fs_mgr: remount: add -R argument (1188ce4e) · Commits · e / os / android_system_core

fs_mgr/Android.bp

+7 −0

Original line number	Diff line number	Diff line
		@@ -115,10 +115,17 @@ cc_library_static {
		cc_binary {
		name: "remount",
		defaults: ["fs_mgr_defaults"],
		static_libs: [
		"libavb_user",
		],
		shared_libs: [
		"libbootloader_message",
		"libbase",
		"libfs_mgr",
		],
		header_libs: [
		"libcutils_headers",
		],
		srcs: [
		"fs_mgr_remount.cpp",
		],

fs_mgr/fs_mgr_remount.cpp

+57 −15

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@

		#include <errno.h>
		#include <getopt.h>
		#include <libavb_user/libavb_user.h>
		#include <stdio.h>
		#include <sys/mount.h>
		#include <sys/types.h>
		@@ -30,6 +31,8 @@
		#include <android-base/logging.h>
		#include <android-base/properties.h>
		#include <android-base/strings.h>
		#include <bootloader_message/bootloader_message.h>
		#include <cutils/android_reboot.h>
		#include <fs_mgr_overlayfs.h>
		#include <fs_mgr_priv.h>
		#include <fstab/fstab.h>
		@@ -38,12 +41,13 @@ namespace {

		[[noreturn]] void usage(int exit_status) {
		LOG(INFO) << getprogname()
		<< " [-h] [-T fstab_file]\n"
		<< " [-h] [-R] [-T fstab_file]\n"
		"\t-h --help\tthis help\n"
		"\t-R --reboot\tdisable verity & reboot to facilitate remount\n"
		"\t-T --fstab\tcustom fstab file location\n"
		"\n"
		"Remount all partitions read-write.\n"
		"Verity must be disabled.";
		"-R notwithstanding, verity must be disabled.";

		::exit(exit_status);
		}
		@@ -110,6 +114,18 @@ void MyLogger(android::base::LogId id, android::base::LogSeverity severity, cons
		logd(id, severity, tag, file, line, message);
		}

		[[noreturn]] void reboot(bool dedupe) {
		if (dedupe) {
		LOG(INFO) << "The device will now reboot to recovery and attempt un-deduplication.";
		} else {
		LOG(INFO) << "Successfully disabled verity\nrebooting device";
		}
		::sync();
		android::base::SetProperty(ANDROID_RB_PROPERTY, dedupe ? "reboot,recovery" : "reboot,remount");
		::sleep(60);
		::exit(0); // SUCCESS
		}

		} // namespace

		int main(int argc, char* argv[]) {
		@@ -136,14 +152,19 @@ int main(int argc, char* argv[]) {
		}

		const char* fstab_file = nullptr;
		auto can_reboot = false;

		struct option longopts[] = {
		{"fstab", required_argument, nullptr, 'T'},
		{"help", no_argument, nullptr, 'h'},
		{"reboot", no_argument, nullptr, 'R'},
		{0, 0, nullptr, 0},
		};
		for (int opt; (opt = ::getopt_long(argc, argv, "hT:", longopts, nullptr)) != -1;) {
		for (int opt; (opt = ::getopt_long(argc, argv, "hRT:", longopts, nullptr)) != -1;) {
		switch (opt) {
		case 'R':
		can_reboot = true;
		break;
		case 'T':
		if (fstab_file) {
		LOG(ERROR) << "Cannot supply two fstabs: -T " << fstab_file << " -T" << optarg;
		@@ -200,11 +221,32 @@ int main(int argc, char* argv[]) {
		}

		// Check verity and optionally setup overlayfs backing.
		auto reboot_later = false;
		for (auto it = partitions.begin(); it != partitions.end();) {
		auto& entry = *it;
		auto& mount_point = entry.mount_point;
		if (fs_mgr_is_verity_enabled(entry)) {
		LOG(ERROR) << "Verity enabled on " << mount_point << ", skipping";
		LOG(WARNING) << "Verity enabled on " << mount_point;
		if (can_reboot &&
		(android::base::GetProperty("ro.boot.vbmeta.devices_state", "") != "locked")) {
		if (AvbOps* ops = avb_ops_user_new()) {
		auto ret = avb_user_verity_set(
		ops, android::base::GetProperty("ro.boot.slot_suffix", "").c_str(),
		false);
		avb_ops_user_free(ops);
		if (ret) {
		if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) {
		retval = VERITY_PARTITION;
		// w/o overlayfs available, also check for dedupe
		reboot_later = true;
		++it;
		continue;
		}
		reboot(false);
		}
		}
		}
		LOG(ERROR) << "Skipping " << mount_point;
		retval = VERITY_PARTITION;
		it = partitions.erase(it);
		continue;
		@@ -278,23 +320,23 @@ int main(int argc, char* argv[]) {
		continue;
		}
		}
		PLOG(WARNING) << "failed to remount partition dev:" << blk_device << " mnt:" << mount_point;
		// If errno = EROFS at this point, we are dealing with r/o
		// filesystem types like squashfs, erofs or ext4 dedupe. We will
		// consider such a device that does not have CONFIG_OVERLAY_FS
		// in the kernel as a misconfigured and take no action.
		//
		// ext4 dedupe _can_ be worked around by performing a reboot into
		// recovery and fsck'ing. However the current decision is to not
		// reboot to reserve only one shell command to do so (reboot). In
		// the future, if this is a problem, a -R flag could be introduced
		// to give permission to do so and as a convenience also implement
		// verity disable operations. We will require this functionality
		// in order for adb remount to call this executable instead of its
		// current internal code that recognizes the -R flag and logistics.
		PLOG(ERROR) << "failed to remount partition dev:" << blk_device << " mnt:" << mount_point;
		// in the kernel as a misconfigured; except for ext4 dedupe.
		if ((errno == EROFS) && can_reboot) {
		const std::vector<std::string> msg = {"--fsck_unshare_blocks"};
		std::string err;
		if (write_bootloader_message(msg, &err)) reboot(true);
		LOG(ERROR) << "Failed to set bootloader message: " << err;
		errno = EROFS;
		}
		retval = REMOUNT_FAILED;
		}

		if (reboot_later) reboot(false);

		try_unmount_bionic(&mounts);

		return retval;

fs_mgr/tests/adb-remount-test.sh

+30 −0

Original line number	Diff line number	Diff line
		@@ -617,6 +617,19 @@ if [ "orange" = "`get_property ro.boot.verifiedbootstate`" -a \
		adb_reboot &&
		adb_wait 2m
		}

		echo "${GREEN}[ RUN ]${NORMAL} Testing adb shell su root remount -R command" >&2

		adb_su remount -R </dev/null \|\| true
		sleep 2
		adb_wait 2m \|\|
		die "waiting for device after remount -R `usb_status`"
		if [ "orange" != "`get_property ro.boot.verifiedbootstate`" -o \
		"2" = "`get_property partition.system.verified`" ]; then
		die "remount -R command failed"
		fi

		echo "${GREEN}[ OK ]${NORMAL} adb shell su root remount -R command" >&2
		fi

		echo "${GREEN}[ RUN ]${NORMAL} Testing kernel support for overlayfs" >&2
		@@ -1173,6 +1186,23 @@ echo "${GREEN}[ OK ]${NORMAL} remount command works from scratch" >&2
		restore
		err=${?}

		if [ ${err} = 0 ] && ${overlayfs_supported}; then
		echo "${GREEN}[ RUN ]${NORMAL} test 'adb remount -R'" >&2
		adb_root &&
		adb remount -R &&
		adb_wait 2m \|\|
		die "adb remount -R"
		if [ "orange" != "`get_property ro.boot.verifiedbootstate`" -o \
		"2" = "`get_property partition.system.verified`" ]; then
		die "remount -R command failed to disable verity"
		fi

		echo "${GREEN}[ OK ]${NORMAL} 'adb remount -R' command" >&2

		restore
		err=${?}
		fi

		restore() {
		true
		}