platform_system_core/init/snapuserd_transition.h
Akilesh Kailash 3b874456fc libsnapshot: Integrate userspace snapshots APIs
dm-user block device will be the snapshot device; thus, no
more explicit call to MapSnapshot(). Additionally, block device
name for dm-user will be the snapshot name so that mount works
seamlessly.

API's to query the snapshot status, merge progress has been
integrated. Since daemon requires base device for merge, we pass
additional parameter during initialization.

Add a new virtual a/b property flag to enable/disable
user-snapshots feature. Propagate this flag to init layer
for first stage mount during boot process.

Some minor cleanup and renaming of variables.

Bug: 193863443
Test: 1: Full OTA on CF and pixel and verify the merge completion.
Tested merge-resume path by rebooting device during merge.
2: Incremental OTA on CF and pixel

Signed-off-by: Akilesh Kailash <akailash@google.com>
Change-Id: I5088f40a55807946cd044b3987678ead3696d996
2021-11-19 23:45:43 +00:00

95 lines
2.9 KiB
C++

/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <sys/types.h>
#include <optional>
#include <string>
#include <vector>
#include <libsnapshot/snapshot.h>
#include "block_dev_initializer.h"
namespace android {
namespace init {
enum class SnapshotDriver {
DM_SNAPSHOT,
DM_USER,
};
// Fork and exec a new copy of snapuserd.
void LaunchFirstStageSnapuserd(SnapshotDriver driver);
class SnapuserdSelinuxHelper final {
using SnapshotManager = android::snapshot::SnapshotManager;
public:
SnapuserdSelinuxHelper(std::unique_ptr<SnapshotManager>&& sm, pid_t old_pid);
void StartTransition();
void FinishTransition();
// Return a helper for facilitating the selinux transition of snapuserd.
// If snapuserd is not in use, null is returned. StartTransition() should
// be called after reading policy. FinishTransition() should be called
// after loading policy. In between, no reads of /system or other dynamic
// partitions are possible.
static std::unique_ptr<SnapuserdSelinuxHelper> CreateIfNeeded();
private:
void RelaunchFirstStageSnapuserd();
void ExecSnapuserd();
std::unique_ptr<SnapshotManager> sm_;
BlockDevInitializer block_dev_init_;
pid_t old_pid_;
std::vector<std::string> argv_;
};
// Remove /dev/socket/snapuserd. This ensures that (1) the existing snapuserd
// will receive no new requests, and (2) the next copy we transition to can
// own the socket.
void CleanupSnapuserdSocket();
// Kill an instance of snapuserd given a pid.
void KillFirstStageSnapuserd(pid_t pid);
// Save an open fd to /system/bin (in the ramdisk) into an environment. This is
// used to later execveat() snapuserd.
void SaveRamdiskPathToSnapuserd();
// Returns true if first-stage snapuserd is running.
bool IsFirstStageSnapuserdRunning();
// Return the pid of the first-stage instances of snapuserd, if it was started.
std::optional<pid_t> GetSnapuserdFirstStagePid();
// Return snapuserd info strings that were set during first-stage init.
std::vector<std::string> GetSnapuserdFirstStageInfo();
// Save an open fd to /system/bin (in the ramdisk) into an environment. This is
// used to later execveat() snapuserd.
void SaveRamdiskPathToSnapuserd();
// Returns true if first-stage snapuserd is running.
bool IsFirstStageSnapuserdRunning();
} // namespace init
} // namespace android