Merge "fs_mgr_overlayfs: Setup remount scratch dir with encoded mountpoint name" into main (aba8c1ee) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_overlayfs_control.cpp

+5 −4

Original line number	Diff line number	Diff line
		@@ -144,7 +144,8 @@ bool fs_mgr_overlayfs_setup_one(const std::string& overlay, const std::string& m
		if (fs_mgr_overlayfs_already_mounted(mount_point)) {
		return true;
		}
		auto fsrec_mount_point = overlay + "/" + android::base::Basename(mount_point) + "/";
		const auto base = GetEncodedBaseDirForMountPoint(mount_point);
		auto fsrec_mount_point = overlay + "/" + base + "/";

		AutoSetFsCreateCon createcon(kOverlayfsFileContext);
		if (!createcon.Ok()) {
		@@ -286,10 +287,10 @@ bool fs_mgr_overlayfs_teardown_one(const std::string& overlay, const std::string
		}

		auto cleanup_all = mount_point.empty();
		const auto partition_name = android::base::Basename(mount_point);
		const auto oldpath = top + (cleanup_all ? "" : ("/" + partition_name));
		const auto base = GetEncodedBaseDirForMountPoint(mount_point);
		const auto oldpath = top + (cleanup_all ? "" : ("/" + base));
		const auto newpath = cleanup_all ? overlay + "/." + kOverlayTopDir + ".teardown"
		: top + "/." + partition_name + ".teardown";
		: top + "/." + base + ".teardown";
		auto ret = fs_mgr_rm_all(newpath);
		if (!rename(oldpath.c_str(), newpath.c_str())) {
		if (change) *change = true;

fs_mgr/fs_mgr_overlayfs_mount.cpp

+31 −23

Original line number	Diff line number	Diff line
		@@ -60,6 +60,7 @@ constexpr char kPhysicalDevice[] = "/dev/block/by-name/";

		constexpr char kLowerdirOption[] = "lowerdir=";
		constexpr char kUpperdirOption[] = "upperdir=";
		constexpr char kWorkdirOption[] = "workdir=";

		bool fs_mgr_is_dsu_running() {
		// Since android::gsi::CanBootIntoGsi() or android::gsi::MarkSystemAsGsi() is
		@@ -89,6 +90,14 @@ std::vector<const std::string> OverlayMountPoints() {
		return {kScratchMountPoint, kCacheMountPoint};
		}

		std::string GetEncodedBaseDirForMountPoint(const std::string& mount_point) {
		std::string normalized_path;
		if (mount_point.empty() \|\| !android::base::Realpath(mount_point, &normalized_path)) {
		return "";
		}
		return android::base::StringReplace(normalized_path, "/", "@", true);
		}

		static bool fs_mgr_is_dir(const std::string& path) {
		struct stat st;
		return !stat(path.c_str(), &st) && S_ISDIR(st.st_mode);
		@@ -202,21 +211,6 @@ static bool fs_mgr_overlayfs_enabled(FstabEntry* entry) {
		return has_shared_blocks;
		}

		static 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 : OverlayMountPoints()) {
		auto dir = overlay_mount_point + "/" + kOverlayTopDir + "/" + base;
		auto upper = dir + kUpperName;
		if (!fs_mgr_is_dir(upper)) continue;
		auto work = dir + kWorkName;
		if (!fs_mgr_is_dir(work)) continue;
		if (access(work.c_str(), R_OK \| W_OK)) continue;
		return dir;
		}
		return "";
		}

		const std::string fs_mgr_mount_point(const std::string& mount_point) {
		if ("/"s != mount_point) return mount_point;
		return "/system";
		@@ -225,10 +219,22 @@ const std::string fs_mgr_mount_point(const std::string& mount_point) {
		// default options for mount_point, returns empty string for none available.
		static std::string fs_mgr_get_overlayfs_options(const FstabEntry& entry) {
		const auto mount_point = fs_mgr_mount_point(entry.mount_point);
		auto candidate = fs_mgr_get_overlayfs_candidate(mount_point);
		if (candidate.empty()) return "";
		auto ret = kLowerdirOption + mount_point + "," + kUpperdirOption + candidate + kUpperName +
		",workdir=" + candidate + kWorkName + android::fs_mgr::CheckOverlayfs().mount_flags;
		if (!fs_mgr_is_dir(mount_point)) {
		return "";
		}
		const auto base = GetEncodedBaseDirForMountPoint(mount_point);
		if (base.empty()) {
		return "";
		}
		for (const auto& overlay_mount_point : OverlayMountPoints()) {
		const auto dir = overlay_mount_point + "/" + kOverlayTopDir + "/" + base + "/";
		const auto upper = dir + kUpperName;
		const auto work = dir + kWorkName;
		if (!fs_mgr_is_dir(upper) \|\| !fs_mgr_is_dir(work) \|\| access(work.c_str(), R_OK \| W_OK)) {
		continue;
		}
		auto ret = kLowerdirOption + mount_point + "," + kUpperdirOption + upper + "," +
		kWorkdirOption + work + android::fs_mgr::CheckOverlayfs().mount_flags;
		for (const auto& flag : android::base::Split(entry.fs_options, ",")) {
		if (android::base::StartsWith(flag, "context=")) {
		ret += "," + flag;
		@@ -236,6 +242,8 @@ static std::string fs_mgr_get_overlayfs_options(const FstabEntry& entry) {
		}
		return ret;
		}
		return "";
		}

		bool AutoSetFsCreateCon::Set(const std::string& context) {
		if (setfscreatecon(context.c_str())) {

fs_mgr/fs_mgr_overlayfs_mount.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -58,3 +58,4 @@ std::vector<const std::string> OverlayMountPoints();
		bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only = true);
		bool fs_mgr_wants_overlayfs(android::fs_mgr::FstabEntry* entry);
		android::fs_mgr::Fstab fs_mgr_overlayfs_candidate_list(const android::fs_mgr::Fstab& fstab);
		std::string GetEncodedBaseDirForMountPoint(const std::string& mount_point);