Merge changes I2581fd7c,I1ed57e6d into main (64062f8f) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_fstab.cpp

+16 −10

Original line number	Diff line number	Diff line
		@@ -328,8 +328,7 @@ bool ParseFsMgrFlags(const std::string& flags, FstabEntry* entry) {
		// some recovery fstabs still contain the FDE options since they didn't do
		// anything in recovery mode anyway (except possibly to cause the
		// reservation of a crypto footer) and thus never got removed.
		if (entry->fs_mgr_flags.crypt && !entry->fs_mgr_flags.vold_managed &&
		access("/system/bin/recovery", F_OK) != 0) {
		if (entry->fs_mgr_flags.crypt && !entry->fs_mgr_flags.vold_managed && !InRecovery()) {
		LERROR << "FDE is no longer supported; 'encryptable' can only be used for adoptable "
		"storage";
		return false;
		@@ -520,6 +519,9 @@ std::vector<FstabPtrEntryType*> GetEntriesByPred(FstabPtr fstab, const Pred& pre
		// ramdisk's copy of the fstab had to be located in the root directory, but now
		// the system/etc directory is supported too and is the preferred location.
		std::string GetFstabPath() {
		if (InRecovery()) {
		return "/etc/recovery.fstab";
		}
		for (const char* prop : {"fstab_suffix", "hardware", "hardware.platform"}) {
		std::string suffix;

		@@ -835,15 +837,8 @@ bool ReadDefaultFstab(Fstab* fstab) {
		fstab->clear();
		ReadFstabFromDt(fstab, false /* verbose */);

		std::string default_fstab_path;
		// Use different fstab paths for normal boot and recovery boot, respectively
		if ((access("/sbin/recovery", F_OK) == 0) \|\| (access("/system/bin/recovery", F_OK) == 0)) {
		default_fstab_path = "/etc/recovery.fstab";
		} else { // normal boot
		default_fstab_path = GetFstabPath();
		}

		Fstab default_fstab;
		const std::string default_fstab_path = GetFstabPath();
		if (!default_fstab_path.empty() && ReadFstabFromFile(default_fstab_path, &default_fstab)) {
		for (auto&& entry : default_fstab) {
		fstab->emplace_back(std::move(entry));
		@@ -936,6 +931,17 @@ std::string GetVerityDeviceName(const FstabEntry& entry) {
		return base_device + "-verity";
		}

		bool InRecovery() {
		// Check the existence of recovery binary instead of using the compile time
		// __ANDROID_RECOVERY__ macro.
		// If BOARD_USES_RECOVERY_AS_BOOT is true, both normal and recovery boot
		// mode would use the same init binary, which would mean during normal boot
		// the '/init' binary is actually a symlink pointing to
		// init_second_stage.recovery, which would be compiled with
		// __ANDROID_RECOVERY__ defined.
		return access("/system/bin/recovery", F_OK) == 0 \|\| access("/sbin/recovery", F_OK) == 0;
		}

		} // namespace fs_mgr
		} // namespace android

fs_mgr/fs_mgr_overlayfs_control.cpp

+25 −130

Original line number	Diff line number	Diff line
		@@ -18,17 +18,10 @@
		#include <errno.h>
		#include <fcntl.h>
		#include <linux/fs.h>
		#include <selinux/selinux.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/mount.h>
		#include <sys/param.h>
		#include <sys/stat.h>
		#include <sys/statvfs.h>
		#include <sys/types.h>
		#include <sys/utsname.h>
		#include <sys/vfs.h>
		#include <unistd.h>

		#include <algorithm>
		@@ -38,13 +31,9 @@
		#include <vector>

		#include <android-base/file.h>
		#include <android-base/macros.h>
		#include <android-base/properties.h>
		#include <android-base/strings.h>
		#include <android-base/unique_fd.h>
		#include <ext4_utils/ext4_utils.h>
		#include <fs_mgr.h>
		#include <fs_mgr/file_wait.h>
		#include <fs_mgr_dm_linear.h>
		#include <fs_mgr_overlayfs.h>
		#include <fstab/fstab.h>
		@@ -71,22 +60,25 @@ namespace {

		constexpr char kDataScratchSizeMbProp[] = "fs_mgr.overlayfs.data_scratch_size_mb";

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

		constexpr char kMkF2fs[] = "/system/bin/make_f2fs";
		constexpr char kMkExt4[] = "/system/bin/mke2fs";

		// Return true if everything is mounted, but before adb is started. Right
		// after 'trigger load_persist_props_action' is done.
		static bool fs_mgr_boot_completed() {
		return android::base::GetBoolProperty("ro.persistent_properties.ready", false);
		}

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

		// Note: this is meant only for recovery/first-stage init.
		static bool ScratchIsOnData() {
		// The scratch partition of DSU is managed by gsid.
		if (fs_mgr_is_dsu_running()) {
		return false;
		}
		return fs_mgr_access(kScratchImageMetadata);
		return access(kScratchImageMetadata, F_OK) == 0;
		}

		static bool fs_mgr_rm_all(const std::string& path, bool* change = nullptr, int level = 0) {
		@@ -131,7 +123,7 @@ static bool fs_mgr_rm_all(const std::string& path, bool* change = nullptr, int l
		}

		std::string fs_mgr_overlayfs_setup_dir(const std::string& dir) {
		auto top = dir + kOverlayTopDir;
		auto top = dir + "/" + kOverlayTopDir;

		AutoSetFsCreateCon createcon(kOverlayfsFileContext);
		if (!createcon.Ok()) {
		@@ -195,10 +187,6 @@ static uint32_t fs_mgr_overlayfs_slot_number() {
		return SlotNumberForSlotSuffix(fs_mgr_get_slot_suffix());
		}

		static std::string fs_mgr_overlayfs_super_device(uint32_t slot_number) {
		return kPhysicalDevice + fs_mgr_get_super_partition_name(slot_number);
		}

		static bool fs_mgr_overlayfs_has_logical(const Fstab& fstab) {
		for (const auto& entry : fstab) {
		if (entry.fs_mgr_flags.logical) {
		@@ -258,8 +246,8 @@ OverlayfsTeardownResult fs_mgr_overlayfs_teardown_scratch(const std::string& ove
		}

		auto slot_number = fs_mgr_overlayfs_slot_number();
		auto super_device = fs_mgr_overlayfs_super_device(slot_number);
		if (!fs_mgr_rw_access(super_device)) {
		const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name();
		if (access(super_device.c_str(), R_OK \| W_OK)) {
		return OverlayfsTeardownResult::Ok;
		}

		@@ -290,9 +278,9 @@ OverlayfsTeardownResult fs_mgr_overlayfs_teardown_scratch(const std::string& ove

		bool fs_mgr_overlayfs_teardown_one(const std::string& overlay, const std::string& mount_point,
		bool* change, bool* should_destroy_scratch = nullptr) {
		const auto top = overlay + kOverlayTopDir;
		const auto top = overlay + "/" + kOverlayTopDir;

		if (!fs_mgr_access(top)) {
		if (access(top.c_str(), F_OK)) {
		if (should_destroy_scratch) *should_destroy_scratch = true;
		return true;
		}
		@@ -300,7 +288,7 @@ 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 newpath = cleanup_all ? overlay + "/." + (kOverlayTopDir + 1) + ".teardown"
		const auto newpath = cleanup_all ? overlay + "/." + kOverlayTopDir + ".teardown"
		: top + "/." + partition_name + ".teardown";
		auto ret = fs_mgr_rm_all(newpath);
		if (!rename(oldpath.c_str(), newpath.c_str())) {
		@@ -346,72 +334,6 @@ bool fs_mgr_overlayfs_teardown_one(const std::string& overlay, const std::string
		return ret;
		}

		// Mount kScratchMountPoint
		bool MountScratch(const std::string& device_path, bool readonly = false) {
		if (readonly) {
		if (!fs_mgr_access(device_path)) {
		LOG(ERROR) << "Path does not exist: " << device_path;
		return false;
		}
		} else if (!fs_mgr_rw_access(device_path)) {
		LOG(ERROR) << "Path does not exist or is not readwrite: " << device_path;
		return false;
		}

		std::vector<const char*> filesystem_candidates;
		if (fs_mgr_is_f2fs(device_path)) {
		filesystem_candidates = {"f2fs", "ext4"};
		} else if (fs_mgr_is_ext4(device_path)) {
		filesystem_candidates = {"ext4", "f2fs"};
		} else {
		LOG(ERROR) << "Scratch partition is not f2fs or ext4";
		return false;
		}

		AutoSetFsCreateCon createcon(kOverlayfsFileContext);
		if (!createcon.Ok()) {
		return false;
		}
		if (mkdir(kScratchMountPoint, 0755) && (errno != EEXIST)) {
		PERROR << "create " << kScratchMountPoint;
		return false;
		}

		FstabEntry entry;
		entry.blk_device = device_path;
		entry.mount_point = kScratchMountPoint;
		entry.flags = MS_NOATIME \| MS_RDONLY;
		if (!readonly) {
		entry.flags &= ~MS_RDONLY;
		entry.flags \|= MS_SYNCHRONOUS;
		entry.fs_options = "nodiscard";
		fs_mgr_set_blk_ro(device_path, false);
		}
		// check_fs requires apex runtime library
		if (fs_mgr_overlayfs_already_mounted("/data", false)) {
		entry.fs_mgr_flags.check = true;
		}
		bool mounted = false;
		for (auto fs_type : filesystem_candidates) {
		entry.fs_type = fs_type;
		if (fs_mgr_do_mount_one(entry) == 0) {
		mounted = true;
		break;
		}
		}
		if (!createcon.Restore()) {
		return false;
		}
		if (!mounted) {
		rmdir(kScratchMountPoint);
		return false;
		}
		return true;
		}

		const std::string kMkF2fs("/system/bin/make_f2fs");
		const std::string kMkExt4("/system/bin/mke2fs");

		// Note: The scratch partition of DSU is managed by gsid, and should be initialized during
		// first-stage-mount. Just check if the DM device for DSU scratch partition is created or not.
		static std::string GetDsuScratchDevice() {
		@@ -456,14 +378,14 @@ bool MakeScratchFilesystem(const std::string& scratch_device) {
		// thus do not rely on fsck to correct problems that could creep in.
		auto fs_type = ""s;
		auto command = ""s;
		if (!access(kMkF2fs.c_str(), X_OK) && fs_mgr_filesystem_available("f2fs")) {
		if (!access(kMkF2fs, X_OK) && fs_mgr_filesystem_available("f2fs")) {
		fs_type = "f2fs";
		command = kMkF2fs + " -w ";
		command = kMkF2fs + " -w "s;
		command += std::to_string(getpagesize());
		command += " -f -d1 -l" + android::base::Basename(kScratchMountPoint);
		} else if (!access(kMkExt4.c_str(), X_OK) && fs_mgr_filesystem_available("ext4")) {
		} else if (!access(kMkExt4, X_OK) && fs_mgr_filesystem_available("ext4")) {
		fs_type = "ext4";
		command = kMkExt4 + " -F -b 4096 -t ext4 -m 0 -O has_journal -M " + kScratchMountPoint;
		command = kMkExt4 + " -F -b 4096 -t ext4 -m 0 -O has_journal -M "s + kScratchMountPoint;
		} else {
		LERROR << "No supported mkfs command or filesystem driver available, supported filesystems "
		"are: f2fs, ext4";
		@@ -506,7 +428,7 @@ static bool CreateDynamicScratch(std::string* scratch_device, bool* partition_ex

		auto partition_create = !*partition_exists;
		auto slot_number = fs_mgr_overlayfs_slot_number();
		auto super_device = fs_mgr_overlayfs_super_device(slot_number);
		const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name();
		auto builder = MetadataBuilder::New(super_device, slot_number);
		if (!builder) {
		LERROR << "open " << super_device << " metadata";
		@@ -646,8 +568,8 @@ static bool CreateScratchOnData(std::string* scratch_device, bool* partition_exi

		static bool CanUseSuperPartition(const Fstab& fstab) {
		auto slot_number = fs_mgr_overlayfs_slot_number();
		auto super_device = fs_mgr_overlayfs_super_device(slot_number);
		if (!fs_mgr_rw_access(super_device) \|\| !fs_mgr_overlayfs_has_logical(fstab)) {
		const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name();
		if (access(super_device.c_str(), R_OK \| W_OK) \|\| !fs_mgr_overlayfs_has_logical(fstab)) {
		return false;
		}
		auto metadata = ReadMetadata(super_device, slot_number);
		@@ -697,8 +619,8 @@ bool fs_mgr_overlayfs_setup_scratch(const Fstab& fstab) {
		// If the partition exists, assume first that it can be mounted.
		if (partition_exists) {
		if (MountScratch(scratch_device)) {
		if (fs_mgr_access(std::string(kScratchMountPoint) + kOverlayTopDir) \|\|
		fs_mgr_filesystem_has_space(kScratchMountPoint)) {
		const auto top = kScratchMountPoint + "/"s + kOverlayTopDir;
		if (access(top.c_str(), F_OK) == 0 \|\| fs_mgr_filesystem_has_space(kScratchMountPoint)) {
		return true;
		}
		// declare it useless, no overrides and no free space
		@@ -717,32 +639,6 @@ bool fs_mgr_overlayfs_setup_scratch(const Fstab& fstab) {
		return MountScratch(scratch_device);
		}

		// NOTE: OverlayfsSetupAllowed() must be "stricter" than OverlayfsTeardownAllowed().
		// Setup is allowed only if teardown is also allowed.
		bool OverlayfsSetupAllowed(bool verbose = false) {
		if (!kAllowOverlayfs) {
		if (verbose) {
		LOG(ERROR) << "Overlayfs remounts can only be used in debuggable builds";
		}
		return false;
		}
		// Check mandatory kernel patches.
		if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) {
		if (verbose) {
		LOG(ERROR) << "Kernel does not support overlayfs";
		}
		return false;
		}
		// in recovery or fastbootd, not allowed!
		if (fs_mgr_in_recovery()) {
		if (verbose) {
		LOG(ERROR) << "Unsupported overlayfs setup from recovery";
		}
		return false;
		}
		return true;
		}

		constexpr bool OverlayfsTeardownAllowed() {
		// Never allow on non-debuggable build.
		return kAllowOverlayfs;
		@@ -844,7 +740,7 @@ static std::optional<MapInfo> EnsureScratchMapped() {
		if (!info.device.empty()) {
		return {std::move(info)};
		}
		if (!fs_mgr_in_recovery()) {
		if (!InRecovery()) {
		return {};
		}

		@@ -867,8 +763,7 @@ static std::optional<MapInfo> EnsureScratchMapped() {
		}

		// Avoid uart spam by first checking for a scratch partition.
		auto metadata_slot = fs_mgr_overlayfs_slot_number();
		auto super_device = fs_mgr_overlayfs_super_device(metadata_slot);
		const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name();
		auto metadata = ReadCurrentMetadata(super_device);
		if (!metadata) {
		return {};
		@@ -1030,7 +925,7 @@ void TeardownAllOverlayForMountPoint(const std::string& mount_point) {
		if (!OverlayfsTeardownAllowed()) {
		return;
		}
		if (!fs_mgr_in_recovery()) {
		if (!InRecovery()) {
		LERROR << __FUNCTION__ << "(): must be called within recovery.";
		return;
		}

fs_mgr/fs_mgr_overlayfs_control.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -14,8 +14,6 @@

		#pragma once

		#include <string>

		#include <fstab/fstab.h>

		// If "mount_point" is non-null, set up exactly one overlay.

fs_mgr/fs_mgr_overlayfs_mount.cpp

+21 −53

Original line number	Diff line number	Diff line
		@@ -14,16 +14,12 @@
		* limitations under the License.
		*/

		#include <dirent.h>
		#include <errno.h>
		#include <fcntl.h>
		#include <linux/fs.h>
		#include <selinux/selinux.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/mount.h>
		#include <sys/param.h>
		#include <sys/stat.h>
		#include <sys/statvfs.h>
		#include <sys/types.h>
		@@ -33,7 +29,6 @@

		#include <algorithm>
		#include <memory>
		#include <optional>
		#include <string>
		#include <vector>

		@@ -45,7 +40,6 @@
		#include <ext4_utils/ext4_utils.h>
		#include <fs_mgr.h>
		#include <fs_mgr/file_wait.h>
		#include <fs_mgr_dm_linear.h>
		#include <fs_mgr_overlayfs.h>
		#include <fstab/fstab.h>
		#include <libdm/dm.h>
		@@ -62,39 +56,21 @@ using namespace android::storage_literals;

		constexpr char kPreferCacheBackingStorageProp[] = "fs_mgr.overlayfs.prefer_cache_backing_storage";

		bool fs_mgr_access(const std::string& path) {
		return access(path.c_str(), F_OK) == 0;
		}

		const auto kLowerdirOption = "lowerdir=";
		const auto kUpperdirOption = "upperdir=";
		constexpr char kCacheMountPoint[] = "/cache";
		constexpr char kPhysicalDevice[] = "/dev/block/by-name/";

		bool fs_mgr_in_recovery() {
		// Check the existence of recovery binary instead of using the compile time
		// __ANDROID_RECOVERY__ macro.
		// If BOARD_USES_RECOVERY_AS_BOOT is true, both normal and recovery boot
		// mode would use the same init binary, which would mean during normal boot
		// the '/init' binary is actually a symlink pointing to
		// init_second_stage.recovery, which would be compiled with
		// __ANDROID_RECOVERY__ defined.
		return fs_mgr_access("/system/bin/recovery");
		}
		constexpr char kLowerdirOption[] = "lowerdir=";
		constexpr char kUpperdirOption[] = "upperdir=";

		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;
		if (InRecovery()) return false;
		return android::gsi::IsGsiRunning();
		}

		const auto kCacheMountPoint = "/cache";

		static bool IsABDevice() {
		return !android::base::GetProperty("ro.boot.slot_suffix", "").empty();
		}

		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
		@@ -105,7 +81,8 @@ std::vector<const std::string> OverlayMountPoints() {

		// For non-A/B devices prefer cache backing storage if
		// kPreferCacheBackingStorageProp property set.
		if (!IsABDevice() && android::base::GetBoolProperty(kPreferCacheBackingStorageProp, false) &&
		if (fs_mgr_get_slot_suffix().empty() &&
		android::base::GetBoolProperty(kPreferCacheBackingStorageProp, false) &&
		android::base::GetIntProperty("ro.vendor.api_level", -1) < __ANDROID_API_T__) {
		return {kCacheMountPoint, kScratchMountPoint};
		}
		@@ -118,11 +95,6 @@ static bool fs_mgr_is_dir(const std::string& path) {
		return !stat(path.c_str(), &st) && S_ISDIR(st.st_mode);
		}

		bool fs_mgr_rw_access(const std::string& path) {
		if (path.empty()) return false;
		return access(path.c_str(), R_OK \| W_OK) == 0;
		}

		// At less than 1% or 8MB of free space return value of false,
		// means we will try to wrap with overlayfs.
		bool fs_mgr_filesystem_has_space(const std::string& mount_point) {
		@@ -141,13 +113,11 @@ bool fs_mgr_filesystem_has_space(const std::string& mount_point) {
		(static_cast<uint64_t>(vst.f_bfree) * vst.f_frsize) >= kSizeThreshold;
		}

		const auto kPhysicalDevice = "/dev/block/by-name/";

		static bool fs_mgr_update_blk_device(FstabEntry* entry) {
		if (entry->fs_mgr_flags.logical) {
		fs_mgr_update_logical_partition(entry);
		}
		if (fs_mgr_access(entry->blk_device)) {
		if (access(entry->blk_device.c_str(), F_OK) == 0) {
		return true;
		}
		if (entry->blk_device != "/dev/root") {
		@@ -155,10 +125,10 @@ static bool fs_mgr_update_blk_device(FstabEntry* entry) {
		}

		// special case for system-as-root (taimen and others)
		auto blk_device = std::string(kPhysicalDevice) + "system";
		if (!fs_mgr_access(blk_device)) {
		auto blk_device = kPhysicalDevice + "system"s;
		if (access(blk_device.c_str(), F_OK)) {
		blk_device += fs_mgr_get_slot_suffix();
		if (!fs_mgr_access(blk_device)) {
		if (access(blk_device.c_str(), F_OK)) {
		return false;
		}
		}
		@@ -237,12 +207,12 @@ 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 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 (!fs_mgr_rw_access(work)) continue;
		if (access(work.c_str(), R_OK \| W_OK)) continue;
		return dir;
		}
		return "";
		@@ -527,13 +497,13 @@ static bool fs_mgr_overlayfs_mount(const FstabEntry& entry) {
		}

		// Mount kScratchMountPoint
		static bool MountScratch(const std::string& device_path, bool readonly = false) {
		bool MountScratch(const std::string& device_path, bool readonly) {
		if (readonly) {
		if (!fs_mgr_access(device_path)) {
		if (access(device_path.c_str(), F_OK)) {
		LOG(ERROR) << "Path does not exist: " << device_path;
		return false;
		}
		} else if (!fs_mgr_rw_access(device_path)) {
		} else if (access(device_path.c_str(), R_OK \| W_OK)) {
		LOG(ERROR) << "Path does not exist or is not readwrite: " << device_path;
		return false;
		}
		@@ -589,9 +559,6 @@ static bool MountScratch(const std::string& device_path, bool readonly = false)
		return true;
		}

		const std::string kMkF2fs("/system/bin/make_f2fs");
		const std::string kMkExt4("/system/bin/mke2fs");

		// Note: The scratch partition of DSU is managed by gsid, and should be initialized during
		// first-stage-mount. Just check if the DM device for DSU scratch partition is created or not.
		static std::string GetDsuScratchDevice() {
		@@ -633,7 +600,7 @@ static std::string GetBootScratchDevice() {

		// NOTE: OverlayfsSetupAllowed() must be "stricter" than OverlayfsTeardownAllowed().
		// Setup is allowed only if teardown is also allowed.
		bool OverlayfsSetupAllowed(bool verbose = false) {
		bool OverlayfsSetupAllowed(bool verbose) {
		if (!kAllowOverlayfs) {
		if (verbose) {
		LOG(ERROR) << "Overlayfs remounts can only be used in debuggable builds";
		@@ -648,7 +615,7 @@ bool OverlayfsSetupAllowed(bool verbose = false) {
		return false;
		}
		// in recovery or fastbootd, not allowed!
		if (fs_mgr_in_recovery()) {
		if (InRecovery()) {
		if (verbose) {
		LOG(ERROR) << "Unsupported overlayfs setup from recovery";
		}
		@@ -728,7 +695,7 @@ static void TryMountScratch() {
		// if verity is still disabled, i.e. no reboot occurred), and skips calling
		// fs_mgr_overlayfs_mount_all().
		auto scratch_device = GetBootScratchDevice();
		if (!fs_mgr_rw_access(scratch_device)) {
		if (access(scratch_device.c_str(), R_OK \| W_OK)) {
		return;
		}
		if (!WaitForFile(scratch_device, 10s)) {
		@@ -737,7 +704,8 @@ static void TryMountScratch() {
		if (!MountScratch(scratch_device, true /* readonly */)) {
		return;
		}
		auto has_overlayfs_dir = fs_mgr_access(std::string(kScratchMountPoint) + kOverlayTopDir);
		const auto top = kScratchMountPoint + "/"s + kOverlayTopDir;
		const bool has_overlayfs_dir = access(top.c_str(), F_OK) == 0;
		fs_mgr_overlayfs_umount_scratch();
		if (has_overlayfs_dir) {
		MountScratch(scratch_device);

fs_mgr/fs_mgr_overlayfs_mount.h

+11 −13

Original line number	Diff line number	Diff line
		@@ -20,9 +20,12 @@

		#include <fstab/fstab.h>

		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);
		constexpr char kOverlayfsFileContext[] = "u:object_r:overlayfs_file:s0";

		constexpr char kScratchMountPoint[] = "/mnt/scratch";
		constexpr char kOverlayTopDir[] = "overlay";
		constexpr char kUpperName[] = "upper";
		constexpr char kWorkName[] = "work";

		#if ALLOW_ADBD_DISABLE_VERITY
		constexpr bool kAllowOverlayfs = true;
		@@ -45,18 +48,13 @@ class AutoSetFsCreateCon final {
		bool restored_ = false;
		};

		constexpr auto kScratchMountPoint = "/mnt/scratch";
		constexpr char kOverlayfsFileContext[] = "u:object_r:overlayfs_file:s0";

		constexpr auto kUpperName = "upper";
		constexpr auto kWorkName = "work";
		constexpr auto kOverlayTopDir = "/overlay";

		bool fs_mgr_is_dsu_running();
		bool fs_mgr_in_recovery();
		bool fs_mgr_access(const std::string& path);
		bool fs_mgr_rw_access(const std::string& path);
		bool fs_mgr_filesystem_has_space(const std::string& mount_point);
		const std::string fs_mgr_mount_point(const std::string& mount_point);
		bool OverlayfsSetupAllowed(bool verbose = false);
		bool MountScratch(const std::string& device_path, bool readonly = false);
		bool fs_mgr_overlayfs_umount_scratch();
		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);