Merge "adb: add remount -R for deduplicated ext4" (3f0225ab) · Commits · e / os / android_system_core

adb/daemon/remount_service.cpp

+91 −29

Original line number	Diff line number	Diff line
		@@ -29,10 +29,13 @@
		#include <sys/vfs.h>
		#include <unistd.h>

		#include <set>
		#include <string>
		#include <vector>

		#include <android-base/properties.h>
		#include <bootloader_message/bootloader_message.h>
		#include <cutils/android_reboot.h>
		#include <ext4_utils/ext4_utils.h>

		#include "adb.h"
		@@ -142,7 +145,7 @@ static bool can_unshare_blocks(int fd, const char* dev) {
		return true;
		}

		static bool remount_partition(int fd, const char* dir, std::vector<std::string>& dedup) {
		static bool remount_partition(int fd, const char* dir) {
		if (!directory_exists(dir)) {
		return true;
		}
		@@ -168,32 +171,83 @@ static bool remount_partition(int fd, const char* dir, std::vector<std::string>&
		return false;
		}
		if (mount(dev.c_str(), dir, "none", MS_REMOUNT, nullptr) == -1) {
		if (errno == EROFS && fs_has_shared_blocks(dev.c_str())) {
		if (!can_unshare_blocks(fd, dev.c_str())) {
		WriteFdFmt(fd, "remount of the %s superblock failed: %s\n", dir, strerror(errno));
		return false;
		}
		// We return true so remount_service() can detect that the only
		// failure was deduplicated filesystems.
		dedup.push_back(dev);
		return true;
		}
		WriteFdFmt(fd, "remount of the %s superblock failed: %s\n", dir, strerror(errno));
		return false;

		static void reboot_for_remount(int fd, bool need_fsck) {
		std::string reboot_cmd = "reboot";
		if (need_fsck) {
		const std::vector<std::string> options = {"--fsck_unshare_blocks"};
		std::string err;
		if (!write_bootloader_message(options, &err)) {
		WriteFdFmt(fd, "Failed to set bootloader message: %s\n", err.c_str());
		return;
		}
		return true;

		WriteFdExactly(fd,
		"The device will now reboot to recovery and attempt "
		"un-deduplication.\n");
		reboot_cmd = "reboot,recovery";
		}

		sync();
		android::base::SetProperty(ANDROID_RB_PROPERTY, reboot_cmd.c_str());
		}

		void remount_service(int fd, void* cookie) {
		unique_fd close_fd(fd);

		const char* cmd = reinterpret_cast<const char*>(cookie);
		bool user_requested_reboot = cmd && !strcmp(cmd, "-R");

		if (getuid() != 0) {
		WriteFdExactly(fd, "Not running as root. Try \"adb root\" first.\n");
		adb_close(fd);
		return;
		}

		bool system_verified = !(android::base::GetProperty("partition.system.verified", "").empty());
		bool vendor_verified = !(android::base::GetProperty("partition.vendor.verified", "").empty());

		if (system_verified \|\| vendor_verified) {
		std::vector<std::string> partitions = {"/odm", "/oem", "/product", "/vendor"};
		if (android::base::GetBoolProperty("ro.build.system_root_image", false)) {
		partitions.push_back("/");
		} else {
		partitions.push_back("/system");
		}

		// Find partitions that are deduplicated, and can be un-deduplicated.
		std::set<std::string> dedup;
		for (const auto& partition : partitions) {
		std::string dev = find_mount(partition.c_str(), partition == "/");
		if (dev.empty() \|\| !fs_has_shared_blocks(dev.c_str())) {
		continue;
		}
		if (can_unshare_blocks(fd, dev.c_str())) {
		dedup.emplace(partition);
		}
		}

		bool verity_enabled = (system_verified \|\| vendor_verified);

		// Reboot now if the user requested it (and an operation needs a reboot).
		if (user_requested_reboot) {
		if (!dedup.empty() \|\| verity_enabled) {
		if (verity_enabled) {
		set_verity_enabled_state_service(fd, nullptr);
		}
		reboot_for_remount(fd, !dedup.empty());
		return;
		}
		WriteFdExactly(fd, "No reboot needed, skipping -R.\n");
		}

		// If we need to disable-verity, but we also need to perform a recovery
		// fsck for deduplicated partitions, hold off on warning about verity. We
		// can handle both verity and the recovery fsck in the same reboot cycle.
		if (verity_enabled && dedup.empty()) {
		// Allow remount but warn of likely bad effects
		bool both = system_verified && vendor_verified;
		WriteFdFmt(fd,
		@@ -206,32 +260,40 @@ void remount_service(int fd, void* cookie) {
		"Use \"adb disable-verity\" to disable verity.\n"
		"If you do not, remount may succeed, however, you will still "
		"not be able to write to these volumes.\n");
		WriteFdExactly(fd,
		"Alternately, use \"adb remount -R\" to disable verity "
		"and automatically reboot.\n");
		}

		bool success = true;
		std::vector<std::string> dedup;
		if (android::base::GetBoolProperty("ro.build.system_root_image", false)) {
		success &= remount_partition(fd, "/", dedup);
		} else {
		success &= remount_partition(fd, "/system", dedup);
		for (const auto& partition : partitions) {
		// Don't try to remount partitions that need an fsck in recovery.
		if (dedup.count(partition)) {
		continue;
		}
		success &= remount_partition(fd, partition.c_str());
		}
		success &= remount_partition(fd, "/odm", dedup);
		success &= remount_partition(fd, "/oem", dedup);
		success &= remount_partition(fd, "/product", dedup);
		success &= remount_partition(fd, "/vendor", dedup);

		if (!success) {
		WriteFdExactly(fd, "remount failed\n");
		} else if (dedup.empty()) {
		WriteFdExactly(fd, "remount succeeded\n");
		} else {
		if (!dedup.empty()) {
		WriteFdExactly(fd,
		"The following partitions are deduplicated and could "
		"not be remounted:\n");
		"The following partitions are deduplicated and cannot "
		"yet be remounted:\n");
		for (const std::string& name : dedup) {
		WriteFdFmt(fd, " %s\n", name.c_str());
		}

		WriteFdExactly(fd,
		"To reboot and un-deduplicate the listed partitions, "
		"please retry with adb remount -R.\n");
		if (system_verified \|\| vendor_verified) {
		WriteFdExactly(fd, "Note: verity will be automatically disabled after reboot.\n");
		}
		return;
		}

		adb_close(fd);
		if (!success) {
		WriteFdExactly(fd, "remount failed\n");
		} else {
		WriteFdExactly(fd, "remount succeeded\n");
		}
		}

adb/services.cpp

+3 −1

Original line number	Diff line number	Diff line
		@@ -291,7 +291,9 @@ int service_to_fd(const char* name, atransport* transport) {
		} else if(!strncmp(name, "sync:", 5)) {
		ret = create_service_thread("sync", file_sync_service, nullptr);
		} else if(!strncmp(name, "remount:", 8)) {
		ret = create_service_thread("remount", remount_service, nullptr);
		const char* options = name + strlen("remount:");
		void* cookie = const_cast<void>(reinterpret_cast<const void>(options));
		ret = create_service_thread("remount", remount_service, cookie);
		} else if(!strncmp(name, "reboot:", 7)) {
		void* arg = strdup(name + 7);
		if (arg == NULL) return -1;