Merge "liblp: Force 10.0 metadata on downgrade to Q." into rvc-dev am: 2ce3ddfee1 (33123fc9) · Commits · e / os / android_system_core

fs_mgr/liblp/builder.cpp

+12 −5

Original line number	Diff line number	Diff line
		@@ -204,13 +204,20 @@ std::unique_ptr<MetadataBuilder> MetadataBuilder::NewForUpdate(const IPartitionO
		}
		}

		if (IPropertyFetcher::GetInstance()->GetBoolProperty("ro.virtual_ab.enabled", false) &&
		!always_keep_source_slot) {
		if (IPropertyFetcher::GetInstance()->GetBoolProperty("ro.virtual_ab.enabled", false)) {
		if (always_keep_source_slot) {
		// always_keep_source_slot implies the target build does not support snapshots.
		// Clear unsupported attributes.
		SetMetadataHeaderV0(metadata.get());
		} else {
		// !always_keep_source_slot implies the target build supports snapshots. Do snapshot
		// updates.
		if (!UpdateMetadataForInPlaceSnapshot(metadata.get(), source_slot_number,
		target_slot_number)) {
		return nullptr;
		}
		}
		}

		return New(*metadata.get(), &opener);
		}

fs_mgr/liblp/include/liblp/builder.h

+4 −2

Original line number	Diff line number	Diff line
		@@ -209,8 +209,10 @@ class MetadataBuilder {
		// metadata may not have the target slot's devices listed yet, in which
		// case, it is automatically upgraded to include all available block
		// devices.
		// If \|always_keep_source_slot\| is set, on a Virtual A/B device, source slot
		// partitions are kept. This is useful when applying a downgrade package.
		// If \|always_keep_source_slot\| is set, on a Virtual A/B device
		// - source slot partitions are kept.
		// - UPDATED flag is cleared.
		// This is useful when applying a downgrade package.
		static std::unique_ptr<MetadataBuilder> NewForUpdate(const IPartitionOpener& opener,
		const std::string& source_partition,
		uint32_t source_slot_number,

fs_mgr/liblp/utility.cpp

+39 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		*/

		#include <fcntl.h>
		#include <inttypes.h>
		#include <stdint.h>
		#include <sys/stat.h>
		#include <unistd.h>
		@@ -29,6 +30,7 @@
		#include <vector>

		#include <android-base/file.h>
		#include <android-base/stringprintf.h>
		#include <ext4_utils/ext4_utils.h>
		#include <openssl/sha.h>

		@@ -285,5 +287,42 @@ bool UpdateMetadataForInPlaceSnapshot(LpMetadata* metadata, uint32_t source_slot
		return true;
		}

		inline std::string ToHexString(uint64_t value) {
		return android::base::StringPrintf("0x%" PRIx64, value);
		}

		void SetMetadataHeaderV0(LpMetadata* metadata) {
		if (metadata->header.minor_version <= LP_METADATA_MINOR_VERSION_MIN) {
		return;
		}
		LINFO << "Forcefully setting metadata header version " << LP_METADATA_MAJOR_VERSION << "."
		<< metadata->header.minor_version << " to " << LP_METADATA_MAJOR_VERSION << "."
		<< LP_METADATA_MINOR_VERSION_MIN;
		metadata->header.minor_version = LP_METADATA_MINOR_VERSION_MIN;
		metadata->header.header_size = sizeof(LpMetadataHeaderV1_0);

		// Retrofit Virtual A/B devices should have version 10.1, so flags shouldn't be set.
		// Warn if this is the case, but zero it out anyways.
		if (metadata->header.flags) {
		LWARN << "Zeroing unexpected flags: " << ToHexString(metadata->header.flags);
		}

		// Zero out all fields beyond LpMetadataHeaderV0.
		static_assert(sizeof(metadata->header) > sizeof(LpMetadataHeaderV1_0));
		memset(reinterpret_cast<uint8_t*>(&metadata->header) + sizeof(LpMetadataHeaderV1_0), 0,
		sizeof(metadata->header) - sizeof(LpMetadataHeaderV1_0));

		// Clear partition attributes unknown to V0.
		// On retrofit Virtual A/B devices, UPDATED flag may be set, so only log info here.
		for (auto& partition : metadata->partitions) {
		if (partition.attributes & ~LP_PARTITION_ATTRIBUTE_MASK_V0) {
		LINFO << "Clearing " << GetPartitionName(partition)
		<< " partition attribute: " << ToHexString(partition.attributes);
		}

		partition.attributes &= LP_PARTITION_ATTRIBUTE_MASK_V0;
		}
		}

		} // namespace fs_mgr
		} // namespace android

fs_mgr/liblp/utility.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -103,6 +103,10 @@ bool SetBlockReadonly(int fd, bool readonly);
		bool UpdateMetadataForInPlaceSnapshot(LpMetadata* metadata, uint32_t source_slot_number,
		uint32_t target_slot_number);

		// Forcefully set metadata header version to 1.0, clearing any incompatible flags and attributes
		// so that when downgrading to a build with liblp V0, the device still boots.
		void SetMetadataHeaderV0(LpMetadata* metadata);

		} // namespace fs_mgr
		} // namespace android