Merge "second-stage-init: Don't move submounts when mounting overlayfs" into main (475599f5) · Commits · e / os / android_system_core

fs_mgr/fs_mgr.cpp

+5 −4

Original line number	Diff line number	Diff line
		@@ -1388,6 +1388,8 @@ MountAllResult fs_mgr_mount_all(Fstab* fstab, int mount_mode) {
		return {FS_MGR_MNTALL_FAIL, userdata_mounted};
		}

		bool scratch_can_be_mounted = true;

		// Keep i int to prevent unsigned integer overflow from (i = top_idx - 1),
		// where top_idx is 0. It will give SIGABRT
		for (int i = 0; i < static_cast<int>(fstab->size()); i++) {
		@@ -1520,6 +1522,9 @@ MountAllResult fs_mgr_mount_all(Fstab* fstab, int mount_mode) {
		if (current_entry.mount_point == "/data") {
		userdata_mounted = true;
		}

		MountOverlayfs(attempted_entry, &scratch_can_be_mounted);

		// Success! Go get the next one.
		continue;
		}
		@@ -1604,10 +1609,6 @@ MountAllResult fs_mgr_mount_all(Fstab* fstab, int mount_mode) {

		set_type_property(encryptable);

		#if ALLOW_ADBD_DISABLE_VERITY == 1 // "userdebug" build
		fs_mgr_overlayfs_mount_all(fstab);
		#endif

		if (error_count) {
		return {FS_MGR_MNTALL_FAIL, userdata_mounted};
		} else {

fs_mgr/fs_mgr_overlayfs_mount.cpp

+55 −19

Original line number	Diff line number	Diff line
		@@ -302,6 +302,25 @@ static bool fs_mgr_overlayfs_move_mount(const std::string& source, const std::st
		return true;
		}

		static bool fs_mgr_overlayfs_mount(const std::string& mount_point, const std::string& options) {
		auto report = "__mount(source=overlay,target="s + mount_point + ",type=overlay";
		for (const auto& opt : android::base::Split(options, ",")) {
		if (android::base::StartsWith(opt, kUpperdirOption)) {
		report = report + "," + opt;
		break;
		}
		}
		report = report + ")=";
		auto ret = mount("overlay", mount_point.c_str(), "overlay", MS_RDONLY \| MS_NOATIME,
		options.c_str());
		if (ret) {
		PERROR << report << ret;
		} else {
		LINFO << report << ret;
		}
		return !ret;
		}

		struct mount_info {
		std::string mount_point;
		bool shared_flag;
		@@ -488,25 +507,7 @@ static bool fs_mgr_overlayfs_mount_one(const FstabEntry& fstab_entry) {
		moved_mounts.push_back(std::move(new_entry));
		}

		// hijack __mount() report format to help triage
		auto report = "__mount(source=overlay,target="s + mount_point + ",type=overlay";
		const auto opt_list = android::base::Split(options, ",");
		for (const auto& opt : opt_list) {
		if (android::base::StartsWith(opt, kUpperdirOption)) {
		report = report + "," + opt;
		break;
		}
		}
		report = report + ")=";

		auto ret = mount("overlay", mount_point.c_str(), "overlay", MS_RDONLY \| MS_NOATIME,
		options.c_str());
		if (ret) {
		retval = false;
		PERROR << report << ret;
		} else {
		LINFO << report << ret;
		}
		retval &= fs_mgr_overlayfs_mount(mount_point, options);

		// Move submounts back.
		for (const auto& entry : moved_mounts) {
		@@ -814,3 +815,38 @@ bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overl
		}
		return false;
		}

		namespace android {
		namespace fs_mgr {

		void MountOverlayfs(const FstabEntry& fstab_entry, bool* scratch_can_be_mounted) {
		if (!OverlayfsSetupAllowed()) {
		return;
		}
		const auto candidates = fs_mgr_overlayfs_candidate_list({fstab_entry});
		if (candidates.empty()) {
		return;
		}
		const auto& entry = candidates.front();
		if (fs_mgr_is_verity_enabled(entry)) {
		return;
		}
		const auto mount_point = fs_mgr_mount_point(entry.mount_point);
		if (fs_mgr_overlayfs_already_mounted(mount_point)) {
		return;
		}
		if (*scratch_can_be_mounted) {
		*scratch_can_be_mounted = false;
		if (!fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
		TryMountScratch();
		}
		}
		const auto options = fs_mgr_get_overlayfs_options(entry);
		if (options.empty()) {
		return;
		}
		fs_mgr_overlayfs_mount(mount_point, options);
		}

		} // namespace fs_mgr
		} // namespace android

fs_mgr/include/fs_mgr_overlayfs.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,9 @@ bool fs_mgr_overlayfs_is_setup();
		namespace android {
		namespace fs_mgr {

		// Mount the overlayfs override for \|fstab_entry\|.
		void MountOverlayfs(const FstabEntry& fstab_entry, bool* scratch_can_be_mounted);

		void MapScratchPartitionIfNeeded(Fstab* fstab,
		const std::function<bool(const std::set<std::string>&)>& init);