Merge "fs_mgr: Add OverlayMountPoints() to get the list of overlayfs backing storage" (ec1b09fc) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_overlayfs.cpp

+33 −24

Original line number	Diff line number	Diff line
		@@ -125,10 +125,38 @@ void TeardownAllOverlayForMountPoint(const std::string&) {}

		namespace {

		bool fs_mgr_in_recovery() {
		// Check the existence of recovery binary instead of using the compile time
		// macro, because first-stage-init is compiled with __ANDROID_RECOVERY__
		// defined, albeit not in recovery. More details: system/core/init/README.md
		return fs_mgr_access("/system/bin/recovery");
		}

		bool fs_mgr_is_dsu_running() {
		// Since android::gsi::CanBootIntoGsi() or android::gsi::MarkSystemAsGsi() is
		// never called in recovery, the return value of android::gsi::IsGsiRunning()
		// is not well-defined. In this case, just return false as being in recovery
		// implies not running a DSU system.
		if (fs_mgr_in_recovery()) return false;
		auto saved_errno = errno;
		auto ret = android::gsi::IsGsiRunning();
		errno = saved_errno;
		return ret;
		}

		// list of acceptable overlayfs backing storage
		const auto kScratchMountPoint = "/mnt/scratch"s;
		const auto kCacheMountPoint = "/cache"s;
		const std::vector<const std::string> kOverlayMountPoints = {kScratchMountPoint, kCacheMountPoint};

		std::vector<const std::string> OverlayMountPoints() {
		// Never fallback to legacy cache mount point if within a DSU system,
		// because running a DSU system implies the device supports dynamic
		// partitions, which means legacy cache mustn't be used.
		if (fs_mgr_is_dsu_running()) {
		return {kScratchMountPoint};
		}
		return {kScratchMountPoint, kCacheMountPoint};
		}

		// Return true if everything is mounted, but before adb is started. Right
		// after 'trigger load_persist_props_action' is done.
		@@ -169,25 +197,6 @@ bool fs_mgr_filesystem_has_space(const std::string& mount_point) {
		(vst.f_bfree * vst.f_bsize) >= kSizeThreshold;
		}

		bool fs_mgr_in_recovery() {
		// Check the existence of recovery binary instead of using the compile time
		// macro, because first-stage-init is compiled with __ANDROID_RECOVERY__
		// defined, albeit not in recovery. More details: system/core/init/README.md
		return fs_mgr_access("/system/bin/recovery");
		}

		bool fs_mgr_is_dsu_running() {
		// Since android::gsi::CanBootIntoGsi() or android::gsi::MarkSystemAsGsi() is
		// never called in recovery, the return value of android::gsi::IsGsiRunning()
		// is not well-defined. In this case, just return false as being in recovery
		// implies not running a DSU system.
		if (fs_mgr_in_recovery()) return false;
		auto saved_errno = errno;
		auto ret = android::gsi::IsGsiRunning();
		errno = saved_errno;
		return ret;
		}

		const auto kPhysicalDevice = "/dev/block/by-name/"s;
		constexpr char kScratchImageMetadata[] = "/metadata/gsi/remount/lp_metadata";

		@@ -300,7 +309,7 @@ const auto kOverlayTopDir = "/overlay"s;
		std::string fs_mgr_get_overlayfs_candidate(const std::string& mount_point) {
		if (!fs_mgr_is_dir(mount_point)) return "";
		const auto base = android::base::Basename(mount_point) + "/";
		for (const auto& overlay_mount_point : kOverlayMountPoints) {
		for (const auto& overlay_mount_point : OverlayMountPoints()) {
		auto dir = overlay_mount_point + kOverlayTopDir + "/" + base;
		auto upper = dir + kUpperName;
		if (!fs_mgr_is_dir(upper)) continue;
		@@ -1344,7 +1353,7 @@ bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool*
		if (candidates.empty()) return ret;

		std::string dir;
		for (const auto& overlay_mount_point : kOverlayMountPoints) {
		for (const auto& overlay_mount_point : OverlayMountPoints()) {
		if (backing && backing[0] && (overlay_mount_point != backing)) continue;
		if (overlay_mount_point == kScratchMountPoint) {
		if (!fs_mgr_overlayfs_setup_scratch(fstab, change)) continue;
		@@ -1465,7 +1474,7 @@ bool fs_mgr_overlayfs_teardown(const char* mount_point, bool* change) {
		}
		}
		bool should_destroy_scratch = false;
		for (const auto& overlay_mount_point : kOverlayMountPoints) {
		for (const auto& overlay_mount_point : OverlayMountPoints()) {
		ret &= fs_mgr_overlayfs_teardown_one(
		overlay_mount_point, mount_point ? fs_mgr_mount_point(mount_point) : "", change,
		overlay_mount_point == kScratchMountPoint ? &should_destroy_scratch : nullptr);
		@@ -1569,7 +1578,7 @@ void TeardownAllOverlayForMountPoint(const std::string& mount_point) {
		constexpr bool* ignore_change = nullptr;

		// Teardown legacy overlay mount points that's not backed by a scratch device.
		for (const auto& overlay_mount_point : kOverlayMountPoints) {
		for (const auto& overlay_mount_point : OverlayMountPoints()) {
		if (overlay_mount_point == kScratchMountPoint) {
		continue;
		}