fs_mgr/libsnapshot/snapshot_metadata_updater.cpp - third_party/android.googlesource.com/platform/system/core - Git at Google

 //
 // 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 "snapshot_metadata_updater.h"

 #include <algorithm>
 #include <map>
 #include <optional>
 #include <set>
 #include <string>
 #include <string_view>
 #include <vector>

 #include <android-base/logging.h>
 #include <android-base/strings.h>
 #include <fs_mgr.h>
 #include <libsnapshot/snapshot.h>

 using android::fs_mgr::MetadataBuilder;
 using android::fs_mgr::Partition;
 using android::fs_mgr::SlotSuffixForSlotNumber;
 using chromeos_update_engine::DeltaArchiveManifest;

 namespace android {
 namespace snapshot {
 SnapshotMetadataUpdater::SnapshotMetadataUpdater(MetadataBuilder* builder, uint32_t target_slot,
                                                  const DeltaArchiveManifest& manifest)
     : builder_(builder), target_suffix_(SlotSuffixForSlotNumber(target_slot)) {
     partial_update_ = manifest.partial_update();

     if (!manifest.has_dynamic_partition_metadata()) {
         return;
     }

     // Key: partition name ("system"). Value: group name ("group").
     // No suffix.
     std::map<std::string_view, std::string_view> partition_group_map;
     const auto& metadata_groups = manifest.dynamic_partition_metadata().groups();
     groups_.reserve(metadata_groups.size());
     for (const auto& group : metadata_groups) {
         groups_.emplace_back(Group{group.name() + target_suffix_, &group});
         for (const auto& partition_name : group.partition_names()) {
             partition_group_map[partition_name] = group.name();
         }
     }

     for (const auto& p : manifest.partitions()) {
         auto it = partition_group_map.find(p.partition_name());
         if (it != partition_group_map.end()) {
             partitions_.emplace_back(Partition{p.partition_name() + target_suffix_,
                                                std::string(it->second) + target_suffix_, &p});
         }
     }

 }

 bool SnapshotMetadataUpdater::ShrinkPartitions() const {
     for (const auto& partition_update : partitions_) {
         auto* existing_partition = builder_->FindPartition(partition_update.name);
         if (existing_partition == nullptr) {
             continue;
         }
         auto new_size = partition_update->new_partition_info().size();
         if (existing_partition->size() <= new_size) {
             continue;
         }
         if (!builder_->ResizePartition(existing_partition, new_size)) {
             return false;
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::DeletePartitions() const {
     // For partial update, not all dynamic partitions are included in the payload.
     // TODO(xunchang) delete the untouched partitions whose group is in the payload.
     // e.g. Delete vendor in the following scenario
     // On device:
     //   Group A: system, vendor
     // In payload:
     //   Group A: system
     if (partial_update_) {
         LOG(INFO) << "Skip deleting partitions for partial update";
         return true;
     }

     std::vector<std::string> partitions_to_delete;
     // Don't delete partitions in groups where the group name doesn't have target_suffix,
     // e.g. default.
     for (auto* existing_partition : ListPartitionsWithSuffix(builder_, target_suffix_)) {
         auto iter = std::find_if(partitions_.begin(), partitions_.end(),
                                  [existing_partition](auto&& partition_update) {
                                      return partition_update.name == existing_partition->name();
                                  });
         // Update package metadata doesn't have this partition. Prepare to delete it.
         // Not deleting from builder_ yet because it may break ListPartitionsWithSuffix if it were
         // to return an iterable view of builder_.
         if (iter == partitions_.end()) {
             partitions_to_delete.push_back(existing_partition->name());
         }
     }

     for (const auto& partition_name : partitions_to_delete) {
         builder_->RemovePartition(partition_name);
     }
     return true;
 }

 bool SnapshotMetadataUpdater::MovePartitionsToDefault() const {
     for (const auto& partition_update : partitions_) {
         auto* existing_partition = builder_->FindPartition(partition_update.name);
         if (existing_partition == nullptr) {
             continue;
         }
         if (existing_partition->group_name() == partition_update.group_name) {
             continue;
         }
         // Move to "default" group (which doesn't have maximum size constraint)
         // temporarily.
         if (!builder_->ChangePartitionGroup(existing_partition, android::fs_mgr::kDefaultGroup)) {
             return false;
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::ShrinkGroups() const {
     for (const auto& group_update : groups_) {
         auto* existing_group = builder_->FindGroup(group_update.name);
         if (existing_group == nullptr) {
             continue;
         }
         if (existing_group->maximum_size() <= group_update->size()) {
             continue;
         }
         if (!builder_->ChangeGroupSize(existing_group->name(), group_update->size())) {
             return false;
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::DeleteGroups() const {
     if (partial_update_) {
         LOG(INFO) << "Skip deleting groups for partial update";
         return true;
     }

     std::vector<std::string> existing_groups = builder_->ListGroups();
     for (const auto& existing_group_name : existing_groups) {
         // Don't delete groups without target suffix, e.g. default.
         if (!android::base::EndsWith(existing_group_name, target_suffix_)) {
             continue;
         }

         auto iter = std::find_if(groups_.begin(), groups_.end(),
                                  [&existing_group_name](auto&& group_update) {
                                      return group_update.name == existing_group_name;
                                  });
         // Update package metadata has this group as well, so not deleting it.
         if (iter != groups_.end()) {
             continue;
         }
         // Update package metadata doesn't have this group. Before deleting it, check that it
         // doesn't have any partitions left. Update metadata shouldn't assign any partitions to
         // this group, so all partitions that originally belong to this group should be moved by
         // MovePartitionsToDefault at this point.
         auto existing_partitions_in_group = builder_->ListPartitionsInGroup(existing_group_name);
         if (!existing_partitions_in_group.empty()) {
             std::vector<std::string> partition_names_in_group;
             std::transform(existing_partitions_in_group.begin(), existing_partitions_in_group.end(),
                            std::back_inserter(partition_names_in_group),
                            [](auto* p) { return p->name(); });
             LOG(ERROR)
                     << "Group " << existing_group_name
                     << " cannot be deleted because the following partitions are left unassigned: ["
                     << android::base::Join(partition_names_in_group, ",") << "]";
             return false;
         }
         builder_->RemoveGroupAndPartitions(existing_group_name);
     }
     return true;
 }

 bool SnapshotMetadataUpdater::AddGroups() const {
     for (const auto& group_update : groups_) {
         if (builder_->FindGroup(group_update.name) == nullptr) {
             if (!builder_->AddGroup(group_update.name, group_update->size())) {
                 return false;
             }
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::GrowGroups() const {
     for (const auto& group_update : groups_) {
         auto* existing_group = builder_->FindGroup(group_update.name);
         if (existing_group == nullptr) {
             continue;
         }
         if (existing_group->maximum_size() >= group_update->size()) {
             continue;
         }
         if (!builder_->ChangeGroupSize(existing_group->name(), group_update->size())) {
             return false;
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::AddPartitions() const {
     for (const auto& partition_update : partitions_) {
         if (builder_->FindPartition(partition_update.name) == nullptr) {
             auto* p =
                     builder_->AddPartition(partition_update.name, partition_update.group_name,
                                            LP_PARTITION_ATTR_READONLY | LP_PARTITION_ATTR_UPDATED);
             if (p == nullptr) {
                 return false;
             }
         }
     }
     // Will be resized in GrowPartitions.
     return true;
 }

 bool SnapshotMetadataUpdater::GrowPartitions() const {
     for (const auto& partition_update : partitions_) {
         auto* existing_partition = builder_->FindPartition(partition_update.name);
         if (existing_partition == nullptr) {
             continue;
         }
         auto new_size = partition_update->new_partition_info().size();
         if (existing_partition->size() >= new_size) {
             continue;
         }
         if (!builder_->ResizePartition(existing_partition, new_size)) {
             return false;
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::MovePartitionsToCorrectGroup() const {
     for (const auto& partition_update : partitions_) {
         auto* existing_partition = builder_->FindPartition(partition_update.name);
         if (existing_partition == nullptr) {
             continue;
         }
         if (existing_partition->group_name() == partition_update.group_name) {
             continue;
         }
         if (!builder_->ChangePartitionGroup(existing_partition, partition_update.group_name)) {
             return false;
         }
     }
     return true;
 }

 bool SnapshotMetadataUpdater::Update() const {
     // Remove extents used by COW devices by removing the COW group completely.
     builder_->RemoveGroupAndPartitions(android::snapshot::kCowGroupName);

     // The order of these operations are important so that we
     // always have enough space to grow or add new partitions / groups.
     // clang-format off
     return ShrinkPartitions() &&
            DeletePartitions() &&
            MovePartitionsToDefault() &&
            ShrinkGroups() &&
            DeleteGroups() &&
            AddGroups() &&
            GrowGroups() &&
            AddPartitions() &&
            GrowPartitions() &&
            MovePartitionsToCorrectGroup();
     // clang-format on
 }
 }  // namespace snapshot
 }  // namespace android
	//
	// 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 "snapshot_metadata_updater.h"

	#include <algorithm>
	#include <map>
	#include <optional>
	#include <set>
	#include <string>
	#include <string_view>
	#include <vector>

	#include <android-base/logging.h>
	#include <android-base/strings.h>
	#include <fs_mgr.h>
	#include <libsnapshot/snapshot.h>

	using android::fs_mgr::MetadataBuilder;
	using android::fs_mgr::Partition;
	using android::fs_mgr::SlotSuffixForSlotNumber;
	using chromeos_update_engine::DeltaArchiveManifest;

	namespace android {
	namespace snapshot {
	SnapshotMetadataUpdater::SnapshotMetadataUpdater(MetadataBuilder* builder, uint32_t target_slot,
	const DeltaArchiveManifest& manifest)
	: builder_(builder), target_suffix_(SlotSuffixForSlotNumber(target_slot)) {
	partial_update_ = manifest.partial_update();

	if (!manifest.has_dynamic_partition_metadata()) {
	return;
	}

	// Key: partition name ("system"). Value: group name ("group").
	// No suffix.
	std::map<std::string_view, std::string_view> partition_group_map;
	const auto& metadata_groups = manifest.dynamic_partition_metadata().groups();
	groups_.reserve(metadata_groups.size());
	for (const auto& group : metadata_groups) {
	groups_.emplace_back(Group{group.name() + target_suffix_, &group});
	for (const auto& partition_name : group.partition_names()) {
	partition_group_map[partition_name] = group.name();
	}
	}

	for (const auto& p : manifest.partitions()) {
	auto it = partition_group_map.find(p.partition_name());
	if (it != partition_group_map.end()) {
	partitions_.emplace_back(Partition{p.partition_name() + target_suffix_,
	std::string(it->second) + target_suffix_, &p});
	}
	}

	}

	bool SnapshotMetadataUpdater::ShrinkPartitions() const {
	for (const auto& partition_update : partitions_) {
	auto* existing_partition = builder_->FindPartition(partition_update.name);
	if (existing_partition == nullptr) {
	continue;
	}
	auto new_size = partition_update->new_partition_info().size();
	if (existing_partition->size() <= new_size) {
	continue;
	}
	if (!builder_->ResizePartition(existing_partition, new_size)) {
	return false;
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::DeletePartitions() const {
	// For partial update, not all dynamic partitions are included in the payload.
	// TODO(xunchang) delete the untouched partitions whose group is in the payload.
	// e.g. Delete vendor in the following scenario
	// On device:
	// Group A: system, vendor
	// In payload:
	// Group A: system
	if (partial_update_) {
	LOG(INFO) << "Skip deleting partitions for partial update";
	return true;
	}

	std::vector<std::string> partitions_to_delete;
	// Don't delete partitions in groups where the group name doesn't have target_suffix,
	// e.g. default.
	for (auto* existing_partition : ListPartitionsWithSuffix(builder_, target_suffix_)) {
	auto iter = std::find_if(partitions_.begin(), partitions_.end(),
	[existing_partition](auto&& partition_update) {
	return partition_update.name == existing_partition->name();
	});
	// Update package metadata doesn't have this partition. Prepare to delete it.
	// Not deleting from builder_ yet because it may break ListPartitionsWithSuffix if it were
	// to return an iterable view of builder_.
	if (iter == partitions_.end()) {
	partitions_to_delete.push_back(existing_partition->name());
	}
	}

	for (const auto& partition_name : partitions_to_delete) {
	builder_->RemovePartition(partition_name);
	}
	return true;
	}

	bool SnapshotMetadataUpdater::MovePartitionsToDefault() const {
	for (const auto& partition_update : partitions_) {
	auto* existing_partition = builder_->FindPartition(partition_update.name);
	if (existing_partition == nullptr) {
	continue;
	}
	if (existing_partition->group_name() == partition_update.group_name) {
	continue;
	}
	// Move to "default" group (which doesn't have maximum size constraint)
	// temporarily.
	if (!builder_->ChangePartitionGroup(existing_partition, android::fs_mgr::kDefaultGroup)) {
	return false;
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::ShrinkGroups() const {
	for (const auto& group_update : groups_) {
	auto* existing_group = builder_->FindGroup(group_update.name);
	if (existing_group == nullptr) {
	continue;
	}
	if (existing_group->maximum_size() <= group_update->size()) {
	continue;
	}
	if (!builder_->ChangeGroupSize(existing_group->name(), group_update->size())) {
	return false;
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::DeleteGroups() const {
	if (partial_update_) {
	LOG(INFO) << "Skip deleting groups for partial update";
	return true;
	}

	std::vector<std::string> existing_groups = builder_->ListGroups();
	for (const auto& existing_group_name : existing_groups) {
	// Don't delete groups without target suffix, e.g. default.
	if (!android::base::EndsWith(existing_group_name, target_suffix_)) {
	continue;
	}

	auto iter = std::find_if(groups_.begin(), groups_.end(),
	[&existing_group_name](auto&& group_update) {
	return group_update.name == existing_group_name;
	});
	// Update package metadata has this group as well, so not deleting it.
	if (iter != groups_.end()) {
	continue;
	}
	// Update package metadata doesn't have this group. Before deleting it, check that it
	// doesn't have any partitions left. Update metadata shouldn't assign any partitions to
	// this group, so all partitions that originally belong to this group should be moved by
	// MovePartitionsToDefault at this point.
	auto existing_partitions_in_group = builder_->ListPartitionsInGroup(existing_group_name);
	if (!existing_partitions_in_group.empty()) {
	std::vector<std::string> partition_names_in_group;
	std::transform(existing_partitions_in_group.begin(), existing_partitions_in_group.end(),
	std::back_inserter(partition_names_in_group),
	[](auto* p) { return p->name(); });
	LOG(ERROR)
	<< "Group " << existing_group_name
	<< " cannot be deleted because the following partitions are left unassigned: ["
	<< android::base::Join(partition_names_in_group, ",") << "]";
	return false;
	}
	builder_->RemoveGroupAndPartitions(existing_group_name);
	}
	return true;
	}

	bool SnapshotMetadataUpdater::AddGroups() const {
	for (const auto& group_update : groups_) {
	if (builder_->FindGroup(group_update.name) == nullptr) {
	if (!builder_->AddGroup(group_update.name, group_update->size())) {
	return false;
	}
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::GrowGroups() const {
	for (const auto& group_update : groups_) {
	auto* existing_group = builder_->FindGroup(group_update.name);
	if (existing_group == nullptr) {
	continue;
	}
	if (existing_group->maximum_size() >= group_update->size()) {
	continue;
	}
	if (!builder_->ChangeGroupSize(existing_group->name(), group_update->size())) {
	return false;
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::AddPartitions() const {
	for (const auto& partition_update : partitions_) {
	if (builder_->FindPartition(partition_update.name) == nullptr) {
	auto* p =
	builder_->AddPartition(partition_update.name, partition_update.group_name,
	LP_PARTITION_ATTR_READONLY \| LP_PARTITION_ATTR_UPDATED);
	if (p == nullptr) {
	return false;
	}
	}
	}
	// Will be resized in GrowPartitions.
	return true;
	}

	bool SnapshotMetadataUpdater::GrowPartitions() const {
	for (const auto& partition_update : partitions_) {
	auto* existing_partition = builder_->FindPartition(partition_update.name);
	if (existing_partition == nullptr) {
	continue;
	}
	auto new_size = partition_update->new_partition_info().size();
	if (existing_partition->size() >= new_size) {
	continue;
	}
	if (!builder_->ResizePartition(existing_partition, new_size)) {
	return false;
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::MovePartitionsToCorrectGroup() const {
	for (const auto& partition_update : partitions_) {
	auto* existing_partition = builder_->FindPartition(partition_update.name);
	if (existing_partition == nullptr) {
	continue;
	}
	if (existing_partition->group_name() == partition_update.group_name) {
	continue;
	}
	if (!builder_->ChangePartitionGroup(existing_partition, partition_update.group_name)) {
	return false;
	}
	}
	return true;
	}

	bool SnapshotMetadataUpdater::Update() const {
	// Remove extents used by COW devices by removing the COW group completely.
	builder_->RemoveGroupAndPartitions(android::snapshot::kCowGroupName);

	// The order of these operations are important so that we
	// always have enough space to grow or add new partitions / groups.
	// clang-format off
	return ShrinkPartitions() &&
	DeletePartitions() &&
	MovePartitionsToDefault() &&
	ShrinkGroups() &&
	DeleteGroups() &&
	AddGroups() &&
	GrowGroups() &&
	AddPartitions() &&
	GrowPartitions() &&
	MovePartitionsToCorrectGroup();
	// clang-format on
	}
	} // namespace snapshot
	} // namespace android