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android_system_core/fs_mgr/fs_mgr.cpp

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/*
* Copyright (C) 2012 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.
*/
#include "fs_mgr.h"
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/swap.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <chrono>
#include <functional>
#include <map>
#include <memory>
#include <string>
#include <thread>
#include <utility>
#include <vector>
#include <android-base/chrono_utils.h>
#include <android-base/file.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <cutils/android_filesystem_config.h>
#include <cutils/android_reboot.h>
#include <cutils/partition_utils.h>
#include <cutils/properties.h>
#include <ext4_utils/ext4.h>
#include <ext4_utils/ext4_sb.h>
#include <ext4_utils/ext4_utils.h>
#include <ext4_utils/wipe.h>
#include <fs_avb/fs_avb.h>
#include <fs_mgr/file_wait.h>
#include <fs_mgr_overlayfs.h>
#include <fscrypt/fscrypt.h>
#include <libdm/dm.h>
#include <libdm/loop_control.h>
#include <liblp/metadata_format.h>
#include <linux/fs.h>
#include <linux/loop.h>
#include <linux/magic.h>
#include <log/log_properties.h>
#include <logwrap/logwrap.h>
#include "fs_mgr_priv.h"
#define KEY_LOC_PROP "ro.crypto.keyfile.userdata"
#define KEY_IN_FOOTER "footer"
#define E2FSCK_BIN "/system/bin/e2fsck"
#define F2FS_FSCK_BIN "/system/bin/fsck.f2fs"
#define MKSWAP_BIN "/system/bin/mkswap"
#define TUNE2FS_BIN "/system/bin/tune2fs"
#define RESIZE2FS_BIN "/system/bin/resize2fs"
#define FSCK_LOG_FILE "/dev/fscklogs/log"
#define ZRAM_CONF_DEV "/sys/block/zram0/disksize"
#define ZRAM_CONF_MCS "/sys/block/zram0/max_comp_streams"
#define ZRAM_BACK_DEV "/sys/block/zram0/backing_dev"
#define SYSFS_EXT4_VERITY "/sys/fs/ext4/features/verity"
#define SYSFS_EXT4_CASEFOLD "/sys/fs/ext4/features/casefold"
// FIXME: this should be in system/extras
#define EXT4_FEATURE_COMPAT_STABLE_INODES 0x0800
#define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
using android::base::Basename;
using android::base::GetBoolProperty;
using android::base::GetUintProperty;
using android::base::Realpath;
using android::base::SetProperty;
using android::base::StartsWith;
using android::base::Timer;
using android::base::unique_fd;
using android::dm::DeviceMapper;
using android::dm::DmDeviceState;
using android::dm::DmTargetLinear;
using android::dm::LoopControl;
// Realistically, this file should be part of the android::fs_mgr namespace;
using namespace android::fs_mgr;
using namespace std::literals;
// record fs stat
enum FsStatFlags {
FS_STAT_IS_EXT4 = 0x0001,
FS_STAT_NEW_IMAGE_VERSION = 0x0002,
FS_STAT_E2FSCK_F_ALWAYS = 0x0004,
FS_STAT_UNCLEAN_SHUTDOWN = 0x0008,
FS_STAT_QUOTA_ENABLED = 0x0010,
FS_STAT_RO_MOUNT_FAILED = 0x0040,
FS_STAT_RO_UNMOUNT_FAILED = 0x0080,
FS_STAT_FULL_MOUNT_FAILED = 0x0100,
FS_STAT_E2FSCK_FAILED = 0x0200,
FS_STAT_E2FSCK_FS_FIXED = 0x0400,
FS_STAT_INVALID_MAGIC = 0x0800,
FS_STAT_TOGGLE_QUOTAS_FAILED = 0x10000,
FS_STAT_SET_RESERVED_BLOCKS_FAILED = 0x20000,
FS_STAT_ENABLE_ENCRYPTION_FAILED = 0x40000,
FS_STAT_ENABLE_VERITY_FAILED = 0x80000,
FS_STAT_ENABLE_CASEFOLD_FAILED = 0x100000,
FS_STAT_ENABLE_METADATA_CSUM_FAILED = 0x200000,
};
static void log_fs_stat(const std::string& blk_device, int fs_stat) {
if ((fs_stat & FS_STAT_IS_EXT4) == 0) return; // only log ext4
std::string msg =
android::base::StringPrintf("\nfs_stat,%s,0x%x\n", blk_device.c_str(), fs_stat);
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(FSCK_LOG_FILE, O_WRONLY | O_CLOEXEC |
O_APPEND | O_CREAT, 0664)));
if (fd == -1 || !android::base::WriteStringToFd(msg, fd)) {
LWARNING << __FUNCTION__ << "() cannot log " << msg;
}
}
static bool is_extfs(const std::string& fs_type) {
return fs_type == "ext4" || fs_type == "ext3" || fs_type == "ext2";
}
static bool is_f2fs(const std::string& fs_type) {
return fs_type == "f2fs";
}
static std::string realpath(const std::string& blk_device) {
std::string real_path;
if (!Realpath(blk_device, &real_path)) {
real_path = blk_device;
}
return real_path;
}
static bool should_force_check(int fs_stat) {
return fs_stat &
(FS_STAT_E2FSCK_F_ALWAYS | FS_STAT_UNCLEAN_SHUTDOWN | FS_STAT_QUOTA_ENABLED |
FS_STAT_RO_MOUNT_FAILED | FS_STAT_RO_UNMOUNT_FAILED | FS_STAT_FULL_MOUNT_FAILED |
FS_STAT_E2FSCK_FAILED | FS_STAT_TOGGLE_QUOTAS_FAILED |
FS_STAT_SET_RESERVED_BLOCKS_FAILED | FS_STAT_ENABLE_ENCRYPTION_FAILED);
}
static void check_fs(const std::string& blk_device, const std::string& fs_type,
const std::string& target, int* fs_stat) {
int status;
int ret;
long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
auto tmpmnt_opts = "errors=remount-ro"s;
const char* e2fsck_argv[] = {E2FSCK_BIN, "-y", blk_device.c_str()};
const char* e2fsck_forced_argv[] = {E2FSCK_BIN, "-f", "-y", blk_device.c_str()};
if (*fs_stat & FS_STAT_INVALID_MAGIC) { // will fail, so do not try
return;
}
Timer t;
/* Check for the types of filesystems we know how to check */
if (is_extfs(fs_type)) {
/*
* First try to mount and unmount the filesystem. We do this because
* the kernel is more efficient than e2fsck in running the journal and
* processing orphaned inodes, and on at least one device with a
* performance issue in the emmc firmware, it can take e2fsck 2.5 minutes
* to do what the kernel does in about a second.
*
* After mounting and unmounting the filesystem, run e2fsck, and if an
* error is recorded in the filesystem superblock, e2fsck will do a full
* check. Otherwise, it does nothing. If the kernel cannot mount the
* filesytsem due to an error, e2fsck is still run to do a full check
* fix the filesystem.
*/
if (!(*fs_stat & FS_STAT_FULL_MOUNT_FAILED)) { // already tried if full mount failed
errno = 0;
if (fs_type == "ext4") {
// This option is only valid with ext4
tmpmnt_opts += ",nomblk_io_submit";
}
ret = mount(blk_device.c_str(), target.c_str(), fs_type.c_str(), tmpmnt_flags,
tmpmnt_opts.c_str());
PINFO << __FUNCTION__ << "(): mount(" << blk_device << "," << target << "," << fs_type
<< ")=" << ret;
if (!ret) {
bool umounted = false;
int retry_count = 5;
while (retry_count-- > 0) {
umounted = umount(target.c_str()) == 0;
if (umounted) {
LINFO << __FUNCTION__ << "(): unmount(" << target << ") succeeded";
break;
}
PERROR << __FUNCTION__ << "(): umount(" << target << ") failed";
if (retry_count) sleep(1);
}
if (!umounted) {
// boot may fail but continue and leave it to later stage for now.
PERROR << __FUNCTION__ << "(): umount(" << target << ") timed out";
*fs_stat |= FS_STAT_RO_UNMOUNT_FAILED;
}
} else {
*fs_stat |= FS_STAT_RO_MOUNT_FAILED;
}
}
/*
* Some system images do not have e2fsck for licensing reasons
* (e.g. recent SDK system images). Detect these and skip the check.
*/
if (access(E2FSCK_BIN, X_OK)) {
LINFO << "Not running " << E2FSCK_BIN << " on " << realpath(blk_device)
<< " (executable not in system image)";
} else {
LINFO << "Running " << E2FSCK_BIN << " on " << realpath(blk_device);
if (should_force_check(*fs_stat)) {
ret = logwrap_fork_execvp(ARRAY_SIZE(e2fsck_forced_argv), e2fsck_forced_argv,
&status, false, LOG_KLOG | LOG_FILE, false,
FSCK_LOG_FILE);
} else {
ret = logwrap_fork_execvp(ARRAY_SIZE(e2fsck_argv), e2fsck_argv, &status, false,
LOG_KLOG | LOG_FILE, false, FSCK_LOG_FILE);
}
if (ret < 0) {
/* No need to check for error in fork, we can't really handle it now */
LERROR << "Failed trying to run " << E2FSCK_BIN;
*fs_stat |= FS_STAT_E2FSCK_FAILED;
} else if (status != 0) {
LINFO << "e2fsck returned status 0x" << std::hex << status;
*fs_stat |= FS_STAT_E2FSCK_FS_FIXED;
}
}
} else if (is_f2fs(fs_type)) {
const char* f2fs_fsck_argv[] = {F2FS_FSCK_BIN, "-a", "-c", "10000", "--debug-cache",
blk_device.c_str()};
const char* f2fs_fsck_forced_argv[] = {
F2FS_FSCK_BIN, "-f", "-c", "10000", "--debug-cache", blk_device.c_str()};
if (should_force_check(*fs_stat)) {
LINFO << "Running " << F2FS_FSCK_BIN << " -f -c 10000 --debug-cache "
<< realpath(blk_device);
ret = logwrap_fork_execvp(ARRAY_SIZE(f2fs_fsck_forced_argv), f2fs_fsck_forced_argv,
&status, false, LOG_KLOG | LOG_FILE, false, FSCK_LOG_FILE);
} else {
LINFO << "Running " << F2FS_FSCK_BIN << " -a -c 10000 --debug-cache "
<< realpath(blk_device);
ret = logwrap_fork_execvp(ARRAY_SIZE(f2fs_fsck_argv), f2fs_fsck_argv, &status, false,
LOG_KLOG | LOG_FILE, false, FSCK_LOG_FILE);
}
if (ret < 0) {
/* No need to check for error in fork, we can't really handle it now */
LERROR << "Failed trying to run " << F2FS_FSCK_BIN;
}
}
android::base::SetProperty("ro.boottime.init.fsck." + Basename(target),
std::to_string(t.duration().count()));
return;
}
static ext4_fsblk_t ext4_blocks_count(const struct ext4_super_block* es) {
return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
le32_to_cpu(es->s_blocks_count_lo);
}
static ext4_fsblk_t ext4_r_blocks_count(const struct ext4_super_block* es) {
return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
le32_to_cpu(es->s_r_blocks_count_lo);
}
static bool is_ext4_superblock_valid(const struct ext4_super_block* es) {
if (es->s_magic != EXT4_SUPER_MAGIC) return false;
if (es->s_rev_level != EXT4_DYNAMIC_REV && es->s_rev_level != EXT4_GOOD_OLD_REV) return false;
if (EXT4_INODES_PER_GROUP(es) == 0) return false;
return true;
}
// Read the primary superblock from an ext4 filesystem. On failure return
// false. If it's not an ext4 filesystem, also set FS_STAT_INVALID_MAGIC.
static bool read_ext4_superblock(const std::string& blk_device, struct ext4_super_block* sb,
int* fs_stat) {
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
if (fd < 0) {
PERROR << "Failed to open '" << blk_device << "'";
return false;
}
if (TEMP_FAILURE_RETRY(pread(fd, sb, sizeof(*sb), 1024)) != sizeof(*sb)) {
PERROR << "Can't read '" << blk_device << "' superblock";
return false;
}
if (!is_ext4_superblock_valid(sb)) {
LINFO << "Invalid ext4 superblock on '" << blk_device << "'";
// not a valid fs, tune2fs, fsck, and mount will all fail.
*fs_stat |= FS_STAT_INVALID_MAGIC;
return false;
}
*fs_stat |= FS_STAT_IS_EXT4;
LINFO << "superblock s_max_mnt_count:" << sb->s_max_mnt_count << "," << blk_device;
if (sb->s_max_mnt_count == 0xffff) { // -1 (int16) in ext2, but uint16 in ext4
*fs_stat |= FS_STAT_NEW_IMAGE_VERSION;
}
return true;
}
// exported silent version of the above that just answer the question is_ext4
bool fs_mgr_is_ext4(const std::string& blk_device) {
android::base::ErrnoRestorer restore;
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
if (fd < 0) return false;
ext4_super_block sb;
if (TEMP_FAILURE_RETRY(pread(fd, &sb, sizeof(sb), 1024)) != sizeof(sb)) return false;
if (!is_ext4_superblock_valid(&sb)) return false;
return true;
}
// Some system images do not have tune2fs for licensing reasons.
// Detect these and skip running it.
static bool tune2fs_available(void) {
return access(TUNE2FS_BIN, X_OK) == 0;
}
static bool run_command(const char* argv[], int argc) {
int ret;
ret = logwrap_fork_execvp(argc, argv, nullptr, false, LOG_KLOG, false, nullptr);
return ret == 0;
}
// Enable/disable quota support on the filesystem if needed.
static void tune_quota(const std::string& blk_device, const FstabEntry& entry,
const struct ext4_super_block* sb, int* fs_stat) {
bool has_quota = (sb->s_feature_ro_compat & cpu_to_le32(EXT4_FEATURE_RO_COMPAT_QUOTA)) != 0;
bool want_quota = entry.fs_mgr_flags.quota;
bool want_projid = android::base::GetBoolProperty("external_storage.projid.enabled", false);
if (has_quota == want_quota) {
return;
}
if (!tune2fs_available()) {
LERROR << "Unable to " << (want_quota ? "enable" : "disable") << " quotas on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
const char* argv[] = {TUNE2FS_BIN, nullptr, nullptr, blk_device.c_str()};
if (want_quota) {
LINFO << "Enabling quotas on " << blk_device;
argv[1] = "-Oquota";
// Once usr/grp unneeded, make just prjquota to save overhead
if (want_projid)
argv[2] = "-Qusrquota,grpquota,prjquota";
else
argv[2] = "-Qusrquota,grpquota";
*fs_stat |= FS_STAT_QUOTA_ENABLED;
} else {
LINFO << "Disabling quotas on " << blk_device;
argv[1] = "-O^quota";
argv[2] = "-Q^usrquota,^grpquota,^prjquota";
}
if (!run_command(argv, ARRAY_SIZE(argv))) {
LERROR << "Failed to run " TUNE2FS_BIN " to " << (want_quota ? "enable" : "disable")
<< " quotas on " << blk_device;
*fs_stat |= FS_STAT_TOGGLE_QUOTAS_FAILED;
}
}
// Set the number of reserved filesystem blocks if needed.
static void tune_reserved_size(const std::string& blk_device, const FstabEntry& entry,
const struct ext4_super_block* sb, int* fs_stat) {
if (entry.reserved_size == 0) {
return;
}
// The size to reserve is given in the fstab, but we won't reserve more
// than 2% of the filesystem.
const uint64_t max_reserved_blocks = ext4_blocks_count(sb) * 0.02;
uint64_t reserved_blocks = entry.reserved_size / EXT4_BLOCK_SIZE(sb);
if (reserved_blocks > max_reserved_blocks) {
LWARNING << "Reserved blocks " << reserved_blocks << " is too large; "
<< "capping to " << max_reserved_blocks;
reserved_blocks = max_reserved_blocks;
}
if ((ext4_r_blocks_count(sb) == reserved_blocks) && (sb->s_def_resgid == AID_RESERVED_DISK)) {
return;
}
if (!tune2fs_available()) {
LERROR << "Unable to set the number of reserved blocks on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
LINFO << "Setting reserved block count on " << blk_device << " to " << reserved_blocks;
auto reserved_blocks_str = std::to_string(reserved_blocks);
auto reserved_gid_str = std::to_string(AID_RESERVED_DISK);
const char* argv[] = {
TUNE2FS_BIN, "-r", reserved_blocks_str.c_str(), "-g", reserved_gid_str.c_str(),
blk_device.c_str()};
if (!run_command(argv, ARRAY_SIZE(argv))) {
LERROR << "Failed to run " TUNE2FS_BIN " to set the number of reserved blocks on "
<< blk_device;
*fs_stat |= FS_STAT_SET_RESERVED_BLOCKS_FAILED;
}
}
// Enable file-based encryption if needed.
static void tune_encrypt(const std::string& blk_device, const FstabEntry& entry,
const struct ext4_super_block* sb, int* fs_stat) {
if (!entry.fs_mgr_flags.file_encryption) {
return; // Nothing needs done.
}
std::vector<std::string> features_needed;
if ((sb->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_ENCRYPT)) == 0) {
features_needed.emplace_back("encrypt");
}
android::fscrypt::EncryptionOptions options;
if (!android::fscrypt::ParseOptions(entry.encryption_options, &options)) {
LERROR << "Unable to parse encryption options on " << blk_device << ": "
<< entry.encryption_options;
return;
}
if ((options.flags &
(FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 | FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) != 0) {
// We can only use this policy on ext4 if the "stable_inodes" feature
// is set on the filesystem, otherwise shrinking will break encrypted files.
if ((sb->s_feature_compat & cpu_to_le32(EXT4_FEATURE_COMPAT_STABLE_INODES)) == 0) {
features_needed.emplace_back("stable_inodes");
}
}
if (features_needed.size() == 0) {
return;
}
if (!tune2fs_available()) {
LERROR << "Unable to enable ext4 encryption on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
auto flags = android::base::Join(features_needed, ',');
auto flag_arg = "-O"s + flags;
const char* argv[] = {TUNE2FS_BIN, flag_arg.c_str(), blk_device.c_str()};
LINFO << "Enabling ext4 flags " << flags << " on " << blk_device;
if (!run_command(argv, ARRAY_SIZE(argv))) {
LERROR << "Failed to run " TUNE2FS_BIN " to enable "
<< "ext4 flags " << flags << " on " << blk_device;
*fs_stat |= FS_STAT_ENABLE_ENCRYPTION_FAILED;
}
}
// Enable fs-verity if needed.
static void tune_verity(const std::string& blk_device, const FstabEntry& entry,
const struct ext4_super_block* sb, int* fs_stat) {
bool has_verity = (sb->s_feature_ro_compat & cpu_to_le32(EXT4_FEATURE_RO_COMPAT_VERITY)) != 0;
bool want_verity = entry.fs_mgr_flags.fs_verity;
if (has_verity || !want_verity) {
return;
}
std::string verity_support;
if (!android::base::ReadFileToString(SYSFS_EXT4_VERITY, &verity_support)) {
LERROR << "Failed to open " << SYSFS_EXT4_VERITY;
return;
}
if (!(android::base::Trim(verity_support) == "supported")) {
LERROR << "Current ext4 verity not supported by kernel";
return;
}
if (!tune2fs_available()) {
LERROR << "Unable to enable ext4 verity on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
LINFO << "Enabling ext4 verity on " << blk_device;
const char* argv[] = {TUNE2FS_BIN, "-O", "verity", blk_device.c_str()};
if (!run_command(argv, ARRAY_SIZE(argv))) {
LERROR << "Failed to run " TUNE2FS_BIN " to enable "
<< "ext4 verity on " << blk_device;
*fs_stat |= FS_STAT_ENABLE_VERITY_FAILED;
}
}
// Enable casefold if needed.
static void tune_casefold(const std::string& blk_device, const FstabEntry& entry,
const struct ext4_super_block* sb, int* fs_stat) {
bool has_casefold = (sb->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_CASEFOLD)) != 0;
bool wants_casefold =
android::base::GetBoolProperty("external_storage.casefold.enabled", false);
if (entry.mount_point != "/data" || !wants_casefold || has_casefold) return;
std::string casefold_support;
if (!android::base::ReadFileToString(SYSFS_EXT4_CASEFOLD, &casefold_support)) {
LERROR << "Failed to open " << SYSFS_EXT4_CASEFOLD;
return;
}
if (!(android::base::Trim(casefold_support) == "supported")) {
LERROR << "Current ext4 casefolding not supported by kernel";
return;
}
if (!tune2fs_available()) {
LERROR << "Unable to enable ext4 casefold on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
LINFO << "Enabling ext4 casefold on " << blk_device;
const char* argv[] = {TUNE2FS_BIN, "-O", "casefold", "-E", "encoding=utf8", blk_device.c_str()};
if (!run_command(argv, ARRAY_SIZE(argv))) {
LERROR << "Failed to run " TUNE2FS_BIN " to enable "
<< "ext4 casefold on " << blk_device;
*fs_stat |= FS_STAT_ENABLE_CASEFOLD_FAILED;
}
}
static bool resize2fs_available(void) {
return access(RESIZE2FS_BIN, X_OK) == 0;
}
// Enable metadata_csum
static void tune_metadata_csum(const std::string& blk_device, const FstabEntry& entry,
const struct ext4_super_block* sb, int* fs_stat) {
bool has_meta_csum =
(sb->s_feature_ro_compat & cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) != 0;
bool want_meta_csum = entry.fs_mgr_flags.ext_meta_csum;
if (has_meta_csum || !want_meta_csum) return;
if (!tune2fs_available()) {
LERROR << "Unable to enable metadata_csum on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
if (!resize2fs_available()) {
LERROR << "Unable to enable metadata_csum on " << blk_device
<< " because " RESIZE2FS_BIN " is missing";
return;
}
LINFO << "Enabling ext4 metadata_csum on " << blk_device;
// Must give `-T now` to prevent last_fsck_time from growing too large,
// otherwise, tune2fs won't enable metadata_csum.
const char* tune2fs_args[] = {TUNE2FS_BIN, "-O", "metadata_csum,64bit,extent",
"-T", "now", blk_device.c_str()};
const char* resize2fs_args[] = {RESIZE2FS_BIN, "-b", blk_device.c_str()};
if (!run_command(tune2fs_args, ARRAY_SIZE(tune2fs_args))) {
LERROR << "Failed to run " TUNE2FS_BIN " to enable "
<< "ext4 metadata_csum on " << blk_device;
*fs_stat |= FS_STAT_ENABLE_METADATA_CSUM_FAILED;
} else if (!run_command(resize2fs_args, ARRAY_SIZE(resize2fs_args))) {
LERROR << "Failed to run " RESIZE2FS_BIN " to enable "
<< "ext4 metadata_csum on " << blk_device;
*fs_stat |= FS_STAT_ENABLE_METADATA_CSUM_FAILED;
}
}
// Read the primary superblock from an f2fs filesystem. On failure return
// false. If it's not an f2fs filesystem, also set FS_STAT_INVALID_MAGIC.
#define F2FS_BLKSIZE 4096
#define F2FS_SUPER_OFFSET 1024
static bool read_f2fs_superblock(const std::string& blk_device, int* fs_stat) {
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
__le32 sb1, sb2;
if (fd < 0) {
PERROR << "Failed to open '" << blk_device << "'";
return false;
}
if (TEMP_FAILURE_RETRY(pread(fd, &sb1, sizeof(sb1), F2FS_SUPER_OFFSET)) != sizeof(sb1)) {
PERROR << "Can't read '" << blk_device << "' superblock1";
return false;
}
if (TEMP_FAILURE_RETRY(pread(fd, &sb2, sizeof(sb2), F2FS_BLKSIZE + F2FS_SUPER_OFFSET)) !=
sizeof(sb2)) {
PERROR << "Can't read '" << blk_device << "' superblock2";
return false;
}
if (sb1 != cpu_to_le32(F2FS_SUPER_MAGIC) && sb2 != cpu_to_le32(F2FS_SUPER_MAGIC)) {
LINFO << "Invalid f2fs superblock on '" << blk_device << "'";
*fs_stat |= FS_STAT_INVALID_MAGIC;
return false;
}
return true;
}
// exported silent version of the above that just answer the question is_f2fs
bool fs_mgr_is_f2fs(const std::string& blk_device) {
android::base::ErrnoRestorer restore;
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
if (fd < 0) return false;
__le32 sb;
if (TEMP_FAILURE_RETRY(pread(fd, &sb, sizeof(sb), F2FS_SUPER_OFFSET)) != sizeof(sb)) {
return false;
}
if (sb == cpu_to_le32(F2FS_SUPER_MAGIC)) return true;
if (TEMP_FAILURE_RETRY(pread(fd, &sb, sizeof(sb), F2FS_BLKSIZE + F2FS_SUPER_OFFSET)) !=
sizeof(sb)) {
return false;
}
return sb == cpu_to_le32(F2FS_SUPER_MAGIC);
}
static void SetReadAheadSize(const std::string& entry_block_device, off64_t size_kb) {
std::string block_device;
if (!Realpath(entry_block_device, &block_device)) {
PERROR << "Failed to realpath " << entry_block_device;
return;
}
static constexpr std::string_view kDevBlockPrefix("/dev/block/");
if (!android::base::StartsWith(block_device, kDevBlockPrefix)) {
LWARNING << block_device << " is not a block device";
return;
}
DeviceMapper& dm = DeviceMapper::Instance();
while (true) {
std::string block_name = block_device;
if (android::base::StartsWith(block_device, kDevBlockPrefix)) {
block_name = block_device.substr(kDevBlockPrefix.length());
}
std::string sys_partition =
android::base::StringPrintf("/sys/class/block/%s/partition", block_name.c_str());
struct stat info;
if (lstat(sys_partition.c_str(), &info) == 0) {
// it has a partition like "sda12".
block_name += "/..";
}
std::string sys_ra = android::base::StringPrintf("/sys/class/block/%s/queue/read_ahead_kb",
block_name.c_str());
std::string size = android::base::StringPrintf("%llu", (long long)size_kb);
android::base::WriteStringToFile(size, sys_ra.c_str());
LINFO << "Set readahead_kb: " << size << " on " << sys_ra;
auto parent = dm.GetParentBlockDeviceByPath(block_device);
if (!parent) {
return;
}
block_device = *parent;
}
}
//
// Prepare the filesystem on the given block device to be mounted.
//
// If the "check" option was given in the fstab record, or it seems that the
// filesystem was uncleanly shut down, we'll run fsck on the filesystem.
//
// If needed, we'll also enable (or disable) filesystem features as specified by
// the fstab record.
//
static int prepare_fs_for_mount(const std::string& blk_device, const FstabEntry& entry,
const std::string& alt_mount_point = "") {
auto& mount_point = alt_mount_point.empty() ? entry.mount_point : alt_mount_point;
// We need this because sometimes we have legacy symlinks that are
// lingering around and need cleaning up.
struct stat info;
if (lstat(mount_point.c_str(), &info) == 0 && (info.st_mode & S_IFMT) == S_IFLNK) {
unlink(mount_point.c_str());
}
mkdir(mount_point.c_str(), 0755);
// Don't need to return error, since it's a salt
if (entry.readahead_size_kb != -1) {
SetReadAheadSize(blk_device, entry.readahead_size_kb);
}
int fs_stat = 0;
if (is_extfs(entry.fs_type)) {
struct ext4_super_block sb;
if (read_ext4_superblock(blk_device, &sb, &fs_stat)) {
if ((sb.s_feature_incompat & EXT4_FEATURE_INCOMPAT_RECOVER) != 0 ||
(sb.s_state & EXT4_VALID_FS) == 0) {
LINFO << "Filesystem on " << blk_device << " was not cleanly shutdown; "
<< "state flags: 0x" << std::hex << sb.s_state << ", "
<< "incompat feature flags: 0x" << std::hex << sb.s_feature_incompat;
fs_stat |= FS_STAT_UNCLEAN_SHUTDOWN;
}
// Note: quotas should be enabled before running fsck.
tune_quota(blk_device, entry, &sb, &fs_stat);
} else {
return fs_stat;
}
} else if (is_f2fs(entry.fs_type)) {
if (!read_f2fs_superblock(blk_device, &fs_stat)) {
return fs_stat;
}
}
if (entry.fs_mgr_flags.check ||
(fs_stat & (FS_STAT_UNCLEAN_SHUTDOWN | FS_STAT_QUOTA_ENABLED))) {
check_fs(blk_device, entry.fs_type, mount_point, &fs_stat);
}
if (is_extfs(entry.fs_type) &&
(entry.reserved_size != 0 || entry.fs_mgr_flags.file_encryption ||
entry.fs_mgr_flags.fs_verity || entry.fs_mgr_flags.ext_meta_csum)) {
struct ext4_super_block sb;
if (read_ext4_superblock(blk_device, &sb, &fs_stat)) {
tune_reserved_size(blk_device, entry, &sb, &fs_stat);
tune_encrypt(blk_device, entry, &sb, &fs_stat);
tune_verity(blk_device, entry, &sb, &fs_stat);
tune_casefold(blk_device, entry, &sb, &fs_stat);
tune_metadata_csum(blk_device, entry, &sb, &fs_stat);
}
}
return fs_stat;
}
// Mark the given block device as read-only, using the BLKROSET ioctl.
bool fs_mgr_set_blk_ro(const std::string& blockdev, bool readonly) {
unique_fd fd(TEMP_FAILURE_RETRY(open(blockdev.c_str(), O_RDONLY | O_CLOEXEC)));
if (fd < 0) {
return false;
}
int ON = readonly;
return ioctl(fd, BLKROSET, &ON) == 0;
}
// Orange state means the device is unlocked, see the following link for details.
// https://source.android.com/security/verifiedboot/verified-boot#device_state
bool fs_mgr_is_device_unlocked() {
std::string verified_boot_state;
if (fs_mgr_get_boot_config("verifiedbootstate", &verified_boot_state)) {
return verified_boot_state == "orange";
}
return false;
}
// __mount(): wrapper around the mount() system call which also
// sets the underlying block device to read-only if the mount is read-only.
// See "man 2 mount" for return values.
static int __mount(const std::string& source, const std::string& target, const FstabEntry& entry) {
errno = 0;
unsigned long mountflags = entry.flags;
int ret = 0;
int save_errno = 0;
int gc_allowance = 0;
std::string opts;
bool try_f2fs_gc_allowance = is_f2fs(entry.fs_type) && entry.fs_checkpoint_opts.length() > 0;
Timer t;
do {
if (save_errno == EINVAL && try_f2fs_gc_allowance) {
PINFO << "Kernel does not support checkpoint=disable:[n]%, trying without.";
try_f2fs_gc_allowance = false;
}
if (try_f2fs_gc_allowance) {
opts = entry.fs_options + entry.fs_checkpoint_opts + ":" +
std::to_string(gc_allowance) + "%";
} else {
opts = entry.fs_options;
}
if (save_errno == EAGAIN) {
PINFO << "Retrying mount (source=" << source << ",target=" << target
<< ",type=" << entry.fs_type << ", gc_allowance=" << gc_allowance << "%)=" << ret
<< "(" << save_errno << ")";
}
ret = mount(source.c_str(), target.c_str(), entry.fs_type.c_str(), mountflags,
opts.c_str());
save_errno = errno;
if (try_f2fs_gc_allowance) gc_allowance += 10;
} while ((ret && save_errno == EAGAIN && gc_allowance <= 100) ||
(ret && save_errno == EINVAL && try_f2fs_gc_allowance));
const char* target_missing = "";
const char* source_missing = "";
if (save_errno == ENOENT) {
if (access(target.c_str(), F_OK)) {
target_missing = "(missing)";
} else if (access(source.c_str(), F_OK)) {
source_missing = "(missing)";
}
errno = save_errno;
}
PINFO << __FUNCTION__ << "(source=" << source << source_missing << ",target=" << target
<< target_missing << ",type=" << entry.fs_type << ")=" << ret;
if ((ret == 0) && (mountflags & MS_RDONLY) != 0) {
fs_mgr_set_blk_ro(source);
}
android::base::SetProperty("ro.boottime.init.mount." + Basename(target),
std::to_string(t.duration().count()));
errno = save_errno;
return ret;
}
static bool fs_match(const std::string& in1, const std::string& in2) {
if (in1.empty() || in2.empty()) {
return false;
}
auto in1_end = in1.size() - 1;
while (in1_end > 0 && in1[in1_end] == '/') {
in1_end--;
}
auto in2_end = in2.size() - 1;
while (in2_end > 0 && in2[in2_end] == '/') {
in2_end--;
}
if (in1_end != in2_end) {
return false;
}
for (size_t i = 0; i <= in1_end; ++i) {
if (in1[i] != in2[i]) {
return false;
}
}
return true;
}
// Tries to mount any of the consecutive fstab entries that match
// the mountpoint of the one given by fstab[start_idx].
//
// end_idx: On return, will be the last entry that was looked at.
// attempted_idx: On return, will indicate which fstab entry
// succeeded. In case of failure, it will be the start_idx.
// Sets errno to match the 1st mount failure on failure.
static bool mount_with_alternatives(const Fstab& fstab, int start_idx, int* end_idx,
int* attempted_idx) {
unsigned long i;
int mount_errno = 0;
bool mounted = false;
// Hunt down an fstab entry for the same mount point that might succeed.
for (i = start_idx;
// We required that fstab entries for the same mountpoint be consecutive.
i < fstab.size() && fstab[start_idx].mount_point == fstab[i].mount_point; i++) {
// Don't try to mount/encrypt the same mount point again.
// Deal with alternate entries for the same point which are required to be all following
// each other.
if (mounted) {
LERROR << __FUNCTION__ << "(): skipping fstab dup mountpoint=" << fstab[i].mount_point
<< " rec[" << i << "].fs_type=" << fstab[i].fs_type << " already mounted as "
<< fstab[*attempted_idx].fs_type;
continue;
}
int fs_stat = prepare_fs_for_mount(fstab[i].blk_device, fstab[i]);
if (fs_stat & FS_STAT_INVALID_MAGIC) {
LERROR << __FUNCTION__
<< "(): skipping mount due to invalid magic, mountpoint=" << fstab[i].mount_point
<< " blk_dev=" << realpath(fstab[i].blk_device) << " rec[" << i
<< "].fs_type=" << fstab[i].fs_type;
mount_errno = EINVAL; // continue bootup for FDE
continue;
}
int retry_count = 2;
while (retry_count-- > 0) {
if (!__mount(fstab[i].blk_device, fstab[i].mount_point, fstab[i])) {
*attempted_idx = i;
mounted = true;
if (i != start_idx) {
LERROR << __FUNCTION__ << "(): Mounted " << fstab[i].blk_device << " on "
<< fstab[i].mount_point << " with fs_type=" << fstab[i].fs_type
<< " instead of " << fstab[start_idx].fs_type;
}
fs_stat &= ~FS_STAT_FULL_MOUNT_FAILED;
mount_errno = 0;
break;
} else {
if (retry_count <= 0) break; // run check_fs only once
fs_stat |= FS_STAT_FULL_MOUNT_FAILED;
// back up the first errno for crypto decisions.
if (mount_errno == 0) {
mount_errno = errno;
}
// retry after fsck
check_fs(fstab[i].blk_device, fstab[i].fs_type, fstab[i].mount_point, &fs_stat);
}
}
log_fs_stat(fstab[i].blk_device, fs_stat);
}
/* Adjust i for the case where it was still withing the recs[] */
if (i < fstab.size()) --i;
*end_idx = i;
if (!mounted) {
*attempted_idx = start_idx;
errno = mount_errno;
return false;
}
return true;
}
static bool TranslateExtLabels(FstabEntry* entry) {
if (!StartsWith(entry->blk_device, "LABEL=")) {
return true;
}
std::string label = entry->blk_device.substr(6);
if (label.size() > 16) {
LERROR << "FS label is longer than allowed by filesystem";
return false;
}
auto blockdir = std::unique_ptr<DIR, decltype(&closedir)>{opendir("/dev/block"), closedir};
if (!blockdir) {
LERROR << "couldn't open /dev/block";
return false;
}
struct dirent* ent;
while ((ent = readdir(blockdir.get()))) {
if (ent->d_type != DT_BLK)
continue;
unique_fd fd(TEMP_FAILURE_RETRY(
openat(dirfd(blockdir.get()), ent->d_name, O_RDONLY | O_CLOEXEC)));
if (fd < 0) {
LERROR << "Cannot open block device /dev/block/" << ent->d_name;
return false;
}
ext4_super_block super_block;
if (TEMP_FAILURE_RETRY(lseek(fd, 1024, SEEK_SET)) < 0 ||
TEMP_FAILURE_RETRY(read(fd, &super_block, sizeof(super_block))) !=
sizeof(super_block)) {
// Probably a loopback device or something else without a readable superblock.
continue;
}
if (super_block.s_magic != EXT4_SUPER_MAGIC) {
LINFO << "/dev/block/" << ent->d_name << " not ext{234}";
continue;
}
if (label == super_block.s_volume_name) {
std::string new_blk_device = "/dev/block/"s + ent->d_name;
LINFO << "resolved label " << entry->blk_device << " to " << new_blk_device;
entry->blk_device = new_blk_device;
return true;
}
}
return false;
}
static bool needs_block_encryption(const FstabEntry& entry) {
if (android::base::GetBoolProperty("ro.vold.forceencryption", false) && entry.is_encryptable())
return true;
if (entry.fs_mgr_flags.force_crypt) return true;
if (entry.fs_mgr_flags.crypt) {
// Check for existence of convert_fde breadcrumb file.
auto convert_fde_name = entry.mount_point + "/misc/vold/convert_fde";
if (access(convert_fde_name.c_str(), F_OK) == 0) return true;
}
if (entry.fs_mgr_flags.force_fde_or_fbe) {
// Check for absence of convert_fbe breadcrumb file.
auto convert_fbe_name = entry.mount_point + "/convert_fbe";
if (access(convert_fbe_name.c_str(), F_OK) != 0) return true;
}
return false;
}
static bool should_use_metadata_encryption(const FstabEntry& entry) {
return !entry.metadata_key_dir.empty() &&
(entry.fs_mgr_flags.file_encryption || entry.fs_mgr_flags.force_fde_or_fbe);
}
// Check to see if a mountable volume has encryption requirements
static int handle_encryptable(const FstabEntry& entry) {
// If this is block encryptable, need to trigger encryption.
if (needs_block_encryption(entry)) {
if (umount(entry.mount_point.c_str()) == 0) {
return FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION;
} else {
PWARNING << "Could not umount " << entry.mount_point << " - allow continue unencrypted";
return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
}
} else if (should_use_metadata_encryption(entry)) {
if (umount(entry.mount_point.c_str()) == 0) {
return FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION;
} else {
PERROR << "Could not umount " << entry.mount_point << " - fail since can't encrypt";
return FS_MGR_MNTALL_FAIL;
}
} else if (entry.fs_mgr_flags.file_encryption || entry.fs_mgr_flags.force_fde_or_fbe) {
LINFO << entry.mount_point << " is file encrypted";
return FS_MGR_MNTALL_DEV_FILE_ENCRYPTED;
} else if (entry.is_encryptable()) {
return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
} else {
return FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE;
}
}
static void set_type_property(int status) {
switch (status) {
case FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED:
SetProperty("ro.crypto.type", "block");
break;
case FS_MGR_MNTALL_DEV_FILE_ENCRYPTED:
case FS_MGR_MNTALL_DEV_IS_METADATA_ENCRYPTED:
case FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION:
SetProperty("ro.crypto.type", "file");
break;
}
}
static bool call_vdc(const std::vector<std::string>& args, int* ret) {
std::vector<char const*> argv;
argv.emplace_back("/system/bin/vdc");
for (auto& arg : args) {
argv.emplace_back(arg.c_str());
}
LOG(INFO) << "Calling: " << android::base::Join(argv, ' ');
int err = logwrap_fork_execvp(argv.size(), argv.data(), ret, false, LOG_ALOG, false, nullptr);
if (err != 0) {
LOG(ERROR) << "vdc call failed with error code: " << err;
return false;
}
LOG(DEBUG) << "vdc finished successfully";
if (ret != nullptr) {
*ret = WEXITSTATUS(*ret);
}
return true;
}
bool fs_mgr_update_logical_partition(FstabEntry* entry) {
// Logical partitions are specified with a named partition rather than a
// block device, so if the block device is a path, then it has already
// been updated.
if (entry->blk_device[0] == '/') {
return true;
}
DeviceMapper& dm = DeviceMapper::Instance();
std::string device_name;
if (!dm.GetDmDevicePathByName(entry->blk_device, &device_name)) {
return false;
}
entry->blk_device = device_name;
return true;
}
static bool SupportsCheckpoint(FstabEntry* entry) {
return entry->fs_mgr_flags.checkpoint_blk || entry->fs_mgr_flags.checkpoint_fs;
}
class CheckpointManager {
public:
CheckpointManager(int needs_checkpoint = -1, bool metadata_encrypted = false)
: needs_checkpoint_(needs_checkpoint), metadata_encrypted_(metadata_encrypted) {}
bool NeedsCheckpoint() {
if (needs_checkpoint_ != UNKNOWN) {
return needs_checkpoint_ == YES;
}
if (!call_vdc({"checkpoint", "needsCheckpoint"}, &needs_checkpoint_)) {
LERROR << "Failed to find if checkpointing is needed. Assuming no.";
needs_checkpoint_ = NO;
}
return needs_checkpoint_ == YES;
}
bool Update(FstabEntry* entry, const std::string& block_device = std::string()) {
if (!SupportsCheckpoint(entry)) {
return true;
}
if (entry->fs_mgr_flags.checkpoint_blk && !metadata_encrypted_) {
call_vdc({"checkpoint", "restoreCheckpoint", entry->blk_device}, nullptr);
}
if (!NeedsCheckpoint()) {
return true;
}
if (!UpdateCheckpointPartition(entry, block_device)) {
LERROR << "Could not set up checkpoint partition, skipping!";
return false;
}
return true;
}
bool Revert(FstabEntry* entry) {
if (!SupportsCheckpoint(entry)) {
return true;
}
if (device_map_.find(entry->blk_device) == device_map_.end()) {
return true;
}
std::string bow_device = entry->blk_device;
entry->blk_device = device_map_[bow_device];
device_map_.erase(bow_device);
DeviceMapper& dm = DeviceMapper::Instance();
if (!dm.DeleteDevice("bow")) {
PERROR << "Failed to remove bow device";
}
return true;
}
private:
bool UpdateCheckpointPartition(FstabEntry* entry, const std::string& block_device) {
if (entry->fs_mgr_flags.checkpoint_fs) {
if (is_f2fs(entry->fs_type)) {
entry->fs_checkpoint_opts = ",checkpoint=disable";
} else {
LERROR << entry->fs_type << " does not implement checkpoints.";
}
} else if (entry->fs_mgr_flags.checkpoint_blk) {
auto actual_block_device = block_device.empty() ? entry->blk_device : block_device;
if (fs_mgr_find_bow_device(actual_block_device).empty()) {
unique_fd fd(
TEMP_FAILURE_RETRY(open(entry->blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
if (fd < 0) {
PERROR << "Cannot open device " << entry->blk_device;
return false;
}
uint64_t size = get_block_device_size(fd) / 512;
if (!size) {
PERROR << "Cannot get device size";
return false;
}
android::dm::DmTable table;
auto bowTarget =
std::make_unique<android::dm::DmTargetBow>(0, size, entry->blk_device);
// dm-bow uses the first block as a log record, and relocates the real first block
// elsewhere. For metadata encrypted devices, dm-bow sits below dm-default-key, and
// for post Android Q devices dm-default-key uses a block size of 4096 always.
// So if dm-bow's block size, which by default is the block size of the underlying
// hardware, is less than dm-default-key's, blocks will get broken up and I/O will
// fail as it won't be data_unit_size aligned.
// However, since it is possible there is an already shipping non
// metadata-encrypted device with smaller blocks, we must not change this for
// devices shipped with Q or earlier unless they explicitly selected dm-default-key
// v2
unsigned int options_format_version = android::base::GetUintProperty<unsigned int>(
"ro.crypto.dm_default_key.options_format.version",
(android::fscrypt::GetFirstApiLevel() <= __ANDROID_API_Q__ ? 1 : 2));
if (options_format_version > 1) {
bowTarget->SetBlockSize(4096);
}
if (!table.AddTarget(std::move(bowTarget))) {
LERROR << "Failed to add bow target";
return false;
}
DeviceMapper& dm = DeviceMapper::Instance();
if (!dm.CreateDevice("bow", table)) {
PERROR << "Failed to create bow device";
return false;
}
std::string name;
if (!dm.GetDmDevicePathByName("bow", &name)) {
PERROR << "Failed to get bow device name";
return false;
}
device_map_[name] = entry->blk_device;
entry->blk_device = name;
}
}
return true;
}
enum { UNKNOWN = -1, NO = 0, YES = 1 };
int needs_checkpoint_;
bool metadata_encrypted_;
std::map<std::string, std::string> device_map_;
};
std::string fs_mgr_find_bow_device(const std::string& block_device) {
if (block_device.substr(0, 5) != "/dev/") {
LOG(ERROR) << "Expected block device, got " << block_device;
return std::string();
}
std::string sys_dir = std::string("/sys/") + block_device.substr(5);
for (;;) {
std::string name;
if (!android::base::ReadFileToString(sys_dir + "/dm/name", &name)) {
PLOG(ERROR) << block_device << " is not dm device";
return std::string();
}
if (name == "bow\n") return sys_dir;
std::string slaves = sys_dir + "/slaves";
std::unique_ptr<DIR, decltype(&closedir)> directory(opendir(slaves.c_str()), closedir);
if (!directory) {
PLOG(ERROR) << "Can't open slave directory " << slaves;
return std::string();
}
int count = 0;
for (dirent* entry = readdir(directory.get()); entry; entry = readdir(directory.get())) {
if (entry->d_type != DT_LNK) continue;
if (count == 1) {
LOG(ERROR) << "Too many slaves in " << slaves;
return std::string();
}
++count;
sys_dir = std::string("/sys/block/") + entry->d_name;
}
if (count != 1) {
LOG(ERROR) << "No slave in " << slaves;
return std::string();
}
}
}
static constexpr const char* kUserdataWrapperName = "userdata-wrapper";
static void WrapUserdata(FstabEntry* entry, dev_t dev, const std::string& block_device) {
DeviceMapper& dm = DeviceMapper::Instance();
if (dm.GetState(kUserdataWrapperName) != DmDeviceState::INVALID) {
// This will report failure for us. If we do fail to get the path,
// we leave the device unwrapped.
dm.GetDmDevicePathByName(kUserdataWrapperName, &entry->blk_device);
return;
}
unique_fd fd(open(block_device.c_str(), O_RDONLY | O_CLOEXEC));
if (fd < 0) {
PLOG(ERROR) << "open failed: " << entry->blk_device;
return;
}
auto dev_str = android::base::StringPrintf("%u:%u", major(dev), minor(dev));
uint64_t sectors = get_block_device_size(fd) / 512;
android::dm::DmTable table;
table.Emplace<DmTargetLinear>(0, sectors, dev_str, 0);
std::string dm_path;
if (!dm.CreateDevice(kUserdataWrapperName, table, &dm_path, 20s)) {
LOG(ERROR) << "Failed to create userdata wrapper device";
return;
}
entry->blk_device = dm_path;
}
// When using Virtual A/B, partitions can be backed by /data and mapped with
// device-mapper in first-stage init. This can happen when merging an OTA or
// when using adb remount to house "scratch". In this case, /data cannot be
// mounted directly off the userdata block device, and e2fsck will refuse to
// scan it, because the kernel reports the block device as in-use.
//
// As a workaround, when mounting /data, we create a trivial dm-linear wrapper
// if the underlying block device already has dependencies. Note that we make
// an exception for metadata-encrypted devices, since dm-default-key is already
// a wrapper.
static void WrapUserdataIfNeeded(FstabEntry* entry, const std::string& actual_block_device = {}) {
const auto& block_device =
actual_block_device.empty() ? entry->blk_device : actual_block_device;
if (entry->mount_point != "/data" || !entry->metadata_key_dir.empty() ||
android::base::StartsWith(block_device, "/dev/block/dm-")) {
return;
}
struct stat st;
if (stat(block_device.c_str(), &st) < 0) {
PLOG(ERROR) << "stat failed: " << block_device;
return;
}
std::string path = android::base::StringPrintf("/sys/dev/block/%u:%u/holders",
major(st.st_rdev), minor(st.st_rdev));
std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(path.c_str()), closedir);
if (!dir) {
PLOG(ERROR) << "opendir failed: " << path;
return;
}
struct dirent* d;
bool has_holders = false;
while ((d = readdir(dir.get())) != nullptr) {
if (strcmp(d->d_name, ".") != 0 && strcmp(d->d_name, "..") != 0) {
has_holders = true;
break;
}
}
if (has_holders) {
WrapUserdata(entry, st.st_rdev, block_device);
}
}
static bool IsMountPointMounted(const std::string& mount_point) {
// Check if this is already mounted.
Fstab fstab;
if (!ReadFstabFromFile("/proc/mounts", &fstab)) {
return false;
}
return GetEntryForMountPoint(&fstab, mount_point) != nullptr;
}
// When multiple fstab records share the same mount_point, it will try to mount each
// one in turn, and ignore any duplicates after a first successful mount.
// Returns -1 on error, and FS_MGR_MNTALL_* otherwise.
MountAllResult fs_mgr_mount_all(Fstab* fstab, int mount_mode) {
int encryptable = FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE;
int error_count = 0;
CheckpointManager checkpoint_manager;
AvbUniquePtr avb_handle(nullptr);
bool wiped = false;
bool userdata_mounted = false;
if (fstab->empty()) {
return {FS_MGR_MNTALL_FAIL, userdata_mounted};
}
// Keep i int to prevent unsigned integer overflow from (i = top_idx - 1),
// where top_idx is 0. It will give SIGABRT
for (int i = 0; i < static_cast<int>(fstab->size()); i++) {
auto& current_entry = (*fstab)[i];
// If a filesystem should have been mounted in the first stage, we
// ignore it here. With one exception, if the filesystem is
// formattable, then it can only be formatted in the second stage,
// so we allow it to mount here.
if (current_entry.fs_mgr_flags.first_stage_mount &&
(!current_entry.fs_mgr_flags.formattable ||
IsMountPointMounted(current_entry.mount_point))) {
continue;
}
// Don't mount entries that are managed by vold or not for the mount mode.
if (current_entry.fs_mgr_flags.vold_managed || current_entry.fs_mgr_flags.recovery_only ||
((mount_mode == MOUNT_MODE_LATE) && !current_entry.fs_mgr_flags.late_mount) ||
((mount_mode == MOUNT_MODE_EARLY) && current_entry.fs_mgr_flags.late_mount)) {
continue;
}
// Skip swap and raw partition entries such as boot, recovery, etc.
if (current_entry.fs_type == "swap" || current_entry.fs_type == "emmc" ||
current_entry.fs_type == "mtd") {
continue;
}
// Skip mounting the root partition, as it will already have been mounted.
if (current_entry.mount_point == "/" || current_entry.mount_point == "/system") {
if ((current_entry.flags & MS_RDONLY) != 0) {
fs_mgr_set_blk_ro(current_entry.blk_device);
}
continue;
}
// Terrible hack to make it possible to remount /data.
// TODO: refactor fs_mgr_mount_all and get rid of this.
if (mount_mode == MOUNT_MODE_ONLY_USERDATA && current_entry.mount_point != "/data") {
continue;
}
// Translate LABEL= file system labels into block devices.
if (is_extfs(current_entry.fs_type)) {
if (!TranslateExtLabels(&current_entry)) {
LERROR << "Could not translate label to block device";
continue;
}
}
if (current_entry.fs_mgr_flags.logical) {
if (!fs_mgr_update_logical_partition(&current_entry)) {
LERROR << "Could not set up logical partition, skipping!";
continue;
}
}
WrapUserdataIfNeeded(&current_entry);
if (!checkpoint_manager.Update(&current_entry)) {
continue;
}
if (current_entry.fs_mgr_flags.wait && !WaitForFile(current_entry.blk_device, 20s)) {
LERROR << "Skipping '" << current_entry.blk_device << "' during mount_all";
continue;
}
if (current_entry.fs_mgr_flags.avb) {
if (!avb_handle) {
avb_handle = AvbHandle::Open();
if (!avb_handle) {
LERROR << "Failed to open AvbHandle";
set_type_property(encryptable);
return {FS_MGR_MNTALL_FAIL, userdata_mounted};
}
}
if (avb_handle->SetUpAvbHashtree(&current_entry, true /* wait_for_verity_dev */) ==
AvbHashtreeResult::kFail) {
LERROR << "Failed to set up AVB on partition: " << current_entry.mount_point
<< ", skipping!";
// Skips mounting the device.
continue;
}
} else if (!current_entry.avb_keys.empty()) {
if (AvbHandle::SetUpStandaloneAvbHashtree(&current_entry) == AvbHashtreeResult::kFail) {
LERROR << "Failed to set up AVB on standalone partition: "
<< current_entry.mount_point << ", skipping!";
// Skips mounting the device.
continue;
}
} else if ((current_entry.fs_mgr_flags.verify)) {
int rc = fs_mgr_setup_verity(&current_entry, true);
if (rc == FS_MGR_SETUP_VERITY_DISABLED || rc == FS_MGR_SETUP_VERITY_SKIPPED) {
LINFO << "Verity disabled";
} else if (rc != FS_MGR_SETUP_VERITY_SUCCESS) {
LERROR << "Could not set up verified partition, skipping!";
continue;
}
}
int last_idx_inspected;
int top_idx = i;
int attempted_idx = -1;
bool mret = mount_with_alternatives(*fstab, i, &last_idx_inspected, &attempted_idx);
auto& attempted_entry = (*fstab)[attempted_idx];
i = last_idx_inspected;
int mount_errno = errno;
// Handle success and deal with encryptability.
if (mret) {
int status = handle_encryptable(attempted_entry);
if (status == FS_MGR_MNTALL_FAIL) {
// Fatal error - no point continuing.
return {status, userdata_mounted};
}
if (status != FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE) {
if (encryptable != FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE) {
// Log and continue
LERROR << "Only one encryptable/encrypted partition supported";
}
encryptable = status;
if (status == FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION) {
if (!call_vdc({"cryptfs", "encryptFstab", attempted_entry.blk_device,
attempted_entry.mount_point, wiped ? "true" : "false",
attempted_entry.fs_type},
nullptr)) {
LERROR << "Encryption failed";
set_type_property(encryptable);
return {FS_MGR_MNTALL_FAIL, userdata_mounted};
}
}
}
if (current_entry.mount_point == "/data") {
userdata_mounted = true;
}
// Success! Go get the next one.
continue;
}
// Mounting failed, understand why and retry.
wiped = partition_wiped(current_entry.blk_device.c_str());
bool crypt_footer = false;
if (mount_errno != EBUSY && mount_errno != EACCES &&
current_entry.fs_mgr_flags.formattable && wiped) {
// current_entry and attempted_entry point at the same partition, but sometimes
// at two different lines in the fstab. Use current_entry for formatting
// as that is the preferred one.
LERROR << __FUNCTION__ << "(): " << realpath(current_entry.blk_device)
<< " is wiped and " << current_entry.mount_point << " " << current_entry.fs_type
<< " is formattable. Format it.";
checkpoint_manager.Revert(&current_entry);
if (current_entry.is_encryptable() && current_entry.key_loc != KEY_IN_FOOTER) {
unique_fd fd(TEMP_FAILURE_RETRY(
open(current_entry.key_loc.c_str(), O_WRONLY | O_CLOEXEC)));
if (fd >= 0) {
LINFO << __FUNCTION__ << "(): also wipe " << current_entry.key_loc;
wipe_block_device(fd, get_file_size(fd));
} else {
PERROR << __FUNCTION__ << "(): " << current_entry.key_loc << " wouldn't open";
}
} else if (current_entry.is_encryptable() && current_entry.key_loc == KEY_IN_FOOTER) {
crypt_footer = true;
}
// EncryptInplace will be used when vdc gives an error or needs to format partitions
// other than /data
if (should_use_metadata_encryption(current_entry) &&
current_entry.mount_point == "/data") {
// vdc->Format requires "ro.crypto.type" to set an encryption flag
encryptable = FS_MGR_MNTALL_DEV_IS_METADATA_ENCRYPTED;
set_type_property(encryptable);
if (!call_vdc({"cryptfs", "encryptFstab", current_entry.blk_device,
current_entry.mount_point, "true" /* shouldFormat */,
current_entry.fs_type},
nullptr)) {
LERROR << "Encryption failed";
} else {
userdata_mounted = true;
continue;
}
}
if (fs_mgr_do_format(current_entry, crypt_footer) == 0) {
// Let's replay the mount actions.
i = top_idx - 1;
continue;
} else {
LERROR << __FUNCTION__ << "(): Format failed. "
<< "Suggest recovery...";
encryptable = FS_MGR_MNTALL_DEV_NEEDS_RECOVERY;
continue;
}
}
// mount(2) returned an error, handle the encryptable/formattable case.
if (mount_errno != EBUSY && mount_errno != EACCES && attempted_entry.is_encryptable()) {
if (wiped) {
LERROR << __FUNCTION__ << "(): " << attempted_entry.blk_device << " is wiped and "
<< attempted_entry.mount_point << " " << attempted_entry.fs_type
<< " is encryptable. Suggest recovery...";
encryptable = FS_MGR_MNTALL_DEV_NEEDS_RECOVERY;
continue;
} else {
// Need to mount a tmpfs at this mountpoint for now, and set
// properties that vold will query later for decrypting
LERROR << __FUNCTION__ << "(): possibly an encryptable blkdev "
<< attempted_entry.blk_device << " for mount " << attempted_entry.mount_point
<< " type " << attempted_entry.fs_type;
if (fs_mgr_do_tmpfs_mount(attempted_entry.mount_point.c_str()) < 0) {
++error_count;
continue;
}
}
encryptable = FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED;
} else if (mount_errno != EBUSY && mount_errno != EACCES &&
should_use_metadata_encryption(attempted_entry)) {
if (!call_vdc({"cryptfs", "mountFstab", attempted_entry.blk_device,
attempted_entry.mount_point},
nullptr)) {
++error_count;
} else if (current_entry.mount_point == "/data") {
userdata_mounted = true;
}
encryptable = FS_MGR_MNTALL_DEV_IS_METADATA_ENCRYPTED;
continue;
} else {
// fs_options might be null so we cannot use PERROR << directly.
// Use StringPrintf to output "(null)" instead.
if (attempted_entry.fs_mgr_flags.no_fail) {
PERROR << android::base::StringPrintf(
"Ignoring failure to mount an un-encryptable or wiped "
"partition on %s at %s options: %s",
attempted_entry.blk_device.c_str(), attempted_entry.mount_point.c_str(),
attempted_entry.fs_options.c_str());
} else {
PERROR << android::base::StringPrintf(
"Failed to mount an un-encryptable or wiped partition "
"on %s at %s options: %s",
attempted_entry.blk_device.c_str(), attempted_entry.mount_point.c_str(),
attempted_entry.fs_options.c_str());
++error_count;
}
continue;
}
}
set_type_property(encryptable);
#if ALLOW_ADBD_DISABLE_VERITY == 1 // "userdebug" build
fs_mgr_overlayfs_mount_all(fstab);
#endif
if (error_count) {
return {FS_MGR_MNTALL_FAIL, userdata_mounted};
} else {
return {encryptable, userdata_mounted};
}
}
int fs_mgr_umount_all(android::fs_mgr::Fstab* fstab) {
AvbUniquePtr avb_handle(nullptr);
int ret = FsMgrUmountStatus::SUCCESS;
for (auto& current_entry : *fstab) {
if (!IsMountPointMounted(current_entry.mount_point)) {
continue;
}
if (umount(current_entry.mount_point.c_str()) == -1) {
PERROR << "Failed to umount " << current_entry.mount_point;
ret |= FsMgrUmountStatus::ERROR_UMOUNT;
continue;
}
if (current_entry.fs_mgr_flags.logical) {
if (!fs_mgr_update_logical_partition(&current_entry)) {
LERROR << "Could not get logical partition blk_device, skipping!";
ret |= FsMgrUmountStatus::ERROR_DEVICE_MAPPER;
continue;
}
}
if (current_entry.fs_mgr_flags.avb || !current_entry.avb_keys.empty()) {
if (!AvbHandle::TearDownAvbHashtree(&current_entry, true /* wait */)) {
LERROR << "Failed to tear down AVB on mount point: " << current_entry.mount_point;
ret |= FsMgrUmountStatus::ERROR_VERITY;
continue;
}
} else if ((current_entry.fs_mgr_flags.verify)) {
if (!fs_mgr_teardown_verity(&current_entry)) {
LERROR << "Failed to tear down verified partition on mount point: "
<< current_entry.mount_point;
ret |= FsMgrUmountStatus::ERROR_VERITY;
continue;
}
}
}
return ret;
}
static std::chrono::milliseconds GetMillisProperty(const std::string& name,
std::chrono::milliseconds default_value) {
auto value = GetUintProperty(name, static_cast<uint64_t>(default_value.count()));
return std::chrono::milliseconds(std::move(value));
}
static bool fs_mgr_unmount_all_data_mounts(const std::string& data_block_device) {
LINFO << __FUNCTION__ << "(): about to umount everything on top of " << data_block_device;
Timer t;
auto timeout = GetMillisProperty("init.userspace_reboot.userdata_remount.timeoutmillis", 5s);
while (true) {
bool umount_done = true;
Fstab proc_mounts;
if (!ReadFstabFromFile("/proc/mounts", &proc_mounts)) {
LERROR << __FUNCTION__ << "(): Can't read /proc/mounts";
return false;
}
// Now proceed with other bind mounts on top of /data.
for (const auto& entry : proc_mounts) {
std::string block_device;
if (StartsWith(entry.blk_device, "/dev/block") &&
!Realpath(entry.blk_device, &block_device)) {
PWARNING << __FUNCTION__ << "(): failed to realpath " << entry.blk_device;
block_device = entry.blk_device;
}
if (data_block_device == block_device) {
if (umount2(entry.mount_point.c_str(), 0) != 0) {
PERROR << __FUNCTION__ << "(): Failed to umount " << entry.mount_point;
umount_done = false;
}
}
}
if (umount_done) {
LINFO << __FUNCTION__ << "(): Unmounting /data took " << t;
return true;
}
if (t.duration() > timeout) {
LERROR << __FUNCTION__ << "(): Timed out unmounting all mounts on "
<< data_block_device;
Fstab remaining_mounts;
if (!ReadFstabFromFile("/proc/mounts", &remaining_mounts)) {
LERROR << __FUNCTION__ << "(): Can't read /proc/mounts";
} else {
LERROR << __FUNCTION__ << "(): Following mounts remaining";
for (const auto& e : remaining_mounts) {
LERROR << __FUNCTION__ << "(): mount point: " << e.mount_point
<< " block device: " << e.blk_device;
}
}
return false;
}
std::this_thread::sleep_for(50ms);
}
}
static bool UnwindDmDeviceStack(const std::string& block_device,
std::vector<std::string>* dm_stack) {
if (!StartsWith(block_device, "/dev/block/")) {
LWARNING << block_device << " is not a block device";
return false;
}
std::string current = block_device;
DeviceMapper& dm = DeviceMapper::Instance();
while (true) {
dm_stack->push_back(current);
if (!dm.IsDmBlockDevice(current)) {
break;
}
auto parent = dm.GetParentBlockDeviceByPath(current);
if (!parent) {
return false;
}
current = *parent;
}
return true;
}
FstabEntry* fs_mgr_get_mounted_entry_for_userdata(Fstab* fstab,
const std::string& data_block_device) {
std::vector<std::string> dm_stack;
if (!UnwindDmDeviceStack(data_block_device, &dm_stack)) {
LERROR << "Failed to unwind dm-device stack for " << data_block_device;
return nullptr;
}
for (auto& entry : *fstab) {
if (entry.mount_point != "/data") {
continue;
}
std::string block_device;
if (entry.fs_mgr_flags.logical) {
if (!fs_mgr_update_logical_partition(&entry)) {
LERROR << "Failed to update logic partition " << entry.blk_device;
continue;
}
block_device = entry.blk_device;
} else if (!Realpath(entry.blk_device, &block_device)) {
PWARNING << "Failed to realpath " << entry.blk_device;
block_device = entry.blk_device;
}
if (std::find(dm_stack.begin(), dm_stack.end(), block_device) != dm_stack.end()) {
return &entry;
}
}
LERROR << "Didn't find entry that was used to mount /data onto " << data_block_device;
return nullptr;
}
// TODO(b/143970043): return different error codes based on which step failed.
int fs_mgr_remount_userdata_into_checkpointing(Fstab* fstab) {
Fstab proc_mounts;
if (!ReadFstabFromFile("/proc/mounts", &proc_mounts)) {
LERROR << "Can't read /proc/mounts";
return -1;
}
auto mounted_entry = GetEntryForMountPoint(&proc_mounts, "/data");
if (mounted_entry == nullptr) {
LERROR << "/data is not mounted";
return -1;
}
std::string block_device;
if (!Realpath(mounted_entry->blk_device, &block_device)) {
PERROR << "Failed to realpath " << mounted_entry->blk_device;
return -1;
}
auto fstab_entry = fs_mgr_get_mounted_entry_for_userdata(fstab, block_device);
if (fstab_entry == nullptr) {
LERROR << "Can't find /data in fstab";
return -1;
}
bool force_umount = GetBoolProperty("sys.init.userdata_remount.force_umount", false);
if (force_umount) {
LINFO << "Will force an umount of userdata even if it's not required";
}
if (!force_umount && !SupportsCheckpoint(fstab_entry)) {
LINFO << "Userdata doesn't support checkpointing. Nothing to do";
return 0;
}
CheckpointManager checkpoint_manager;
if (!force_umount && !checkpoint_manager.NeedsCheckpoint()) {
LINFO << "Checkpointing not needed. Don't remount";
return 0;
}
if (!force_umount && fstab_entry->fs_mgr_flags.checkpoint_fs) {
// Userdata is f2fs, simply remount it.
if (!checkpoint_manager.Update(fstab_entry)) {
LERROR << "Failed to remount userdata in checkpointing mode";
return -1;
}
if (mount(block_device.c_str(), fstab_entry->mount_point.c_str(), "none",
MS_REMOUNT | fstab_entry->flags, fstab_entry->fs_options.c_str()) != 0) {
PERROR << "Failed to remount userdata in checkpointing mode";
return -1;
}
} else {
LINFO << "Unmounting /data before remounting into checkpointing mode";
if (!fs_mgr_unmount_all_data_mounts(block_device)) {
LERROR << "Failed to umount /data";
return -1;
}
DeviceMapper& dm = DeviceMapper::Instance();
while (dm.IsDmBlockDevice(block_device)) {
auto next_device = dm.GetParentBlockDeviceByPath(block_device);
auto name = dm.GetDmDeviceNameByPath(block_device);
if (!name) {
LERROR << "Failed to get dm-name for " << block_device;
return -1;
}
LINFO << "Deleting " << block_device << " named " << *name;
if (!dm.DeleteDevice(*name, 3s)) {
return -1;
}
if (!next_device) {
LERROR << "Failed to find parent device for " << block_device;
}
block_device = *next_device;
}
LINFO << "Remounting /data";
// TODO(b/143970043): remove this hack after fs_mgr_mount_all is refactored.
auto result = fs_mgr_mount_all(fstab, MOUNT_MODE_ONLY_USERDATA);
return result.code == FS_MGR_MNTALL_FAIL ? -1 : 0;
}
return 0;
}
// wrapper to __mount() and expects a fully prepared fstab_rec,
// unlike fs_mgr_do_mount which does more things with avb / verity etc.
int fs_mgr_do_mount_one(const FstabEntry& entry, const std::string& alt_mount_point) {
// First check the filesystem if requested.
if (entry.fs_mgr_flags.wait && !WaitForFile(entry.blk_device, 20s)) {
LERROR << "Skipping mounting '" << entry.blk_device << "'";
}
auto& mount_point = alt_mount_point.empty() ? entry.mount_point : alt_mount_point;
// Run fsck if needed
prepare_fs_for_mount(entry.blk_device, entry, mount_point);
int ret = __mount(entry.blk_device, mount_point, entry);
if (ret) {
ret = (errno == EBUSY) ? FS_MGR_DOMNT_BUSY : FS_MGR_DOMNT_FAILED;
}
return ret;
}
// If tmp_mount_point is non-null, mount the filesystem there. This is for the
// tmp mount we do to check the user password
// If multiple fstab entries are to be mounted on "n_name", it will try to mount each one
// in turn, and stop on 1st success, or no more match.
static int fs_mgr_do_mount_helper(Fstab* fstab, const std::string& n_name,
const std::string& n_blk_device, const char* tmp_mount_point,
int needs_checkpoint, bool metadata_encrypted) {
int mount_errors = 0;
int first_mount_errno = 0;
std::string mount_point;
CheckpointManager checkpoint_manager(needs_checkpoint, metadata_encrypted);
AvbUniquePtr avb_handle(nullptr);
if (!fstab) {
return FS_MGR_DOMNT_FAILED;
}
for (auto& fstab_entry : *fstab) {
if (!fs_match(fstab_entry.mount_point, n_name)) {
continue;
}
// We found our match.
// If this swap or a raw partition, report an error.
if (fstab_entry.fs_type == "swap" || fstab_entry.fs_type == "emmc" ||
fstab_entry.fs_type == "mtd") {
LERROR << "Cannot mount filesystem of type " << fstab_entry.fs_type << " on "
<< n_blk_device;
return FS_MGR_DOMNT_FAILED;
}
if (fstab_entry.fs_mgr_flags.logical) {
if (!fs_mgr_update_logical_partition(&fstab_entry)) {
LERROR << "Could not set up logical partition, skipping!";
continue;
}
}
WrapUserdataIfNeeded(&fstab_entry, n_blk_device);
if (!checkpoint_manager.Update(&fstab_entry, n_blk_device)) {
LERROR << "Could not set up checkpoint partition, skipping!";
continue;
}
// First check the filesystem if requested.
if (fstab_entry.fs_mgr_flags.wait && !WaitForFile(n_blk_device, 20s)) {
LERROR << "Skipping mounting '" << n_blk_device << "'";
continue;
}
// Now mount it where requested */
if (tmp_mount_point) {
mount_point = tmp_mount_point;
} else {
mount_point = fstab_entry.mount_point;
}
int fs_stat = prepare_fs_for_mount(n_blk_device, fstab_entry, mount_point);
if (fstab_entry.fs_mgr_flags.avb) {
if (!avb_handle) {
avb_handle = AvbHandle::Open();
if (!avb_handle) {
LERROR << "Failed to open AvbHandle";
return FS_MGR_DOMNT_FAILED;
}
}
if (avb_handle->SetUpAvbHashtree(&fstab_entry, true /* wait_for_verity_dev */) ==
AvbHashtreeResult::kFail) {
LERROR << "Failed to set up AVB on partition: " << fstab_entry.mount_point
<< ", skipping!";
// Skips mounting the device.
continue;
}
} else if (!fstab_entry.avb_keys.empty()) {
if (AvbHandle::SetUpStandaloneAvbHashtree(&fstab_entry) == AvbHashtreeResult::kFail) {
LERROR << "Failed to set up AVB on standalone partition: "
<< fstab_entry.mount_point << ", skipping!";
// Skips mounting the device.
continue;
}
} else if (fstab_entry.fs_mgr_flags.verify) {
int rc = fs_mgr_setup_verity(&fstab_entry, true);
if (rc == FS_MGR_SETUP_VERITY_DISABLED || rc == FS_MGR_SETUP_VERITY_SKIPPED) {
LINFO << "Verity disabled";
} else if (rc != FS_MGR_SETUP_VERITY_SUCCESS) {
LERROR << "Could not set up verified partition, skipping!";
continue;
}
}
int retry_count = 2;
while (retry_count-- > 0) {
if (!__mount(n_blk_device, mount_point, fstab_entry)) {
fs_stat &= ~FS_STAT_FULL_MOUNT_FAILED;
return FS_MGR_DOMNT_SUCCESS;
} else {
if (retry_count <= 0) break; // run check_fs only once
if (!first_mount_errno) first_mount_errno = errno;
mount_errors++;
fs_stat |= FS_STAT_FULL_MOUNT_FAILED;
// try again after fsck
check_fs(n_blk_device, fstab_entry.fs_type, mount_point, &fs_stat);
}
}
log_fs_stat(fstab_entry.blk_device, fs_stat);
}
// Reach here means the mount attempt fails.
if (mount_errors) {
PERROR << "Cannot mount filesystem on " << n_blk_device << " at " << mount_point;
if (first_mount_errno == EBUSY) return FS_MGR_DOMNT_BUSY;
} else {
// We didn't find a match, say so and return an error.
LERROR << "Cannot find mount point " << n_name << " in fstab";
}
return FS_MGR_DOMNT_FAILED;
}
int fs_mgr_do_mount(Fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point) {
return fs_mgr_do_mount_helper(fstab, n_name, n_blk_device, tmp_mount_point, -1, false);
}
int fs_mgr_do_mount(Fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point,
bool needs_checkpoint, bool metadata_encrypted) {
return fs_mgr_do_mount_helper(fstab, n_name, n_blk_device, tmp_mount_point, needs_checkpoint,
metadata_encrypted);
}
/*
* mount a tmpfs filesystem at the given point.
* return 0 on success, non-zero on failure.
*/
int fs_mgr_do_tmpfs_mount(const char *n_name)
{
int ret;
ret = mount("tmpfs", n_name, "tmpfs", MS_NOATIME | MS_NOSUID | MS_NODEV | MS_NOEXEC,
CRYPTO_TMPFS_OPTIONS);
if (ret < 0) {
LERROR << "Cannot mount tmpfs filesystem at " << n_name;
return -1;
}
/* Success */
return 0;
}
static bool InstallZramDevice(const std::string& device) {
if (!android::base::WriteStringToFile(device, ZRAM_BACK_DEV)) {
PERROR << "Cannot write " << device << " in: " << ZRAM_BACK_DEV;
return false;
}
LINFO << "Success to set " << device << " to " << ZRAM_BACK_DEV;
return true;
}
static bool PrepareZramBackingDevice(off64_t size) {
constexpr const char* file_path = "/data/per_boot/zram_swap";
if (size == 0) return true;
// Prepare target path
unique_fd target_fd(TEMP_FAILURE_RETRY(open(file_path, O_RDWR | O_CREAT | O_CLOEXEC, 0600)));
if (target_fd.get() == -1) {
PERROR << "Cannot open target path: " << file_path;
return false;
}
if (fallocate(target_fd.get(), 0, 0, size) < 0) {
PERROR << "Cannot truncate target path: " << file_path;
return false;
}
// Allocate loop device and attach it to file_path.
LoopControl loop_control;
std::string device;
if (!loop_control.Attach(target_fd.get(), 5s, &device)) {
return false;
}
// set block size & direct IO
unique_fd device_fd(TEMP_FAILURE_RETRY(open(device.c_str(), O_RDWR | O_CLOEXEC)));
if (device_fd.get() == -1) {
PERROR << "Cannot open " << device;
return false;
}
if (!LoopControl::EnableDirectIo(device_fd.get())) {
return false;
}
return InstallZramDevice(device);
}
bool fs_mgr_swapon_all(const Fstab& fstab) {
bool ret = true;
for (const auto& entry : fstab) {
// Skip non-swap entries.
if (entry.fs_type != "swap") {
continue;
}
if (entry.zram_size > 0) {
if (!PrepareZramBackingDevice(entry.zram_backingdev_size)) {
LERROR << "Failure of zram backing device file for '" << entry.blk_device << "'";
}
// A zram_size was specified, so we need to configure the
// device. There is no point in having multiple zram devices
// on a system (all the memory comes from the same pool) so
// we can assume the device number is 0.
if (entry.max_comp_streams >= 0) {
auto zram_mcs_fp = std::unique_ptr<FILE, decltype(&fclose)>{
fopen(ZRAM_CONF_MCS, "re"), fclose};
if (zram_mcs_fp == nullptr) {
LERROR << "Unable to open zram conf comp device " << ZRAM_CONF_MCS;
ret = false;
continue;
}
fprintf(zram_mcs_fp.get(), "%d\n", entry.max_comp_streams);
}
auto zram_fp =
std::unique_ptr<FILE, decltype(&fclose)>{fopen(ZRAM_CONF_DEV, "re+"), fclose};
if (zram_fp == nullptr) {
LERROR << "Unable to open zram conf device " << ZRAM_CONF_DEV;
ret = false;
continue;
}
fprintf(zram_fp.get(), "%" PRId64 "\n", entry.zram_size);
}
if (entry.fs_mgr_flags.wait && !WaitForFile(entry.blk_device, 20s)) {
LERROR << "Skipping mkswap for '" << entry.blk_device << "'";
ret = false;
continue;
}
// Initialize the swap area.
const char* mkswap_argv[2] = {
MKSWAP_BIN,
entry.blk_device.c_str(),
};
int err = logwrap_fork_execvp(ARRAY_SIZE(mkswap_argv), mkswap_argv, nullptr, false,
LOG_KLOG, false, nullptr);
if (err) {
LERROR << "mkswap failed for " << entry.blk_device;
ret = false;
continue;
}
/* If -1, then no priority was specified in fstab, so don't set
* SWAP_FLAG_PREFER or encode the priority */
int flags = 0;
if (entry.swap_prio >= 0) {
flags = (entry.swap_prio << SWAP_FLAG_PRIO_SHIFT) & SWAP_FLAG_PRIO_MASK;
flags |= SWAP_FLAG_PREFER;
} else {
flags = 0;
}
err = swapon(entry.blk_device.c_str(), flags);
if (err) {
LERROR << "swapon failed for " << entry.blk_device;
ret = false;
}
}
return ret;
}
bool fs_mgr_is_verity_enabled(const FstabEntry& entry) {
if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
return false;
}
DeviceMapper& dm = DeviceMapper::Instance();
std::string mount_point = GetVerityDeviceName(entry);
if (dm.GetState(mount_point) == DmDeviceState::INVALID) {
return false;
}
const char* status;
std::vector<DeviceMapper::TargetInfo> table;
if (!dm.GetTableStatus(mount_point, &table) || table.empty() || table[0].data.empty()) {
if (!entry.fs_mgr_flags.verify_at_boot) {
return false;
}
status = "V";
} else {
status = table[0].data.c_str();
}
if (*status == 'C' || *status == 'V') {
return true;
}
return false;
}
std::string fs_mgr_get_hashtree_algorithm(const android::fs_mgr::FstabEntry& entry) {
if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
return "";
}
DeviceMapper& dm = DeviceMapper::Instance();
std::string device = GetVerityDeviceName(entry);
std::vector<DeviceMapper::TargetInfo> table;
if (dm.GetState(device) == DmDeviceState::INVALID || !dm.GetTableInfo(device, &table)) {
return "";
}
for (const auto& target : table) {
if (strcmp(target.spec.target_type, "verity") != 0) {
continue;
}
// The format is stable for dm-verity version 0 & 1. And the data is expected to have
// the fixed format:
// <version> <dev> <hash_dev> <data_block_size> <hash_block_size> <num_data_blocks>
// <hash_start_block> <algorithm> <digest> <salt>
// Details in https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/verity.html
std::vector<std::string> tokens = android::base::Split(target.data, " \t\r\n");
if (tokens[0] != "0" && tokens[0] != "1") {
LOG(WARNING) << "Unrecognized device mapper version in " << target.data;
return "";
}
// Hashtree algorithm is the 8th token in the output
return android::base::Trim(tokens[7]);
}
return "";
}
bool fs_mgr_verity_is_check_at_most_once(const android::fs_mgr::FstabEntry& entry) {
if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
return false;
}
DeviceMapper& dm = DeviceMapper::Instance();
std::string device = GetVerityDeviceName(entry);
std::vector<DeviceMapper::TargetInfo> table;
if (dm.GetState(device) == DmDeviceState::INVALID || !dm.GetTableInfo(device, &table)) {
return false;
}
for (const auto& target : table) {
if (strcmp(target.spec.target_type, "verity") == 0 &&
target.data.find("check_at_most_once") != std::string::npos) {
return true;
}
}
return false;
}
std::string fs_mgr_get_super_partition_name(int slot) {
// Devices upgrading to dynamic partitions are allowed to specify a super
// partition name. This includes cuttlefish, which is a non-A/B device.
std::string super_partition;
if (fs_mgr_get_boot_config_from_bootconfig_source("super_partition", &super_partition) ||
fs_mgr_get_boot_config_from_kernel_cmdline("super_partition", &super_partition)) {
if (fs_mgr_get_slot_suffix().empty()) {
return super_partition;
}
std::string suffix;
if (slot == 0) {
suffix = "_a";
} else if (slot == 1) {
suffix = "_b";
} else if (slot == -1) {
suffix = fs_mgr_get_slot_suffix();
}
return super_partition + suffix;
}
return LP_METADATA_DEFAULT_PARTITION_NAME;
}
bool fs_mgr_create_canonical_mount_point(const std::string& mount_point) {
auto saved_errno = errno;
auto ok = true;
auto created_mount_point = !mkdir(mount_point.c_str(), 0755);
std::string real_mount_point;
if (!Realpath(mount_point, &real_mount_point)) {
ok = false;
PERROR << "failed to realpath(" << mount_point << ")";
} else if (mount_point != real_mount_point) {
ok = false;
LERROR << "mount point is not canonical: realpath(" << mount_point << ") -> "
<< real_mount_point;
}
if (!ok && created_mount_point) {
rmdir(mount_point.c_str());
}
errno = saved_errno;
return ok;
}
bool fs_mgr_mount_overlayfs_fstab_entry(const FstabEntry& entry) {
auto overlayfs_valid_result = fs_mgr_overlayfs_valid();
if (overlayfs_valid_result == OverlayfsValidResult::kNotSupported) {
LERROR << __FUNCTION__ << "(): kernel does not support overlayfs";
return false;
}
#if ALLOW_ADBD_DISABLE_VERITY == 0
// Allowlist the mount point if user build.
static const std::vector<const std::string> kAllowedPaths = {
"/odm", "/odm_dlkm", "/oem", "/product", "/system_ext", "/vendor", "/vendor_dlkm",
};
static const std::vector<const std::string> kAllowedPrefixes = {
"/mnt/product/",
"/mnt/vendor/",
};
if (std::none_of(kAllowedPaths.begin(), kAllowedPaths.end(),
[&entry](const auto& path) -> bool {
return entry.mount_point == path ||
StartsWith(entry.mount_point, path + "/");
}) &&
std::none_of(kAllowedPrefixes.begin(), kAllowedPrefixes.end(),
[&entry](const auto& prefix) -> bool {
return entry.mount_point != prefix &&
StartsWith(entry.mount_point, prefix);
})) {
LERROR << __FUNCTION__
<< "(): mount point is forbidden on user build: " << entry.mount_point;
return false;
}
#endif // ALLOW_ADBD_DISABLE_VERITY == 0
if (!fs_mgr_create_canonical_mount_point(entry.mount_point)) {
return false;
}
auto options = "lowerdir=" + entry.lowerdir;
if (overlayfs_valid_result == OverlayfsValidResult::kOverrideCredsRequired) {
options += ",override_creds=off";
}
// Use "overlay-" + entry.blk_device as the mount() source, so that adb-remout-test don't
// confuse this with adb remount overlay, whose device name is "overlay".
// Overlayfs is a pseudo filesystem, so the source device is a symbolic value and isn't used to
// back the filesystem. However the device name would be shown in /proc/mounts.
auto source = "overlay-" + entry.blk_device;
auto report = "__mount(source=" + source + ",target=" + entry.mount_point + ",type=overlay," +
options + ")=";
auto ret = mount(source.c_str(), entry.mount_point.c_str(), "overlay", MS_RDONLY | MS_NOATIME,
options.c_str());
if (ret) {
PERROR << report << ret;
return false;
}
LINFO << report << ret;
return true;
}
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