Merge "liblp: Force 10.0 metadata on downgrade to Q." into rvc-dev (2ce3ddfe) · Commits · e / os / android_system_core

fs_mgr/liblp/builder.cpp

+12 −5

Original line number	Original line	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) &&		if (IPropertyFetcher::GetInstance()->GetBoolProperty("ro.virtual_ab.enabled", false)) {
	!always_keep_source_slot) {		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,		if (!UpdateMetadataForInPlaceSnapshot(metadata.get(), source_slot_number,
	target_slot_number)) {		target_slot_number)) {
	return nullptr;		return nullptr;
	}		}
	}		}
			}

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

fs_mgr/liblp/include/liblp/builder.h

+4 −2

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

fs_mgr/liblp/utility.cpp

+39 −0

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

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

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

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

fs_mgr/liblp/utility.h

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -103,6 +103,10 @@ bool SetBlockReadonly(int fd, bool readonly);
	bool UpdateMetadataForInPlaceSnapshot(LpMetadata* metadata, uint32_t source_slot_number,		bool UpdateMetadataForInPlaceSnapshot(LpMetadata* metadata, uint32_t source_slot_number,
	uint32_t target_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 fs_mgr
	} // namespace android		} // namespace android