| // Copyright (C) 2019 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. |
| |
| #include <libsnapshot/snapshot.h> |
| |
| #include <dirent.h> |
| #include <fcntl.h> |
| #include <math.h> |
| #include <sys/file.h> |
| #include <sys/types.h> |
| #include <sys/unistd.h> |
| |
| #include <filesystem> |
| #include <optional> |
| #include <thread> |
| #include <unordered_set> |
| |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/parseint.h> |
| #include <android-base/properties.h> |
| #include <android-base/strings.h> |
| #include <android-base/unique_fd.h> |
| #include <cutils/sockets.h> |
| #include <ext4_utils/ext4_utils.h> |
| #include <fs_mgr.h> |
| #include <fs_mgr/file_wait.h> |
| #include <fs_mgr_dm_linear.h> |
| #include <fstab/fstab.h> |
| #include <libdm/dm.h> |
| #include <libfiemap/image_manager.h> |
| #include <liblp/liblp.h> |
| |
| #include <android/snapshot/snapshot.pb.h> |
| #include <libsnapshot/snapshot_stats.h> |
| #include "device_info.h" |
| #include "partition_cow_creator.h" |
| #include "snapshot_metadata_updater.h" |
| #include "snapshot_reader.h" |
| #include "utility.h" |
| |
| namespace android { |
| namespace snapshot { |
| |
| using android::base::unique_fd; |
| using android::dm::DeviceMapper; |
| using android::dm::DmDeviceState; |
| using android::dm::DmTable; |
| using android::dm::DmTargetLinear; |
| using android::dm::DmTargetSnapshot; |
| using android::dm::DmTargetUser; |
| using android::dm::kSectorSize; |
| using android::dm::SnapshotStorageMode; |
| using android::fiemap::FiemapStatus; |
| using android::fiemap::IImageManager; |
| using android::fs_mgr::CreateDmTable; |
| using android::fs_mgr::CreateLogicalPartition; |
| using android::fs_mgr::CreateLogicalPartitionParams; |
| using android::fs_mgr::GetPartitionGroupName; |
| using android::fs_mgr::GetPartitionName; |
| using android::fs_mgr::LpMetadata; |
| using android::fs_mgr::MetadataBuilder; |
| using android::fs_mgr::SlotNumberForSlotSuffix; |
| using android::hardware::boot::V1_1::MergeStatus; |
| using chromeos_update_engine::DeltaArchiveManifest; |
| using chromeos_update_engine::Extent; |
| using chromeos_update_engine::FileDescriptor; |
| using chromeos_update_engine::PartitionUpdate; |
| template <typename T> |
| using RepeatedPtrField = google::protobuf::RepeatedPtrField<T>; |
| using std::chrono::duration_cast; |
| using namespace std::chrono_literals; |
| using namespace std::string_literals; |
| |
| static constexpr char kBootIndicatorPath[] = "/metadata/ota/snapshot-boot"; |
| static constexpr char kRollbackIndicatorPath[] = "/metadata/ota/rollback-indicator"; |
| static constexpr auto kUpdateStateCheckInterval = 2s; |
| |
| MergeFailureCode CheckMergeConsistency(const std::string& name, const SnapshotStatus& status); |
| |
| // Note: IImageManager is an incomplete type in the header, so the default |
| // destructor doesn't work. |
| SnapshotManager::~SnapshotManager() {} |
| |
| std::unique_ptr<SnapshotManager> SnapshotManager::New(IDeviceInfo* info) { |
| if (!info) { |
| info = new DeviceInfo(); |
| } |
| |
| return std::unique_ptr<SnapshotManager>(new SnapshotManager(info)); |
| } |
| |
| std::unique_ptr<SnapshotManager> SnapshotManager::NewForFirstStageMount(IDeviceInfo* info) { |
| if (!info) { |
| DeviceInfo* impl = new DeviceInfo(); |
| impl->set_first_stage_init(true); |
| info = impl; |
| } |
| auto sm = New(info); |
| |
| // The first-stage version of snapuserd is explicitly started by init. Do |
| // not attempt to using it during tests (which run in normal AOSP). |
| if (!sm->device()->IsTestDevice()) { |
| sm->use_first_stage_snapuserd_ = true; |
| } |
| return sm; |
| } |
| |
| SnapshotManager::SnapshotManager(IDeviceInfo* device) |
| : dm_(device->GetDeviceMapper()), device_(device), metadata_dir_(device_->GetMetadataDir()) { |
| merge_consistency_checker_ = android::snapshot::CheckMergeConsistency; |
| } |
| |
| static std::string GetCowName(const std::string& snapshot_name) { |
| return snapshot_name + "-cow"; |
| } |
| |
| SnapshotManager::SnapshotDriver SnapshotManager::GetSnapshotDriver(LockedFile* lock) { |
| if (UpdateUsesUserSnapshots(lock)) { |
| return SnapshotManager::SnapshotDriver::DM_USER; |
| } else { |
| return SnapshotManager::SnapshotDriver::DM_SNAPSHOT; |
| } |
| } |
| |
| static std::string GetDmUserCowName(const std::string& snapshot_name, |
| SnapshotManager::SnapshotDriver driver) { |
| // dm-user block device will act as a snapshot device. We identify it with |
| // the same partition name so that when partitions can be mounted off |
| // dm-user. |
| |
| switch (driver) { |
| case SnapshotManager::SnapshotDriver::DM_USER: { |
| return snapshot_name; |
| } |
| |
| case SnapshotManager::SnapshotDriver::DM_SNAPSHOT: { |
| return snapshot_name + "-user-cow"; |
| } |
| |
| default: { |
| LOG(ERROR) << "Invalid snapshot driver"; |
| return ""; |
| } |
| } |
| } |
| |
| static std::string GetCowImageDeviceName(const std::string& snapshot_name) { |
| return snapshot_name + "-cow-img"; |
| } |
| |
| static std::string GetBaseDeviceName(const std::string& partition_name) { |
| return partition_name + "-base"; |
| } |
| |
| static std::string GetSourceDeviceName(const std::string& partition_name) { |
| return partition_name + "-src"; |
| } |
| |
| bool SnapshotManager::BeginUpdate() { |
| bool needs_merge = false; |
| if (!TryCancelUpdate(&needs_merge)) { |
| return false; |
| } |
| if (needs_merge) { |
| LOG(INFO) << "Wait for merge (if any) before beginning a new update."; |
| auto state = ProcessUpdateState(); |
| LOG(INFO) << "Merged with state = " << state; |
| } |
| |
| auto file = LockExclusive(); |
| if (!file) return false; |
| |
| // Purge the ImageManager just in case there is a corrupt lp_metadata file |
| // lying around. (NB: no need to return false on an error, we can let the |
| // update try to progress.) |
| if (EnsureImageManager()) { |
| images_->RemoveAllImages(); |
| } |
| |
| // Clear any cached metadata (this allows re-using one manager across tests). |
| old_partition_metadata_ = nullptr; |
| |
| auto state = ReadUpdateState(file.get()); |
| if (state != UpdateState::None) { |
| LOG(ERROR) << "An update is already in progress, cannot begin a new update"; |
| return false; |
| } |
| return WriteUpdateState(file.get(), UpdateState::Initiated); |
| } |
| |
| bool SnapshotManager::CancelUpdate() { |
| bool needs_merge = false; |
| if (!TryCancelUpdate(&needs_merge)) { |
| return false; |
| } |
| if (needs_merge) { |
| LOG(ERROR) << "Cannot cancel update after it has completed or started merging"; |
| } |
| return !needs_merge; |
| } |
| |
| bool SnapshotManager::TryCancelUpdate(bool* needs_merge) { |
| *needs_merge = false; |
| |
| auto file = LockExclusive(); |
| if (!file) return false; |
| |
| UpdateState state = ReadUpdateState(file.get()); |
| if (state == UpdateState::None) return true; |
| |
| if (state == UpdateState::Initiated) { |
| LOG(INFO) << "Update has been initiated, now canceling"; |
| return RemoveAllUpdateState(file.get()); |
| } |
| |
| if (state == UpdateState::Unverified) { |
| // We completed an update, but it can still be canceled if we haven't booted into it. |
| auto slot = GetCurrentSlot(); |
| if (slot != Slot::Target) { |
| LOG(INFO) << "Canceling previously completed updates (if any)"; |
| return RemoveAllUpdateState(file.get()); |
| } |
| } |
| *needs_merge = true; |
| return true; |
| } |
| |
| std::string SnapshotManager::ReadUpdateSourceSlotSuffix() { |
| auto boot_file = GetSnapshotBootIndicatorPath(); |
| std::string contents; |
| if (!android::base::ReadFileToString(boot_file, &contents)) { |
| PLOG(WARNING) << "Cannot read " << boot_file; |
| return {}; |
| } |
| return contents; |
| } |
| |
| SnapshotManager::Slot SnapshotManager::GetCurrentSlot() { |
| auto contents = ReadUpdateSourceSlotSuffix(); |
| if (contents.empty()) { |
| return Slot::Unknown; |
| } |
| if (device_->GetSlotSuffix() == contents) { |
| return Slot::Source; |
| } |
| return Slot::Target; |
| } |
| |
| std::string SnapshotManager::GetSnapshotSlotSuffix() { |
| switch (GetCurrentSlot()) { |
| case Slot::Target: |
| return device_->GetSlotSuffix(); |
| default: |
| return device_->GetOtherSlotSuffix(); |
| } |
| } |
| |
| static bool RemoveFileIfExists(const std::string& path) { |
| std::string message; |
| if (!android::base::RemoveFileIfExists(path, &message)) { |
| LOG(ERROR) << "Remove failed: " << path << ": " << message; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::RemoveAllUpdateState(LockedFile* lock, const std::function<bool()>& prolog) { |
| if (prolog && !prolog()) { |
| LOG(WARNING) << "Can't RemoveAllUpdateState: prolog failed."; |
| return false; |
| } |
| |
| LOG(INFO) << "Removing all update state."; |
| |
| if (!RemoveAllSnapshots(lock)) { |
| LOG(ERROR) << "Could not remove all snapshots"; |
| return false; |
| } |
| |
| // It's okay if these fail: |
| // - For SnapshotBoot and Rollback, first-stage init performs a deeper check after |
| // reading the indicator file, so it's not a problem if it still exists |
| // after the update completes. |
| // - For ForwardMerge, FinishedSnapshotWrites asserts that the existence of the indicator |
| // matches the incoming update. |
| std::vector<std::string> files = { |
| GetSnapshotBootIndicatorPath(), |
| GetRollbackIndicatorPath(), |
| GetForwardMergeIndicatorPath(), |
| GetOldPartitionMetadataPath(), |
| }; |
| for (const auto& file : files) { |
| RemoveFileIfExists(file); |
| } |
| |
| // If this fails, we'll keep trying to remove the update state (as the |
| // device reboots or starts a new update) until it finally succeeds. |
| return WriteUpdateState(lock, UpdateState::None); |
| } |
| |
| bool SnapshotManager::FinishedSnapshotWrites(bool wipe) { |
| auto lock = LockExclusive(); |
| if (!lock) return false; |
| |
| auto update_state = ReadUpdateState(lock.get()); |
| if (update_state == UpdateState::Unverified) { |
| LOG(INFO) << "FinishedSnapshotWrites already called before. Ignored."; |
| return true; |
| } |
| |
| if (update_state != UpdateState::Initiated) { |
| LOG(ERROR) << "Can only transition to the Unverified state from the Initiated state."; |
| return false; |
| } |
| |
| if (!EnsureNoOverflowSnapshot(lock.get())) { |
| LOG(ERROR) << "Cannot ensure there are no overflow snapshots."; |
| return false; |
| } |
| |
| if (!UpdateForwardMergeIndicator(wipe)) { |
| return false; |
| } |
| |
| // This file is written on boot to detect whether a rollback occurred. It |
| // MUST NOT exist before rebooting, otherwise, we're at risk of deleting |
| // snapshots too early. |
| if (!RemoveFileIfExists(GetRollbackIndicatorPath())) { |
| return false; |
| } |
| |
| // This file acts as both a quick indicator for init (it can use access(2) |
| // to decide how to do first-stage mounts), and it stores the old slot, so |
| // we can tell whether or not we performed a rollback. |
| auto contents = device_->GetSlotSuffix(); |
| auto boot_file = GetSnapshotBootIndicatorPath(); |
| if (!WriteStringToFileAtomic(contents, boot_file)) { |
| PLOG(ERROR) << "write failed: " << boot_file; |
| return false; |
| } |
| return WriteUpdateState(lock.get(), UpdateState::Unverified); |
| } |
| |
| bool SnapshotManager::CreateSnapshot(LockedFile* lock, PartitionCowCreator* cow_creator, |
| SnapshotStatus* status) { |
| CHECK(lock); |
| CHECK(lock->lock_mode() == LOCK_EX); |
| CHECK(status); |
| |
| if (status->name().empty()) { |
| LOG(ERROR) << "SnapshotStatus has no name."; |
| return false; |
| } |
| // Check these sizes. Like liblp, we guarantee the partition size is |
| // respected, which means it has to be sector-aligned. (This guarantee is |
| // useful for locating avb footers correctly). The COW file size, however, |
| // can be arbitrarily larger than specified, so we can safely round it up. |
| if (status->device_size() % kSectorSize != 0) { |
| LOG(ERROR) << "Snapshot " << status->name() |
| << " device size is not a multiple of the sector size: " |
| << status->device_size(); |
| return false; |
| } |
| if (status->snapshot_size() % kSectorSize != 0) { |
| LOG(ERROR) << "Snapshot " << status->name() |
| << " snapshot size is not a multiple of the sector size: " |
| << status->snapshot_size(); |
| return false; |
| } |
| if (status->cow_partition_size() % kSectorSize != 0) { |
| LOG(ERROR) << "Snapshot " << status->name() |
| << " cow partition size is not a multiple of the sector size: " |
| << status->cow_partition_size(); |
| return false; |
| } |
| if (status->cow_file_size() % kSectorSize != 0) { |
| LOG(ERROR) << "Snapshot " << status->name() |
| << " cow file size is not a multiple of the sector size: " |
| << status->cow_file_size(); |
| return false; |
| } |
| |
| status->set_state(SnapshotState::CREATED); |
| status->set_sectors_allocated(0); |
| status->set_metadata_sectors(0); |
| status->set_compression_enabled(cow_creator->compression_enabled); |
| status->set_compression_algorithm(cow_creator->compression_algorithm); |
| |
| if (!WriteSnapshotStatus(lock, *status)) { |
| PLOG(ERROR) << "Could not write snapshot status: " << status->name(); |
| return false; |
| } |
| return true; |
| } |
| |
| Return SnapshotManager::CreateCowImage(LockedFile* lock, const std::string& name) { |
| CHECK(lock); |
| CHECK(lock->lock_mode() == LOCK_EX); |
| if (!EnsureImageManager()) return Return::Error(); |
| |
| SnapshotStatus status; |
| if (!ReadSnapshotStatus(lock, name, &status)) { |
| return Return::Error(); |
| } |
| |
| // The COW file size should have been rounded up to the nearest sector in CreateSnapshot. |
| if (status.cow_file_size() % kSectorSize != 0) { |
| LOG(ERROR) << "Snapshot " << name << " COW file size is not a multiple of the sector size: " |
| << status.cow_file_size(); |
| return Return::Error(); |
| } |
| |
| std::string cow_image_name = GetCowImageDeviceName(name); |
| int cow_flags = IImageManager::CREATE_IMAGE_DEFAULT; |
| return Return(images_->CreateBackingImage(cow_image_name, status.cow_file_size(), cow_flags)); |
| } |
| |
| bool SnapshotManager::MapDmUserCow(LockedFile* lock, const std::string& name, |
| const std::string& cow_file, const std::string& base_device, |
| const std::string& base_path_merge, |
| const std::chrono::milliseconds& timeout_ms, std::string* path) { |
| CHECK(lock); |
| |
| if (UpdateUsesUserSnapshots(lock)) { |
| SnapshotStatus status; |
| if (!ReadSnapshotStatus(lock, name, &status)) { |
| LOG(ERROR) << "MapDmUserCow: ReadSnapshotStatus failed..."; |
| return false; |
| } |
| |
| if (status.state() == SnapshotState::NONE || |
| status.state() == SnapshotState::MERGE_COMPLETED) { |
| LOG(ERROR) << "Should not create a snapshot device for " << name |
| << " after merging has completed."; |
| return false; |
| } |
| |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| if (update_status.state() == UpdateState::MergeCompleted || |
| update_status.state() == UpdateState::MergeNeedsReboot) { |
| LOG(ERROR) << "Should not create a snapshot device for " << name |
| << " after global merging has completed."; |
| return false; |
| } |
| } |
| |
| // Use an extra decoration for first-stage init, so we can transition |
| // to a new table entry in second-stage. |
| std::string misc_name = name; |
| if (use_first_stage_snapuserd_) { |
| misc_name += "-init"; |
| } |
| |
| if (!EnsureSnapuserdConnected()) { |
| return false; |
| } |
| |
| uint64_t base_sectors = 0; |
| if (!UpdateUsesUserSnapshots(lock)) { |
| base_sectors = snapuserd_client_->InitDmUserCow(misc_name, cow_file, base_device); |
| if (base_sectors == 0) { |
| LOG(ERROR) << "Failed to retrieve base_sectors from Snapuserd"; |
| return false; |
| } |
| } else { |
| // For userspace snapshots, the size of the base device is taken as the |
| // size of the dm-user block device. Since there is no pseudo mapping |
| // created in the daemon, we no longer need to rely on the daemon for |
| // sizing the dm-user block device. |
| unique_fd fd(TEMP_FAILURE_RETRY(open(base_path_merge.c_str(), O_RDONLY | O_CLOEXEC))); |
| if (fd < 0) { |
| LOG(ERROR) << "Cannot open block device: " << base_path_merge; |
| return false; |
| } |
| |
| uint64_t dev_sz = get_block_device_size(fd.get()); |
| if (!dev_sz) { |
| LOG(ERROR) << "Failed to find block device size: " << base_path_merge; |
| return false; |
| } |
| |
| base_sectors = dev_sz >> 9; |
| } |
| |
| DmTable table; |
| table.Emplace<DmTargetUser>(0, base_sectors, misc_name); |
| if (!dm_.CreateDevice(name, table, path, timeout_ms)) { |
| LOG(ERROR) << " dm-user: CreateDevice failed... "; |
| return false; |
| } |
| if (!WaitForDevice(*path, timeout_ms)) { |
| LOG(ERROR) << " dm-user: timeout: Failed to create block device for: " << name; |
| return false; |
| } |
| |
| auto control_device = "/dev/dm-user/" + misc_name; |
| if (!WaitForDevice(control_device, timeout_ms)) { |
| return false; |
| } |
| |
| if (UpdateUsesUserSnapshots(lock)) { |
| // Now that the dm-user device is created, initialize the daemon and |
| // spin up the worker threads. |
| if (!snapuserd_client_->InitDmUserCow(misc_name, cow_file, base_device, base_path_merge)) { |
| LOG(ERROR) << "InitDmUserCow failed"; |
| return false; |
| } |
| } |
| |
| return snapuserd_client_->AttachDmUser(misc_name); |
| } |
| |
| bool SnapshotManager::MapSnapshot(LockedFile* lock, const std::string& name, |
| const std::string& base_device, const std::string& cow_device, |
| const std::chrono::milliseconds& timeout_ms, |
| std::string* dev_path) { |
| CHECK(lock); |
| |
| SnapshotStatus status; |
| if (!ReadSnapshotStatus(lock, name, &status)) { |
| return false; |
| } |
| if (status.state() == SnapshotState::NONE || status.state() == SnapshotState::MERGE_COMPLETED) { |
| LOG(ERROR) << "Should not create a snapshot device for " << name |
| << " after merging has completed."; |
| return false; |
| } |
| |
| // Validate the block device size, as well as the requested snapshot size. |
| // Note that during first-stage init, we don't have the device paths. |
| if (android::base::StartsWith(base_device, "/")) { |
| unique_fd fd(open(base_device.c_str(), O_RDONLY | O_CLOEXEC)); |
| if (fd < 0) { |
| PLOG(ERROR) << "open failed: " << base_device; |
| return false; |
| } |
| auto dev_size = get_block_device_size(fd); |
| if (!dev_size) { |
| PLOG(ERROR) << "Could not determine block device size: " << base_device; |
| return false; |
| } |
| if (status.device_size() != dev_size) { |
| LOG(ERROR) << "Block device size for " << base_device << " does not match" |
| << "(expected " << status.device_size() << ", got " << dev_size << ")"; |
| return false; |
| } |
| } |
| if (status.device_size() % kSectorSize != 0) { |
| LOG(ERROR) << "invalid blockdev size for " << base_device << ": " << status.device_size(); |
| return false; |
| } |
| if (status.snapshot_size() % kSectorSize != 0 || |
| status.snapshot_size() > status.device_size()) { |
| LOG(ERROR) << "Invalid snapshot size for " << base_device << ": " << status.snapshot_size(); |
| return false; |
| } |
| if (status.device_size() != status.snapshot_size()) { |
| LOG(ERROR) << "Device size and snapshot size must be the same (device size = " |
| << status.device_size() << ", snapshot size = " << status.snapshot_size(); |
| return false; |
| } |
| |
| uint64_t snapshot_sectors = status.snapshot_size() / kSectorSize; |
| |
| // Note that merging is a global state. We do track whether individual devices |
| // have completed merging, but the start of the merge process is considered |
| // atomic. |
| SnapshotStorageMode mode; |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| switch (update_status.state()) { |
| case UpdateState::MergeCompleted: |
| case UpdateState::MergeNeedsReboot: |
| LOG(ERROR) << "Should not create a snapshot device for " << name |
| << " after global merging has completed."; |
| return false; |
| case UpdateState::Merging: |
| case UpdateState::MergeFailed: |
| // Note: MergeFailed indicates that a merge is in progress, but |
| // is possibly stalled. We still have to honor the merge. |
| if (DecideMergePhase(status) == update_status.merge_phase()) { |
| mode = SnapshotStorageMode::Merge; |
| } else { |
| mode = SnapshotStorageMode::Persistent; |
| } |
| break; |
| default: |
| mode = SnapshotStorageMode::Persistent; |
| break; |
| } |
| |
| if (mode == SnapshotStorageMode::Persistent && status.state() == SnapshotState::MERGING) { |
| LOG(ERROR) << "Snapshot: " << name |
| << " has snapshot status Merging but mode set to Persistent." |
| << " Changing mode to Snapshot-Merge."; |
| mode = SnapshotStorageMode::Merge; |
| } |
| |
| DmTable table; |
| table.Emplace<DmTargetSnapshot>(0, snapshot_sectors, base_device, cow_device, mode, |
| kSnapshotChunkSize); |
| if (!dm_.CreateDevice(name, table, dev_path, timeout_ms)) { |
| LOG(ERROR) << "Could not create snapshot device: " << name; |
| return false; |
| } |
| return true; |
| } |
| |
| std::optional<std::string> SnapshotManager::MapCowImage( |
| const std::string& name, const std::chrono::milliseconds& timeout_ms) { |
| if (!EnsureImageManager()) return std::nullopt; |
| auto cow_image_name = GetCowImageDeviceName(name); |
| |
| bool ok; |
| std::string cow_dev; |
| if (device_->IsRecovery() || device_->IsFirstStageInit()) { |
| const auto& opener = device_->GetPartitionOpener(); |
| ok = images_->MapImageWithDeviceMapper(opener, cow_image_name, &cow_dev); |
| } else { |
| ok = images_->MapImageDevice(cow_image_name, timeout_ms, &cow_dev); |
| } |
| |
| if (ok) { |
| LOG(INFO) << "Mapped " << cow_image_name << " to " << cow_dev; |
| return cow_dev; |
| } |
| LOG(ERROR) << "Could not map image device: " << cow_image_name; |
| return std::nullopt; |
| } |
| |
| bool SnapshotManager::MapSourceDevice(LockedFile* lock, const std::string& name, |
| const std::chrono::milliseconds& timeout_ms, |
| std::string* path) { |
| CHECK(lock); |
| |
| auto metadata = ReadOldPartitionMetadata(lock); |
| if (!metadata) { |
| LOG(ERROR) << "Could not map source device due to missing or corrupt metadata"; |
| return false; |
| } |
| |
| auto old_name = GetOtherPartitionName(name); |
| auto slot_suffix = device_->GetSlotSuffix(); |
| auto slot = SlotNumberForSlotSuffix(slot_suffix); |
| |
| CreateLogicalPartitionParams params = { |
| .block_device = device_->GetSuperDevice(slot), |
| .metadata = metadata, |
| .partition_name = old_name, |
| .timeout_ms = timeout_ms, |
| .device_name = GetSourceDeviceName(name), |
| .partition_opener = &device_->GetPartitionOpener(), |
| }; |
| if (!CreateLogicalPartition(std::move(params), path)) { |
| LOG(ERROR) << "Could not create source device for snapshot " << name; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapSnapshot(LockedFile* lock, const std::string& name) { |
| CHECK(lock); |
| |
| if (UpdateUsesUserSnapshots(lock)) { |
| if (!UnmapUserspaceSnapshotDevice(lock, name)) { |
| return false; |
| } |
| } else { |
| if (!DeleteDeviceIfExists(name)) { |
| LOG(ERROR) << "Could not delete snapshot device: " << name; |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapCowImage(const std::string& name) { |
| if (!EnsureImageManager()) return false; |
| return images_->UnmapImageIfExists(GetCowImageDeviceName(name)); |
| } |
| |
| bool SnapshotManager::DeleteSnapshot(LockedFile* lock, const std::string& name) { |
| CHECK(lock); |
| CHECK(lock->lock_mode() == LOCK_EX); |
| if (!EnsureImageManager()) return false; |
| |
| if (!UnmapCowDevices(lock, name)) { |
| return false; |
| } |
| |
| // We can't delete snapshots in recovery. The only way we'd try is it we're |
| // completing or canceling a merge in preparation for a data wipe, in which |
| // case, we don't care if the file sticks around. |
| if (device_->IsRecovery()) { |
| LOG(INFO) << "Skipping delete of snapshot " << name << " in recovery."; |
| return true; |
| } |
| |
| auto cow_image_name = GetCowImageDeviceName(name); |
| if (images_->BackingImageExists(cow_image_name)) { |
| if (!images_->DeleteBackingImage(cow_image_name)) { |
| return false; |
| } |
| } |
| |
| std::string error; |
| auto file_path = GetSnapshotStatusFilePath(name); |
| if (!android::base::RemoveFileIfExists(file_path, &error)) { |
| LOG(ERROR) << "Failed to remove status file " << file_path << ": " << error; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::InitiateMerge() { |
| auto lock = LockExclusive(); |
| if (!lock) return false; |
| |
| UpdateState state = ReadUpdateState(lock.get()); |
| if (state != UpdateState::Unverified) { |
| LOG(ERROR) << "Cannot begin a merge if an update has not been verified"; |
| return false; |
| } |
| |
| auto slot = GetCurrentSlot(); |
| if (slot != Slot::Target) { |
| LOG(ERROR) << "Device cannot merge while not booting from new slot"; |
| return false; |
| } |
| |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock.get(), &snapshots)) { |
| LOG(ERROR) << "Could not list snapshots"; |
| return false; |
| } |
| |
| auto other_suffix = device_->GetOtherSlotSuffix(); |
| |
| for (const auto& snapshot : snapshots) { |
| if (android::base::EndsWith(snapshot, other_suffix)) { |
| // Allow the merge to continue, but log this unexpected case. |
| LOG(ERROR) << "Unexpected snapshot found during merge: " << snapshot; |
| continue; |
| } |
| |
| // The device has to be mapped, since everything should be merged at |
| // the same time. This is a fairly serious error. We could forcefully |
| // map everything here, but it should have been mapped during first- |
| // stage init. |
| if (dm_.GetState(snapshot) == DmDeviceState::INVALID) { |
| LOG(ERROR) << "Cannot begin merge; device " << snapshot << " is not mapped."; |
| return false; |
| } |
| } |
| |
| auto metadata = ReadCurrentMetadata(); |
| for (auto it = snapshots.begin(); it != snapshots.end();) { |
| switch (GetMetadataPartitionState(*metadata, *it)) { |
| case MetadataPartitionState::Flashed: |
| LOG(WARNING) << "Detected re-flashing for partition " << *it |
| << ". Skip merging it."; |
| [[fallthrough]]; |
| case MetadataPartitionState::None: { |
| LOG(WARNING) << "Deleting snapshot for partition " << *it; |
| if (!DeleteSnapshot(lock.get(), *it)) { |
| LOG(WARNING) << "Cannot delete snapshot for partition " << *it |
| << ". Skip merging it anyways."; |
| } |
| it = snapshots.erase(it); |
| } break; |
| case MetadataPartitionState::Updated: { |
| ++it; |
| } break; |
| } |
| } |
| |
| bool compression_enabled = false; |
| |
| std::vector<std::string> first_merge_group; |
| |
| DmTargetSnapshot::Status initial_target_values = {}; |
| for (const auto& snapshot : snapshots) { |
| if (!UpdateUsesUserSnapshots(lock.get())) { |
| DmTargetSnapshot::Status current_status; |
| if (!QuerySnapshotStatus(snapshot, nullptr, ¤t_status)) { |
| return false; |
| } |
| initial_target_values.sectors_allocated += current_status.sectors_allocated; |
| initial_target_values.total_sectors += current_status.total_sectors; |
| initial_target_values.metadata_sectors += current_status.metadata_sectors; |
| } |
| |
| SnapshotStatus snapshot_status; |
| if (!ReadSnapshotStatus(lock.get(), snapshot, &snapshot_status)) { |
| return false; |
| } |
| |
| compression_enabled |= snapshot_status.compression_enabled(); |
| if (DecideMergePhase(snapshot_status) == MergePhase::FIRST_PHASE) { |
| first_merge_group.emplace_back(snapshot); |
| } |
| } |
| |
| SnapshotUpdateStatus initial_status = ReadSnapshotUpdateStatus(lock.get()); |
| initial_status.set_state(UpdateState::Merging); |
| initial_status.set_compression_enabled(compression_enabled); |
| |
| if (!UpdateUsesUserSnapshots(lock.get())) { |
| initial_status.set_sectors_allocated(initial_target_values.sectors_allocated); |
| initial_status.set_total_sectors(initial_target_values.total_sectors); |
| initial_status.set_metadata_sectors(initial_target_values.metadata_sectors); |
| } |
| |
| // If any partitions shrunk, we need to merge them before we merge any other |
| // partitions (see b/177935716). Otherwise, a merge from another partition |
| // may overwrite the source block of a copy operation. |
| const std::vector<std::string>* merge_group; |
| if (first_merge_group.empty()) { |
| merge_group = &snapshots; |
| initial_status.set_merge_phase(MergePhase::SECOND_PHASE); |
| } else { |
| merge_group = &first_merge_group; |
| initial_status.set_merge_phase(MergePhase::FIRST_PHASE); |
| } |
| |
| // Point of no return - mark that we're starting a merge. From now on every |
| // eligible snapshot must be a merge target. |
| if (!WriteSnapshotUpdateStatus(lock.get(), initial_status)) { |
| return false; |
| } |
| |
| auto reported_code = MergeFailureCode::Ok; |
| for (const auto& snapshot : *merge_group) { |
| // If this fails, we have no choice but to continue. Everything must |
| // be merged. This is not an ideal state to be in, but it is safe, |
| // because we the next boot will try again. |
| auto code = SwitchSnapshotToMerge(lock.get(), snapshot); |
| if (code != MergeFailureCode::Ok) { |
| LOG(ERROR) << "Failed to switch snapshot to a merge target: " << snapshot; |
| if (reported_code == MergeFailureCode::Ok) { |
| reported_code = code; |
| } |
| } |
| } |
| |
| // If we couldn't switch everything to a merge target, pre-emptively mark |
| // this merge as failed. It will get acknowledged when WaitForMerge() is |
| // called. |
| if (reported_code != MergeFailureCode::Ok) { |
| WriteUpdateState(lock.get(), UpdateState::MergeFailed, reported_code); |
| } |
| |
| // Return true no matter what, because a merge was initiated. |
| return true; |
| } |
| |
| MergeFailureCode SnapshotManager::SwitchSnapshotToMerge(LockedFile* lock, const std::string& name) { |
| SnapshotStatus status; |
| if (!ReadSnapshotStatus(lock, name, &status)) { |
| return MergeFailureCode::ReadStatus; |
| } |
| if (status.state() != SnapshotState::CREATED) { |
| LOG(WARNING) << "Snapshot " << name |
| << " has unexpected state: " << SnapshotState_Name(status.state()); |
| } |
| |
| if (UpdateUsesUserSnapshots(lock)) { |
| if (EnsureSnapuserdConnected()) { |
| // This is the point where we inform the daemon to initiate/resume |
| // the merge |
| if (!snapuserd_client_->InitiateMerge(name)) { |
| return MergeFailureCode::UnknownTable; |
| } |
| } else { |
| LOG(ERROR) << "Failed to connect to snapuserd daemon to initiate merge"; |
| return MergeFailureCode::UnknownTable; |
| } |
| } else { |
| // After this, we return true because we technically did switch to a merge |
| // target. Everything else we do here is just informational. |
| if (auto code = RewriteSnapshotDeviceTable(name); code != MergeFailureCode::Ok) { |
| return code; |
| } |
| } |
| |
| status.set_state(SnapshotState::MERGING); |
| |
| if (!UpdateUsesUserSnapshots(lock)) { |
| DmTargetSnapshot::Status dm_status; |
| if (!QuerySnapshotStatus(name, nullptr, &dm_status)) { |
| LOG(ERROR) << "Could not query merge status for snapshot: " << name; |
| } |
| status.set_sectors_allocated(dm_status.sectors_allocated); |
| status.set_metadata_sectors(dm_status.metadata_sectors); |
| } |
| |
| if (!WriteSnapshotStatus(lock, status)) { |
| LOG(ERROR) << "Could not update status file for snapshot: " << name; |
| } |
| return MergeFailureCode::Ok; |
| } |
| |
| MergeFailureCode SnapshotManager::RewriteSnapshotDeviceTable(const std::string& name) { |
| std::vector<DeviceMapper::TargetInfo> old_targets; |
| if (!dm_.GetTableInfo(name, &old_targets)) { |
| LOG(ERROR) << "Could not read snapshot device table: " << name; |
| return MergeFailureCode::GetTableInfo; |
| } |
| if (old_targets.size() != 1 || DeviceMapper::GetTargetType(old_targets[0].spec) != "snapshot") { |
| LOG(ERROR) << "Unexpected device-mapper table for snapshot: " << name; |
| return MergeFailureCode::UnknownTable; |
| } |
| |
| std::string base_device, cow_device; |
| if (!DmTargetSnapshot::GetDevicesFromParams(old_targets[0].data, &base_device, &cow_device)) { |
| LOG(ERROR) << "Could not derive underlying devices for snapshot: " << name; |
| return MergeFailureCode::GetTableParams; |
| } |
| |
| DmTable table; |
| table.Emplace<DmTargetSnapshot>(0, old_targets[0].spec.length, base_device, cow_device, |
| SnapshotStorageMode::Merge, kSnapshotChunkSize); |
| if (!dm_.LoadTableAndActivate(name, table)) { |
| LOG(ERROR) << "Could not swap device-mapper tables on snapshot device " << name; |
| return MergeFailureCode::ActivateNewTable; |
| } |
| LOG(INFO) << "Successfully switched snapshot device to a merge target: " << name; |
| return MergeFailureCode::Ok; |
| } |
| |
| bool SnapshotManager::GetSingleTarget(const std::string& dm_name, TableQuery query, |
| DeviceMapper::TargetInfo* target) { |
| if (dm_.GetState(dm_name) == DmDeviceState::INVALID) { |
| return false; |
| } |
| |
| std::vector<DeviceMapper::TargetInfo> targets; |
| bool result; |
| if (query == TableQuery::Status) { |
| result = dm_.GetTableStatus(dm_name, &targets); |
| } else { |
| result = dm_.GetTableInfo(dm_name, &targets); |
| } |
| if (!result) { |
| LOG(ERROR) << "Could not query device: " << dm_name; |
| return false; |
| } |
| if (targets.size() != 1) { |
| return false; |
| } |
| |
| *target = std::move(targets[0]); |
| return true; |
| } |
| |
| bool SnapshotManager::IsSnapshotDevice(const std::string& dm_name, TargetInfo* target) { |
| DeviceMapper::TargetInfo snap_target; |
| if (!GetSingleTarget(dm_name, TableQuery::Status, &snap_target)) { |
| return false; |
| } |
| auto type = DeviceMapper::GetTargetType(snap_target.spec); |
| |
| // If this is not a user-snapshot device then it should either |
| // be a dm-snapshot or dm-snapshot-merge target |
| if (type != "user") { |
| if (type != "snapshot" && type != "snapshot-merge") { |
| return false; |
| } |
| } |
| |
| if (target) { |
| *target = std::move(snap_target); |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::QuerySnapshotStatus(const std::string& dm_name, std::string* target_type, |
| DmTargetSnapshot::Status* status) { |
| DeviceMapper::TargetInfo target; |
| if (!IsSnapshotDevice(dm_name, &target)) { |
| LOG(ERROR) << "Device " << dm_name << " is not a snapshot or snapshot-merge device"; |
| return false; |
| } |
| if (!DmTargetSnapshot::ParseStatusText(target.data, status)) { |
| LOG(ERROR) << "Could not parse snapshot status text: " << dm_name; |
| return false; |
| } |
| if (target_type) { |
| *target_type = DeviceMapper::GetTargetType(target.spec); |
| } |
| if (!status->error.empty()) { |
| LOG(ERROR) << "Snapshot: " << dm_name << " returned error code: " << status->error; |
| return false; |
| } |
| return true; |
| } |
| |
| // Note that when a merge fails, we will *always* try again to complete the |
| // merge each time the device boots. There is no harm in doing so, and if |
| // the problem was transient, we might manage to get a new outcome. |
| UpdateState SnapshotManager::ProcessUpdateState(const std::function<bool()>& callback, |
| const std::function<bool()>& before_cancel) { |
| while (true) { |
| auto result = CheckMergeState(before_cancel); |
| LOG(INFO) << "ProcessUpdateState handling state: " << result.state; |
| |
| if (result.state == UpdateState::MergeFailed) { |
| AcknowledgeMergeFailure(result.failure_code); |
| } |
| if (result.state != UpdateState::Merging) { |
| // Either there is no merge, or the merge was finished, so no need |
| // to keep waiting. |
| return result.state; |
| } |
| |
| if (callback && !callback()) { |
| return result.state; |
| } |
| |
| // This wait is not super time sensitive, so we have a relatively |
| // low polling frequency. |
| std::this_thread::sleep_for(kUpdateStateCheckInterval); |
| } |
| } |
| |
| auto SnapshotManager::CheckMergeState(const std::function<bool()>& before_cancel) -> MergeResult { |
| auto lock = LockExclusive(); |
| if (!lock) { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::AcquireLock); |
| } |
| |
| auto result = CheckMergeState(lock.get(), before_cancel); |
| LOG(INFO) << "CheckMergeState for snapshots returned: " << result.state; |
| |
| if (result.state == UpdateState::MergeCompleted) { |
| // Do this inside the same lock. Failures get acknowledged without the |
| // lock, because flock() might have failed. |
| AcknowledgeMergeSuccess(lock.get()); |
| } else if (result.state == UpdateState::Cancelled) { |
| if (!device_->IsRecovery() && !RemoveAllUpdateState(lock.get(), before_cancel)) { |
| LOG(ERROR) << "Failed to remove all update state after acknowleding cancelled update."; |
| } |
| } |
| return result; |
| } |
| |
| auto SnapshotManager::CheckMergeState(LockedFile* lock, const std::function<bool()>& before_cancel) |
| -> MergeResult { |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| switch (update_status.state()) { |
| case UpdateState::None: |
| case UpdateState::MergeCompleted: |
| // Harmless races are allowed between two callers of WaitForMerge, |
| // so in both of these cases we just propagate the state. |
| return MergeResult(update_status.state()); |
| |
| case UpdateState::Merging: |
| case UpdateState::MergeNeedsReboot: |
| case UpdateState::MergeFailed: |
| // We'll poll each snapshot below. Note that for the NeedsReboot |
| // case, we always poll once to give cleanup another opportunity to |
| // run. |
| break; |
| |
| case UpdateState::Unverified: |
| // This is an edge case. Normally cancelled updates are detected |
| // via the merge poll below, but if we never started a merge, we |
| // need to also check here. |
| if (HandleCancelledUpdate(lock, before_cancel)) { |
| return MergeResult(UpdateState::Cancelled); |
| } |
| return MergeResult(update_status.state()); |
| |
| default: |
| return MergeResult(update_status.state()); |
| } |
| |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock, &snapshots)) { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::ListSnapshots); |
| } |
| |
| auto other_suffix = device_->GetOtherSlotSuffix(); |
| |
| bool cancelled = false; |
| bool merging = false; |
| bool needs_reboot = false; |
| bool wrong_phase = false; |
| MergeFailureCode failure_code = MergeFailureCode::Ok; |
| for (const auto& snapshot : snapshots) { |
| if (android::base::EndsWith(snapshot, other_suffix)) { |
| // This will have triggered an error message in InitiateMerge already. |
| LOG(INFO) << "Skipping merge validation of unexpected snapshot: " << snapshot; |
| continue; |
| } |
| |
| auto result = CheckTargetMergeState(lock, snapshot, update_status); |
| LOG(INFO) << "CheckTargetMergeState for " << snapshot << " returned: " << result.state; |
| |
| switch (result.state) { |
| case UpdateState::MergeFailed: |
| // Take the first failure code in case other failures compound. |
| if (failure_code == MergeFailureCode::Ok) { |
| failure_code = result.failure_code; |
| } |
| break; |
| case UpdateState::Merging: |
| merging = true; |
| break; |
| case UpdateState::MergeNeedsReboot: |
| needs_reboot = true; |
| break; |
| case UpdateState::MergeCompleted: |
| break; |
| case UpdateState::Cancelled: |
| cancelled = true; |
| break; |
| case UpdateState::None: |
| wrong_phase = true; |
| break; |
| default: |
| LOG(ERROR) << "Unknown merge status for \"" << snapshot << "\": " |
| << "\"" << result.state << "\""; |
| if (failure_code == MergeFailureCode::Ok) { |
| failure_code = MergeFailureCode::UnexpectedMergeState; |
| } |
| break; |
| } |
| } |
| |
| if (merging) { |
| // Note that we handle "Merging" before we handle anything else. We |
| // want to poll until *nothing* is merging if we can, so everything has |
| // a chance to get marked as completed or failed. |
| return MergeResult(UpdateState::Merging); |
| } |
| if (failure_code != MergeFailureCode::Ok) { |
| // Note: since there are many drop-out cases for failure, we acknowledge |
| // it in WaitForMerge rather than here and elsewhere. |
| return MergeResult(UpdateState::MergeFailed, failure_code); |
| } |
| if (wrong_phase) { |
| // If we got here, no other partitions are being merged, and nothing |
| // failed to merge. It's safe to move to the next merge phase. |
| auto code = MergeSecondPhaseSnapshots(lock); |
| if (code != MergeFailureCode::Ok) { |
| return MergeResult(UpdateState::MergeFailed, code); |
| } |
| return MergeResult(UpdateState::Merging); |
| } |
| if (needs_reboot) { |
| WriteUpdateState(lock, UpdateState::MergeNeedsReboot); |
| return MergeResult(UpdateState::MergeNeedsReboot); |
| } |
| if (cancelled) { |
| // This is an edge case, that we handle as correctly as we sensibly can. |
| // The underlying partition has changed behind update_engine, and we've |
| // removed the snapshot as a result. The exact state of the update is |
| // undefined now, but this can only happen on an unlocked device where |
| // partitions can be flashed without wiping userdata. |
| return MergeResult(UpdateState::Cancelled); |
| } |
| return MergeResult(UpdateState::MergeCompleted); |
| } |
| |
| auto SnapshotManager::CheckTargetMergeState(LockedFile* lock, const std::string& name, |
| const SnapshotUpdateStatus& update_status) |
| -> MergeResult { |
| SnapshotStatus snapshot_status; |
| if (!ReadSnapshotStatus(lock, name, &snapshot_status)) { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::ReadStatus); |
| } |
| |
| std::unique_ptr<LpMetadata> current_metadata; |
| |
| if (!IsSnapshotDevice(name)) { |
| if (!current_metadata) { |
| current_metadata = ReadCurrentMetadata(); |
| } |
| |
| if (!current_metadata || |
| GetMetadataPartitionState(*current_metadata, name) != MetadataPartitionState::Updated) { |
| DeleteSnapshot(lock, name); |
| return MergeResult(UpdateState::Cancelled); |
| } |
| |
| // During a check, we decided the merge was complete, but we were unable to |
| // collapse the device-mapper stack and perform COW cleanup. If we haven't |
| // rebooted after this check, the device will still be a snapshot-merge |
| // target. If we have rebooted, the device will now be a linear target, |
| // and we can try cleanup again. |
| if (snapshot_status.state() == SnapshotState::MERGE_COMPLETED) { |
| // NB: It's okay if this fails now, we gave cleanup our best effort. |
| OnSnapshotMergeComplete(lock, name, snapshot_status); |
| return MergeResult(UpdateState::MergeCompleted); |
| } |
| |
| LOG(ERROR) << "Expected snapshot or snapshot-merge for device: " << name; |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::UnknownTargetType); |
| } |
| |
| // This check is expensive so it is only enabled for debugging. |
| DCHECK((current_metadata = ReadCurrentMetadata()) && |
| GetMetadataPartitionState(*current_metadata, name) == MetadataPartitionState::Updated); |
| |
| if (UpdateUsesUserSnapshots(lock)) { |
| std::string merge_status; |
| if (EnsureSnapuserdConnected()) { |
| // Query the snapshot status from the daemon |
| merge_status = snapuserd_client_->QuerySnapshotStatus(name); |
| } else { |
| MergeResult(UpdateState::MergeFailed, MergeFailureCode::QuerySnapshotStatus); |
| } |
| |
| if (merge_status == "snapshot-merge-failed") { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::UnknownTargetType); |
| } |
| |
| // This is the case when device reboots during merge. Once the device boots, |
| // snapuserd daemon will not resume merge immediately in first stage init. |
| // This is slightly different as compared to dm-snapshot-merge; In this |
| // case, metadata file will have "MERGING" state whereas the daemon will be |
| // waiting to resume the merge. Thus, we resume the merge at this point. |
| if (merge_status == "snapshot" && snapshot_status.state() == SnapshotState::MERGING) { |
| if (!snapuserd_client_->InitiateMerge(name)) { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::UnknownTargetType); |
| } |
| return MergeResult(UpdateState::Merging); |
| } |
| |
| if (merge_status == "snapshot" && |
| DecideMergePhase(snapshot_status) == MergePhase::SECOND_PHASE && |
| update_status.merge_phase() == MergePhase::FIRST_PHASE) { |
| // The snapshot is not being merged because it's in the wrong phase. |
| return MergeResult(UpdateState::None); |
| } |
| |
| if (merge_status == "snapshot-merge") { |
| if (snapshot_status.state() == SnapshotState::MERGE_COMPLETED) { |
| LOG(ERROR) << "Snapshot " << name |
| << " is merging after being marked merge-complete."; |
| return MergeResult(UpdateState::MergeFailed, |
| MergeFailureCode::UnmergedSectorsAfterCompletion); |
| } |
| return MergeResult(UpdateState::Merging); |
| } |
| |
| if (merge_status != "snapshot-merge-complete") { |
| LOG(ERROR) << "Snapshot " << name << " has incorrect status: " << merge_status; |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::ExpectedMergeTarget); |
| } |
| } else { |
| // dm-snapshot in the kernel |
| std::string target_type; |
| DmTargetSnapshot::Status status; |
| if (!QuerySnapshotStatus(name, &target_type, &status)) { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::QuerySnapshotStatus); |
| } |
| if (target_type == "snapshot" && |
| DecideMergePhase(snapshot_status) == MergePhase::SECOND_PHASE && |
| update_status.merge_phase() == MergePhase::FIRST_PHASE) { |
| // The snapshot is not being merged because it's in the wrong phase. |
| return MergeResult(UpdateState::None); |
| } |
| if (target_type != "snapshot-merge") { |
| // We can get here if we failed to rewrite the target type in |
| // InitiateMerge(). If we failed to create the target in first-stage |
| // init, boot would not succeed. |
| LOG(ERROR) << "Snapshot " << name << " has incorrect target type: " << target_type; |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::ExpectedMergeTarget); |
| } |
| |
| // These two values are equal when merging is complete. |
| if (status.sectors_allocated != status.metadata_sectors) { |
| if (snapshot_status.state() == SnapshotState::MERGE_COMPLETED) { |
| LOG(ERROR) << "Snapshot " << name |
| << " is merging after being marked merge-complete."; |
| return MergeResult(UpdateState::MergeFailed, |
| MergeFailureCode::UnmergedSectorsAfterCompletion); |
| } |
| return MergeResult(UpdateState::Merging); |
| } |
| } |
| |
| // Merge is complete at this point |
| |
| auto code = CheckMergeConsistency(lock, name, snapshot_status); |
| if (code != MergeFailureCode::Ok) { |
| return MergeResult(UpdateState::MergeFailed, code); |
| } |
| |
| // Merging is done. First, update the status file to indicate the merge |
| // is complete. We do this before calling OnSnapshotMergeComplete, even |
| // though this means the write is potentially wasted work (since in the |
| // ideal case we'll immediately delete the file). |
| // |
| // This makes it simpler to reason about the next reboot: no matter what |
| // part of cleanup failed, first-stage init won't try to create another |
| // snapshot device for this partition. |
| snapshot_status.set_state(SnapshotState::MERGE_COMPLETED); |
| if (!WriteSnapshotStatus(lock, snapshot_status)) { |
| return MergeResult(UpdateState::MergeFailed, MergeFailureCode::WriteStatus); |
| } |
| if (!OnSnapshotMergeComplete(lock, name, snapshot_status)) { |
| return MergeResult(UpdateState::MergeNeedsReboot); |
| } |
| return MergeResult(UpdateState::MergeCompleted, MergeFailureCode::Ok); |
| } |
| |
| // This returns the backing device, not the dm-user layer. |
| static std::string GetMappedCowDeviceName(const std::string& snapshot, |
| const SnapshotStatus& status) { |
| // If no partition was created (the COW exists entirely on /data), the |
| // device-mapper layering is different than if we had a partition. |
| if (status.cow_partition_size() == 0) { |
| return GetCowImageDeviceName(snapshot); |
| } |
| return GetCowName(snapshot); |
| } |
| |
| MergeFailureCode SnapshotManager::CheckMergeConsistency(LockedFile* lock, const std::string& name, |
| const SnapshotStatus& status) { |
| CHECK(lock); |
| |
| return merge_consistency_checker_(name, status); |
| } |
| |
| MergeFailureCode CheckMergeConsistency(const std::string& name, const SnapshotStatus& status) { |
| if (!status.compression_enabled()) { |
| // Do not try to verify old-style COWs yet. |
| return MergeFailureCode::Ok; |
| } |
| |
| auto& dm = DeviceMapper::Instance(); |
| |
| std::string cow_image_name = GetMappedCowDeviceName(name, status); |
| std::string cow_image_path; |
| if (!dm.GetDmDevicePathByName(cow_image_name, &cow_image_path)) { |
| LOG(ERROR) << "Failed to get path for cow device: " << cow_image_name; |
| return MergeFailureCode::GetCowPathConsistencyCheck; |
| } |
| |
| // First pass, count # of ops. |
| size_t num_ops = 0; |
| { |
| unique_fd fd(open(cow_image_path.c_str(), O_RDONLY | O_CLOEXEC)); |
| if (fd < 0) { |
| PLOG(ERROR) << "Failed to open " << cow_image_name; |
| return MergeFailureCode::OpenCowConsistencyCheck; |
| } |
| |
| CowReader reader; |
| if (!reader.Parse(std::move(fd))) { |
| LOG(ERROR) << "Failed to parse cow " << cow_image_path; |
| return MergeFailureCode::ParseCowConsistencyCheck; |
| } |
| |
| num_ops = reader.get_num_total_data_ops(); |
| } |
| |
| // Second pass, try as hard as we can to get the actual number of blocks |
| // the system thinks is merged. |
| unique_fd fd(open(cow_image_path.c_str(), O_RDONLY | O_DIRECT | O_SYNC | O_CLOEXEC)); |
| if (fd < 0) { |
| PLOG(ERROR) << "Failed to open direct " << cow_image_name; |
| return MergeFailureCode::OpenCowDirectConsistencyCheck; |
| } |
| |
| void* addr; |
| size_t page_size = getpagesize(); |
| if (posix_memalign(&addr, page_size, page_size) < 0) { |
| PLOG(ERROR) << "posix_memalign with page size " << page_size; |
| return MergeFailureCode::MemAlignConsistencyCheck; |
| } |
| |
| // COWs are always at least 2MB, this is guaranteed in snapshot creation. |
| std::unique_ptr<void, decltype(&::free)> buffer(addr, ::free); |
| if (!android::base::ReadFully(fd, buffer.get(), page_size)) { |
| PLOG(ERROR) << "Direct read failed " << cow_image_name; |
| return MergeFailureCode::DirectReadConsistencyCheck; |
| } |
| |
| auto header = reinterpret_cast<CowHeader*>(buffer.get()); |
| if (header->num_merge_ops != num_ops) { |
| LOG(ERROR) << "COW consistency check failed, expected " << num_ops << " to be merged, " |
| << "but " << header->num_merge_ops << " were actually recorded."; |
| LOG(ERROR) << "Aborting merge progress for snapshot " << name |
| << ", will try again next boot"; |
| return MergeFailureCode::WrongMergeCountConsistencyCheck; |
| } |
| |
| return MergeFailureCode::Ok; |
| } |
| |
| MergeFailureCode SnapshotManager::MergeSecondPhaseSnapshots(LockedFile* lock) { |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock, &snapshots)) { |
| return MergeFailureCode::ListSnapshots; |
| } |
| |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| CHECK(update_status.state() == UpdateState::Merging || |
| update_status.state() == UpdateState::MergeFailed); |
| CHECK(update_status.merge_phase() == MergePhase::FIRST_PHASE); |
| |
| update_status.set_state(UpdateState::Merging); |
| update_status.set_merge_phase(MergePhase::SECOND_PHASE); |
| if (!WriteSnapshotUpdateStatus(lock, update_status)) { |
| return MergeFailureCode::WriteStatus; |
| } |
| |
| MergeFailureCode result = MergeFailureCode::Ok; |
| for (const auto& snapshot : snapshots) { |
| SnapshotStatus snapshot_status; |
| if (!ReadSnapshotStatus(lock, snapshot, &snapshot_status)) { |
| return MergeFailureCode::ReadStatus; |
| } |
| if (DecideMergePhase(snapshot_status) != MergePhase::SECOND_PHASE) { |
| continue; |
| } |
| auto code = SwitchSnapshotToMerge(lock, snapshot); |
| if (code != MergeFailureCode::Ok) { |
| LOG(ERROR) << "Failed to switch snapshot to a second-phase merge target: " << snapshot; |
| if (result == MergeFailureCode::Ok) { |
| result = code; |
| } |
| } |
| } |
| return result; |
| } |
| |
| std::string SnapshotManager::GetSnapshotBootIndicatorPath() { |
| return metadata_dir_ + "/" + android::base::Basename(kBootIndicatorPath); |
| } |
| |
| std::string SnapshotManager::GetRollbackIndicatorPath() { |
| return metadata_dir_ + "/" + android::base::Basename(kRollbackIndicatorPath); |
| } |
| |
| std::string SnapshotManager::GetForwardMergeIndicatorPath() { |
| return metadata_dir_ + "/allow-forward-merge"; |
| } |
| |
| std::string SnapshotManager::GetOldPartitionMetadataPath() { |
| return metadata_dir_ + "/old-partition-metadata"; |
| } |
| |
| void SnapshotManager::AcknowledgeMergeSuccess(LockedFile* lock) { |
| // It's not possible to remove update state in recovery, so write an |
| // indicator that cleanup is needed on reboot. If a factory data reset |
| // was requested, it doesn't matter, everything will get wiped anyway. |
| // To make testing easier we consider a /data wipe as cleaned up. |
| if (device_->IsRecovery()) { |
| WriteUpdateState(lock, UpdateState::MergeCompleted); |
| return; |
| } |
| |
| RemoveAllUpdateState(lock); |
| |
| if (UpdateUsesUserSnapshots(lock) && !device()->IsTestDevice()) { |
| if (snapuserd_client_) { |
| snapuserd_client_->DetachSnapuserd(); |
| snapuserd_client_->CloseConnection(); |
| snapuserd_client_ = nullptr; |
| } |
| } |
| } |
| |
| void SnapshotManager::AcknowledgeMergeFailure(MergeFailureCode failure_code) { |
| // Log first, so worst case, we always have a record of why the calls below |
| // were being made. |
| LOG(ERROR) << "Merge could not be completed and will be marked as failed."; |
| |
| auto lock = LockExclusive(); |
| if (!lock) return; |
| |
| // Since we released the lock in between WaitForMerge and here, it's |
| // possible (1) the merge successfully completed or (2) was already |
| // marked as a failure. So make sure to check the state again, and |
| // only mark as a failure if appropriate. |
| UpdateState state = ReadUpdateState(lock.get()); |
| if (state != UpdateState::Merging && state != UpdateState::MergeNeedsReboot) { |
| return; |
| } |
| |
| WriteUpdateState(lock.get(), UpdateState::MergeFailed, failure_code); |
| } |
| |
| bool SnapshotManager::OnSnapshotMergeComplete(LockedFile* lock, const std::string& name, |
| const SnapshotStatus& status) { |
| if (!UpdateUsesUserSnapshots(lock)) { |
| if (IsSnapshotDevice(name)) { |
| // We are extra-cautious here, to avoid deleting the wrong table. |
| std::string target_type; |
| DmTargetSnapshot::Status dm_status; |
| if (!QuerySnapshotStatus(name, &target_type, &dm_status)) { |
| return false; |
| } |
| if (target_type != "snapshot-merge") { |
| LOG(ERROR) << "Unexpected target type " << target_type |
| << " for snapshot device: " << name; |
| return false; |
| } |
| if (dm_status.sectors_allocated != dm_status.metadata_sectors) { |
| LOG(ERROR) << "Merge is unexpectedly incomplete for device " << name; |
| return false; |
| } |
| if (!CollapseSnapshotDevice(lock, name, status)) { |
| LOG(ERROR) << "Unable to collapse snapshot: " << name; |
| return false; |
| } |
| } |
| } else { |
| // Just collapse the device - no need to query again as we just did |
| // prior to calling this function |
| if (!CollapseSnapshotDevice(lock, name, status)) { |
| LOG(ERROR) << "Unable to collapse snapshot: " << name; |
| return false; |
| } |
| } |
| |
| // Note that collapsing is implicitly an Unmap, so we don't need to |
| // unmap the snapshot. |
| |
| if (!DeleteSnapshot(lock, name)) { |
| LOG(ERROR) << "Could not delete snapshot: " << name; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::CollapseSnapshotDevice(LockedFile* lock, const std::string& name, |
| const SnapshotStatus& status) { |
| if (!UpdateUsesUserSnapshots(lock)) { |
| // Verify we have a snapshot-merge device. |
| DeviceMapper::TargetInfo target; |
| if (!GetSingleTarget(name, TableQuery::Table, &target)) { |
| return false; |
| } |
| if (DeviceMapper::GetTargetType(target.spec) != "snapshot-merge") { |
| // This should be impossible, it was checked earlier. |
| LOG(ERROR) << "Snapshot device has invalid target type: " << name; |
| return false; |
| } |
| |
| std::string base_device, cow_device; |
| if (!DmTargetSnapshot::GetDevicesFromParams(target.data, &base_device, &cow_device)) { |
| LOG(ERROR) << "Could not parse snapshot device " << name |
| << " parameters: " << target.data; |
| return false; |
| } |
| } |
| |
| uint64_t snapshot_sectors = status.snapshot_size() / kSectorSize; |
| if (snapshot_sectors * kSectorSize != status.snapshot_size()) { |
| LOG(ERROR) << "Snapshot " << name |
| << " size is not sector aligned: " << status.snapshot_size(); |
| return false; |
| } |
| |
| uint32_t slot = SlotNumberForSlotSuffix(device_->GetSlotSuffix()); |
| // Create a DmTable that is identical to the base device. |
| CreateLogicalPartitionParams base_device_params{ |
| .block_device = device_->GetSuperDevice(slot), |
| .metadata_slot = slot, |
| .partition_name = name, |
| .partition_opener = &device_->GetPartitionOpener(), |
| }; |
| DmTable table; |
| if (!CreateDmTable(base_device_params, &table)) { |
| LOG(ERROR) << "Could not create a DmTable for partition: " << name; |
| return false; |
| } |
| |
| if (!dm_.LoadTableAndActivate(name, table)) { |
| return false; |
| } |
| |
| if (!UpdateUsesUserSnapshots(lock)) { |
| // Attempt to delete the snapshot device if one still exists. Nothing |
| // should be depending on the device, and device-mapper should have |
| // flushed remaining I/O. We could in theory replace with dm-zero (or |
| // re-use the table above), but for now it's better to know why this |
| // would fail. |
| // |
| // Furthermore, we should not be trying to unmap for userspace snapshot |
| // as unmap will fail since dm-user itself was a snapshot device prior |
| // to switching of tables. Unmap will fail as the device will be mounted |
| // by system partitions |
| if (status.compression_enabled()) { |
| auto dm_user_name = GetDmUserCowName(name, GetSnapshotDriver(lock)); |
| UnmapDmUserDevice(dm_user_name); |
| } |
| } |
| |
| // We can't delete base device immediately as daemon holds a reference. |
| // Make sure we wait for all the worker threads to terminate and release |
| // the reference |
| if (UpdateUsesUserSnapshots(lock) && EnsureSnapuserdConnected()) { |
| if (!snapuserd_client_->WaitForDeviceDelete(name)) { |
| LOG(ERROR) << "Failed to wait for " << name << " control device to delete"; |
| } |
| } |
| |
| auto base_name = GetBaseDeviceName(name); |
| if (!DeleteDeviceIfExists(base_name)) { |
| LOG(ERROR) << "Unable to delete base device for snapshot: " << base_name; |
| } |
| |
| if (!DeleteDeviceIfExists(GetSourceDeviceName(name), 4000ms)) { |
| LOG(ERROR) << "Unable to delete source device for snapshot: " << GetSourceDeviceName(name); |
| } |
| |
| return true; |
| } |
| |
| bool SnapshotManager::HandleCancelledUpdate(LockedFile* lock, |
| const std::function<bool()>& before_cancel) { |
| auto slot = GetCurrentSlot(); |
| if (slot == Slot::Unknown) { |
| return false; |
| } |
| |
| // If all snapshots were reflashed, then cancel the entire update. |
| if (AreAllSnapshotsCancelled(lock)) { |
| LOG(WARNING) << "Detected re-flashing, cancelling unverified update."; |
| return RemoveAllUpdateState(lock, before_cancel); |
| } |
| |
| // If update has been rolled back, then cancel the entire update. |
| // Client (update_engine) is responsible for doing additional cleanup work on its own states |
| // when ProcessUpdateState() returns UpdateState::Cancelled. |
| auto current_slot = GetCurrentSlot(); |
| if (current_slot != Slot::Source) { |
| LOG(INFO) << "Update state is being processed while booting at " << current_slot |
| << " slot, taking no action."; |
| return false; |
| } |
| |
| // current_slot == Source. Attempt to detect rollbacks. |
| if (access(GetRollbackIndicatorPath().c_str(), F_OK) != 0) { |
| // This unverified update is not attempted. Take no action. |
| PLOG(INFO) << "Rollback indicator not detected. " |
| << "Update state is being processed before reboot, taking no action."; |
| return false; |
| } |
| |
| LOG(WARNING) << "Detected rollback, cancelling unverified update."; |
| return RemoveAllUpdateState(lock, before_cancel); |
| } |
| |
| bool SnapshotManager::PerformInitTransition(InitTransition transition, |
| std::vector<std::string>* snapuserd_argv) { |
| LOG(INFO) << "Performing transition for snapuserd."; |
| |
| // Don't use EnsureSnapuserdConnected() because this is called from init, |
| // and attempting to do so will deadlock. |
| if (!snapuserd_client_ && transition != InitTransition::SELINUX_DETACH) { |
| snapuserd_client_ = SnapuserdClient::Connect(kSnapuserdSocket, 10s); |
| if (!snapuserd_client_) { |
| LOG(ERROR) << "Unable to connect to snapuserd"; |
| return false; |
| } |
| } |
| |
| auto lock = LockExclusive(); |
| if (!lock) return false; |
| |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock.get(), &snapshots)) { |
| LOG(ERROR) << "Failed to list snapshots."; |
| return false; |
| } |
| |
| if (UpdateUsesUserSnapshots(lock.get()) && transition == InitTransition::SELINUX_DETACH) { |
| snapuserd_argv->emplace_back("-user_snapshot"); |
| if (UpdateUsesIouring(lock.get())) { |
| snapuserd_argv->emplace_back("-io_uring"); |
| } |
| } |
| |
| size_t num_cows = 0; |
| size_t ok_cows = 0; |
| for (const auto& snapshot : snapshots) { |
| std::string user_cow_name = GetDmUserCowName(snapshot, GetSnapshotDriver(lock.get())); |
| |
| if (dm_.GetState(user_cow_name) == DmDeviceState::INVALID) { |
| continue; |
| } |
| |
| DeviceMapper::TargetInfo target; |
| if (!GetSingleTarget(user_cow_name, TableQuery::Table, &target)) { |
| continue; |
| } |
| |
| auto target_type = DeviceMapper::GetTargetType(target.spec); |
| if (target_type != "user") { |
| LOG(ERROR) << "Unexpected target type for " << user_cow_name << ": " << target_type; |
| continue; |
| } |
| |
| num_cows++; |
| |
| SnapshotStatus snapshot_status; |
| if (!ReadSnapshotStatus(lock.get(), snapshot, &snapshot_status)) { |
| LOG(ERROR) << "Unable to read snapshot status: " << snapshot; |
| continue; |
| } |
| |
| auto misc_name = user_cow_name; |
| |
| DmTable table; |
| table.Emplace<DmTargetUser>(0, target.spec.length, misc_name); |
| if (!dm_.LoadTableAndActivate(user_cow_name, table)) { |
| LOG(ERROR) << "Unable to swap tables for " << misc_name; |
| continue; |
| } |
| |
| std::string source_device_name; |
| if (snapshot_status.old_partition_size() > 0) { |
| source_device_name = GetSourceDeviceName(snapshot); |
| } else { |
| source_device_name = GetBaseDeviceName(snapshot); |
| } |
| |
| std::string source_device; |
| if (!dm_.GetDmDevicePathByName(source_device_name, &source_device)) { |
| LOG(ERROR) << "Could not get device path for " << GetSourceDeviceName(snapshot); |
| continue; |
| } |
| |
| std::string base_path_merge; |
| if (!dm_.GetDmDevicePathByName(GetBaseDeviceName(snapshot), &base_path_merge)) { |
| LOG(ERROR) << "Could not get device path for " << GetSourceDeviceName(snapshot); |
| continue; |
| } |
| |
| std::string cow_image_name = GetMappedCowDeviceName(snapshot, snapshot_status); |
| |
| std::string cow_image_device; |
| if (!dm_.GetDmDevicePathByName(cow_image_name, &cow_image_device)) { |
| LOG(ERROR) << "Could not get device path for " << cow_image_name; |
| continue; |
| } |
| |
| // Wait for ueventd to acknowledge and create the control device node. |
| std::string control_device = "/dev/dm-user/" + misc_name; |
| if (!WaitForDevice(control_device, 10s)) { |
| LOG(ERROR) << "dm-user control device no found: " << misc_name; |
| continue; |
| } |
| |
| if (transition == InitTransition::SELINUX_DETACH) { |
| if (!UpdateUsesUserSnapshots(lock.get())) { |
| auto message = misc_name + "," + cow_image_device + "," + source_device; |
| snapuserd_argv->emplace_back(std::move(message)); |
| } else { |
| auto message = misc_name + "," + cow_image_device + "," + source_device + "," + |
| base_path_merge; |
| snapuserd_argv->emplace_back(std::move(message)); |
| } |
| |
| // Do not attempt to connect to the new snapuserd yet, it hasn't |
| // been started. We do however want to wait for the misc device |
| // to have been created. |
| ok_cows++; |
| continue; |
| } |
| |
| uint64_t base_sectors; |
| if (!UpdateUsesUserSnapshots(lock.get())) { |
| base_sectors = |
| snapuserd_client_->InitDmUserCow(misc_name, cow_image_device, source_device); |
| } else { |
| base_sectors = snapuserd_client_->InitDmUserCow(misc_name, cow_image_device, |
| source_device, base_path_merge); |
| } |
| |
| if (base_sectors == 0) { |
| // Unrecoverable as metadata reads from cow device failed |
| LOG(FATAL) << "Failed to retrieve base_sectors from Snapuserd"; |
| return false; |
| } |
| |
| CHECK(base_sectors <= target.spec.length); |
| |
| if (!snapuserd_client_->AttachDmUser(misc_name)) { |
| // This error is unrecoverable. We cannot proceed because reads to |
| // the underlying device will fail. |
| LOG(FATAL) << "Could not initialize snapuserd for " << user_cow_name; |
| return false; |
| } |
| |
| ok_cows++; |
| } |
| |
| if (ok_cows != num_cows) { |
| LOG(ERROR) << "Could not transition all snapuserd consumers."; |
| return false; |
| } |
| return true; |
| } |
| |
| std::unique_ptr<LpMetadata> SnapshotManager::ReadCurrentMetadata() { |
| const auto& opener = device_->GetPartitionOpener(); |
| uint32_t slot = SlotNumberForSlotSuffix(device_->GetSlotSuffix()); |
| auto super_device = device_->GetSuperDevice(slot); |
| auto metadata = android::fs_mgr::ReadMetadata(opener, super_device, slot); |
| if (!metadata) { |
| LOG(ERROR) << "Could not read dynamic partition metadata for device: " << super_device; |
| return nullptr; |
| } |
| return metadata; |
| } |
| |
| SnapshotManager::MetadataPartitionState SnapshotManager::GetMetadataPartitionState( |
| const LpMetadata& metadata, const std::string& name) { |
| auto partition = android::fs_mgr::FindPartition(metadata, name); |
| if (!partition) return MetadataPartitionState::None; |
| if (partition->attributes & LP_PARTITION_ATTR_UPDATED) { |
| return MetadataPartitionState::Updated; |
| } |
| return MetadataPartitionState::Flashed; |
| } |
| |
| bool SnapshotManager::AreAllSnapshotsCancelled(LockedFile* lock) { |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock, &snapshots)) { |
| LOG(WARNING) << "Failed to list snapshots to determine whether device has been flashed " |
| << "after applying an update. Assuming no snapshots."; |
| // Let HandleCancelledUpdate resets UpdateState. |
| return true; |
| } |
| |
| std::map<std::string, bool> flashing_status; |
| |
| if (!GetSnapshotFlashingStatus(lock, snapshots, &flashing_status)) { |
| LOG(WARNING) << "Failed to determine whether partitions have been flashed. Not" |
| << "removing update states."; |
| return false; |
| } |
| |
| bool all_snapshots_cancelled = std::all_of(flashing_status.begin(), flashing_status.end(), |
| [](const auto& pair) { return pair.second; }); |
| |
| if (all_snapshots_cancelled) { |
| LOG(WARNING) << "All partitions are re-flashed after update, removing all update states."; |
| } |
| return all_snapshots_cancelled; |
| } |
| |
| bool SnapshotManager::GetSnapshotFlashingStatus(LockedFile* lock, |
| const std::vector<std::string>& snapshots, |
| std::map<std::string, bool>* out) { |
| CHECK(lock); |
| |
| auto source_slot_suffix = ReadUpdateSourceSlotSuffix(); |
| if (source_slot_suffix.empty()) { |
| return false; |
| } |
| uint32_t source_slot = SlotNumberForSlotSuffix(source_slot_suffix); |
| uint32_t target_slot = (source_slot == 0) ? 1 : 0; |
| |
| // Attempt to detect re-flashing on each partition. |
| // - If all partitions are re-flashed, we can proceed to cancel the whole update. |
| // - If only some of the partitions are re-flashed, snapshots for re-flashed partitions are |
| // deleted. Caller is responsible for merging the rest of the snapshots. |
| // - If none of the partitions are re-flashed, caller is responsible for merging the snapshots. |
| // |
| // Note that we use target slot metadata, since if an OTA has been applied |
| // to the target slot, we can detect the UPDATED flag. Any kind of flash |
| // operation against dynamic partitions ensures that all copies of the |
| // metadata are in sync, so flashing all partitions on the source slot will |
| // remove the UPDATED flag on the target slot as well. |
| const auto& opener = device_->GetPartitionOpener(); |
| auto super_device = device_->GetSuperDevice(target_slot); |
| auto metadata = android::fs_mgr::ReadMetadata(opener, super_device, target_slot); |
| if (!metadata) { |
| return false; |
| } |
| |
| for (const auto& snapshot_name : snapshots) { |
| if (GetMetadataPartitionState(*metadata, snapshot_name) == |
| MetadataPartitionState::Updated) { |
| out->emplace(snapshot_name, false); |
| } else { |
| // Delete snapshots for partitions that are re-flashed after the update. |
| LOG(WARNING) << "Detected re-flashing of partition " << snapshot_name << "."; |
| out->emplace(snapshot_name, true); |
| } |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::RemoveAllSnapshots(LockedFile* lock) { |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock, &snapshots)) { |
| LOG(ERROR) << "Could not list snapshots"; |
| return false; |
| } |
| |
| std::map<std::string, bool> flashing_status; |
| if (!GetSnapshotFlashingStatus(lock, snapshots, &flashing_status)) { |
| LOG(WARNING) << "Failed to get flashing status"; |
| } |
| |
| auto current_slot = GetCurrentSlot(); |
| bool ok = true; |
| bool has_mapped_cow_images = false; |
| for (const auto& name : snapshots) { |
| // If booting off source slot, it is okay to unmap and delete all the snapshots. |
| // If boot indicator is missing, update state is None or Initiated, so |
| // it is also okay to unmap and delete all the snapshots. |
| // If booting off target slot, |
| // - should not unmap because: |
| // - In Android mode, snapshots are not mapped, but |
| // filesystems are mounting off dm-linear targets directly. |
| // - In recovery mode, assume nothing is mapped, so it is optional to unmap. |
| // - If partition is flashed or unknown, it is okay to delete snapshots. |
| // Otherwise (UPDATED flag), only delete snapshots if they are not mapped |
| // as dm-snapshot (for example, after merge completes). |
| bool should_unmap = current_slot != Slot::Target; |
| bool should_delete = ShouldDeleteSnapshot(flashing_status, current_slot, name); |
| if (should_unmap && android::base::EndsWith(name, device_->GetSlotSuffix())) { |
| // Something very unexpected has happened - we want to unmap this |
| // snapshot, but it's on the wrong slot. We can't unmap an active |
| // partition. If this is not really a snapshot, skip the unmap |
| // step. |
| if (dm_.GetState(name) == DmDeviceState::INVALID || !IsSnapshotDevice(name)) { |
| LOG(ERROR) << "Detected snapshot " << name << " on " << current_slot << " slot" |
| << " for source partition; removing without unmap."; |
| should_unmap = false; |
| } |
| } |
| |
| bool partition_ok = true; |
| if (should_unmap && !UnmapPartitionWithSnapshot(lock, name)) { |
| partition_ok = false; |
| } |
| if (partition_ok && should_delete && !DeleteSnapshot(lock, name)) { |
| partition_ok = false; |
| } |
| |
| if (!partition_ok) { |
| // Remember whether or not we were able to unmap the cow image. |
| auto cow_image_device = GetCowImageDeviceName(name); |
| has_mapped_cow_images |= |
| (EnsureImageManager() && images_->IsImageMapped(cow_image_device)); |
| |
| ok = false; |
| } |
| } |
| |
| if (ok || !has_mapped_cow_images) { |
| // Delete any image artifacts as a precaution, in case an update is |
| // being cancelled due to some corrupted state in an lp_metadata file. |
| // Note that we do not do this if some cow images are still mapped, |
| // since we must not remove backing storage if it's in use. |
| if (!EnsureImageManager() || !images_->RemoveAllImages()) { |
| LOG(ERROR) << "Could not remove all snapshot artifacts"; |
| return false; |
| } |
| } |
| return ok; |
| } |
| |
| // See comments in RemoveAllSnapshots(). |
| bool SnapshotManager::ShouldDeleteSnapshot(const std::map<std::string, bool>& flashing_status, |
| Slot current_slot, const std::string& name) { |
| if (current_slot != Slot::Target) { |
| return true; |
| } |
| auto it = flashing_status.find(name); |
| if (it == flashing_status.end()) { |
| LOG(WARNING) << "Can't determine flashing status for " << name; |
| return true; |
| } |
| if (it->second) { |
| // partition flashed, okay to delete obsolete snapshots |
| return true; |
| } |
| return !IsSnapshotDevice(name); |
| } |
| |
| UpdateState SnapshotManager::GetUpdateState(double* progress) { |
| // If we've never started an update, the state file won't exist. |
| auto state_file = GetStateFilePath(); |
| if (access(state_file.c_str(), F_OK) != 0 && errno == ENOENT) { |
| return UpdateState::None; |
| } |
| |
| auto lock = LockShared(); |
| if (!lock) { |
| return UpdateState::None; |
| } |
| |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock.get()); |
| auto state = update_status.state(); |
| if (progress == nullptr) { |
| return state; |
| } |
| |
| if (state == UpdateState::MergeCompleted) { |
| *progress = 100.0; |
| return state; |
| } |
| |
| *progress = 0.0; |
| if (state != UpdateState::Merging) { |
| return state; |
| } |
| |
| if (!UpdateUsesUserSnapshots(lock.get())) { |
| // Sum all the snapshot states as if the system consists of a single huge |
| // snapshots device, then compute the merge completion percentage of that |
| // device. |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock.get(), &snapshots)) { |
| LOG(ERROR) << "Could not list snapshots"; |
| return state; |
| } |
| |
| DmTargetSnapshot::Status fake_snapshots_status = {}; |
| for (const auto& snapshot : snapshots) { |
| DmTargetSnapshot::Status current_status; |
| |
| if (!IsSnapshotDevice(snapshot)) continue; |
| if (!QuerySnapshotStatus(snapshot, nullptr, ¤t_status)) continue; |
| |
| fake_snapshots_status.sectors_allocated += current_status.sectors_allocated; |
| fake_snapshots_status.total_sectors += current_status.total_sectors; |
| fake_snapshots_status.metadata_sectors += current_status.metadata_sectors; |
| } |
| |
| *progress = DmTargetSnapshot::MergePercent(fake_snapshots_status, |
| update_status.sectors_allocated()); |
| } else { |
| if (EnsureSnapuserdConnected()) { |
| *progress = snapuserd_client_->GetMergePercent(); |
| } |
| } |
| |
| return state; |
| } |
| |
| bool SnapshotManager::UpdateUsesCompression() { |
| auto lock = LockShared(); |
| if (!lock) return false; |
| return UpdateUsesCompression(lock.get()); |
| } |
| |
| bool SnapshotManager::UpdateUsesCompression(LockedFile* lock) { |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| return update_status.compression_enabled(); |
| } |
| |
| bool SnapshotManager::UpdateUsesIouring(LockedFile* lock) { |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| return update_status.io_uring_enabled(); |
| } |
| |
| bool SnapshotManager::UpdateUsesUserSnapshots() { |
| // This and the following function is constantly |
| // invoked during snapshot merge. We want to avoid |
| // constantly reading from disk. Hence, store this |
| // value in memory. |
| // |
| // Furthermore, this value in the disk is set |
| // only when OTA is applied and doesn't change |
| // during merge phase. Hence, once we know that |
| // the value is read from disk the very first time, |
| // it is safe to read successive checks from memory. |
| if (is_snapshot_userspace_.has_value()) { |
| return is_snapshot_userspace_.value(); |
| } |
| |
| auto lock = LockShared(); |
| if (!lock) return false; |
| |
| return UpdateUsesUserSnapshots(lock.get()); |
| } |
| |
| bool SnapshotManager::UpdateUsesUserSnapshots(LockedFile* lock) { |
| // See UpdateUsesUserSnapshots() |
| if (is_snapshot_userspace_.has_value()) { |
| return is_snapshot_userspace_.value(); |
| } |
| |
| SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock); |
| is_snapshot_userspace_ = update_status.userspace_snapshots(); |
| return is_snapshot_userspace_.value(); |
| } |
| |
| bool SnapshotManager::ListSnapshots(LockedFile* lock, std::vector<std::string>* snapshots, |
| const std::string& suffix) { |
| CHECK(lock); |
| |
| auto dir_path = metadata_dir_ + "/snapshots"s; |
| std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(dir_path.c_str()), closedir); |
| if (!dir) { |
| PLOG(ERROR) << "opendir failed: " << dir_path; |
| return false; |
| } |
| |
| struct dirent* dp; |
| while ((dp = readdir(dir.get())) != nullptr) { |
| if (dp->d_type != DT_REG) continue; |
| |
| std::string name(dp->d_name); |
| if (!suffix.empty() && !android::base::EndsWith(name, suffix)) { |
| continue; |
| } |
| snapshots->emplace_back(std::move(name)); |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::IsSnapshotManagerNeeded() { |
| return access(kBootIndicatorPath, F_OK) == 0; |
| } |
| |
| std::string SnapshotManager::GetGlobalRollbackIndicatorPath() { |
| return kRollbackIndicatorPath; |
| } |
| |
| bool SnapshotManager::NeedSnapshotsInFirstStageMount() { |
| // If we fail to read, we'll wind up using CreateLogicalPartitions, which |
| // will create devices that look like the old slot, except with extra |
| // content at the end of each device. This will confuse dm-verity, and |
| // ultimately we'll fail to boot. Why not make it a fatal error and have |
| // the reason be clearer? Because the indicator file still exists, and |
| // if this was FATAL, reverting to the old slot would be broken. |
| auto slot = GetCurrentSlot(); |
| |
| if (slot != Slot::Target) { |
| if (slot == Slot::Source) { |
| // Device is rebooting into the original slot, so mark this as a |
| // rollback. |
| auto path = GetRollbackIndicatorPath(); |
| if (!android::base::WriteStringToFile("1", path)) { |
| PLOG(ERROR) << "Unable to write rollback indicator: " << path; |
| } else { |
| LOG(INFO) << "Rollback detected, writing rollback indicator to " << path; |
| } |
| } |
| LOG(INFO) << "Not booting from new slot. Will not mount snapshots."; |
| return false; |
| } |
| |
| // If we can't read the update state, it's unlikely anything else will |
| // succeed, so this is a fatal error. We'll eventually exhaust boot |
| // attempts and revert to the old slot. |
| auto lock = LockShared(); |
| if (!lock) { |
| LOG(FATAL) << "Could not read update state to determine snapshot status"; |
| return false; |
| } |
| switch (ReadUpdateState(lock.get())) { |
| case UpdateState::Unverified: |
| case UpdateState::Merging: |
| case UpdateState::MergeFailed: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| bool SnapshotManager::CreateLogicalAndSnapshotPartitions( |
| const std::string& super_device, const std::chrono::milliseconds& timeout_ms) { |
| LOG(INFO) << "Creating logical partitions with snapshots as needed"; |
| |
| auto lock = LockExclusive(); |
| if (!lock) return false; |
| |
| uint32_t slot = SlotNumberForSlotSuffix(device_->GetSlotSuffix()); |
| return MapAllPartitions(lock.get(), super_device, slot, timeout_ms); |
| } |
| |
| bool SnapshotManager::MapAllPartitions(LockedFile* lock, const std::string& super_device, |
| uint32_t slot, const std::chrono::milliseconds& timeout_ms) { |
| const auto& opener = device_->GetPartitionOpener(); |
| auto metadata = android::fs_mgr::ReadMetadata(opener, super_device, slot); |
| if (!metadata) { |
| LOG(ERROR) << "Could not read dynamic partition metadata for device: " << super_device; |
| return false; |
| } |
| |
| if (!EnsureImageManager()) { |
| return false; |
| } |
| |
| for (const auto& partition : metadata->partitions) { |
| if (GetPartitionGroupName(metadata->groups[partition.group_index]) == kCowGroupName) { |
| LOG(INFO) << "Skip mapping partition " << GetPartitionName(partition) << " in group " |
| << kCowGroupName; |
| continue; |
| } |
| |
| CreateLogicalPartitionParams params = { |
| .block_device = super_device, |
| .metadata = metadata.get(), |
| .partition = &partition, |
| .partition_opener = &opener, |
| .timeout_ms = timeout_ms, |
| }; |
| if (!MapPartitionWithSnapshot(lock, std::move(params), SnapshotContext::Mount, nullptr)) { |
| return false; |
| } |
| } |
| |
| LOG(INFO) << "Created logical partitions with snapshot."; |
| return true; |
| } |
| |
| static std::chrono::milliseconds GetRemainingTime( |
| const std::chrono::milliseconds& timeout, |
| const std::chrono::time_point<std::chrono::steady_clock>& begin) { |
| // If no timeout is specified, execute all commands without specifying any timeout. |
| if (timeout.count() == 0) return std::chrono::milliseconds(0); |
| auto passed_time = std::chrono::steady_clock::now() - begin; |
| auto remaining_time = timeout - duration_cast<std::chrono::milliseconds>(passed_time); |
| if (remaining_time.count() <= 0) { |
| LOG(ERROR) << "MapPartitionWithSnapshot has reached timeout " << timeout.count() << "ms (" |
| << remaining_time.count() << "ms remaining)"; |
| // Return min() instead of remaining_time here because 0 is treated as a special value for |
| // no timeout, where the rest of the commands will still be executed. |
| return std::chrono::milliseconds::min(); |
| } |
| return remaining_time; |
| } |
| |
| bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock, |
| CreateLogicalPartitionParams params, |
| SnapshotContext context, SnapshotPaths* paths) { |
| auto begin = std::chrono::steady_clock::now(); |
| |
| CHECK(lock); |
| |
| if (params.GetPartitionName() != params.GetDeviceName()) { |
| LOG(ERROR) << "Mapping snapshot with a different name is unsupported: partition_name = " |
| << params.GetPartitionName() << ", device_name = " << params.GetDeviceName(); |
| return false; |
| } |
| |
| // Fill out fields in CreateLogicalPartitionParams so that we have more information (e.g. by |
| // reading super partition metadata). |
| CreateLogicalPartitionParams::OwnedData params_owned_data; |
| if (!params.InitDefaults(¶ms_owned_data)) { |
| return false; |
| } |
| |
| if (!params.partition->num_extents) { |
| LOG(INFO) << "Skipping zero-length logical partition: " << params.GetPartitionName(); |
| return true; // leave path empty to indicate that nothing is mapped. |
| } |
| |
| // Determine if there is a live snapshot for the SnapshotStatus of the partition; i.e. if the |
| // partition still has a snapshot that needs to be mapped. If no live snapshot or merge |
| // completed, live_snapshot_status is set to nullopt. |
| std::optional<SnapshotStatus> live_snapshot_status; |
| do { |
| if (!(params.partition->attributes & LP_PARTITION_ATTR_UPDATED)) { |
| LOG(INFO) << "Detected re-flashing of partition, will skip snapshot: " |
| << params.GetPartitionName(); |
| break; |
| } |
| auto file_path = GetSnapshotStatusFilePath(params.GetPartitionName()); |
| if (access(file_path.c_str(), F_OK) != 0) { |
| if (errno != ENOENT) { |
| PLOG(INFO) << "Can't map snapshot for " << params.GetPartitionName() |
| << ": Can't access " << file_path; |
| return false; |
| } |
| break; |
| } |
| live_snapshot_status = std::make_optional<SnapshotStatus>(); |
| if (!ReadSnapshotStatus(lock, params.GetPartitionName(), &*live_snapshot_status)) { |
| return false; |
| } |
| // No live snapshot if merge is completed. |
| if (live_snapshot_status->state() == SnapshotState::MERGE_COMPLETED) { |
| live_snapshot_status.reset(); |
| } |
| |
| if (live_snapshot_status->state() == SnapshotState::NONE || |
| live_snapshot_status->cow_partition_size() + live_snapshot_status->cow_file_size() == |
| 0) { |
| LOG(WARNING) << "Snapshot status for " << params.GetPartitionName() |
| << " is invalid, ignoring: state = " |
| << SnapshotState_Name(live_snapshot_status->state()) |
| << ", cow_partition_size = " << live_snapshot_status->cow_partition_size() |
| << ", cow_file_size = " << live_snapshot_status->cow_file_size(); |
| live_snapshot_status.reset(); |
| } |
| } while (0); |
| |
| if (live_snapshot_status.has_value()) { |
| // dm-snapshot requires the base device to be writable. |
| params.force_writable = true; |
| // Map the base device with a different name to avoid collision. |
| params.device_name = GetBaseDeviceName(params.GetPartitionName()); |
| } |
| |
| AutoDeviceList created_devices; |
| |
| // Create the base device for the snapshot, or if there is no snapshot, the |
| // device itself. This device consists of the real blocks in the super |
| // partition that this logical partition occupies. |
| std::string base_path; |
| if (!CreateLogicalPartition(params, &base_path)) { |
| LOG(ERROR) << "Could not create logical partition " << params.GetPartitionName() |
| << " as device " << params.GetDeviceName(); |
| return false; |
| } |
| created_devices.EmplaceBack<AutoUnmapDevice>(&dm_, params.GetDeviceName()); |
| |
| if (paths) { |
| paths->target_device = base_path; |
| } |
| |
| auto remaining_time = GetRemainingTime(params.timeout_ms, begin); |
| if (remaining_time.count() < 0) { |
| return false; |
| } |
| |
| // Wait for the base device to appear |
| if (!WaitForDevice(base_path, remaining_time)) { |
| return false; |
| } |
| |
| if (!live_snapshot_status.has_value()) { |
| created_devices.Release(); |
| return true; |
| } |
| |
| // We don't have ueventd in first-stage init, so use device major:minor |
| // strings instead. |
| std::string base_device; |
| if (!dm_.GetDeviceString(params.GetDeviceName(), &base_device)) { |
| LOG(ERROR) << "Could not determine major/minor for: " << params.GetDeviceName(); |
| return false; |
| } |
| |
| remaining_time = GetRemainingTime(params.timeout_ms, begin); |
| if (remaining_time.count() < 0) return false; |
| |
| std::string cow_name; |
| CreateLogicalPartitionParams cow_params = params; |
| cow_params.timeout_ms = remaining_time; |
| if (!MapCowDevices(lock, cow_params, *live_snapshot_status, &created_devices, &cow_name)) { |
| return false; |
| } |
| std::string cow_device; |
| if (!GetMappedImageDeviceStringOrPath(cow_name, &cow_device)) { |
| LOG(ERROR) << "Could not determine major/minor for: " << cow_name; |
| return false; |
| } |
| if (paths) { |
| paths->cow_device_name = cow_name; |
| } |
| |
| remaining_time = GetRemainingTime(params.timeout_ms, begin); |
| if (remaining_time.count() < 0) return false; |
| |
| if (context == SnapshotContext::Update && live_snapshot_status->compression_enabled()) { |
| // Stop here, we can't run dm-user yet, the COW isn't built. |
| created_devices.Release(); |
| return true; |
| } |
| |
| if (live_snapshot_status->compression_enabled()) { |
| // Get the source device (eg the view of the partition from before it was resized). |
| std::string source_device_path; |
| if (live_snapshot_status->old_partition_size() > 0) { |
| if (!MapSourceDevice(lock, params.GetPartitionName(), remaining_time, |
| &source_device_path)) { |
| LOG(ERROR) << "Could not map source device for: " << cow_name; |
| return false; |
| } |
| |
| auto source_device = GetSourceDeviceName(params.GetPartitionName()); |
| created_devices.EmplaceBack<AutoUnmapDevice>(&dm_, source_device); |
| } else { |
| source_device_path = base_path; |
| } |
| |
| if (!WaitForDevice(source_device_path, remaining_time)) { |
| return false; |
| } |
| |
| std::string cow_path; |
| if (!GetMappedImageDevicePath(cow_name, &cow_path)) { |
| LOG(ERROR) << "Could not determine path for: " << cow_name; |
| return false; |
| } |
| if (!WaitForDevice(cow_path, remaining_time)) { |
| return false; |
| } |
| |
| auto name = GetDmUserCowName(params.GetPartitionName(), GetSnapshotDriver(lock)); |
| |
| std::string new_cow_device; |
| if (!MapDmUserCow(lock, name, cow_path, source_device_path, base_path, remaining_time, |
| &new_cow_device)) { |
| LOG(ERROR) << "Could not map dm-user device for partition " |
| << params.GetPartitionName(); |
| return false; |
| } |
| created_devices.EmplaceBack<AutoUnmapDevice>(&dm_, name); |
| |
| remaining_time = GetRemainingTime(params.timeout_ms, begin); |
| if (remaining_time.count() < 0) return false; |
| |
| cow_device = new_cow_device; |
| } |
| |
| // For userspace snapshots, dm-user block device itself will act as a |
| // snapshot device. There is one subtle difference - MapSnapshot will create |
| // either snapshot target or snapshot-merge target based on the underlying |
| // state of the snapshot device. If snapshot-merge target is created, merge |
| // will immediately start in the kernel. |
| // |
| // This is no longer true with respect to userspace snapshots. When dm-user |
| // block device is created, we just have the snapshots ready but daemon in |
| // the user-space will not start the merge. We have to explicitly inform the |
| // daemon to resume the merge. Check ProcessUpdateState() call stack. |
| if (!UpdateUsesUserSnapshots(lock)) { |
| std::string path; |
| if (!MapSnapshot(lock, params.GetPartitionName(), base_device, cow_device, remaining_time, |
| &path)) { |
| LOG(ERROR) << "Could not map snapshot for partition: " << params.GetPartitionName(); |
| return false; |
| } |
| // No need to add params.GetPartitionName() to created_devices since it is immediately |
| // released. |
| |
| if (paths) { |
| paths->snapshot_device = path; |
| } |
| LOG(INFO) << "Mapped " << params.GetPartitionName() << " as snapshot device at " << path; |
| } else { |
| LOG(INFO) << "Mapped " << params.GetPartitionName() << " as snapshot device at " |
| << cow_device; |
| } |
| |
| created_devices.Release(); |
| |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapPartitionWithSnapshot(LockedFile* lock, |
| const std::string& target_partition_name) { |
| CHECK(lock); |
| |
| if (!UnmapSnapshot(lock, target_partition_name)) { |
| return false; |
| } |
| |
| if (!UnmapCowDevices(lock, target_partition_name)) { |
| return false; |
| } |
| |
| auto base_name = GetBaseDeviceName(target_partition_name); |
| if (!DeleteDeviceIfExists(base_name)) { |
| LOG(ERROR) << "Cannot delete base device: " << base_name; |
| return false; |
| } |
| |
| auto source_name = GetSourceDeviceName(target_partition_name); |
| if (!DeleteDeviceIfExists(source_name)) { |
| LOG(ERROR) << "Cannot delete source device: " << source_name; |
| return false; |
| } |
| |
| LOG(INFO) << "Successfully unmapped snapshot " << target_partition_name; |
| |
| return true; |
| } |
| |
| bool SnapshotManager::MapCowDevices(LockedFile* lock, const CreateLogicalPartitionParams& params, |
| const SnapshotStatus& snapshot_status, |
| AutoDeviceList* created_devices, std::string* cow_name) { |
| CHECK(lock); |
| CHECK(snapshot_status.cow_partition_size() + snapshot_status.cow_file_size() > 0); |
| auto begin = std::chrono::steady_clock::now(); |
| |
| std::string partition_name = params.GetPartitionName(); |
| std::string cow_image_name = GetCowImageDeviceName(partition_name); |
| *cow_name = GetCowName(partition_name); |
| |
| // Map COW image if necessary. |
| if (snapshot_status.cow_file_size() > 0) { |
| if (!EnsureImageManager()) return false; |
| auto remaining_time = GetRemainingTime(params.timeout_ms, begin); |
| if (remaining_time.count() < 0) return false; |
| |
| if (!MapCowImage(partition_name, remaining_time).has_value()) { |
| LOG(ERROR) << "Could not map cow image for partition: " << partition_name; |
| return false; |
| } |
| created_devices->EmplaceBack<AutoUnmapImage>(images_.get(), cow_image_name); |
| |
| // If no COW partition exists, just return the image alone. |
| if (snapshot_status.cow_partition_size() == 0) { |
| *cow_name = std::move(cow_image_name); |
| LOG(INFO) << "Mapped COW image for " << partition_name << " at " << *cow_name; |
| return true; |
| } |
| } |
| |
| auto remaining_time = GetRemainingTime(params.timeout_ms, begin); |
| if (remaining_time.count() < 0) return false; |
| |
| CHECK(snapshot_status.cow_partition_size() > 0); |
| |
| // Create the DmTable for the COW device. It is the DmTable of the COW partition plus |
| // COW image device as the last extent. |
| CreateLogicalPartitionParams cow_partition_params = params; |
| cow_partition_params.partition = nullptr; |
| cow_partition_params.partition_name = *cow_name; |
| cow_partition_params.device_name.clear(); |
| DmTable table; |
| if (!CreateDmTable(cow_partition_params, &table)) { |
| return false; |
| } |
| // If the COW image exists, append it as the last extent. |
| if (snapshot_status.cow_file_size() > 0) { |
| std::string cow_image_device; |
| if (!GetMappedImageDeviceStringOrPath(cow_image_name, &cow_image_device)) { |
| LOG(ERROR) << "Cannot determine major/minor for: " << cow_image_name; |
| return false; |
| } |
| auto cow_partition_sectors = snapshot_status.cow_partition_size() / kSectorSize; |
| auto cow_image_sectors = snapshot_status.cow_file_size() / kSectorSize; |
| table.Emplace<DmTargetLinear>(cow_partition_sectors, cow_image_sectors, cow_image_device, |
| 0); |
| } |
| |
| // We have created the DmTable now. Map it. |
| std::string cow_path; |
| if (!dm_.CreateDevice(*cow_name, table, &cow_path, remaining_time)) { |
| LOG(ERROR) << "Could not create COW device: " << *cow_name; |
| return false; |
| } |
| created_devices->EmplaceBack<AutoUnmapDevice>(&dm_, *cow_name); |
| LOG(INFO) << "Mapped COW device for " << params.GetPartitionName() << " at " << cow_path; |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapCowDevices(LockedFile* lock, const std::string& name) { |
| CHECK(lock); |
| if (!EnsureImageManager()) return false; |
| |
| if (UpdateUsesCompression(lock) && !UpdateUsesUserSnapshots(lock)) { |
| auto dm_user_name = GetDmUserCowName(name, GetSnapshotDriver(lock)); |
| if (!UnmapDmUserDevice(dm_user_name)) { |
| return false; |
| } |
| } |
| |
| if (!DeleteDeviceIfExists(GetCowName(name), 4000ms)) { |
| LOG(ERROR) << "Cannot unmap: " << GetCowName(name); |
| return false; |
| } |
| |
| std::string cow_image_name = GetCowImageDeviceName(name); |
| if (!images_->UnmapImageIfExists(cow_image_name)) { |
| LOG(ERROR) << "Cannot unmap image " << cow_image_name; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapDmUserDevice(const std::string& dm_user_name) { |
| if (dm_.GetState(dm_user_name) == DmDeviceState::INVALID) { |
| return true; |
| } |
| |
| if (!DeleteDeviceIfExists(dm_user_name)) { |
| LOG(ERROR) << "Cannot unmap " << dm_user_name; |
| return false; |
| } |
| |
| if (EnsureSnapuserdConnected()) { |
| if (!snapuserd_client_->WaitForDeviceDelete(dm_user_name)) { |
| LOG(ERROR) << "Failed to wait for " << dm_user_name << " control device to delete"; |
| return false; |
| } |
| } |
| |
| // Ensure the control device is gone so we don't run into ABA problems. |
| auto control_device = "/dev/dm-user/" + dm_user_name; |
| if (!android::fs_mgr::WaitForFileDeleted(control_device, 10s)) { |
| LOG(ERROR) << "Timed out waiting for " << control_device << " to unlink"; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapUserspaceSnapshotDevice(LockedFile* lock, |
| const std::string& snapshot_name) { |
| auto dm_user_name = GetDmUserCowName(snapshot_name, GetSnapshotDriver(lock)); |
| if (dm_.GetState(dm_user_name) == DmDeviceState::INVALID) { |
| return true; |
| } |
| |
| CHECK(lock); |
| |
| SnapshotStatus snapshot_status; |
| |
| if (!ReadSnapshotStatus(lock, snapshot_name, &snapshot_status)) { |
| return false; |
| } |
| // If the merge is complete, then we switch dm tables which is equivalent |
| // to unmap; hence, we can't be deleting the device |
| // as the table would be mounted off partitions and will fail. |
| if (snapshot_status.state() != SnapshotState::MERGE_COMPLETED) { |
| if (!DeleteDeviceIfExists(dm_user_name)) { |
| LOG(ERROR) << "Cannot unmap " << dm_user_name; |
| return false; |
| } |
| } |
| |
| if (EnsureSnapuserdConnected()) { |
| if (!snapuserd_client_->WaitForDeviceDelete(dm_user_name)) { |
| LOG(ERROR) << "Failed to wait for " << dm_user_name << " control device to delete"; |
| return false; |
| } |
| } |
| |
| // Ensure the control device is gone so we don't run into ABA problems. |
| auto control_device = "/dev/dm-user/" + dm_user_name; |
| if (!android::fs_mgr::WaitForFileDeleted(control_device, 10s)) { |
| LOG(ERROR) << "Timed out waiting for " << control_device << " to unlink"; |
| return false; |
| } |
| return true; |
| } |
| |
| bool SnapshotManager::MapAllSnapshots(const std::chrono::milliseconds& timeout_ms) { |
| auto lock = LockExclusive(); |
| if (!lock) return false; |
| |
| auto state = ReadUpdateState(lock.get()); |
| if (state == UpdateState::Unverified) { |
| if (GetCurrentSlot() == Slot::Target) { |
| LOG(ERROR) << "Cannot call MapAllSnapshots when booting from the target slot."; |
| return false; |
| } |
| } else if (state != UpdateState::Initiated) { |
| LOG(ERROR) << "Cannot call MapAllSnapshots from update state: " << state; |
| return false; |
| } |
| |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock.get(), &snapshots)) { |
| return false; |
| } |
| |
| const auto& opener = device_->GetPartitionOpener(); |
| auto slot_suffix = device_->GetOtherSlotSuffix(); |
| auto slot_number = SlotNumberForSlotSuffix(slot_suffix); |
| auto super_device = device_->GetSuperDevice(slot_number); |
| auto metadata = android::fs_mgr::ReadMetadata(opener, super_device, slot_number); |
| if (!metadata) { |
| LOG(ERROR) << "MapAllSnapshots could not read dynamic partition metadata for device: " |
| << super_device; |
| return false; |
| } |
| |
| for (const auto& snapshot : snapshots) { |
| if (!UnmapPartitionWithSnapshot(lock.get(), snapshot)) { |
| LOG(ERROR) << "MapAllSnapshots could not unmap snapshot: " << snapshot; |
| return false; |
| } |
| |
| CreateLogicalPartitionParams params = { |
| .block_device = super_device, |
| .metadata = metadata.get(), |
| .partition_name = snapshot, |
| .partition_opener = &opener, |
| .timeout_ms = timeout_ms, |
| }; |
| if (!MapPartitionWithSnapshot(lock.get(), std::move(params), SnapshotContext::Mount, |
| nullptr)) { |
| LOG(ERROR) << "MapAllSnapshots failed to map: " << snapshot; |
| return false; |
| } |
| } |
| |
| LOG(INFO) << "MapAllSnapshots succeeded."; |
| return true; |
| } |
| |
| bool SnapshotManager::UnmapAllSnapshots() { |
| auto lock = LockExclusive(); |
| if (!lock) return false; |
| |
| return UnmapAllSnapshots(lock.get()); |
| } |
| |
| bool SnapshotManager::UnmapAllSnapshots(LockedFile* lock) { |
| std::vector<std::string> snapshots; |
| if (!ListSnapshots(lock, &snapshots)) { |
| return false; |
| } |
| |
| for (const auto& snapshot : snapshots) { |
| if (!UnmapPartitionWithSnapshot(lock, snapshot)) { |
| LOG(ERROR) <<
|