Merge "fs_mgr: Allow using major:minor device strings in CreateLogicalPartition." (63fe0e9a) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_dm_linear.cpp

+29 −17

Original line number	Diff line number	Diff line
		@@ -52,29 +52,36 @@ using DmTarget = android::dm::DmTarget;
		using DmTargetZero = android::dm::DmTargetZero;
		using DmTargetLinear = android::dm::DmTargetLinear;

		static bool GetPhysicalPartitionDevicePath(const LpMetadata& metadata,
		static bool GetPhysicalPartitionDevicePath(const IPartitionOpener& opener,
		const LpMetadata& metadata,
		const LpMetadataBlockDevice& block_device,
		const std::string& super_device,
		std::string* result) {
		// Note: device-mapper will not accept symlinks, so we must use realpath
		// here.
		std::string name = GetBlockDevicePartitionName(block_device);
		std::string path = "/dev/block/by-name/" + name;
		const std::string& super_device, std::string* result) {
		// If the super device is the source of this block device's metadata,
		// make sure we use the correct super device (and not just "super",
		// which might not exist.)
		std::string name = GetBlockDevicePartitionName(block_device);
		std::string dev_string = opener.GetDeviceString(name);
		if (GetMetadataSuperBlockDevice(metadata) == &block_device) {
		path = super_device;
		dev_string = opener.GetDeviceString(super_device);
		}
		if (!android::base::Realpath(path, result)) {
		PERROR << "realpath: " << path;

		// Note: device-mapper will not accept symlinks, so we must use realpath
		// here. If the device string is a major:minor sequence, we don't need to
		// to call Realpath (it would not work anyway).
		if (android::base::StartsWith(dev_string, "/")) {
		if (!android::base::Realpath(dev_string, result)) {
		PERROR << "realpath: " << dev_string;
		return false;
		}
		} else {
		*result = dev_string;
		}
		return true;
		}

		static bool CreateDmTable(const LpMetadata& metadata, const LpMetadataPartition& partition,
		const std::string& super_device, DmTable* table) {
		static bool CreateDmTable(const IPartitionOpener& opener, const LpMetadata& metadata,
		const LpMetadataPartition& partition, const std::string& super_device,
		DmTable* table) {
		uint64_t sector = 0;
		for (size_t i = 0; i < partition.num_extents; i++) {
		const auto& extent = metadata.extents[partition.first_extent_index + i];
		@@ -85,12 +92,13 @@ static bool CreateDmTable(const LpMetadata& metadata, const LpMetadataPartition&
		break;
		case LP_TARGET_TYPE_LINEAR: {
		const auto& block_device = metadata.block_devices[extent.target_source];
		std::string path;
		if (!GetPhysicalPartitionDevicePath(metadata, block_device, super_device, &path)) {
		std::string dev_string;
		if (!GetPhysicalPartitionDevicePath(opener, metadata, block_device, super_device,
		&dev_string)) {
		LOG(ERROR) << "Unable to complete device-mapper table, unknown block device";
		return false;
		}
		target = std::make_unique<DmTargetLinear>(sector, extent.num_sectors, path,
		target = std::make_unique<DmTargetLinear>(sector, extent.num_sectors, dev_string,
		extent.target_data);
		break;
		}
		@@ -179,8 +187,12 @@ bool CreateLogicalPartition(const CreateLogicalPartitionParams& params, std::str
		}
		}

		PartitionOpener default_opener;
		const IPartitionOpener* opener =
		params.partition_opener ? params.partition_opener : &default_opener;

		DmTable table;
		if (!CreateDmTable(metadata, partition, params.block_device, &table)) {
		if (!CreateDmTable(opener, metadata, *partition, params.block_device, &table)) {
		return false;
		}
		if (params.force_writable) {

fs_mgr/include/fs_mgr_dm_linear.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,10 @@ struct CreateLogicalPartitionParams {
		// If this is non-empty, it will override the device mapper name (by
		// default the partition name will be used).
		std::string device_name;

		// If non-null, this will use the specified IPartitionOpener rather than
		// the default one.
		const IPartitionOpener* partition_opener = nullptr;
		};

		bool CreateLogicalPartition(const CreateLogicalPartitionParams& params, std::string* path);

fs_mgr/liblp/include/liblp/partition_opener.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -62,6 +62,11 @@ class IPartitionOpener {
		// Return block device information about the given named physical partition.
		// The name can be an absolute path if the full path is already known.
		virtual bool GetInfo(const std::string& partition_name, BlockDeviceInfo* info) const = 0;

		// Return a path that can be used to pass the block device to device-mapper.
		// This must either result in an absolute path, or a major:minor device
		// sequence.
		virtual std::string GetDeviceString(const std::string& partition_name) const = 0;
		};

		// Helper class to implement IPartitionOpener. If \|partition_name\| is not an
		@@ -71,6 +76,7 @@ class PartitionOpener : public IPartitionOpener {
		virtual android::base::unique_fd Open(const std::string& partition_name,
		int flags) const override;
		virtual bool GetInfo(const std::string& partition_name, BlockDeviceInfo* info) const override;
		virtual std::string GetDeviceString(const std::string& partition_name) const override;
		};

		} // namespace fs_mgr

fs_mgr/liblp/partition_opener.cpp

+4 −0

Original line number	Diff line number	Diff line
		@@ -100,5 +100,9 @@ bool PartitionOpener::GetInfo(const std::string& partition_name, BlockDeviceInfo
		return GetBlockDeviceInfo(path, info);
		}

		std::string PartitionOpener::GetDeviceString(const std::string& partition_name) const {
		return GetPartitionAbsolutePath(partition_name);
		}

		} // namespace fs_mgr
		} // namespace android