     abi.ChainEpoch = -4
-	UpgradeActorsV2Height abi.ChainEpoch = 10
-	UpgradeLiftoffHeight  abi.ChainEpoch = -5
-	UpgradeKumquatHeight  abi.ChainEpoch = -6
-	UpgradeCalicoHeight   abi.ChainEpoch = -7
-	UpgradePersianHeight  abi.ChainEpoch = -8
-	UpgradeOrangeHeight   abi.ChainEpoch = -9
-	UpgradeClausHeight    abi.ChainEpoch = -10
-	UpgradeActorsV3Height abi.ChainEpoch = -11
+	UpgradeSmokeHeight     abi.ChainEpoch = -1
+	UpgradeIgnitionHeight  abi.ChainEpoch = -2
+	UpgradeRefuelHeight    abi.ChainEpoch = -3
+	UpgradeTapeHeight      abi.ChainEpoch = -4
+	UpgradeActorsV2Height  abi.ChainEpoch = 10
+	UpgradeLiftoffHeight   abi.ChainEpoch = -5
+	UpgradeKumquatHeight   abi.ChainEpoch = -6
+	UpgradeCalicoHeight    abi.ChainEpoch = -7
+	UpgradePersianHeight   abi.ChainEpoch = -8
+	UpgradeOrangeHeight    abi.ChainEpoch = -9
+	UpgradeClausHeight     abi.ChainEpoch = -10
+	UpgradeActorsV3Height  abi.ChainEpoch = -11
+	UpgradeNorwegianHeight abi.ChainEpoch = -12
+	UpgradeActorsV4Height  abi.ChainEpoch = -13

 	DrandSchedule = map[abi.ChainEpoch]DrandEnum{
 		0: DrandMainnet,
@@ -3,5 +3,7 @@
 package build

 import (
+	_ "github.com/GeertJohan/go.rice/rice"
+	_ "github.com/golang/mock/mockgen"
 	_ "github.com/whyrusleeping/bencher"
 )
@@ -1,11 +1,5 @@
 package build

-import (
-	"fmt"
-
-	"golang.org/x/xerrors"
-)
-
 var CurrentCommit string
 var BuildType int

@@ -35,72 +29,8 @@ func buildType() string {
 }

 // BuildVersion is the local build version, set by build system
-const BuildVersion = "1.4.2"
+const BuildVersion = "1.8.0"

 func UserVersion() string {
 	return BuildVersion + buildType() + CurrentCommit
 }
-
-type Version uint32
-
-func newVer(major, minor, patch uint8) Version {
-	return Version(uint32(major)<<16 | uint32(minor)<<8 | uint32(patch))
-}
-
-// Ints returns (major, minor, patch) versions
-func (ve Version) Ints() (uint32, uint32, uint32) {
-	v := uint32(ve)
-	return (v & majorOnlyMask) >> 16, (v & minorOnlyMask) >> 8, v & patchOnlyMask
-}
-
-func (ve Version) String() string {
-	vmj, vmi, vp := ve.Ints()
-	return fmt.Sprintf("%d.%d.%d", vmj, vmi, vp)
-}
-
-func (ve Version) EqMajorMinor(v2 Version) bool {
-	return ve&minorMask == v2&minorMask
-}
-
-type NodeType int
-
-const (
-	NodeUnknown NodeType = iota
-
-	NodeFull
-	NodeMiner
-	NodeWorker
-)
-
-var RunningNodeType NodeType
-
-func VersionForType(nodeType NodeType) (Version, error) {
-	switch nodeType {
-	case NodeFull:
-		return FullAPIVersion, nil
-	case NodeMiner:
-		return MinerAPIVersion, nil
-	case NodeWorker:
-		return WorkerAPIVersion, nil
-	default:
-		return Version(0), xerrors.Errorf("unknown node type %d", nodeType)
-	}
-}
-
-// semver versions of the rpc api exposed
-var (
-	FullAPIVersion   = newVer(1, 1, 0)
-	MinerAPIVersion  = newVer(1, 0, 1)
-	WorkerAPIVersion = newVer(1, 0, 0)
-)
-
-//nolint:varcheck,deadcode
-const (
-	majorMask = 0xff0000
-	minorMask = 0xffff00
-	patchMask = 0xffffff
-
-	majorOnlyMask = 0xff0000
-	minorOnlyMask = 0x00ff00
-	patchOnlyMask = 0x0000ff
-)
@@ -16,7 +16,7 @@ import (
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	adt2 "github.com/filecoin-project/specs-actors/v2/actors/util/adt"

-	bstore "github.com/filecoin-project/lotus/lib/blockstore"
+	bstore "github.com/filecoin-project/lotus/blockstore"
 )

 func TestDiffAdtArray(t *testing.T) {
@@ -295,7 +295,7 @@ func (t *TestDiffArray) Remove(key uint64, val *typegen.Deferred) error {

 func newContextStore() Store {
 	ctx := context.Background()
-	bs := bstore.NewTemporarySync()
+	bs := bstore.NewMemorySync()
 	store := cbornode.NewCborStore(bs)
 	return WrapStore(ctx, store)
 }
@@ -14,6 +14,7 @@ import (
 	builtin0 "github.com/filecoin-project/specs-actors/actors/builtin"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
 )

 func init() {
@@ -26,9 +27,12 @@ func init() {
 	builtin.RegisterActorState(builtin3.AccountActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.AccountActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

-var Methods = builtin3.MethodsAccount
+var Methods = builtin4.MethodsAccount

 func Load(store adt.Store, act *types.Actor) (State, error) {
 	switch act.Code {
@@ -38,6 +42,8 @@ func Load(store adt.Store, act *types.Actor) (State, error) {
 		return load2(store, act.Head)
 	case builtin3.AccountActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.AccountActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,30 @@
+package account
+
+import (
+	"github.com/filecoin-project/go-address"
+	"github.com/ipfs/go-cid"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+
+	account4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/account"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	account4.State
+	store adt.Store
+}
+
+func (s *state4) PubkeyAddress() (address.Address, error) {
+	return s.Address, nil
+}
@@ -8,6 +8,7 @@ import (
 	builtin0 "github.com/filecoin-project/specs-actors/actors/builtin"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"

 	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/filecoin-project/go-state-types/cbor"
@@ -18,6 +19,7 @@ import (
 	smoothing0 "github.com/filecoin-project/specs-actors/actors/util/smoothing"
 	smoothing2 "github.com/filecoin-project/specs-actors/v2/actors/util/smoothing"
 	smoothing3 "github.com/filecoin-project/specs-actors/v3/actors/util/smoothing"
+	smoothing4 "github.com/filecoin-project/specs-actors/v4/actors/util/smoothing"

 	miner0 "github.com/filecoin-project/specs-actors/actors/builtin/miner"
 	proof0 "github.com/filecoin-project/specs-actors/actors/runtime/proof"
@@ -41,8 +43,8 @@ const (
 )

 const (
-	MethodSend        = builtin3.MethodSend
-	MethodConstructor = builtin3.MethodConstructor
+	MethodSend        = builtin4.MethodSend
+	MethodConstructor = builtin4.MethodConstructor
 )

 // These are all just type aliases across actor versions 0, 2, & 3. In the future, that might change
@@ -68,6 +70,10 @@ func FromV3FilterEstimate(v3 smoothing3.FilterEstimate) FilterEstimate {
 	return (FilterEstimate)(v3)
 }

+func FromV4FilterEstimate(v4 smoothing4.FilterEstimate) FilterEstimate {
+	return (FilterEstimate)(v4)
+}
+
 type ActorStateLoader func(store adt.Store, root cid.Cid) (cbor.Marshaler, error)

 var ActorStateLoaders = make(map[cid.Cid]ActorStateLoader)
@@ -92,6 +98,8 @@ func ActorNameByCode(c cid.Cid) string {
 		return builtin2.ActorNameByCode(c)
 	case builtin3.IsBuiltinActor(c):
 		return builtin3.ActorNameByCode(c)
+	case builtin4.IsBuiltinActor(c):
+		return builtin4.ActorNameByCode(c)
 	default:
 		return "<unknown>"
 	}
@@ -100,32 +108,36 @@ func ActorNameByCode(c cid.Cid) string {
 func IsBuiltinActor(c cid.Cid) bool {
 	return builtin0.IsBuiltinActor(c) ||
 		builtin2.IsBuiltinActor(c) ||
-		builtin3.IsBuiltinActor(c)
+		builtin3.IsBuiltinActor(c) ||
+		builtin4.IsBuiltinActor(c)
 }

 func IsAccountActor(c cid.Cid) bool {
 	return c == builtin0.AccountActorCodeID ||
 		c == builtin2.AccountActorCodeID ||
-		c == builtin3.AccountActorCodeID
+		c == builtin3.AccountActorCodeID ||
+		c == builtin4.AccountActorCodeID
 }

 func IsStorageMinerActor(c cid.Cid) bool {
 	return c == builtin0.StorageMinerActorCodeID ||
 		c == builtin2.StorageMinerActorCodeID ||
-		c == builtin3.StorageMinerActorCodeID
+		c == builtin3.StorageMinerActorCodeID ||
+		c == builtin4.StorageMinerActorCodeID
 }

 func IsMultisigActor(c cid.Cid) bool {
 	return c == builtin0.MultisigActorCodeID ||
 		c == builtin2.MultisigActorCodeID ||
-		c == builtin3.MultisigActorCodeID
-
+		c == builtin3.MultisigActorCodeID ||
+		c == builtin4.MultisigActorCodeID
 }

 func IsPaymentChannelActor(c cid.Cid) bool {
 	return c == builtin0.PaymentChannelActorCodeID ||
 		c == builtin2.PaymentChannelActorCodeID ||
-		c == builtin3.PaymentChannelActorCodeID
+		c == builtin3.PaymentChannelActorCodeID ||
+		c == builtin4.PaymentChannelActorCodeID
 }

 func makeAddress(addr string) address.Address {
@@ -1,10 +1,10 @@
 package cron

 import (
-	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
 )

 var (
-	Address = builtin3.CronActorAddr
-	Methods = builtin3.MethodsCron
+	Address = builtin4.CronActorAddr
+	Methods = builtin4.MethodsCron
 )
@@ -16,6 +16,7 @@ import (
 	builtin0 "github.com/filecoin-project/specs-actors/actors/builtin"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
 )

 func init() {
@@ -28,11 +29,14 @@ func init() {
 	builtin.RegisterActorState(builtin3.InitActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.InitActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 var (
-	Address = builtin3.InitActorAddr
-	Methods = builtin3.MethodsInit
+	Address = builtin4.InitActorAddr
+	Methods = builtin4.MethodsInit
 )

 func Load(store adt.Store, act *types.Actor) (State, error) {
@@ -43,6 +47,8 @@ func Load(store adt.Store, act *types.Actor) (State, error) {
 		return load2(store, act.Head)
 	case builtin3.InitActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.InitActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,86 @@
+package init
+
+import (
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	"github.com/ipfs/go-cid"
+	cbg "github.com/whyrusleeping/cbor-gen"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+	"github.com/filecoin-project/lotus/node/modules/dtypes"
+
+	init4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/init"
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	init4.State
+	store adt.Store
+}
+
+func (s *state4) ResolveAddress(address address.Address) (address.Address, bool, error) {
+	return s.State.ResolveAddress(s.store, address)
+}
+
+func (s *state4) MapAddressToNewID(address address.Address) (address.Address, error) {
+	return s.State.MapAddressToNewID(s.store, address)
+}
+
+func (s *state4) ForEachActor(cb func(id abi.ActorID, address address.Address) error) error {
+	addrs, err := adt4.AsMap(s.store, s.State.AddressMap, builtin4.DefaultHamtBitwidth)
+	if err != nil {
+		return err
+	}
+	var actorID cbg.CborInt
+	return addrs.ForEach(&actorID, func(key string) error {
+		addr, err := address.NewFromBytes([]byte(key))
+		if err != nil {
+			return err
+		}
+		return cb(abi.ActorID(actorID), addr)
+	})
+}
+
+func (s *state4) NetworkName() (dtypes.NetworkName, error) {
+	return dtypes.NetworkName(s.State.NetworkName), nil
+}
+
+func (s *state4) SetNetworkName(name string) error {
+	s.State.NetworkName = name
+	return nil
+}
+
+func (s *state4) Remove(addrs ...address.Address) (err error) {
+	m, err := adt4.AsMap(s.store, s.State.AddressMap, builtin4.DefaultHamtBitwidth)
+	if err != nil {
+		return err
+	}
+	for _, addr := range addrs {
+		if err = m.Delete(abi.AddrKey(addr)); err != nil {
+			return xerrors.Errorf("failed to delete entry for address: %s; err: %w", addr, err)
+		}
+	}
+	amr, err := m.Root()
+	if err != nil {
+		return xerrors.Errorf("failed to get address map root: %w", err)
+	}
+	s.State.AddressMap = amr
+	return nil
+}
+
+func (s *state4) addressMap() (adt.Map, error) {
+	return adt4.AsMap(s.store, s.AddressMap, builtin4.DefaultHamtBitwidth)
+}
@@ -13,6 +13,7 @@ import (
 	market0 "github.com/filecoin-project/specs-actors/actors/builtin/market"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"

 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors/builtin"
@@ -29,11 +30,14 @@ func init() {
 	builtin.RegisterActorState(builtin3.StorageMarketActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.StorageMarketActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 var (
-	Address = builtin3.StorageMarketActorAddr
-	Methods = builtin3.MethodsMarket
+	Address = builtin4.StorageMarketActorAddr
+	Methods = builtin4.MethodsMarket
 )

 func Load(store adt.Store, act *types.Actor) (st State, err error) {
@@ -44,6 +48,8 @@ func Load(store adt.Store, act *types.Actor) (st State, err error) {
 		return load2(store, act.Head)
 	case builtin3.StorageMarketActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.StorageMarketActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,205 @@
+package market
+
+import (
+	"bytes"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/ipfs/go-cid"
+	cbg "github.com/whyrusleeping/cbor-gen"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+	"github.com/filecoin-project/lotus/chain/types"
+
+	market4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/market"
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	market4.State
+	store adt.Store
+}
+
+func (s *state4) TotalLocked() (abi.TokenAmount, error) {
+	fml := types.BigAdd(s.TotalClientLockedCollateral, s.TotalProviderLockedCollateral)
+	fml = types.BigAdd(fml, s.TotalClientStorageFee)
+	return fml, nil
+}
+
+func (s *state4) BalancesChanged(otherState State) (bool, error) {
+	otherState2, ok := otherState.(*state4)
+	if !ok {
+		// there's no way to compare different versions of the state, so let's
+		// just say that means the state of balances has changed
+		return true, nil
+	}
+	return !s.State.EscrowTable.Equals(otherState2.State.EscrowTable) || !s.State.LockedTable.Equals(otherState2.State.LockedTable), nil
+}
+
+func (s *state4) StatesChanged(otherState State) (bool, error) {
+	otherState2, ok := otherState.(*state4)
+	if !ok {
+		// there's no way to compare different versions of the state, so let's
+		// just say that means the state of balances has changed
+		return true, nil
+	}
+	return !s.State.States.Equals(otherState2.State.States), nil
+}
+
+func (s *state4) States() (DealStates, error) {
+	stateArray, err := adt4.AsArray(s.store, s.State.States, market4.StatesAmtBitwidth)
+	if err != nil {
+		return nil, err
+	}
+	return &dealStates4{stateArray}, nil
+}
+
+func (s *state4) ProposalsChanged(otherState State) (bool, error) {
+	otherState2, ok := otherState.(*state4)
+	if !ok {
+		// there's no way to compare different versions of the state, so let's
+		// just say that means the state of balances has changed
+		return true, nil
+	}
+	return !s.State.Proposals.Equals(otherState2.State.Proposals), nil
+}
+
+func (s *state4) Proposals() (DealProposals, error) {
+	proposalArray, err := adt4.AsArray(s.store, s.State.Proposals, market4.ProposalsAmtBitwidth)
+	if err != nil {
+		return nil, err
+	}
+	return &dealProposals4{proposalArray}, nil
+}
+
+func (s *state4) EscrowTable() (BalanceTable, error) {
+	bt, err := adt4.AsBalanceTable(s.store, s.State.EscrowTable)
+	if err != nil {
+		return nil, err
+	}
+	return &balanceTable4{bt}, nil
+}
+
+func (s *state4) LockedTable() (BalanceTable, error) {
+	bt, err := adt4.AsBalanceTable(s.store, s.State.LockedTable)
+	if err != nil {
+		return nil, err
+	}
+	return &balanceTable4{bt}, nil
+}
+
+func (s *state4) VerifyDealsForActivation(
+	minerAddr address.Address, deals []abi.DealID, currEpoch, sectorExpiry abi.ChainEpoch,
+) (weight, verifiedWeight abi.DealWeight, err error) {
+	w, vw, _, err := market4.ValidateDealsForActivation(&s.State, s.store, deals, minerAddr, sectorExpiry, currEpoch)
+	return w, vw, err
+}
+
+type balanceTable4 struct {
+	*adt4.BalanceTable
+}
+
+func (bt *balanceTable4) ForEach(cb func(address.Address, abi.TokenAmount) error) error {
+	asMap := (*adt4.Map)(bt.BalanceTable)
+	var ta abi.TokenAmount
+	return asMap.ForEach(&ta, func(key string) error {
+		a, err := address.NewFromBytes([]byte(key))
+		if err != nil {
+			return err
+		}
+		return cb(a, ta)
+	})
+}
+
+type dealStates4 struct {
+	adt.Array
+}
+
+func (s *dealStates4) Get(dealID abi.DealID) (*DealState, bool, error) {
+	var deal2 market4.DealState
+	found, err := s.Array.Get(uint64(dealID), &deal2)
+	if err != nil {
+		return nil, false, err
+	}
+	if !found {
+		return nil, false, nil
+	}
+	deal := fromV4DealState(deal2)
+	return &deal, true, nil
+}
+
+func (s *dealStates4) ForEach(cb func(dealID abi.DealID, ds DealState) error) error {
+	var ds1 market4.DealState
+	return s.Array.ForEach(&ds1, func(idx int64) error {
+		return cb(abi.DealID(idx), fromV4DealState(ds1))
+	})
+}
+
+func (s *dealStates4) decode(val *cbg.Deferred) (*DealState, error) {
+	var ds1 market4.DealState
+	if err := ds1.UnmarshalCBOR(bytes.NewReader(val.Raw)); err != nil {
+		return nil, err
+	}
+	ds := fromV4DealState(ds1)
+	return &ds, nil
+}
+
+func (s *dealStates4) array() adt.Array {
+	return s.Array
+}
+
+func fromV4DealState(v4 market4.DealState) DealState {
+	return (DealState)(v4)
+}
+
+type dealProposals4 struct {
+	adt.Array
+}
+
+func (s *dealProposals4) Get(dealID abi.DealID) (*DealProposal, bool, error) {
+	var proposal2 market4.DealProposal
+	found, err := s.Array.Get(uint64(dealID), &proposal2)
+	if err != nil {
+		return nil, false, err
+	}
+	if !found {
+		return nil, false, nil
+	}
+	proposal := fromV4DealProposal(proposal2)
+	return &proposal, true, nil
+}
+
+func (s *dealProposals4) ForEach(cb func(dealID abi.DealID, dp DealProposal) error) error {
+	var dp1 market4.DealProposal
+	return s.Array.ForEach(&dp1, func(idx int64) error {
+		return cb(abi.DealID(idx), fromV4DealProposal(dp1))
+	})
+}
+
+func (s *dealProposals4) decode(val *cbg.Deferred) (*DealProposal, error) {
+	var dp1 market4.DealProposal
+	if err := dp1.UnmarshalCBOR(bytes.NewReader(val.Raw)); err != nil {
+		return nil, err
+	}
+	dp := fromV4DealProposal(dp1)
+	return &dp, nil
+}
+
+func (s *dealProposals4) array() adt.Array {
+	return s.Array
+}
+
+func fromV4DealProposal(v4 market4.DealProposal) DealProposal {
+	return (DealProposal)(v4)
+}
@@ -24,6 +24,7 @@ import (
 	miner2 "github.com/filecoin-project/specs-actors/v2/actors/builtin/miner"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
 	miner3 "github.com/filecoin-project/specs-actors/v3/actors/builtin/miner"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
 )

 func init() {
@@ -36,11 +37,14 @@ func init() {
 	builtin.RegisterActorState(builtin3.StorageMinerActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.StorageMinerActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

-var Methods = builtin3.MethodsMiner
+var Methods = builtin4.MethodsMiner

-// Unchanged between v0, v2, and v3 actors
+// Unchanged between v0, v2, v3, and v4 actors
 var WPoStProvingPeriod = miner0.WPoStProvingPeriod
 var WPoStPeriodDeadlines = miner0.WPoStPeriodDeadlines
 var WPoStChallengeWindow = miner0.WPoStChallengeWindow
@@ -50,6 +54,7 @@ var FaultDeclarationCutoff = miner0.FaultDeclarationCutoff
 const MinSectorExpiration = miner0.MinSectorExpiration

 // Not used / checked in v0
+// TODO: Abstract over network versions
 var DeclarationsMax = miner2.DeclarationsMax
 var AddressedSectorsMax = miner2.AddressedSectorsMax

@@ -61,6 +66,8 @@ func Load(store adt.Store, act *types.Actor) (st State, err error) {
 		return load2(store, act.Head)
 	case builtin3.StorageMinerActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.StorageMinerActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -93,6 +100,7 @@ type State interface {
 	MinerInfoChanged(State) (bool, error)

 	DeadlineInfo(epoch abi.ChainEpoch) (*dline.Info, error)
+	DeadlineCronActive() (bool, error)

 	// Diff helpers. Used by Diff* functions internally.
 	sectors() (adt.Array, error)
@@ -330,6 +330,10 @@ func (s *state0) DeadlineInfo(epoch abi.ChainEpoch) (*dline.Info, error) {
 	return s.State.DeadlineInfo(epoch), nil
 }

+func (s *state0) DeadlineCronActive() (bool, error) {
+	return true, nil // always active in this version
+}
+
 func (s *state0) sectors() (adt.Array, error) {
 	return adt0.AsArray(s.store, s.Sectors)
 }
@@ -329,6 +329,10 @@ func (s *state2) DeadlineInfo(epoch abi.ChainEpoch) (*dline.Info, error) {
 	return s.State.DeadlineInfo(epoch), nil
 }

+func (s *state2) DeadlineCronActive() (bool, error) {
+	return true, nil // always active in this version
+}
+
 func (s *state2) sectors() (adt.Array, error) {
 	return adt2.AsArray(s.store, s.Sectors)
 }
@@ -325,6 +325,10 @@ func (s *state3) DeadlineInfo(epoch abi.ChainEpoch) (*dline.Info, error) {
 	return s.State.DeadlineInfo(epoch), nil
 }

+func (s *state3) DeadlineCronActive() (bool, error) {
+	return true, nil // always active in this version
+}
+
 func (s *state3) sectors() (adt.Array, error) {
 	return adt3.AsArray(s.store, s.Sectors, miner3.SectorsAmtBitwidth)
 }
@@ -0,0 +1,438 @@
+package miner
+
+import (
+	"bytes"
+	"errors"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-bitfield"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/dline"
+	"github.com/ipfs/go-cid"
+	"github.com/libp2p/go-libp2p-core/peer"
+	cbg "github.com/whyrusleeping/cbor-gen"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	miner4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/miner"
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	miner4.State
+	store adt.Store
+}
+
+type deadline4 struct {
+	miner4.Deadline
+	store adt.Store
+}
+
+type partition4 struct {
+	miner4.Partition
+	store adt.Store
+}
+
+func (s *state4) AvailableBalance(bal abi.TokenAmount) (available abi.TokenAmount, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = xerrors.Errorf("failed to get available balance: %w", r)
+			available = abi.NewTokenAmount(0)
+		}
+	}()
+	// this panics if the miner doesnt have enough funds to cover their locked pledge
+	available, err = s.GetAvailableBalance(bal)
+	return available, err
+}
+
+func (s *state4) VestedFunds(epoch abi.ChainEpoch) (abi.TokenAmount, error) {
+	return s.CheckVestedFunds(s.store, epoch)
+}
+
+func (s *state4) LockedFunds() (LockedFunds, error) {
+	return LockedFunds{
+		VestingFunds:             s.State.LockedFunds,
+		InitialPledgeRequirement: s.State.InitialPledge,
+		PreCommitDeposits:        s.State.PreCommitDeposits,
+	}, nil
+}
+
+func (s *state4) FeeDebt() (abi.TokenAmount, error) {
+	return s.State.FeeDebt, nil
+}
+
+func (s *state4) InitialPledge() (abi.TokenAmount, error) {
+	return s.State.InitialPledge, nil
+}
+
+func (s *state4) PreCommitDeposits() (abi.TokenAmount, error) {
+	return s.State.PreCommitDeposits, nil
+}
+
+func (s *state4) GetSector(num abi.SectorNumber) (*SectorOnChainInfo, error) {
+	info, ok, err := s.State.GetSector(s.store, num)
+	if !ok || err != nil {
+		return nil, err
+	}
+
+	ret := fromV4SectorOnChainInfo(*info)
+	return &ret, nil
+}
+
+func (s *state4) FindSector(num abi.SectorNumber) (*SectorLocation, error) {
+	dlIdx, partIdx, err := s.State.FindSector(s.store, num)
+	if err != nil {
+		return nil, err
+	}
+	return &SectorLocation{
+		Deadline:  dlIdx,
+		Partition: partIdx,
+	}, nil
+}
+
+func (s *state4) NumLiveSectors() (uint64, error) {
+	dls, err := s.State.LoadDeadlines(s.store)
+	if err != nil {
+		return 0, err
+	}
+	var total uint64
+	if err := dls.ForEach(s.store, func(dlIdx uint64, dl *miner4.Deadline) error {
+		total += dl.LiveSectors
+		return nil
+	}); err != nil {
+		return 0, err
+	}
+	return total, nil
+}
+
+// GetSectorExpiration returns the effective expiration of the given sector.
+//
+// If the sector does not expire early, the Early expiration field is 0.
+func (s *state4) GetSectorExpiration(num abi.SectorNumber) (*SectorExpiration, error) {
+	dls, err := s.State.LoadDeadlines(s.store)
+	if err != nil {
+		return nil, err
+	}
+	// NOTE: this can be optimized significantly.
+	// 1. If the sector is non-faulty, it will either expire on-time (can be
+	// learned from the sector info), or in the next quantized expiration
+	// epoch (i.e., the first element in the partition's expiration queue.
+	// 2. If it's faulty, it will expire early within the first 14 entries
+	// of the expiration queue.
+	stopErr := errors.New("stop")
+	out := SectorExpiration{}
+	err = dls.ForEach(s.store, func(dlIdx uint64, dl *miner4.Deadline) error {
+		partitions, err := dl.PartitionsArray(s.store)
+		if err != nil {
+			return err
+		}
+		quant := s.State.QuantSpecForDeadline(dlIdx)
+		var part miner4.Partition
+		return partitions.ForEach(&part, func(partIdx int64) error {
+			if found, err := part.Sectors.IsSet(uint64(num)); err != nil {
+				return err
+			} else if !found {
+				return nil
+			}
+			if found, err := part.Terminated.IsSet(uint64(num)); err != nil {
+				return err
+			} else if found {
+				// already terminated
+				return stopErr
+			}
+
+			q, err := miner4.LoadExpirationQueue(s.store, part.ExpirationsEpochs, quant, miner4.PartitionExpirationAmtBitwidth)
+			if err != nil {
+				return err
+			}
+			var exp miner4.ExpirationSet
+			return q.ForEach(&exp, func(epoch int64) error {
+				if early, err := exp.EarlySectors.IsSet(uint64(num)); err != nil {
+					return err
+				} else if early {
+					out.Early = abi.ChainEpoch(epoch)
+					return nil
+				}
+				if onTime, err := exp.OnTimeSectors.IsSet(uint64(num)); err != nil {
+					return err
+				} else if onTime {
+					out.OnTime = abi.ChainEpoch(epoch)
+					return stopErr
+				}
+				return nil
+			})
+		})
+	})
+	if err == stopErr {
+		err = nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	if out.Early == 0 && out.OnTime == 0 {
+		return nil, xerrors.Errorf("failed to find sector %d", num)
+	}
+	return &out, nil
+}
+
+func (s *state4) GetPrecommittedSector(num abi.SectorNumber) (*SectorPreCommitOnChainInfo, error) {
+	info, ok, err := s.State.GetPrecommittedSector(s.store, num)
+	if !ok || err != nil {
+		return nil, err
+	}
+
+	ret := fromV4SectorPreCommitOnChainInfo(*info)
+
+	return &ret, nil
+}
+
+func (s *state4) LoadSectors(snos *bitfield.BitField) ([]*SectorOnChainInfo, error) {
+	sectors, err := miner4.LoadSectors(s.store, s.State.Sectors)
+	if err != nil {
+		return nil, err
+	}
+
+	// If no sector numbers are specified, load all.
+	if snos == nil {
+		infos := make([]*SectorOnChainInfo, 0, sectors.Length())
+		var info2 miner4.SectorOnChainInfo
+		if err := sectors.ForEach(&info2, func(_ int64) error {
+			info := fromV4SectorOnChainInfo(info2)
+			infos = append(infos, &info)
+			return nil
+		}); err != nil {
+			return nil, err
+		}
+		return infos, nil
+	}
+
+	// Otherwise, load selected.
+	infos2, err := sectors.Load(*snos)
+	if err != nil {
+		return nil, err
+	}
+	infos := make([]*SectorOnChainInfo, len(infos2))
+	for i, info2 := range infos2 {
+		info := fromV4SectorOnChainInfo(*info2)
+		infos[i] = &info
+	}
+	return infos, nil
+}
+
+func (s *state4) IsAllocated(num abi.SectorNumber) (bool, error) {
+	var allocatedSectors bitfield.BitField
+	if err := s.store.Get(s.store.Context(), s.State.AllocatedSectors, &allocatedSectors); err != nil {
+		return false, err
+	}
+
+	return allocatedSectors.IsSet(uint64(num))
+}
+
+func (s *state4) LoadDeadline(idx uint64) (Deadline, error) {
+	dls, err := s.State.LoadDeadlines(s.store)
+	if err != nil {
+		return nil, err
+	}
+	dl, err := dls.LoadDeadline(s.store, idx)
+	if err != nil {
+		return nil, err
+	}
+	return &deadline4{*dl, s.store}, nil
+}
+
+func (s *state4) ForEachDeadline(cb func(uint64, Deadline) error) error {
+	dls, err := s.State.LoadDeadlines(s.store)
+	if err != nil {
+		return err
+	}
+	return dls.ForEach(s.store, func(i uint64, dl *miner4.Deadline) error {
+		return cb(i, &deadline4{*dl, s.store})
+	})
+}
+
+func (s *state4) NumDeadlines() (uint64, error) {
+	return miner4.WPoStPeriodDeadlines, nil
+}
+
+func (s *state4) DeadlinesChanged(other State) (bool, error) {
+	other2, ok := other.(*state4)
+	if !ok {
+		// treat an upgrade as a change, always
+		return true, nil
+	}
+
+	return !s.State.Deadlines.Equals(other2.Deadlines), nil
+}
+
+func (s *state4) MinerInfoChanged(other State) (bool, error) {
+	other0, ok := other.(*state4)
+	if !ok {
+		// treat an upgrade as a change, always
+		return true, nil
+	}
+	return !s.State.Info.Equals(other0.State.Info), nil
+}
+
+func (s *state4) Info() (MinerInfo, error) {
+	info, err := s.State.GetInfo(s.store)
+	if err != nil {
+		return MinerInfo{}, err
+	}
+
+	var pid *peer.ID
+	if peerID, err := peer.IDFromBytes(info.PeerId); err == nil {
+		pid = &peerID
+	}
+
+	mi := MinerInfo{
+		Owner:            info.Owner,
+		Worker:           info.Worker,
+		ControlAddresses: info.ControlAddresses,
+
+		NewWorker:         address.Undef,
+		WorkerChangeEpoch: -1,
+
+		PeerId:                     pid,
+		Multiaddrs:                 info.Multiaddrs,
+		WindowPoStProofType:        info.WindowPoStProofType,
+		SectorSize:                 info.SectorSize,
+		WindowPoStPartitionSectors: info.WindowPoStPartitionSectors,
+		ConsensusFaultElapsed:      info.ConsensusFaultElapsed,
+	}
+
+	if info.PendingWorkerKey != nil {
+		mi.NewWorker = info.PendingWorkerKey.NewWorker
+		mi.WorkerChangeEpoch = info.PendingWorkerKey.EffectiveAt
+	}
+
+	return mi, nil
+}
+
+func (s *state4) DeadlineInfo(epoch abi.ChainEpoch) (*dline.Info, error) {
+	return s.State.RecordedDeadlineInfo(epoch), nil
+}
+
+func (s *state4) DeadlineCronActive() (bool, error) {
+	return s.State.DeadlineCronActive, nil
+}
+
+func (s *state4) sectors() (adt.Array, error) {
+	return adt4.AsArray(s.store, s.Sectors, miner4.SectorsAmtBitwidth)
+}
+
+func (s *state4) decodeSectorOnChainInfo(val *cbg.Deferred) (SectorOnChainInfo, error) {
+	var si miner4.SectorOnChainInfo
+	err := si.UnmarshalCBOR(bytes.NewReader(val.Raw))
+	if err != nil {
+		return SectorOnChainInfo{}, err
+	}
+
+	return fromV4SectorOnChainInfo(si), nil
+}
+
+func (s *state4) precommits() (adt.Map, error) {
+	return adt4.AsMap(s.store, s.PreCommittedSectors, builtin4.DefaultHamtBitwidth)
+}
+
+func (s *state4) decodeSectorPreCommitOnChainInfo(val *cbg.Deferred) (SectorPreCommitOnChainInfo, error) {
+	var sp miner4.SectorPreCommitOnChainInfo
+	err := sp.UnmarshalCBOR(bytes.NewReader(val.Raw))
+	if err != nil {
+		return SectorPreCommitOnChainInfo{}, err
+	}
+
+	return fromV4SectorPreCommitOnChainInfo(sp), nil
+}
+
+func (d *deadline4) LoadPartition(idx uint64) (Partition, error) {
+	p, err := d.Deadline.LoadPartition(d.store, idx)
+	if err != nil {
+		return nil, err
+	}
+	return &partition4{*p, d.store}, nil
+}
+
+func (d *deadline4) ForEachPartition(cb func(uint64, Partition) error) error {
+	ps, err := d.Deadline.PartitionsArray(d.store)
+	if err != nil {
+		return err
+	}
+	var part miner4.Partition
+	return ps.ForEach(&part, func(i int64) error {
+		return cb(uint64(i), &partition4{part, d.store})
+	})
+}
+
+func (d *deadline4) PartitionsChanged(other Deadline) (bool, error) {
+	other2, ok := other.(*deadline4)
+	if !ok {
+		// treat an upgrade as a change, always
+		return true, nil
+	}
+
+	return !d.Deadline.Partitions.Equals(other2.Deadline.Partitions), nil
+}
+
+func (d *deadline4) PartitionsPoSted() (bitfield.BitField, error) {
+	return d.Deadline.PartitionsPoSted, nil
+}
+
+func (d *deadline4) DisputableProofCount() (uint64, error) {
+	ops, err := d.OptimisticProofsSnapshotArray(d.store)
+	if err != nil {
+		return 0, err
+	}
+
+	return ops.Length(), nil
+}
+
+func (p *partition4) AllSectors() (bitfield.BitField, error) {
+	return p.Partition.Sectors, nil
+}
+
+func (p *partition4) FaultySectors() (bitfield.BitField, error) {
+	return p.Partition.Faults, nil
+}
+
+func (p *partition4) RecoveringSectors() (bitfield.BitField, error) {
+	return p.Partition.Recoveries, nil
+}
+
+func fromV4SectorOnChainInfo(v4 miner4.SectorOnChainInfo) SectorOnChainInfo {
+	return SectorOnChainInfo{
+		SectorNumber:          v4.SectorNumber,
+		SealProof:             v4.SealProof,
+		SealedCID:             v4.SealedCID,
+		DealIDs:               v4.DealIDs,
+		Activation:            v4.Activation,
+		Expiration:            v4.Expiration,
+		DealWeight:            v4.DealWeight,
+		VerifiedDealWeight:    v4.VerifiedDealWeight,
+		InitialPledge:         v4.InitialPledge,
+		ExpectedDayReward:     v4.ExpectedDayReward,
+		ExpectedStoragePledge: v4.ExpectedStoragePledge,
+	}
+}
+
+func fromV4SectorPreCommitOnChainInfo(v4 miner4.SectorPreCommitOnChainInfo) SectorPreCommitOnChainInfo {
+	return SectorPreCommitOnChainInfo{
+		Info:               (SectorPreCommitInfo)(v4.Info),
+		PreCommitDeposit:   v4.PreCommitDeposit,
+		PreCommitEpoch:     v4.PreCommitEpoch,
+		DealWeight:         v4.DealWeight,
+		VerifiedDealWeight: v4.VerifiedDealWeight,
+	}
+}
@@ -9,14 +9,14 @@ import (
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-state-types/abi"

-	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
-	multisig3 "github.com/filecoin-project/specs-actors/v3/actors/builtin/multisig"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	multisig4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/multisig"

 	"github.com/filecoin-project/lotus/chain/actors"
 	"github.com/filecoin-project/lotus/chain/types"
 )

-var Methods = builtin3.MethodsMultisig
+var Methods = builtin4.MethodsMultisig

 func Message(version actors.Version, from address.Address) MessageBuilder {
 	switch version {
@@ -26,6 +26,8 @@ func Message(version actors.Version, from address.Address) MessageBuilder {
 		return message2{message0{from}}
 	case actors.Version3:
 		return message3{message0{from}}
+	case actors.Version4:
+		return message4{message0{from}}
 	default:
 		panic(fmt.Sprintf("unsupported actors version: %d", version))
 	}
@@ -49,12 +51,12 @@ type MessageBuilder interface {
 }

 // this type is the same between v0 and v2
-type ProposalHashData = multisig3.ProposalHashData
-type ProposeReturn = multisig3.ProposeReturn
-type ProposeParams = multisig3.ProposeParams
+type ProposalHashData = multisig4.ProposalHashData
+type ProposeReturn = multisig4.ProposeReturn
+type ProposeParams = multisig4.ProposeParams

 func txnParams(id uint64, data *ProposalHashData) ([]byte, error) {
-	params := multisig3.TxnIDParams{ID: multisig3.TxnID(id)}
+	params := multisig4.TxnIDParams{ID: multisig4.TxnID(id)}
 	if data != nil {
 		if data.Requester.Protocol() != address.ID {
 			return nil, xerrors.Errorf("proposer address must be an ID address, was %s", data.Requester)
@@ -0,0 +1,71 @@
+package multisig
+
+import (
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	init4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/init"
+	multisig4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/multisig"
+
+	"github.com/filecoin-project/lotus/chain/actors"
+	init_ "github.com/filecoin-project/lotus/chain/actors/builtin/init"
+	"github.com/filecoin-project/lotus/chain/types"
+)
+
+type message4 struct{ message0 }
+
+func (m message4) Create(
+	signers []address.Address, threshold uint64,
+	unlockStart, unlockDuration abi.ChainEpoch,
+	initialAmount abi.TokenAmount,
+) (*types.Message, error) {
+
+	lenAddrs := uint64(len(signers))
+
+	if lenAddrs < threshold {
+		return nil, xerrors.Errorf("cannot require signing of more addresses than provided for multisig")
+	}
+
+	if threshold == 0 {
+		threshold = lenAddrs
+	}
+
+	if m.from == address.Undef {
+		return nil, xerrors.Errorf("must provide source address")
+	}
+
+	// Set up constructor parameters for multisig
+	msigParams := &multisig4.ConstructorParams{
+		Signers:               signers,
+		NumApprovalsThreshold: threshold,
+		UnlockDuration:        unlockDuration,
+		StartEpoch:            unlockStart,
+	}
+
+	enc, actErr := actors.SerializeParams(msigParams)
+	if actErr != nil {
+		return nil, actErr
+	}
+
+	// new actors are created by invoking 'exec' on the init actor with the constructor params
+	execParams := &init4.ExecParams{
+		CodeCID:           builtin4.MultisigActorCodeID,
+		ConstructorParams: enc,
+	}
+
+	enc, actErr = actors.SerializeParams(execParams)
+	if actErr != nil {
+		return nil, actErr
+	}
+
+	return &types.Message{
+		To:     init_.Address,
+		From:   m.from,
+		Method: builtin4.MethodsInit.Exec,
+		Params: enc,
+		Value:  initialAmount,
+	}, nil
+}
@@ -13,6 +13,7 @@ import (
 	msig0 "github.com/filecoin-project/specs-actors/actors/builtin/multisig"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"

 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors/builtin"
@@ -29,6 +30,9 @@ func init() {
 	builtin.RegisterActorState(builtin3.MultisigActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.MultisigActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 func Load(store adt.Store, act *types.Actor) (State, error) {
@@ -39,6 +43,8 @@ func Load(store adt.Store, act *types.Actor) (State, error) {
 		return load2(store, act.Head)
 	case builtin3.MultisigActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.MultisigActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,95 @@
+package multisig
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/ipfs/go-cid"
+	cbg "github.com/whyrusleeping/cbor-gen"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	msig4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/multisig"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	msig4.State
+	store adt.Store
+}
+
+func (s *state4) LockedBalance(currEpoch abi.ChainEpoch) (abi.TokenAmount, error) {
+	return s.State.AmountLocked(currEpoch - s.State.StartEpoch), nil
+}
+
+func (s *state4) StartEpoch() (abi.ChainEpoch, error) {
+	return s.State.StartEpoch, nil
+}
+
+func (s *state4) UnlockDuration() (abi.ChainEpoch, error) {
+	return s.State.UnlockDuration, nil
+}
+
+func (s *state4) InitialBalance() (abi.TokenAmount, error) {
+	return s.State.InitialBalance, nil
+}
+
+func (s *state4) Threshold() (uint64, error) {
+	return s.State.NumApprovalsThreshold, nil
+}
+
+func (s *state4) Signers() ([]address.Address, error) {
+	return s.State.Signers, nil
+}
+
+func (s *state4) ForEachPendingTxn(cb func(id int64, txn Transaction) error) error {
+	arr, err := adt4.AsMap(s.store, s.State.PendingTxns, builtin4.DefaultHamtBitwidth)
+	if err != nil {
+		return err
+	}
+	var out msig4.Transaction
+	return arr.ForEach(&out, func(key string) error {
+		txid, n := binary.Varint([]byte(key))
+		if n <= 0 {
+			return xerrors.Errorf("invalid pending transaction key: %v", key)
+		}
+		return cb(txid, (Transaction)(out))
+	})
+}
+
+func (s *state4) PendingTxnChanged(other State) (bool, error) {
+	other2, ok := other.(*state4)
+	if !ok {
+		// treat an upgrade as a change, always
+		return true, nil
+	}
+	return !s.State.PendingTxns.Equals(other2.PendingTxns), nil
+}
+
+func (s *state4) transactions() (adt.Map, error) {
+	return adt4.AsMap(s.store, s.PendingTxns, builtin4.DefaultHamtBitwidth)
+}
+
+func (s *state4) decodeTransaction(val *cbg.Deferred) (Transaction, error) {
+	var tx msig4.Transaction
+	if err := tx.UnmarshalCBOR(bytes.NewReader(val.Raw)); err != nil {
+		return Transaction{}, err
+	}
+	return tx, nil
+}
@@ -8,10 +8,10 @@ import (
 	"github.com/filecoin-project/lotus/chain/actors"
 	"github.com/filecoin-project/lotus/chain/types"

-	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
 )

-var Methods = builtin3.MethodsPaych
+var Methods = builtin4.MethodsPaych

 func Message(version actors.Version, from address.Address) MessageBuilder {
 	switch version {
@@ -21,6 +21,8 @@ func Message(version actors.Version, from address.Address) MessageBuilder {
 		return message2{from}
 	case actors.Version3:
 		return message3{from}
+	case actors.Version4:
+		return message4{from}
 	default:
 		panic(fmt.Sprintf("unsupported actors version: %d", version))
 	}
@@ -0,0 +1,74 @@
+package paych
+
+import (
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	init4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/init"
+	paych4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/paych"
+
+	"github.com/filecoin-project/lotus/chain/actors"
+	init_ "github.com/filecoin-project/lotus/chain/actors/builtin/init"
+	"github.com/filecoin-project/lotus/chain/types"
+)
+
+type message4 struct{ from address.Address }
+
+func (m message4) Create(to address.Address, initialAmount abi.TokenAmount) (*types.Message, error) {
+	params, aerr := actors.SerializeParams(&paych4.ConstructorParams{From: m.from, To: to})
+	if aerr != nil {
+		return nil, aerr
+	}
+	enc, aerr := actors.SerializeParams(&init4.ExecParams{
+		CodeCID:           builtin4.PaymentChannelActorCodeID,
+		ConstructorParams: params,
+	})
+	if aerr != nil {
+		return nil, aerr
+	}
+
+	return &types.Message{
+		To:     init_.Address,
+		From:   m.from,
+		Value:  initialAmount,
+		Method: builtin4.MethodsInit.Exec,
+		Params: enc,
+	}, nil
+}
+
+func (m message4) Update(paych address.Address, sv *SignedVoucher, secret []byte) (*types.Message, error) {
+	params, aerr := actors.SerializeParams(&paych4.UpdateChannelStateParams{
+		Sv:     *sv,
+		Secret: secret,
+	})
+	if aerr != nil {
+		return nil, aerr
+	}
+
+	return &types.Message{
+		To:     paych,
+		From:   m.from,
+		Value:  abi.NewTokenAmount(0),
+		Method: builtin4.MethodsPaych.UpdateChannelState,
+		Params: params,
+	}, nil
+}
+
+func (m message4) Settle(paych address.Address) (*types.Message, error) {
+	return &types.Message{
+		To:     paych,
+		From:   m.from,
+		Value:  abi.NewTokenAmount(0),
+		Method: builtin4.MethodsPaych.Settle,
+	}, nil
+}
+
+func (m message4) Collect(paych address.Address) (*types.Message, error) {
+	return &types.Message{
+		To:     paych,
+		From:   m.from,
+		Value:  abi.NewTokenAmount(0),
+		Method: builtin4.MethodsPaych.Collect,
+	}, nil
+}
@@ -16,6 +16,7 @@ import (
 	paych0 "github.com/filecoin-project/specs-actors/actors/builtin/paych"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"

 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors/builtin"
@@ -32,6 +33,9 @@ func init() {
 	builtin.RegisterActorState(builtin3.PaymentChannelActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.PaymentChannelActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 // Load returns an abstract copy of payment channel state, irregardless of actor version
@@ -43,6 +47,8 @@ func Load(store adt.Store, act *types.Actor) (State, error) {
 		return load2(store, act.Head)
 	case builtin3.PaymentChannelActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.PaymentChannelActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,104 @@
+package paych
+
+import (
+	"github.com/ipfs/go-cid"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/big"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+
+	paych4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/paych"
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	paych4.State
+	store adt.Store
+	lsAmt *adt4.Array
+}
+
+// Channel owner, who has funded the actor
+func (s *state4) From() (address.Address, error) {
+	return s.State.From, nil
+}
+
+// Recipient of payouts from channel
+func (s *state4) To() (address.Address, error) {
+	return s.State.To, nil
+}
+
+// Height at which the channel can be `Collected`
+func (s *state4) SettlingAt() (abi.ChainEpoch, error) {
+	return s.State.SettlingAt, nil
+}
+
+// Amount successfully redeemed through the payment channel, paid out on `Collect()`
+func (s *state4) ToSend() (abi.TokenAmount, error) {
+	return s.State.ToSend, nil
+}
+
+func (s *state4) getOrLoadLsAmt() (*adt4.Array, error) {
+	if s.lsAmt != nil {
+		return s.lsAmt, nil
+	}
+
+	// Get the lane state from the chain
+	lsamt, err := adt4.AsArray(s.store, s.State.LaneStates, paych4.LaneStatesAmtBitwidth)
+	if err != nil {
+		return nil, err
+	}
+
+	s.lsAmt = lsamt
+	return lsamt, nil
+}
+
+// Get total number of lanes
+func (s *state4) LaneCount() (uint64, error) {
+	lsamt, err := s.getOrLoadLsAmt()
+	if err != nil {
+		return 0, err
+	}
+	return lsamt.Length(), nil
+}
+
+// Iterate lane states
+func (s *state4) ForEachLaneState(cb func(idx uint64, dl LaneState) error) error {
+	// Get the lane state from the chain
+	lsamt, err := s.getOrLoadLsAmt()
+	if err != nil {
+		return err
+	}
+
+	// Note: we use a map instead of an array to store laneStates because the
+	// client sets the lane ID (the index) and potentially they could use a
+	// very large index.
+	var ls paych4.LaneState
+	return lsamt.ForEach(&ls, func(i int64) error {
+		return cb(uint64(i), &laneState4{ls})
+	})
+}
+
+type laneState4 struct {
+	paych4.LaneState
+}
+
+func (ls *laneState4) Redeemed() (big.Int, error) {
+	return ls.LaneState.Redeemed, nil
+}
+
+func (ls *laneState4) Nonce() (uint64, error) {
+	return ls.LaneState.Nonce, nil
+}
@@ -17,6 +17,7 @@ import (
 	builtin0 "github.com/filecoin-project/specs-actors/actors/builtin"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
 )

 func init() {
@@ -29,11 +30,14 @@ func init() {
 	builtin.RegisterActorState(builtin3.StoragePowerActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.StoragePowerActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 var (
-	Address = builtin3.StoragePowerActorAddr
-	Methods = builtin3.MethodsPower
+	Address = builtin4.StoragePowerActorAddr
+	Methods = builtin4.MethodsPower
 )

 func Load(store adt.Store, act *types.Actor) (st State, err error) {
@@ -44,6 +48,8 @@ func Load(store adt.Store, act *types.Actor) (st State, err error) {
 		return load2(store, act.Head)
 	case builtin3.StoragePowerActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.StoragePowerActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,149 @@
+package power
+
+import (
+	"bytes"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/ipfs/go-cid"
+	cbg "github.com/whyrusleeping/cbor-gen"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+	"github.com/filecoin-project/lotus/chain/actors/builtin"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	power4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/power"
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	power4.State
+	store adt.Store
+}
+
+func (s *state4) TotalLocked() (abi.TokenAmount, error) {
+	return s.TotalPledgeCollateral, nil
+}
+
+func (s *state4) TotalPower() (Claim, error) {
+	return Claim{
+		RawBytePower:    s.TotalRawBytePower,
+		QualityAdjPower: s.TotalQualityAdjPower,
+	}, nil
+}
+
+// Committed power to the network. Includes miners below the minimum threshold.
+func (s *state4) TotalCommitted() (Claim, error) {
+	return Claim{
+		RawBytePower:    s.TotalBytesCommitted,
+		QualityAdjPower: s.TotalQABytesCommitted,
+	}, nil
+}
+
+func (s *state4) MinerPower(addr address.Address) (Claim, bool, error) {
+	claims, err := s.claims()
+	if err != nil {
+		return Claim{}, false, err
+	}
+	var claim power4.Claim
+	ok, err := claims.Get(abi.AddrKey(addr), &claim)
+	if err != nil {
+		return Claim{}, false, err
+	}
+	return Claim{
+		RawBytePower:    claim.RawBytePower,
+		QualityAdjPower: claim.QualityAdjPower,
+	}, ok, nil
+}
+
+func (s *state4) MinerNominalPowerMeetsConsensusMinimum(a address.Address) (bool, error) {
+	return s.State.MinerNominalPowerMeetsConsensusMinimum(s.store, a)
+}
+
+func (s *state4) TotalPowerSmoothed() (builtin.FilterEstimate, error) {
+	return builtin.FromV4FilterEstimate(s.State.ThisEpochQAPowerSmoothed), nil
+}
+
+func (s *state4) MinerCounts() (uint64, uint64, error) {
+	return uint64(s.State.MinerAboveMinPowerCount), uint64(s.State.MinerCount), nil
+}
+
+func (s *state4) ListAllMiners() ([]address.Address, error) {
+	claims, err := s.claims()
+	if err != nil {
+		return nil, err
+	}
+
+	var miners []address.Address
+	err = claims.ForEach(nil, func(k string) error {
+		a, err := address.NewFromBytes([]byte(k))
+		if err != nil {
+			return err
+		}
+		miners = append(miners, a)
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return miners, nil
+}
+
+func (s *state4) ForEachClaim(cb func(miner address.Address, claim Claim) error) error {
+	claims, err := s.claims()
+	if err != nil {
+		return err
+	}
+
+	var claim power4.Claim
+	return claims.ForEach(&claim, func(k string) error {
+		a, err := address.NewFromBytes([]byte(k))
+		if err != nil {
+			return err
+		}
+		return cb(a, Claim{
+			RawBytePower:    claim.RawBytePower,
+			QualityAdjPower: claim.QualityAdjPower,
+		})
+	})
+}
+
+func (s *state4) ClaimsChanged(other State) (bool, error) {
+	other2, ok := other.(*state4)
+	if !ok {
+		// treat an upgrade as a change, always
+		return true, nil
+	}
+	return !s.State.Claims.Equals(other2.State.Claims), nil
+}
+
+func (s *state4) claims() (adt.Map, error) {
+	return adt4.AsMap(s.store, s.Claims, builtin4.DefaultHamtBitwidth)
+}
+
+func (s *state4) decodeClaim(val *cbg.Deferred) (Claim, error) {
+	var ci power4.Claim
+	if err := ci.UnmarshalCBOR(bytes.NewReader(val.Raw)); err != nil {
+		return Claim{}, err
+	}
+	return fromV4Claim(ci), nil
+}
+
+func fromV4Claim(v4 power4.Claim) Claim {
+	return Claim{
+		RawBytePower:    v4.RawBytePower,
+		QualityAdjPower: v4.QualityAdjPower,
+	}
+}
@@ -10,6 +10,7 @@ import (
 	builtin0 "github.com/filecoin-project/specs-actors/actors/builtin"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"

 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors/builtin"
@@ -26,11 +27,14 @@ func init() {
 	builtin.RegisterActorState(builtin3.RewardActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.RewardActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 var (
-	Address = builtin3.RewardActorAddr
-	Methods = builtin3.MethodsReward
+	Address = builtin4.RewardActorAddr
+	Methods = builtin4.MethodsReward
 )

 func Load(store adt.Store, act *types.Actor) (st State, err error) {
@@ -41,6 +45,8 @@ func Load(store adt.Store, act *types.Actor) (st State, err error) {
 		return load2(store, act.Head)
 	case builtin3.RewardActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.RewardActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -0,0 +1,86 @@
+package reward
+
+import (
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/ipfs/go-cid"
+
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+	"github.com/filecoin-project/lotus/chain/actors/builtin"
+
+	miner4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/miner"
+	reward4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/reward"
+	smoothing4 "github.com/filecoin-project/specs-actors/v4/actors/util/smoothing"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	reward4.State
+	store adt.Store
+}
+
+func (s *state4) ThisEpochReward() (abi.TokenAmount, error) {
+	return s.State.ThisEpochReward, nil
+}
+
+func (s *state4) ThisEpochRewardSmoothed() (builtin.FilterEstimate, error) {
+	return builtin.FilterEstimate{
+		PositionEstimate: s.State.ThisEpochRewardSmoothed.PositionEstimate,
+		VelocityEstimate: s.State.ThisEpochRewardSmoothed.VelocityEstimate,
+	}, nil
+}
+
+func (s *state4) ThisEpochBaselinePower() (abi.StoragePower, error) {
+	return s.State.ThisEpochBaselinePower, nil
+}
+
+func (s *state4) TotalStoragePowerReward() (abi.TokenAmount, error) {
+	return s.State.TotalStoragePowerReward, nil
+}
+
+func (s *state4) EffectiveBaselinePower() (abi.StoragePower, error) {
+	return s.State.EffectiveBaselinePower, nil
+}
+
+func (s *state4) EffectiveNetworkTime() (abi.ChainEpoch, error) {
+	return s.State.EffectiveNetworkTime, nil
+}
+
+func (s *state4) CumsumBaseline() (reward4.Spacetime, error) {
+	return s.State.CumsumBaseline, nil
+}
+
+func (s *state4) CumsumRealized() (reward4.Spacetime, error) {
+	return s.State.CumsumRealized, nil
+}
+
+func (s *state4) InitialPledgeForPower(qaPower abi.StoragePower, networkTotalPledge abi.TokenAmount, networkQAPower *builtin.FilterEstimate, circSupply abi.TokenAmount) (abi.TokenAmount, error) {
+	return miner4.InitialPledgeForPower(
+		qaPower,
+		s.State.ThisEpochBaselinePower,
+		s.State.ThisEpochRewardSmoothed,
+		smoothing4.FilterEstimate{
+			PositionEstimate: networkQAPower.PositionEstimate,
+			VelocityEstimate: networkQAPower.VelocityEstimate,
+		},
+		circSupply,
+	), nil
+}
+
+func (s *state4) PreCommitDepositForPower(networkQAPower builtin.FilterEstimate, sectorWeight abi.StoragePower) (abi.TokenAmount, error) {
+	return miner4.PreCommitDepositForPower(s.State.ThisEpochRewardSmoothed,
+		smoothing4.FilterEstimate{
+			PositionEstimate: networkQAPower.PositionEstimate,
+			VelocityEstimate: networkQAPower.VelocityEstimate,
+		},
+		sectorWeight), nil
+}
@@ -0,0 +1,58 @@
+package verifreg
+
+import (
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/ipfs/go-cid"
+
+	"github.com/filecoin-project/lotus/chain/actors"
+	"github.com/filecoin-project/lotus/chain/actors/adt"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	verifreg4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/verifreg"
+	adt4 "github.com/filecoin-project/specs-actors/v4/actors/util/adt"
+)
+
+var _ State = (*state4)(nil)
+
+func load4(store adt.Store, root cid.Cid) (State, error) {
+	out := state4{store: store}
+	err := store.Get(store.Context(), root, &out)
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+type state4 struct {
+	verifreg4.State
+	store adt.Store
+}
+
+func (s *state4) RootKey() (address.Address, error) {
+	return s.State.RootKey, nil
+}
+
+func (s *state4) VerifiedClientDataCap(addr address.Address) (bool, abi.StoragePower, error) {
+	return getDataCap(s.store, actors.Version4, s.verifiedClients, addr)
+}
+
+func (s *state4) VerifierDataCap(addr address.Address) (bool, abi.StoragePower, error) {
+	return getDataCap(s.store, actors.Version4, s.verifiers, addr)
+}
+
+func (s *state4) ForEachVerifier(cb func(addr address.Address, dcap abi.StoragePower) error) error {
+	return forEachCap(s.store, actors.Version4, s.verifiers, cb)
+}
+
+func (s *state4) ForEachClient(cb func(addr address.Address, dcap abi.StoragePower) error) error {
+	return forEachCap(s.store, actors.Version4, s.verifiedClients, cb)
+}
+
+func (s *state4) verifiedClients() (adt.Map, error) {
+	return adt4.AsMap(s.store, s.VerifiedClients, builtin4.DefaultHamtBitwidth)
+}
+
+func (s *state4) verifiers() (adt.Map, error) {
+	return adt4.AsMap(s.store, s.Verifiers, builtin4.DefaultHamtBitwidth)
+}
@@ -1,15 +1,17 @@
 package verifreg

 import (
-	"github.com/filecoin-project/go-address"
-	"github.com/filecoin-project/go-state-types/abi"
-	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
 	"github.com/ipfs/go-cid"
 	"golang.org/x/xerrors"

+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+
 	"github.com/filecoin-project/go-state-types/cbor"
 	builtin0 "github.com/filecoin-project/specs-actors/actors/builtin"
 	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
+	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"

 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors/builtin"
@@ -26,11 +28,14 @@ func init() {
 	builtin.RegisterActorState(builtin3.VerifiedRegistryActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
 		return load3(store, root)
 	})
+	builtin.RegisterActorState(builtin4.VerifiedRegistryActorCodeID, func(store adt.Store, root cid.Cid) (cbor.Marshaler, error) {
+		return load4(store, root)
+	})
 }

 var (
-	Address = builtin3.VerifiedRegistryActorAddr
-	Methods = builtin3.MethodsVerifiedRegistry
+	Address = builtin4.VerifiedRegistryActorAddr
+	Methods = builtin4.MethodsVerifiedRegistry
 )

 func Load(store adt.Store, act *types.Actor) (State, error) {
@@ -41,6 +46,8 @@ func Load(store adt.Store, act *types.Actor) (State, error) {
 		return load2(store, act.Head)
 	case builtin3.VerifiedRegistryActorCodeID:
 		return load3(store, act.Head)
+	case builtin4.VerifiedRegistryActorCodeID:
+		return load4(store, act.Head)
 	}
 	return nil, xerrors.Errorf("unknown actor code %s", act.Code)
 }
@@ -20,14 +20,19 @@ import (
 	builtin3 "github.com/filecoin-project/specs-actors/v3/actors/builtin"
 	market3 "github.com/filecoin-project/specs-actors/v3/actors/builtin/market"
 	miner3 "github.com/filecoin-project/specs-actors/v3/actors/builtin/miner"
-	paych3 "github.com/filecoin-project/specs-actors/v3/actors/builtin/paych"
 	verifreg3 "github.com/filecoin-project/specs-actors/v3/actors/builtin/verifreg"
+
+	builtin4 "github.com/filecoin-project/specs-actors/v4/actors/builtin"
+	market4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/market"
+	miner4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/miner"
+	paych4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/paych"
+	verifreg4 "github.com/filecoin-project/specs-actors/v4/actors/builtin/verifreg"
 )

 const (
-	ChainFinality          = miner3.ChainFinality
+	ChainFinality          = miner4.ChainFinality
 	SealRandomnessLookback = ChainFinality
-	PaychSettleDelay       = paych3.SettleDelay
+	PaychSettleDelay       = paych4.SettleDelay
 )

 // SetSupportedProofTypes sets supported proof types, across all actor versions.
@@ -42,6 +47,10 @@ func SetSupportedProofTypes(types ...abi.RegisteredSealProof) {
 	miner3.PreCommitSealProofTypesV7 = make(map[abi.RegisteredSealProof]struct{}, len(types)*2)
 	miner3.PreCommitSealProofTypesV8 = make(map[abi.RegisteredSealProof]struct{}, len(types))

+	miner4.PreCommitSealProofTypesV0 = make(map[abi.RegisteredSealProof]struct{}, len(types))
+	miner4.PreCommitSealProofTypesV7 = make(map[abi.RegisteredSealProof]struct{}, len(types)*2)
+	miner4.PreCommitSealProofTypesV8 = make(map[abi.RegisteredSealProof]struct{}, len(types))
+
 	AddSupportedProofTypes(types...)
 }

@@ -54,19 +63,21 @@ func AddSupportedProofTypes(types ...abi.RegisteredSealProof) {
 		}
 		// Set for all miner versions.
 		miner0.SupportedProofTypes[t] = struct{}{}
-		miner2.PreCommitSealProofTypesV0[t] = struct{}{}

+		miner2.PreCommitSealProofTypesV0[t] = struct{}{}
 		miner2.PreCommitSealProofTypesV7[t] = struct{}{}
 		miner2.PreCommitSealProofTypesV7[t+abi.RegisteredSealProof_StackedDrg2KiBV1_1] = struct{}{}
-
 		miner2.PreCommitSealProofTypesV8[t+abi.RegisteredSealProof_StackedDrg2KiBV1_1] = struct{}{}

 		miner3.PreCommitSealProofTypesV0[t] = struct{}{}
-
 		miner3.PreCommitSealProofTypesV7[t] = struct{}{}
 		miner3.PreCommitSealProofTypesV7[t+abi.RegisteredSealProof_StackedDrg2KiBV1_1] = struct{}{}
-
 		miner3.PreCommitSealProofTypesV8[t+abi.RegisteredSealProof_StackedDrg2KiBV1_1] = struct{}{}
+
+		miner4.PreCommitSealProofTypesV0[t] = struct{}{}
+		miner4.PreCommitSealProofTypesV7[t] = struct{}{}
+		miner4.PreCommitSealProofTypesV7[t+abi.RegisteredSealProof_StackedDrg2KiBV1_1] = struct{}{}
+		miner4.PreCommitSealProofTypesV8[t+abi.RegisteredSealProof_StackedDrg2KiBV1_1] = struct{}{}
 	}
 }

@@ -77,6 +88,7 @@ func SetPreCommitChallengeDelay(delay abi.ChainEpoch) {
 	miner0.PreCommitChallengeDelay = delay
 	miner2.PreCommitChallengeDelay = delay
 	miner3.PreCommitChallengeDelay = delay
+	miner4.PreCommitChallengeDelay = delay
 }

 // TODO: this function shouldn't really exist. Instead, the API should expose the precommit delay.
@@ -96,6 +108,10 @@ func SetConsensusMinerMinPower(p abi.StoragePower) {
 	for _, policy := range builtin3.PoStProofPolicies {
 		policy.ConsensusMinerMinPower = p
 	}
+
+	for _, policy := range builtin4.PoStProofPolicies {
+		policy.ConsensusMinerMinPower = p
+	}
 }

 // SetMinVerifiedDealSize sets the minimum size of a verified deal. This should
@@ -104,6 +120,7 @@ func SetMinVerifiedDealSize(size abi.StoragePower) {
 	verifreg0.MinVerifiedDealSize = size
 	verifreg2.MinVerifiedDealSize = size
 	verifreg3.MinVerifiedDealSize = size
+	verifreg4.MinVerifiedDealSize = size
 }

 func GetMaxProveCommitDuration(ver actors.Version, t abi.RegisteredSealProof) abi.ChainEpoch {
@@ -114,6 +131,8 @@ func GetMaxProveCommitDuration(ver actors.Version, t abi.RegisteredSealProof) ab
 		return miner2.MaxProveCommitDuration[t]
 	case actors.Version3:
 		return miner3.MaxProveCommitDuration[t]
+	case actors.Version4:
+		return miner4.MaxProveCommitDuration[t]
 	default:
 		panic("unsupported actors version")
 	}
@@ -131,8 +150,10 @@ func DealProviderCollateralBounds(
 		return market2.DealProviderCollateralBounds(size, verified, rawBytePower, qaPower, baselinePower, circulatingFil)
 	case actors.Version3:
 		return market3.DealProviderCollateralBounds(size, verified, rawBytePower, qaPower, baselinePower, circulatingFil)
+	case actors.Version4:
+		return market4.DealProviderCollateralBounds(size, verified, rawBytePower, qaPower, baselinePower, circulatingFil)
 	default:
-		panic("unsupported network version")
+		panic("unsupported actors version")
 	}
 }

@@ -150,6 +171,10 @@ func SetWPoStChallengeWindow(period abi.ChainEpoch) {
 	// by default, this is 2x finality which is 30 periods.
 	// scale it if we're scaling the challenge period.
 	miner3.WPoStDisputeWindow = period * 30
+
+	miner4.WPoStChallengeWindow = period
+	miner4.WPoStProvingPeriod = period * abi.ChainEpoch(miner4.WPoStPeriodDeadlines)
+	miner4.WPoStDisputeWindow = period * 30 // see the miner3 comment
 }

 func GetWinningPoStSectorSetLookback(nwVer network.Version) abi.ChainEpoch {
@@ -170,13 +195,13 @@ func GetMaxPoStPartitions(p abi.RegisteredPoStProof) (int, error) {
 	if err != nil {
 		return 0, err
 	}
-	return int(miner3.AddressedSectorsMax / sectorsPerPart), nil
+	return int(miner4.AddressedSectorsMax / sectorsPerPart), nil
 }

 func GetDefaultSectorSize() abi.SectorSize {
 	// supported sector sizes are the same across versions.
-	szs := make([]abi.SectorSize, 0, len(miner3.PreCommitSealProofTypesV8))
-	for spt := range miner3.PreCommitSealProofTypesV8 {
+	szs := make([]abi.SectorSize, 0, len(miner4.PreCommitSealProofTypesV8))
+	for spt := range miner4.PreCommitSealProofTypesV8 {
 		ss, err := spt.SectorSize()
 		if err != nil {
 			panic(err)
@@ -191,3 +216,42 @@ func GetDefaultSectorSize() abi.SectorSize {

 	return szs[0]
 }
+
+func GetSectorMaxLifetime(proof abi.RegisteredSealProof, nwVer network.Version) abi.ChainEpoch {
+	if nwVer <= network.Version10 {
+		return builtin4.SealProofPoliciesV0[proof].SectorMaxLifetime
+	}
+
+	return builtin4.SealProofPoliciesV11[proof].SectorMaxLifetime
+}
+
+func GetAddressedSectorsMax(nwVer network.Version) int {
+	switch actors.VersionForNetwork(nwVer) {
+	case actors.Version0:
+		return miner0.AddressedSectorsMax
+	case actors.Version2:
+		return miner2.AddressedSectorsMax
+	case actors.Version3:
+		return miner3.AddressedSectorsMax
+	case actors.Version4:
+		return miner4.AddressedSectorsMax
+	default:
+		panic("unsupported network version")
+	}
+}
+
+func GetDeclarationsMax(nwVer network.Version) int {
+	switch actors.VersionForNetwork(nwVer) {
+	case actors.Version0:
+		// TODO: Should we instead panic here since the concept doesn't exist yet?
+		return miner0.AddressedPartitionsMax
+	case actors.Version2:
+		return miner2.DeclarationsMax
+	case actors.Version3:
+		return miner3.DeclarationsMax
+	case actors.Version4:
+		return miner4.DeclarationsMax
+	default:
+		panic("unsupported network version")
+	}
+}
@@ -12,6 +12,7 @@ const (
 	Version0 Version = 0
 	Version2 Version = 2
 	Version3 Version = 3
+	Version4 Version = 4
 )

 // Converts a network version into an actors adt version.
@@ -21,8 +22,10 @@ func VersionForNetwork(version network.Version) Version {
 		return Version0
 	case network.Version4, network.Version5, network.Version6, network.Version7, network.Version8, network.Version9:
 		return Version2
-	case network.Version10:
+	case network.Version10, network.Version11:
 		return Version3
+	case network.Version12:
+		return Version4
 	default:
 		panic(fmt.Sprintf("unsupported network version %d", version))
 	}
@@ -3,7 +3,6 @@ package drand
 import (
 	"bytes"
 	"context"
-	"sync"
 	"time"

 	dchain "github.com/drand/drand/chain"
@@ -13,6 +12,7 @@ import (
 	gclient "github.com/drand/drand/lp2p/client"
 	"github.com/drand/kyber"
 	kzap "github.com/go-kit/kit/log/zap"
+	lru "github.com/hashicorp/golang-lru"
 	"go.uber.org/zap/zapcore"
 	"golang.org/x/xerrors"

@@ -61,8 +61,7 @@ type DrandBeacon struct {
 	filGenTime   uint64
 	filRoundTime uint64

-	cacheLk    sync.Mutex
-	localCache map[uint64]types.BeaconEntry
+	localCache *lru.Cache
 }

 // DrandHTTPClient interface overrides the user agent used by drand
@@ -111,9 +110,14 @@ func NewDrandBeacon(genesisTs, interval uint64, ps *pubsub.PubSub, config dtypes
 		return nil, xerrors.Errorf("creating drand client")
 	}

+	lc, err := lru.New(1024)
+	if err != nil {
+		return nil, err
+	}
+
 	db := &DrandBeacon{
 		client:     client,
-		localCache: make(map[uint64]types.BeaconEntry),
+		localCache: lc,
 	}

 	db.pubkey = drandChain.PublicKey
@@ -156,19 +160,16 @@ func (db *DrandBeacon) Entry(ctx context.Context, round uint64) <-chan beacon.Re
 	return out
 }
 func (db *DrandBeacon) cacheValue(e types.BeaconEntry) {
-	db.cacheLk.Lock()
-	defer db.cacheLk.Unlock()
-	db.localCache[e.Round] = e
+	db.localCache.Add(e.Round, e)
 }

 func (db *DrandBeacon) getCachedValue(round uint64) *types.BeaconEntry {
-	db.cacheLk.Lock()
-	defer db.cacheLk.Unlock()
-	v, ok := db.localCache[round]
+	v, ok := db.localCache.Get(round)
 	if !ok {
 		return nil
 	}
-	return &v
+	e, _ := v.(*types.BeaconEntry)
+	return e
 }

 func (db *DrandBeacon) VerifyEntry(curr types.BeaconEntry, prev types.BeaconEntry) error {
--- a/Show More
+++ b/Show More