Merge "remount: Remove errno interaction from fs_mgr_overlayfs_teardown." am: eec8932c35 (81e9c6ad) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_overlayfs.cpp

+92 −71

Original line number	Diff line number	Diff line
		@@ -481,30 +481,35 @@ bool fs_mgr_overlayfs_has_logical(const Fstab& fstab) {
		return false;
		}

		void fs_mgr_overlayfs_umount_scratch() {
		// Lazy umount will allow us to move on and possibly later
		// establish a new fresh mount without requiring a reboot should
		// the developer wish to restart. Old references should melt
		// away or have no data. Main goal is to shut the door on the
		// current overrides with an expectation of a subsequent reboot,
		// thus any errors here are ignored.
		umount2(kScratchMountPoint.c_str(), MNT_DETACH);
		LINFO << "umount(" << kScratchMountPoint << ")";
		rmdir(kScratchMountPoint.c_str());
		// Returns true if immediate unmount succeeded and the scratch mount point was
		// removed.
		bool fs_mgr_overlayfs_umount_scratch() {
		if (umount(kScratchMountPoint.c_str()) != 0) {
		return false;
		}
		if (rmdir(kScratchMountPoint.c_str()) != 0 && errno != ENOENT) {
		PLOG(ERROR) << "rmdir " << kScratchMountPoint;
		}
		return true;
		}

		bool fs_mgr_overlayfs_teardown_scratch(const std::string& overlay, bool* change) {
		OverlayfsTeardownResult fs_mgr_overlayfs_teardown_scratch(const std::string& overlay,
		bool* change) {
		// umount and delete kScratchMountPoint storage if we have logical partitions
		if (overlay != kScratchMountPoint) return true;
		if (overlay != kScratchMountPoint) {
		return OverlayfsTeardownResult::Ok;
		}

		// Validation check.
		if (fs_mgr_is_dsu_running()) {
		LERROR << "Destroying DSU scratch is not allowed.";
		return false;
		return OverlayfsTeardownResult::Error;
		}

		auto save_errno = errno;
		if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {

		bool was_mounted = fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false);
		if (was_mounted) {
		fs_mgr_overlayfs_umount_scratch();
		}

		@@ -512,42 +517,58 @@ bool fs_mgr_overlayfs_teardown_scratch(const std::string& overlay, bool* change)

		auto images = IImageManager::Open("remount", 10s);
		if (images && images->BackingImageExists(partition_name)) {
		#if defined __ANDROID_RECOVERY__
		if (!images->DisableImage(partition_name)) {
		return false;
		return OverlayfsTeardownResult::Error;
		}
		#else
		if (!images->UnmapImageIfExists(partition_name) \|\|
		!images->DeleteBackingImage(partition_name)) {
		return false;
		if (was_mounted) {
		// If overlayfs was mounted, don't bother trying to unmap since
		// it'll fail and create error spam.
		return OverlayfsTeardownResult::Busy;
		}
		if (!images->UnmapImageIfExists(partition_name)) {
		return OverlayfsTeardownResult::Busy;
		}
		if (!images->DeleteBackingImage(partition_name)) {
		return OverlayfsTeardownResult::Busy;
		}
		#endif

		// No need to check super partition, if we knew we had a scratch device
		// in /data.
		return OverlayfsTeardownResult::Ok;
		}

		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)) return true;
		if (!fs_mgr_rw_access(super_device)) {
		return OverlayfsTeardownResult::Ok;
		}

		auto builder = MetadataBuilder::New(super_device, slot_number);
		if (!builder) {
		errno = save_errno;
		return true;
		return OverlayfsTeardownResult::Ok;
		}
		if (builder->FindPartition(partition_name) == nullptr) {
		errno = save_errno;
		return true;
		return OverlayfsTeardownResult::Ok;
		}
		builder->RemovePartition(partition_name);
		auto metadata = builder->Export();
		if (metadata && UpdatePartitionTable(super_device, *metadata.get(), slot_number)) {
		if (change) *change = true;
		if (!DestroyLogicalPartition(partition_name)) return false;
		if (!DestroyLogicalPartition(partition_name)) {
		return OverlayfsTeardownResult::Error;
		}
		} else {
		LERROR << "delete partition " << overlay;
		return false;
		return OverlayfsTeardownResult::Error;
		}
		errno = save_errno;
		return true;

		if (was_mounted) {
		return OverlayfsTeardownResult::Busy;
		}
		return OverlayfsTeardownResult::Ok;
		}

		bool fs_mgr_overlayfs_teardown_one(const std::string& overlay, const std::string& mount_point,
		@@ -869,17 +890,6 @@ bool fs_mgr_overlayfs_mount_scratch(const std::string& device_path, const std::s
		entry.flags = MS_NOATIME \| MS_RDONLY;
		auto mounted = true;
		if (!readonly) {
		if (entry.fs_type == "ext4") {
		// check if ext4 de-dupe
		entry.flags \|= MS_RDONLY;
		auto save_errno = errno;
		mounted = fs_mgr_do_mount_one(entry) == 0;
		if (mounted) {
		mounted = !fs_mgr_has_shared_blocks(entry.mount_point, entry.blk_device);
		fs_mgr_overlayfs_umount_scratch();
		}
		errno = save_errno;
		}
		entry.flags &= ~MS_RDONLY;
		entry.flags \|= MS_SYNCHRONOUS;
		entry.fs_options = "nodiscard";
		@@ -1246,7 +1256,10 @@ bool fs_mgr_overlayfs_setup_scratch(const Fstab& fstab) {
		return true;
		}
		// declare it useless, no overrides and no free space
		fs_mgr_overlayfs_umount_scratch();
		if (!fs_mgr_overlayfs_umount_scratch()) {
		LOG(ERROR) << "Unable to unmount scratch partition";
		return false;
		}
		}
		}

		@@ -1548,50 +1561,57 @@ static bool MapDsuScratchDevice(std::string* device) {
		return true;
		}

		// Returns false if teardown not permitted, errno set to last error.
		// If something is altered, set *change.
		bool fs_mgr_overlayfs_teardown(const char* mount_point, bool* change) {
		if (change) *change = false;
		auto ret = true;

		// If scratch exists, but is not mounted, lets gain access to clean
		// specific override entries.
		auto mount_scratch = false;
		if ((mount_point != nullptr) && !fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
		std::string scratch_device = GetBootScratchDevice();
		if (!scratch_device.empty()) {
		mount_scratch = fs_mgr_overlayfs_mount_scratch(scratch_device,
		fs_mgr_overlayfs_scratch_mount_type());
		}
		}
		OverlayfsTeardownResult TeardownMountsAndScratch(const char* mount_point, bool* want_reboot) {
		bool should_destroy_scratch = false;
		auto rv = OverlayfsTeardownResult::Ok;
		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,
		auto ok = fs_mgr_overlayfs_teardown_one(
		overlay_mount_point, mount_point ? fs_mgr_mount_point(mount_point) : "",
		want_reboot,
		overlay_mount_point == kScratchMountPoint ? &should_destroy_scratch : nullptr);
		if (!ok) {
		rv = OverlayfsTeardownResult::Error;
		}
		}

		// Do not attempt to destroy DSU scratch if within a DSU system,
		// because DSU scratch partition is managed by gsid.
		if (should_destroy_scratch && !fs_mgr_is_dsu_running()) {
		ret &= fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, change);
		auto rv = fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, want_reboot);
		if (rv != OverlayfsTeardownResult::Ok) {
		return rv;
		}
		if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) {
		// After obligatory teardown to make sure everything is clean, but if
		// we didn't want overlayfs in the first place, we do not want to
		// waste time on a reboot (or reboot request message).
		if (change) *change = false;
		}
		// And now that we did what we could, lets inform
		// caller that there may still be more to do.
		if (!fs_mgr_boot_completed()) {
		errno = EBUSY;
		PERROR << "teardown";
		ret = false;
		LOG(ERROR) << "Cannot teardown overlayfs before persistent properties are ready";
		return OverlayfsTeardownResult::Error;
		}
		return rv;
		}

		// Returns false if teardown not permitted. If something is altered, set *want_reboot.
		OverlayfsTeardownResult fs_mgr_overlayfs_teardown(const char* mount_point, bool* want_reboot) {
		// If scratch exists, but is not mounted, lets gain access to clean
		// specific override entries.
		auto mount_scratch = false;
		if ((mount_point != nullptr) && !fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
		std::string scratch_device = GetBootScratchDevice();
		if (!scratch_device.empty()) {
		mount_scratch = fs_mgr_overlayfs_mount_scratch(scratch_device,
		fs_mgr_overlayfs_scratch_mount_type());
		}
		}

		auto rv = TeardownMountsAndScratch(mount_point, want_reboot);

		if (mount_scratch) {
		fs_mgr_overlayfs_umount_scratch();
		if (!fs_mgr_overlayfs_umount_scratch()) {
		return OverlayfsTeardownResult::Busy;
		}
		return ret;
		}
		return rv;
		}

		bool fs_mgr_overlayfs_is_setup() {
		@@ -1689,6 +1709,7 @@ void TeardownAllOverlayForMountPoint(const std::string& mount_point) {
		}
		}

		// Note if we just disabled scratch, this mount will fail.
		if (auto info = EnsureScratchMapped(); info.has_value()) {
		// Map scratch device, mount kScratchMountPoint and teardown kScratchMountPoint.
		fs_mgr_overlayfs_umount_scratch();

fs_mgr/include/fs_mgr_overlayfs.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -28,7 +28,6 @@ android::fs_mgr::Fstab fs_mgr_overlayfs_candidate_list(const android::fs_mgr::Fs

		bool fs_mgr_wants_overlayfs(android::fs_mgr::FstabEntry* entry);
		bool fs_mgr_overlayfs_mount_all(android::fs_mgr::Fstab* fstab);
		bool fs_mgr_overlayfs_teardown(const char* mount_point = nullptr, bool* change = nullptr);
		bool fs_mgr_overlayfs_is_setup();
		bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev);
		bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only = true);
		@@ -42,6 +41,14 @@ std::string fs_mgr_get_context(const std::string& mount_point);
		bool fs_mgr_overlayfs_setup(const char* mount_point = nullptr, bool* want_reboot = nullptr,
		bool just_disabled_verity = true);

		enum class OverlayfsTeardownResult {
		Ok,
		Busy, // Indicates that overlays are still in use.
		Error
		};
		OverlayfsTeardownResult fs_mgr_overlayfs_teardown(const char* mount_point = nullptr,
		bool* want_reboot = nullptr);

		enum class OverlayfsValidResult {
		kNotSupported = 0,
		kOk,

fs_mgr/libfiemap/binder.cpp

+8 −3

Original line number	Diff line number	Diff line
		@@ -195,10 +195,15 @@ bool ImageManagerBinder::RemoveAllImages() {
		return true;
		}

		bool ImageManagerBinder::DisableImage(const std::string&) {
		LOG(ERROR) << __PRETTY_FUNCTION__ << " is not available over binder";
		bool ImageManagerBinder::DisableImage(const std::string& name) {
		auto status = manager_->disableImage(name);
		if (!status.isOk()) {
		LOG(ERROR) << __PRETTY_FUNCTION__
		<< " binder returned: " << status.exceptionMessage().string();
		return false;
		}
		return true;
		}

		bool ImageManagerBinder::RemoveDisabledImages() {
		auto status = manager_->removeDisabledImages();

fs_mgr/libfiemap/include/libfiemap/image_manager.h

+0 −3

Original line number	Diff line number	Diff line
		@@ -112,9 +112,6 @@ class IImageManager {

		// Mark an image as disabled. This is useful for marking an image as
		// will-be-deleted in recovery, since recovery cannot mount /data.
		//
		// This is not available in binder, since it is intended for recovery.
		// When binder is available, images can simply be removed.
		virtual bool DisableImage(const std::string& name) = 0;

		// Remove all images that been marked as disabled.

set-verity-state/set-verity-state.cpp

+28 −15

Original line number	Diff line number	Diff line
		@@ -47,6 +47,33 @@ const bool kAllowDisableVerity = true;
		const bool kAllowDisableVerity = false;
		#endif

		static bool SetupOrTeardownOverlayfs(bool enable) {
		bool want_reboot = false;
		if (enable) {
		if (!fs_mgr_overlayfs_setup(nullptr, &want_reboot)) {
		LOG(ERROR) << "Overlayfs setup failed.";
		return want_reboot;
		}
		if (want_reboot) {
		printf("enabling overlayfs\n");
		}
		} else {
		auto rv = fs_mgr_overlayfs_teardown(nullptr, &want_reboot);
		if (rv == OverlayfsTeardownResult::Error) {
		LOG(ERROR) << "Overlayfs teardown failed.";
		return want_reboot;
		}
		if (rv == OverlayfsTeardownResult::Busy) {
		LOG(ERROR) << "Overlayfs is still active until reboot.";
		return true;
		}
		if (want_reboot) {
		printf("disabling overlayfs\n");
		}
		}
		return want_reboot;
		}

		/* Helper function to get A/B suffix, if any. If the device isn't
		* using A/B the empty string is returned. Otherwise either "_a",
		* "_b", ... is returned.
		@@ -79,20 +106,6 @@ bool is_using_avb() {
		::exit(1);
		}

		bool overlayfs_setup(bool enable) {
		auto want_reboot = false;
		errno = 0;
		if (enable ? fs_mgr_overlayfs_setup(nullptr, &want_reboot)
		: fs_mgr_overlayfs_teardown(nullptr, &want_reboot)) {
		if (want_reboot) {
		LOG(INFO) << (enable ? "Enabled" : "Disabled") << " overlayfs";
		}
		} else {
		LOG(ERROR) << "Failed to " << (enable ? "enable" : "disable") << " overlayfs";
		}
		return want_reboot;
		}

		struct SetVerityStateResult {
		bool success = false;
		bool want_reboot = false;
		@@ -229,7 +242,7 @@ int main(int argc, char* argv[]) {
		// Start a threadpool to service waitForService() callbacks as
		// fs_mgr_overlayfs_* might call waitForService() to get the image service.
		android::ProcessState::self()->startThreadPool();
		want_reboot \|= overlayfs_setup(!enable_verity);
		want_reboot \|= SetupOrTeardownOverlayfs(!enable_verity);
		}

		if (want_reboot) {