liblp: Add a helper method for upgrading metadata on retrofit devices.
This adds a new MetadataBuilder constructor, NewForUpdate, that can be
used by update_engine to simplify upgrading metadata. It is safe to call
whether or not the device is a retrofit. If the metadata has block
devices assigned to a specific slot, and that slot matches the slot
suffix, it will ensure that an equivalent entry exists for the alternate
slot.
Thus, if the source slot is _a and the target slot is _b, and the
metadata has "system_a" as a block device but not "system_b", this will
automatically add "system_b" as a block device.
Bug: 116802789
Test: liblp_test gtest
Change-Id: Ie89d4dbf4c708b5705e658220227ebf33fcb1930
diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index 1e031ad..6b4901b 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -113,18 +113,7 @@
if (!metadata) {
return nullptr;
}
- std::unique_ptr<MetadataBuilder> builder = New(*metadata.get());
- if (!builder) {
- return nullptr;
- }
- for (size_t i = 0; i < builder->block_devices_.size(); i++) {
- std::string partition_name = GetBlockDevicePartitionName(builder->block_devices_[i]);
- BlockDeviceInfo device_info;
- if (opener.GetInfo(partition_name, &device_info)) {
- builder->UpdateBlockDeviceInfo(i, device_info);
- }
- }
- return builder;
+ return New(*metadata.get(), &opener);
}
std::unique_ptr<MetadataBuilder> MetadataBuilder::New(const std::string& super_partition,
@@ -142,14 +131,69 @@
return builder;
}
-std::unique_ptr<MetadataBuilder> MetadataBuilder::New(const LpMetadata& metadata) {
+std::unique_ptr<MetadataBuilder> MetadataBuilder::New(const LpMetadata& metadata,
+ const IPartitionOpener* opener) {
std::unique_ptr<MetadataBuilder> builder(new MetadataBuilder());
if (!builder->Init(metadata)) {
return nullptr;
}
+ if (opener) {
+ for (size_t i = 0; i < builder->block_devices_.size(); i++) {
+ std::string partition_name = GetBlockDevicePartitionName(builder->block_devices_[i]);
+ BlockDeviceInfo device_info;
+ if (opener->GetInfo(partition_name, &device_info)) {
+ builder->UpdateBlockDeviceInfo(i, device_info);
+ }
+ }
+ }
return builder;
}
+std::unique_ptr<MetadataBuilder> MetadataBuilder::NewForUpdate(const IPartitionOpener& opener,
+ const std::string& source_partition,
+ uint32_t source_slot_number,
+ uint32_t target_slot_number) {
+ auto metadata = ReadMetadata(opener, source_partition, source_slot_number);
+ if (!metadata) {
+ return nullptr;
+ }
+
+ // Get the list of devices we already have.
+ std::set<std::string> block_devices;
+ for (const auto& block_device : metadata->block_devices) {
+ block_devices.emplace(GetBlockDevicePartitionName(block_device));
+ }
+
+ auto new_block_devices = metadata->block_devices;
+
+ // Add missing block devices.
+ std::string source_slot_suffix = SlotSuffixForSlotNumber(source_slot_number);
+ std::string target_slot_suffix = SlotSuffixForSlotNumber(target_slot_number);
+ for (const auto& block_device : metadata->block_devices) {
+ std::string partition_name = GetBlockDevicePartitionName(block_device);
+ std::string slot_suffix = GetPartitionSlotSuffix(partition_name);
+ if (slot_suffix.empty() || slot_suffix != source_slot_suffix) {
+ continue;
+ }
+ std::string new_name =
+ partition_name.substr(0, partition_name.size() - slot_suffix.size()) +
+ target_slot_suffix;
+ if (block_devices.find(new_name) != block_devices.end()) {
+ continue;
+ }
+
+ auto new_device = block_device;
+ if (!UpdateBlockDevicePartitionName(&new_device, new_name)) {
+ LERROR << "Partition name too long: " << new_name;
+ return nullptr;
+ }
+ new_block_devices.emplace_back(new_device);
+ }
+
+ metadata->block_devices = new_block_devices;
+ return New(*metadata.get(), &opener);
+}
+
MetadataBuilder::MetadataBuilder() : auto_slot_suffixing_(false) {
memset(&geometry_, 0, sizeof(geometry_));
geometry_.magic = LP_METADATA_GEOMETRY_MAGIC;
diff --git a/fs_mgr/liblp/include/liblp/builder.h b/fs_mgr/liblp/include/liblp/builder.h
index 47ebf6d..59717d1 100644
--- a/fs_mgr/liblp/include/liblp/builder.h
+++ b/fs_mgr/liblp/include/liblp/builder.h
@@ -150,10 +150,24 @@
static std::unique_ptr<MetadataBuilder> New(const std::string& super_partition,
uint32_t slot_number);
+ // This is when performing an A/B update. The source partition must be a
+ // super partition. On a normal device, the metadata for the source slot
+ // is imported and the target slot is ignored. On a retrofit device, the
+ // metadata may not have the target slot's devices listed yet, in which
+ // case, it is automatically upgraded to include all available block
+ // devices.
+ static std::unique_ptr<MetadataBuilder> NewForUpdate(const IPartitionOpener& opener,
+ const std::string& source_partition,
+ uint32_t source_slot_number,
+ uint32_t target_slot_number);
+
// Import an existing table for modification. If the table is not valid, for
// example it contains duplicate partition names, then nullptr is returned.
- // This method is for testing or changing off-line tables.
- static std::unique_ptr<MetadataBuilder> New(const LpMetadata& metadata);
+ //
+ // If an IPartitionOpener is specified, then block device informatiom will
+ // be updated.
+ static std::unique_ptr<MetadataBuilder> New(const LpMetadata& metadata,
+ const IPartitionOpener* opener = nullptr);
// Helper function for a single super partition, for tests.
static std::unique_ptr<MetadataBuilder> New(const BlockDeviceInfo& device_info,
diff --git a/fs_mgr/liblp/io_test.cpp b/fs_mgr/liblp/io_test.cpp
index 5f0d9c8..9acf23e 100644
--- a/fs_mgr/liblp/io_test.cpp
+++ b/fs_mgr/liblp/io_test.cpp
@@ -649,3 +649,42 @@
ASSERT_EQ(metadata->block_devices.size(), static_cast<size_t>(1));
EXPECT_EQ(GetBlockDevicePartitionName(metadata->block_devices[0]), "super_a");
}
+
+TEST(liblp, UpdateRetrofit) {
+ unique_ptr<MetadataBuilder> builder = CreateDefaultBuilder();
+ ASSERT_NE(builder, nullptr);
+ ASSERT_TRUE(AddDefaultPartitions(builder.get()));
+ builder->SetAutoSlotSuffixing();
+
+ auto fd = CreateFakeDisk();
+ ASSERT_GE(fd, 0);
+
+ // Note: we bind the same fd to both names, since we want to make sure the
+ // exact same bits are getting read back in each test.
+ TestPartitionOpener opener({{"super_a", fd}, {"super_b", fd}},
+ {{"super_a", kSuperInfo}, {"super_b", kSuperInfo}});
+ auto exported = builder->Export();
+ ASSERT_NE(exported, nullptr);
+ ASSERT_TRUE(FlashPartitionTable(opener, "super_a", *exported.get()));
+
+ builder = MetadataBuilder::NewForUpdate(opener, "super_a", 0, 1);
+ ASSERT_NE(builder, nullptr);
+ auto updated = builder->Export();
+ ASSERT_NE(updated, nullptr);
+ ASSERT_EQ(updated->block_devices.size(), static_cast<size_t>(2));
+ EXPECT_EQ(GetBlockDevicePartitionName(updated->block_devices[0]), "super_a");
+ EXPECT_EQ(GetBlockDevicePartitionName(updated->block_devices[1]), "super_b");
+}
+
+TEST(liblp, UpdateNonRetrofit) {
+ unique_fd fd = CreateFlashedDisk();
+ ASSERT_GE(fd, 0);
+
+ DefaultPartitionOpener opener(fd);
+ auto builder = MetadataBuilder::NewForUpdate(opener, "super", 0, 1);
+ ASSERT_NE(builder, nullptr);
+ auto updated = builder->Export();
+ ASSERT_NE(updated, nullptr);
+ ASSERT_EQ(updated->block_devices.size(), static_cast<size_t>(1));
+ EXPECT_EQ(GetBlockDevicePartitionName(updated->block_devices[0]), "super");
+}
diff --git a/fs_mgr/liblp/reader.cpp b/fs_mgr/liblp/reader.cpp
index 3319956..b36ba0e 100644
--- a/fs_mgr/liblp/reader.cpp
+++ b/fs_mgr/liblp/reader.cpp
@@ -369,12 +369,10 @@
continue;
}
std::string partition_name = GetBlockDevicePartitionName(block_device) + slot_suffix;
- if (partition_name.size() > sizeof(block_device.partition_name)) {
+ if (!UpdateBlockDevicePartitionName(&block_device, partition_name)) {
LERROR << __PRETTY_FUNCTION__ << " partition name too long: " << partition_name;
return false;
}
- strncpy(block_device.partition_name, partition_name.c_str(),
- sizeof(block_device.partition_name));
block_device.flags &= ~LP_BLOCK_DEVICE_SLOT_SUFFIXED;
}
return true;
diff --git a/fs_mgr/liblp/utility.cpp b/fs_mgr/liblp/utility.cpp
index 2d34ce5..4f20b6b 100644
--- a/fs_mgr/liblp/utility.cpp
+++ b/fs_mgr/liblp/utility.cpp
@@ -137,5 +137,13 @@
return (slot_number == 0) ? "_a" : "_b";
}
+bool UpdateBlockDevicePartitionName(LpMetadataBlockDevice* device, const std::string& name) {
+ if (name.size() > sizeof(device->partition_name)) {
+ return false;
+ }
+ strncpy(device->partition_name, name.c_str(), sizeof(device->partition_name));
+ return true;
+}
+
} // namespace fs_mgr
} // namespace android
diff --git a/fs_mgr/liblp/utility.h b/fs_mgr/liblp/utility.h
index 65e643b..55ecb5a 100644
--- a/fs_mgr/liblp/utility.h
+++ b/fs_mgr/liblp/utility.h
@@ -84,6 +84,9 @@
return aligned;
}
+// Update names from C++ strings.
+bool UpdateBlockDevicePartitionName(LpMetadataBlockDevice* device, const std::string& name);
+
} // namespace fs_mgr
} // namespace android