Add WSLCVolumes class to track volumes with Docker event-driven synchronization by kvega005 · Pull Request #40300 · microsoft/WSL

kvega005 · 2026-04-24T00:51:18Z

Summary of the Pull Request

Refactors WSLC volume management into a dedicated WSLCVolumes class and replaces the old ContainerEventTracker with a broader DockerEventTracker that tracks both container and volume lifecycle events.

PR Checklist

Closes: Link to issue #xxx
Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
Tests: Added/updated if needed and all pass
Localization: All end user facing strings can be localized
Dev docs: Added/updated if needed
Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

…SLCVolumes manager

Co-authored-by: Copilot <copilot@github.com>

…olumesManager

Copilot

Pull request overview

This PR refactors WSLC volume management into a new WSLCVolumes component and broadens Docker event handling by replacing ContainerEventTracker with DockerEventTracker, enabling event-driven synchronization for both containers and volumes.

Changes:

Introduces WSLCVolumes to own volume recovery, tracking, and COM-facing volume operations.
Replaces ContainerEventTracker with DockerEventTracker, adding volume lifecycle event handling and “wait for create/destroy event” helpers.
Updates container volume behavior/tests to allow Docker to auto-create missing named volumes and to validate anonymous volume cleanup via the new tracking.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
test/windows/wslc/e2e/WSLCE2EContainerRunTests.cpp	Updates E2E expectation: named volume is auto-created and removable.
test/windows/WSLCTests.cpp	Switches anonymous volume listing/cleanup logic to use `ListVolumes()` and event-driven waits.
src/windows/wslcsession/WSLCVolumes.h	Adds new volume-tracking class interface.
src/windows/wslcsession/WSLCVolumes.cpp	Implements volume recovery, event callbacks, and volume CRUD/inspect/list.
src/windows/wslcsession/WSLCVhdVolume.h	Marks `OnDeleted()` as `override` to match new base hook.
src/windows/wslcsession/WSLCSession.h	Replaces raw volume maps/locks with `std::optional<WSLCVolumes>` and swaps in `DockerEventTracker`.
src/windows/wslcsession/WSLCSession.cpp	Wires up `WSLCVolumes` + `DockerEventTracker`; routes volume COM methods through `WSLCVolumes`.
src/windows/wslcsession/WSLCProcessControl.h / .cpp	Updates process controls to use `DockerEventTracker` references.
src/windows/wslcsession/WSLCGuestVolume.cpp	Removes WSLC metadata label dependency for guest volumes; opens from Docker fields directly.
src/windows/wslcsession/WSLCContainer.h / .cpp	Removes session-side named-volume existence checks; adds waits for Docker create/destroy events.
src/windows/wslcsession/IWSLCVolume.h	Adds `OnDeleted()` hook for “Docker already destroyed the volume” cleanup.
src/windows/wslcsession/DockerHTTPClient.h / .cpp	Adds `InspectVolume()` endpoint wrapper.
src/windows/wslcsession/DockerEventTracker.h / .cpp	New tracker for container+volume events and object create/destroy waiting.
src/windows/wslcsession/ContainerEventTracker.h / .cpp	Removes the old container-only event tracker.
src/windows/wslcsession/CMakeLists.txt	Updates build inputs for new/removed tracker and new `WSLCVolumes`.
src/windows/inc/docker_schema.h	Extends `InspectContainer` schema to include `Mounts`.

Copilot

Pull request overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 4 comments.

Co-authored-by: Copilot <copilot@github.com>

…olumesManager

Co-authored-by: Copilot <copilot@github.com>

Copilot

Pull request overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 8 comments.

Co-authored-by: Copilot <copilot@github.com>

Copilot

Pull request overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 6 comments.

Co-authored-by: Copilot <copilot@github.com>

…into WslcVolumesManager

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 4 comments.

Copilot · 2026-04-25T06:29:25Z

+    // Validate that all named volumes mounted by the container were successfully recovered
+    // by the volumes manager. If any are missing (e.g. backing VHD removed while the service was
+    // down), refuse to open the container so it cannot enter a broken state.
+    for (const auto& mount : dockerContainer.Mounts)
+    {
+        if (mount.Type == "volume" && !mount.Name.empty())
+        {
+            THROW_HR_IF_MSG(
+                E_INVALIDARG,
+                !volumes.ContainsVolume(mount.Name),
+                "Cannot open container %hs: referenced volume '%hs' is not available",
+                dockerContainer.Id.c_str(),
+                mount.Name.c_str());
+        }


Container recovery now hard-fails if any mounted volume name isn’t present in WSLCVolumes. Given WSLCVolumes currently only tracks volumes it can successfully Open(), this can break recovery for containers that reference valid Docker volumes that WSLC chooses not to track (or failed to open due to stricter validation). Either ensure WSLCVolumes reliably tracks all volume mounts a container might reference (including non-WSLC local volumes), or scope this check to WSLC-managed volumes only (e.g., only enforce for volumes with the WSLC metadata label / VHD driver), and return a user-facing error (localized) when the check fails so callers don’t just get E_INVALIDARG.

Copilot · 2026-04-25T06:29:25Z

+    if (vol.Labels.has_value() && vol.Labels->contains(WSLCVolumeMetadataLabel))
+    {
+        auto metadata = wsl::shared::FromJson<WSLCVolumeMetadata>(vol.Labels->at(WSLCVolumeMetadataLabel).c_str());
+
+        if (metadata.Driver == WSLCVhdVolumeDriver)
+        {
+            m_volumes.insert({vol.Name, WSLCVhdVolumeImpl::Open(vol, m_virtualMachine, m_dockerClient)});
+            return;
+        }
+    }
+
+    m_volumes.insert({vol.Name, WSLCGuestVolumeImpl::Open(vol, m_dockerClient)});
+}


WSLCVolumes::OpenVolumeExclusiveLockHeld treats any volume with a WSLC metadata label but an unrecognized metadata.Driver as a guest volume (falls through to WSLCGuestVolumeImpl::Open). This can silently mis-handle future/unknown WSLC drivers and potentially leak host-side resources (e.g., if a new driver needs cleanup). Consider explicitly handling only the known drivers (vhd/guest) and skipping/logging unknown metadata.Driver values instead of defaulting to guest.

Copilot · 2026-04-25T06:29:25Z

+            // Clean up any leaked anonymous volumes when this block exits.
+            auto volumeCleanup = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, [&]() {
+                auto volumes = listAnonymousVolumes();
+                for (const auto& name : volumes)
+                {
+                    LOG_IF_FAILED(m_defaultSession->DeleteVolume(name.c_str()));
+                }


This cleanup scope deletes every volume returned by listAnonymousVolumes(), which currently includes all volumes with Driver == "guest". If the session contains other guest volumes (named volumes created by other tests), this cleanup will remove them and can cascade into unrelated failures. Tighten the selection criteria (e.g., track the specific volume names created during this test, or filter on Docker’s anonymous label).

Copilot · 2026-04-25T06:29:26Z

 std::unique_ptr<WSLCGuestVolumeImpl> WSLCGuestVolumeImpl::Open(const wsl::windows::common::docker_schema::Volume& Volume, DockerHTTPClient& DockerClient)
 {
-    THROW_HR_IF(E_INVALIDARG, !Volume.Labels.has_value());
-
-    auto metadataIt = Volume.Labels->find(WSLCVolumeMetadataLabel);
-    THROW_HR_IF(E_INVALIDARG, metadataIt == Volume.Labels->end());
-
-    auto metadata = wsl::shared::FromJson<WSLCVolumeMetadata>(metadataIt->second.c_str());
-    THROW_HR_IF(E_INVALIDARG, metadata.Driver != WSLCGuestVolumeDriver);
-
    THROW_HR_IF(E_INVALIDARG, Volume.Driver != "local");

    if (Volume.Options.has_value())
    {
        ValidateDriverOpts(Volume.Options.value());
    }

-    // Extract user labels (all labels except our internal metadata label).
-    std::map<std::string, std::string> userLabels;
-    for (const auto& [key, value] : *Volume.Labels)
-    {
-        if (key != WSLCVolumeMetadataLabel)
-        {
-            userLabels[key] = value;
-        }
-    }
-
-    auto volume = std::make_unique<WSLCGuestVolumeImpl>(
-        std::string{Volume.Name}, std::string{Volume.CreatedAt}, std::move(metadata.DriverOpts), std::move(userLabels), DockerClient);
+    std::map<std::string, std::string> driverOpts = Volume.Options.value_or(std::map<std::string, std::string>{});
+    std::map<std::string, std::string> labels = Volume.Labels.value_or(std::map<std::string, std::string>{});

-    return volume;
+    return std::make_unique<WSLCGuestVolumeImpl>(
+        std::string{Volume.Name}, std::string{Volume.CreatedAt}, std::move(driverOpts), std::move(labels), DockerClient);
 }


WSLCGuestVolumeImpl::Open now accepts any Docker "local" volume (no WSLC metadata required) and still enforces ValidateDriverOpts (only empty or type=tmpfs). This means non-WSLC local volumes created with common options (e.g. type=none,o=bind,device=...) will fail to open, causing WSLCVolumes recovery to skip them and later container recovery to fail when checking ContainsVolume(). Consider distinguishing WSLC-managed guest volumes from arbitrary Docker volumes (e.g. keep a WSLC metadata/label for guest volumes, or relax validation for volumes without WSLC labels, or track unknown volumes with a minimal implementation that doesn’t enforce WSLC-specific constraints).

kvega005 and others added 6 commits April 23, 2026 15:56

Rename ContainerEventTracker to DockerEventTracker

cc18d03

Add guest volume driver, Docker event tracker with volume sync, and W…

efa122b

…SLCVolumes manager

Address feedback and fix formatting

f5cb90e

Co-authored-by: Copilot <copilot@github.com>

Merge remote-tracking branch 'origin/feature/wsl-for-apps' into WslcV…

c9dcaa0

…olumesManager

refactor

35962d6

address comment

6bc4123

Copilot AI review requested due to automatic review settings April 24, 2026 00:51

Copilot started reviewing on behalf of kvega005 April 24, 2026 00:52 View session

Copilot AI reviewed Apr 24, 2026

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kvega005 and others added 2 commits April 23, 2026 18:38

Address feedback

081263f

Merge branch 'feature/wsl-for-apps' into WslcVolumesManager

77caa60

Copilot AI review requested due to automatic review settings April 24, 2026 03:04

Copilot started reviewing on behalf of kvega005 April 24, 2026 03:05 View session

Copilot AI reviewed Apr 24, 2026

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Comment thread src/windows/wslcsession/WSLCVolumes.cpp

Comment thread src/windows/wslcsession/DockerEventTracker.cpp

Comment thread src/windows/wslcsession/DockerEventTracker.cpp

Comment thread src/windows/wslcsession/DockerEventTracker.h Outdated

kvega005 and others added 3 commits April 24, 2026 00:48

Address copilot feedback

94f4bd5

Co-authored-by: Copilot <copilot@github.com>

Merge remote-tracking branch 'origin/feature/wsl-for-apps' into WslcV…

ab6e0ce

…olumesManager

FIX ABBA deadlock

1e5f709

Co-authored-by: Copilot <copilot@github.com>

Copilot AI review requested due to automatic review settings April 24, 2026 21:16

Copilot started reviewing on behalf of kvega005 April 24, 2026 21:17 View session

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kvega005 and others added 2 commits April 24, 2026 14:44

Address feedback

cfc4992

Co-authored-by: Copilot <copilot@github.com>

Merge branch 'feature/wsl-for-apps' into WslcVolumesManager

887db36

Copilot AI review requested due to automatic review settings April 24, 2026 21:44

Copilot started reviewing on behalf of kvega005 April 24, 2026 21:49 View session

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kvega005 and others added 3 commits April 24, 2026 22:47

Validate opened containers

71c9dfd

Co-authored-by: Copilot <copilot@github.com>

Merge branch 'WslcVolumesManager' of https://github.com/kvega005/WSL …

a2b6b93

…into WslcVolumesManager

Update src/windows/wslcsession/DockerEventTracker.cpp

1a6181a

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings April 25, 2026 06:23

kvega005 marked this pull request as ready for review April 25, 2026 06:24

Merge branch 'feature/wsl-for-apps' into WslcVolumesManager

c84dff1

kvega005 requested a review from a team as a code owner April 25, 2026 06:24

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kvega005 commented Apr 24, 2026

Summary of the Pull Request

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