fs_mgr_overlayfs: Polish fs_mgr_overlayfs_mount_fstab_entry() am: 94d1f3b4fa (f75a8ead) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_overlayfs.cpp

+21 −7

Original line number	Diff line number	Diff line
		@@ -92,7 +92,7 @@ bool fs_mgr_overlayfs_mount_all(Fstab*) {
		return false;
		}

		bool fs_mgr_overlayfs_mount_fstab_entry(const std::string&, const std::string&) {
		bool fs_mgr_overlayfs_mount_fstab_entry(const android::fs_mgr::FstabEntry&) {
		return false;
		}

		@@ -1299,17 +1299,31 @@ static void TryMountScratch() {
		}
		}

		bool fs_mgr_overlayfs_mount_fstab_entry(const std::string& lowers,
		const std::string& mount_point) {
		bool fs_mgr_overlayfs_mount_fstab_entry(const android::fs_mgr::FstabEntry& entry) {
		if (fs_mgr_overlayfs_invalid()) return false;

		std::string aux = "lowerdir=" + lowers + ",override_creds=off";
		auto rc = mount("overlay", mount_point.c_str(), "overlay", MS_RDONLY \| MS_NOATIME, aux.c_str());
		// Create the mount point in case it doesn't exist.
		mkdir(entry.mount_point.c_str(), 0755);

		if (rc == 0) return true;
		auto options = kLowerdirOption + entry.lowerdir;
		if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kOverrideCredsRequired) {
		options += ",override_creds=off";
		}

		// Use .blk_device as the mount() source for debugging purposes.
		// Overlayfs is pseudo filesystem, so the source device is a symbolic value and isn't used to
		// back the filesystem. /proc/mounts would show the source as the device name of the mount.
		auto report = "__mount(source=" + entry.blk_device + ",target=" + entry.mount_point +
		",type=overlay," + options + ")=";
		auto ret = mount(entry.blk_device.c_str(), entry.mount_point.c_str(), "overlay",
		MS_RDONLY \| MS_NOATIME, options.c_str());
		if (ret) {
		PERROR << report << ret;
		return false;
		}
		LINFO << report << ret;
		return true;
		}

		bool fs_mgr_overlayfs_mount_all(Fstab* fstab) {
		auto ret = false;

fs_mgr/include/fs_mgr_overlayfs.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -27,7 +27,7 @@
		android::fs_mgr::Fstab fs_mgr_overlayfs_candidate_list(const android::fs_mgr::Fstab& fstab);

		bool fs_mgr_overlayfs_mount_all(android::fs_mgr::Fstab* fstab);
		bool fs_mgr_overlayfs_mount_fstab_entry (const std::string& lowers, const std::string& mount_point);
		bool fs_mgr_overlayfs_mount_fstab_entry(const android::fs_mgr::FstabEntry& entry);
		std::vector<std::string> fs_mgr_overlayfs_required_devices(android::fs_mgr::Fstab* fstab);
		bool fs_mgr_overlayfs_setup(const char* backing = nullptr, const char* mount_point = nullptr,
		bool* change = nullptr, bool force = true);

init/first_stage_mount.cpp

+7 −7

Original line number	Diff line number	Diff line
		@@ -542,6 +542,7 @@ bool FirstStageMount::MountPartitions() {
		continue;
		}

		// Handle overlayfs entries later.
		if (current->fs_type == "overlay") {
		++current;
		continue;
		@@ -571,6 +572,12 @@ bool FirstStageMount::MountPartitions() {
		current = end;
		}

		for (const auto& entry : fstab_) {
		if (entry.fs_type == "overlay") {
		fs_mgr_overlayfs_mount_fstab_entry(entry);
		}
		}

		// If we don't see /system or / in the fstab, then we need to create an root entry for
		// overlayfs.
		if (!GetEntryForMountPoint(&fstab_, "/system") && !GetEntryForMountPoint(&fstab_, "/")) {
		@@ -596,13 +603,6 @@ bool FirstStageMount::MountPartitions() {
		};
		MapScratchPartitionIfNeeded(&fstab_, init_devices);

		for (auto current = fstab_.begin(); current != fstab_.end(); ) {
		if (current->fs_type == "overlay") {
		fs_mgr_overlayfs_mount_fstab_entry(current->lowerdir, current->mount_point);
		}
		++current;
		}

		fs_mgr_overlayfs_mount_all(&fstab_);

		return true;