Merge "init: do not fork before doing (u)mount_all()" (fc174928) · Commits · e / os / android_system_core

init/builtins.cpp

+14 −80

Original line number	Diff line number	Diff line
		@@ -451,78 +451,6 @@ static void import_late(const std::vector<std::string>& args, size_t start_index
		if (false) DumpState();
		}

		/* handle_fstab
		*
		* Read the given fstab file and execute func on it.
		*/
		static Result<int> handle_fstab(const std::string& fstabfile, std::function<int(Fstab*)> func) {
		/*
		* Call fs_mgr_[u]mount_all() to [u]mount all filesystems. We fork(2) and
		* do the call in the child to provide protection to the main init
		* process if anything goes wrong (crash or memory leak), and wait for
		* the child to finish in the parent.
		*/
		pid_t pid = fork();
		if (pid > 0) {
		/* Parent. Wait for the child to return */
		int status;
		int wp_ret = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
		if (wp_ret == -1) {
		// Unexpected error code. We will continue anyway.
		PLOG(WARNING) << "waitpid failed";
		}

		if (WIFEXITED(status)) {
		return WEXITSTATUS(status);
		} else {
		return Error() << "child aborted";
		}
		} else if (pid == 0) {
		/* child, call fs_mgr_[u]mount_all() */

		// So we can always see what fs_mgr_[u]mount_all() does.
		// Only needed if someone explicitly changes the default log level in their init.rc.
		android::base::ScopedLogSeverity info(android::base::INFO);

		Fstab fstab;
		ReadFstabFromFile(fstabfile, &fstab);

		int child_ret = func(&fstab);

		_exit(child_ret);
		} else {
		return Error() << "fork() failed";
		}
		}

		/* mount_fstab
		*
		* Call fs_mgr_mount_all() to mount the given fstab
		*/
		static Result<int> mount_fstab(const std::string& fstabfile, int mount_mode) {
		return handle_fstab(fstabfile, [mount_mode](Fstab* fstab) {
		int ret = fs_mgr_mount_all(fstab, mount_mode);
		if (ret == -1) {
		PLOG(ERROR) << "fs_mgr_mount_all returned an error";
		}
		return ret;
		});
		}

		/* umount_fstab
		*
		* Call fs_mgr_umount_all() to umount the given fstab
		*/
		static Result<int> umount_fstab(const std::string& fstabfile) {
		return handle_fstab(fstabfile, [](Fstab* fstab) {
		int ret = fs_mgr_umount_all(fstab);
		if (ret != 0) {
		PLOG(ERROR) << "fs_mgr_umount_all returned " << ret;
		}
		return ret;
		});
		}

		/* Queue event based on fs_mgr return code.
		*
		* code: return code of fs_mgr_mount_all
		@@ -609,7 +537,7 @@ static Result<Success> do_mount_all(const BuiltinArguments& args) {
		bool import_rc = true;
		bool queue_event = true;
		int mount_mode = MOUNT_MODE_DEFAULT;
		const auto& fstabfile = args[1];
		const auto& fstab_file = args[1];
		std::size_t path_arg_end = args.size();
		const char* prop_post_fix = "default";

		@@ -629,10 +557,12 @@ static Result<Success> do_mount_all(const BuiltinArguments& args) {

		std::string prop_name = "ro.boottime.init.mount_all."s + prop_post_fix;
		android::base::Timer t;
		auto mount_fstab_return_code = mount_fstab(fstabfile, mount_mode);
		if (!mount_fstab_return_code) {
		return Error() << "mount_fstab() failed " << mount_fstab_return_code.error();

		Fstab fstab;
		if (!ReadFstabFromFile(fstab_file, &fstab)) {
		return Error() << "Could not read fstab";
		}
		auto mount_fstab_return_code = fs_mgr_mount_all(&fstab, mount_mode);
		property_set(prop_name, std::to_string(t.duration().count()));

		if (import_rc) {
		@@ -643,7 +573,7 @@ static Result<Success> do_mount_all(const BuiltinArguments& args) {
		if (queue_event) {
		/* queue_fs_event will queue event based on mount_fstab return code
		* and return processed return code*/
		auto queue_fs_result = queue_fs_event(*mount_fstab_return_code);
		auto queue_fs_result = queue_fs_event(mount_fstab_return_code);
		if (!queue_fs_result) {
		return Error() << "queue_fs_event() failed: " << queue_fs_result.error();
		}
		@@ -654,9 +584,13 @@ static Result<Success> do_mount_all(const BuiltinArguments& args) {

		/* umount_all <fstab> */
		static Result<Success> do_umount_all(const BuiltinArguments& args) {
		auto umount_fstab_return_code = umount_fstab(args[1]);
		if (!umount_fstab_return_code) {
		return Error() << "umount_fstab() failed " << umount_fstab_return_code.error();
		Fstab fstab;
		if (!ReadFstabFromFile(args[1], &fstab)) {
		return Error() << "Could not read fstab";
		}

		if (auto result = fs_mgr_umount_all(&fstab); result != 0) {
		return Error() << "umount_fstab() failed " << result;
		}
		return Success();
		}