Merge "Truncate the given userdata_exp alias partition" into main (25754f24) · Commits · e / os / android_system_core

fs_mgr/Android.bp

+22 −0

Original line number	Diff line number	Diff line
		@@ -238,3 +238,25 @@ cc_binary {
		"set-verity-state",
		],
		}

		cc_binary {
		name: "userdata_alias_remove",
		srcs: [
		"userdata_alias_remove.cpp",
		],
		header_libs: [
		"libbase_headers",
		],
		static_libs: [
		"libfstab",
		],
		shared_libs: [
		"libbase",
		],
		init_rc: ["userdata.alias.remove.rc"],
		cflags: [
		"-Werror",
		"-Wall",
		"-Wextra",
		],
		}

fs_mgr/libfstab/fstab.cpp

+15 −1

Original line number	Diff line number	Diff line
		@@ -170,7 +170,21 @@ void ParseUserDevices(const std::string& arg, FstabEntry* entry) {
		entry->fs_mgr_flags.is_zoned = true;
		}
		entry->user_devices.push_back(param[1]);
		entry->device_aliased.push_back(param[0] == "exp_alias" ? 1 : 0);

		if (param[0] == "exp_alias") {
		std::string_view exp_alias_prefix = "userdata_exp.";
		std::string deviceName = android::base::Basename(param[1]);
		if (!android::base::StartsWith(deviceName, exp_alias_prefix)) {
		LERROR << "Device aliasing file " << deviceName << " doesn't start with "
		<< exp_alias_prefix;
		entry->user_devices.pop_back();
		return;
		}

		entry->device_aliased.push_back(1);
		} else {
		entry->device_aliased.push_back(0);
		}
		}

		bool ParseFsMgrFlags(const std::string& flags, FstabEntry* entry) {

fs_mgr/userdata.alias.remove.rc

0 → 100644

+7 −0

Original line number	Diff line number	Diff line
		# Userdata device aliasing file control service

		service userdata_alias_remove /system/bin/userdata_alias_remove
		user root
		group system
		disabled
		oneshot

fs_mgr/userdata_alias_remove.cpp

0 → 100644

+66 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2025 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		/*
		* This removes a userdata aliasing file, which maps storage space for
		* a specific purpose to a special-purpose partition, allowing for its
		* later release.
		*/

		#include <errno.h>
		#include <error.h>
		#include <stdio.h>

		#include <android-base/file.h>
		#include <android-base/properties.h>

		#include <fstab/fstab.h>

		static constexpr const char* ALIAS_REMOVE_PROP_NAME = "userdata.alias.remove";

		int main(void) {
		android::fs_mgr::Fstab fstab;
		if (!android::fs_mgr::ReadDefaultFstab(&fstab)) {
		error(1, 0, "no valid fstab");
		}

		android::fs_mgr::FstabEntry* dataEntry =
		android::fs_mgr::GetEntryForMountPoint(&fstab, "/data");
		if (!dataEntry) {
		error(1, 0, "/data is not mounted yet");
		}

		/* Only F2FS supports device aliasing file */
		if (dataEntry->fs_type != "f2fs") {
		return 0;
		}

		std::string target = android::base::GetProperty(ALIAS_REMOVE_PROP_NAME, "");
		for (size_t i = 0; i < dataEntry->user_devices.size(); ++i) {
		if (dataEntry->device_aliased[i]) {
		std::string deviceName = android::base::Basename(dataEntry->user_devices[i]);
		if (target == deviceName) {
		std::string filename = "/data/" + target;
		if (unlink(filename.c_str())) {
		error(1, errno, "Failed to remove file: %s", filename.c_str());
		}
		return 0;
		}
		}
		}

		error(1, 0, "%s is not a device aliasing file", target.c_str());
		}