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fs_mgr.cpp
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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 <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.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 <functional>
#include <memory>
#include <string>
#include <thread>
#include <vector>
#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_crypt_init_extensions.h>
#include <ext4_utils/ext4_sb.h>
#include <ext4_utils/ext4_utils.h>
#include <ext4_utils/wipe.h>
#include <libdm/dm.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.h"
#include "fs_mgr_avb.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 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 ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
using DeviceMapper = android::dm::DeviceMapper;
// 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_EXT4_INVALID_MAGIC = 0x0800,
FS_STAT_TOGGLE_QUOTAS_FAILED = 0x10000,
FS_STAT_SET_RESERVED_BLOCKS_FAILED = 0x20000,
FS_STAT_ENABLE_ENCRYPTION_FAILED = 0x40000,
};
// TODO: switch to inotify()
bool fs_mgr_wait_for_file(const std::string& filename,
const std::chrono::milliseconds relative_timeout) {
auto start_time = std::chrono::steady_clock::now();
while (true) {
if (!access(filename.c_str(), F_OK) || errno != ENOENT) {
return true;
}
std::this_thread::sleep_for(50ms);
auto now = std::chrono::steady_clock::now();
auto time_elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(now - start_time);
if (time_elapsed > relative_timeout) return false;
}
}
static void log_fs_stat(const char* 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, 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 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 char *blk_device, char *fs_type, char *target, int *fs_stat)
{
int status;
int ret;
long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
char tmpmnt_opts[64] = "errors=remount-ro";
const char* e2fsck_argv[] = {E2FSCK_BIN, "-y", blk_device};
const char* e2fsck_forced_argv[] = {E2FSCK_BIN, "-f", "-y", blk_device};
/* Check for the types of filesystems we know how to check */
if (is_extfs(fs_type)) {
if (*fs_stat & FS_STAT_EXT4_INVALID_MAGIC) { // will fail, so do not try
return;
}
/*
* 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 (!strcmp(fs_type, "ext4")) {
// This option is only valid with ext4
strlcat(tmpmnt_opts, ",nomblk_io_submit", sizeof(tmpmnt_opts));
}
ret = mount(blk_device, target, fs_type, tmpmnt_flags, tmpmnt_opts);
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) == 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 " << blk_device
<< " (executable not in system image)";
} else {
LINFO << "Running " << E2FSCK_BIN << " on " << blk_device;
if (should_force_check(*fs_stat)) {
ret = android_fork_execvp_ext(
ARRAY_SIZE(e2fsck_forced_argv), const_cast<char**>(e2fsck_forced_argv), &status,
true, LOG_KLOG | LOG_FILE, true, const_cast<char*>(FSCK_LOG_FILE), NULL, 0);
} else {
ret = android_fork_execvp_ext(
ARRAY_SIZE(e2fsck_argv), const_cast<char**>(e2fsck_argv), &status, true,
LOG_KLOG | LOG_FILE, true, const_cast<char*>(FSCK_LOG_FILE), NULL, 0);
}
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 (!strcmp(fs_type, "f2fs")) {
const char *f2fs_fsck_argv[] = {
F2FS_FSCK_BIN,
"-a",
blk_device
};
LINFO << "Running " << F2FS_FSCK_BIN << " -a " << blk_device;
ret = android_fork_execvp_ext(ARRAY_SIZE(f2fs_fsck_argv),
const_cast<char **>(f2fs_fsck_argv),
&status, true, LOG_KLOG | LOG_FILE,
true, const_cast<char *>(FSCK_LOG_FILE),
NULL, 0);
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;
}
}
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_EXT4_INVALID_MAGIC.
static bool read_ext4_superblock(const char* blk_device, struct ext4_super_block* sb, int* fs_stat) {
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC)));
if (fd < 0) {
PERROR << "Failed to open '" << blk_device << "'";
return false;
}
if (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_EXT4_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;
}
// 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_tune2fs(const char* argv[], int argc) {
int ret;
ret = android_fork_execvp_ext(argc, const_cast<char**>(argv), nullptr, true,
LOG_KLOG | LOG_FILE, true, nullptr, nullptr, 0);
return ret == 0;
}
// Enable/disable quota support on the filesystem if needed.
static void tune_quota(const char* blk_device, const struct fstab_rec* rec,
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 = fs_mgr_is_quota(rec) != 0;
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};
if (want_quota) {
LINFO << "Enabling quotas on " << blk_device;
argv[1] = "-Oquota";
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";
}
if (!run_tune2fs(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 char* blk_device, const struct fstab_rec* rec,
const struct ext4_super_block* sb, int* fs_stat) {
if (!(rec->fs_mgr_flags & MF_RESERVEDSIZE)) {
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 = rec->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};
if (!run_tune2fs(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 char* blk_device, const struct fstab_rec* rec,
const struct ext4_super_block* sb, int* fs_stat) {
bool has_encrypt = (sb->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_ENCRYPT)) != 0;
bool want_encrypt = fs_mgr_is_file_encrypted(rec) != 0;
if (has_encrypt || !want_encrypt) {
return;
}
if (!tune2fs_available()) {
LERROR << "Unable to enable ext4 encryption on " << blk_device
<< " because " TUNE2FS_BIN " is missing";
return;
}
const char* argv[] = {TUNE2FS_BIN, "-Oencrypt", blk_device};
LINFO << "Enabling ext4 encryption on " << blk_device;
if (!run_tune2fs(argv, ARRAY_SIZE(argv))) {
LERROR << "Failed to run " TUNE2FS_BIN " to enable "
<< "ext4 encryption on " << blk_device;
*fs_stat |= FS_STAT_ENABLE_ENCRYPTION_FAILED;
}
}
//
// 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 char* blk_device, const struct fstab_rec* rec) {
int fs_stat = 0;
if (is_extfs(rec->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, rec, &sb, &fs_stat);
} else {
return fs_stat;
}
}
if ((rec->fs_mgr_flags & MF_CHECK) ||
(fs_stat & (FS_STAT_UNCLEAN_SHUTDOWN | FS_STAT_QUOTA_ENABLED))) {
check_fs(blk_device, rec->fs_type, rec->mount_point, &fs_stat);
}
if (is_extfs(rec->fs_type) && (rec->fs_mgr_flags & (MF_RESERVEDSIZE | MF_FILEENCRYPTION))) {
struct ext4_super_block sb;
if (read_ext4_superblock(blk_device, &sb, &fs_stat)) {
tune_reserved_size(blk_device, rec, &sb, &fs_stat);
tune_encrypt(blk_device, rec, &sb, &fs_stat);
}
}
return fs_stat;
}
static void remove_trailing_slashes(char *n)
{
int len;
len = strlen(n) - 1;
while ((*(n + len) == '/') && len) {
*(n + len) = '\0';
len--;
}
}
/*
* Mark the given block device as read-only, using the BLKROSET ioctl.
* Return 0 on success, and -1 on error.
*/
int fs_mgr_set_blk_ro(const char *blockdev)
{
int fd;
int rc = -1;
int ON = 1;
fd = TEMP_FAILURE_RETRY(open(blockdev, O_RDONLY | O_CLOEXEC));
if (fd < 0) {
// should never happen
return rc;
}
rc = ioctl(fd, BLKROSET, &ON);
close(fd);
return rc;
}
// 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 char *source, const char *target, const struct fstab_rec *rec)
{
unsigned long mountflags = rec->flags;
int ret;
int save_errno;
/* We need this because sometimes we have legacy symlinks
* that are lingering around and need cleaning up.
*/
struct stat info;
if (!lstat(target, &info))
if ((info.st_mode & S_IFMT) == S_IFLNK)
unlink(target);
mkdir(target, 0755);
errno = 0;
ret = mount(source, target, rec->fs_type, mountflags, rec->fs_options);
save_errno = errno;
PINFO << __FUNCTION__ << "(source=" << source << ",target=" << target
<< ",type=" << rec->fs_type << ")=" << ret;
if ((ret == 0) && (mountflags & MS_RDONLY) != 0) {
fs_mgr_set_blk_ro(source);
}
errno = save_errno;
return ret;
}
static int fs_match(const char *in1, const char *in2)
{
char *n1;
char *n2;
int ret;
n1 = strdup(in1);
n2 = strdup(in2);
remove_trailing_slashes(n1);
remove_trailing_slashes(n2);
ret = !strcmp(n1, n2);
free(n1);
free(n2);
return ret;
}
/*
* Tries to mount any of the consecutive fstab entries that match
* the mountpoint of the one given by fstab->recs[start_idx].
*
* end_idx: On return, will be the last rec that was looked at.
* attempted_idx: On return, will indicate which fstab rec
* succeeded. In case of failure, it will be the start_idx.
* Returns
* -1 on failure with errno set to match the 1st mount failure.
* 0 on success.
*/
static int mount_with_alternatives(struct fstab *fstab, int start_idx, int *end_idx, int *attempted_idx)
{
int i;
int mount_errno = 0;
int mounted = 0;
if (!end_idx || !attempted_idx || start_idx >= fstab->num_entries) {
errno = EINVAL;
if (end_idx) *end_idx = start_idx;
if (attempted_idx) *attempted_idx = start_idx;
return -1;
}
/* 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->num_entries && !strcmp(fstab->recs[start_idx].mount_point, fstab->recs[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->recs[i].mount_point << " rec[" << i
<< "].fs_type=" << fstab->recs[i].fs_type
<< " already mounted as "
<< fstab->recs[*attempted_idx].fs_type;
continue;
}
int fs_stat = prepare_fs_for_mount(fstab->recs[i].blk_device, &fstab->recs[i]);
if (fs_stat & FS_STAT_EXT4_INVALID_MAGIC) {
LERROR << __FUNCTION__ << "(): skipping mount, invalid ext4, mountpoint="
<< fstab->recs[i].mount_point << " rec[" << i
<< "].fs_type=" << fstab->recs[i].fs_type;
mount_errno = EINVAL; // continue bootup for FDE
continue;
}
int retry_count = 2;
while (retry_count-- > 0) {
if (!__mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point,
&fstab->recs[i])) {
*attempted_idx = i;
mounted = 1;
if (i != start_idx) {
LERROR << __FUNCTION__ << "(): Mounted " << fstab->recs[i].blk_device
<< " on " << fstab->recs[i].mount_point
<< " with fs_type=" << fstab->recs[i].fs_type << " instead of "
<< fstab->recs[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->recs[i].blk_device, fstab->recs[i].fs_type,
fstab->recs[i].mount_point, &fs_stat);
}
}
log_fs_stat(fstab->recs[i].blk_device, fs_stat);
}
/* Adjust i for the case where it was still withing the recs[] */
if (i < fstab->num_entries) --i;
*end_idx = i;
if (!mounted) {
*attempted_idx = start_idx;
errno = mount_errno;
return -1;
}
return 0;
}
static int translate_ext_labels(struct fstab_rec *rec)
{
DIR *blockdir = NULL;
struct dirent *ent;
char *label;
size_t label_len;
int ret = -1;
if (strncmp(rec->blk_device, "LABEL=", 6))
return 0;
label = rec->blk_device + 6;
label_len = strlen(label);
if (label_len > 16) {
LERROR << "FS label is longer than allowed by filesystem";
goto out;
}
blockdir = opendir("/dev/block");
if (!blockdir) {
LERROR << "couldn't open /dev/block";
goto out;
}
while ((ent = readdir(blockdir))) {
int fd;
char super_buf[1024];
struct ext4_super_block *sb;
if (ent->d_type != DT_BLK)
continue;
fd = openat(dirfd(blockdir), ent->d_name, O_RDONLY);
if (fd < 0) {
LERROR << "Cannot open block device /dev/block/" << ent->d_name;
goto out;
}
if (TEMP_FAILURE_RETRY(lseek(fd, 1024, SEEK_SET)) < 0 ||
TEMP_FAILURE_RETRY(read(fd, super_buf, 1024)) != 1024) {
/* Probably a loopback device or something else without a readable
* superblock.
*/
close(fd);
continue;
}
sb = (struct ext4_super_block *)super_buf;
if (sb->s_magic != EXT4_SUPER_MAGIC) {
LINFO << "/dev/block/" << ent->d_name << " not ext{234}";
continue;
}
if (!strncmp(label, sb->s_volume_name, label_len)) {
char *new_blk_device;
if (asprintf(&new_blk_device, "/dev/block/%s", ent->d_name) < 0) {
LERROR << "Could not allocate block device string";
goto out;
}
LINFO << "resolved label " << rec->blk_device << " to "
<< new_blk_device;
free(rec->blk_device);
rec->blk_device = new_blk_device;
ret = 0;
break;
}
}
out:
closedir(blockdir);
return ret;
}
static bool needs_block_encryption(const struct fstab_rec* rec)
{
if (android::base::GetBoolProperty("ro.vold.forceencryption", false) &&
fs_mgr_is_encryptable(rec))
return true;
if (rec->fs_mgr_flags & MF_FORCECRYPT) return true;
if (rec->fs_mgr_flags & MF_CRYPT) {
/* Check for existence of convert_fde breadcrumb file */
char convert_fde_name[PATH_MAX];
snprintf(convert_fde_name, sizeof(convert_fde_name),
"%s/misc/vold/convert_fde", rec->mount_point);
if (access(convert_fde_name, F_OK) == 0) return true;
}
if (rec->fs_mgr_flags & MF_FORCEFDEORFBE) {
/* Check for absence of convert_fbe breadcrumb file */
char convert_fbe_name[PATH_MAX];
snprintf(convert_fbe_name, sizeof(convert_fbe_name),
"%s/convert_fbe", rec->mount_point);
if (access(convert_fbe_name, F_OK) != 0) return true;
}
return false;
}
static bool should_use_metadata_encryption(const struct fstab_rec* rec) {
if (!(rec->fs_mgr_flags & (MF_FILEENCRYPTION | MF_FORCEFDEORFBE))) return false;
if (!(rec->fs_mgr_flags & MF_KEYDIRECTORY)) return false;
return true;
}
// Check to see if a mountable volume has encryption requirements
static int handle_encryptable(const struct fstab_rec* rec)
{
/* If this is block encryptable, need to trigger encryption */
if (needs_block_encryption(rec)) {
if (umount(rec->mount_point) == 0) {
return FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION;
} else {
PWARNING << "Could not umount " << rec->mount_point
<< " - allow continue unencrypted";
return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
}
} else if (should_use_metadata_encryption(rec)) {
if (umount(rec->mount_point) == 0) {
return FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION;
} else {
PERROR << "Could not umount " << rec->mount_point << " - fail since can't encrypt";
return FS_MGR_MNTALL_FAIL;
}
} else if (rec->fs_mgr_flags & (MF_FILEENCRYPTION | MF_FORCEFDEORFBE)) {
LINFO << rec->mount_point << " is file encrypted";
return FS_MGR_MNTALL_DEV_FILE_ENCRYPTED;
} else if (fs_mgr_is_encryptable(rec)) {
return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
} else {
return FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE;
}
}
static bool call_vdc(const std::vector<std::string>& args) {
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 ret = android_fork_execvp(4, const_cast<char**>(argv.data()), nullptr, false, true);
if (ret != 0) {
LOG(ERROR) << "vdc returned error code: " << ret;
return false;
}
LOG(DEBUG) << "vdc finished successfully";
return true;
}
bool fs_mgr_update_logical_partition(struct fstab_rec* rec) {
// 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 (rec->blk_device[0] == '/') {
return true;
}
DeviceMapper& dm = DeviceMapper::Instance();
std::string device_name;
if (!dm.GetDmDevicePathByName(rec->blk_device, &device_name)) {
return false;
}
free(rec->blk_device);
rec->blk_device = strdup(device_name.c_str());
return true;
}
/* 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.
*/
int fs_mgr_mount_all(struct fstab *fstab, int mount_mode)
{
int i = 0;
int encryptable = FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE;
int error_count = 0;
int mret = -1;
int mount_errno = 0;
int attempted_idx = -1;
FsManagerAvbUniquePtr avb_handle(nullptr);
if (!fstab) {
return FS_MGR_MNTALL_FAIL;
}
for (i = 0; i < fstab->num_entries; i++) {
/* Don't mount entries that are managed by vold or not for the mount mode*/
if ((fstab->recs[i].fs_mgr_flags & (MF_VOLDMANAGED | MF_RECOVERYONLY)) ||
((mount_mode == MOUNT_MODE_LATE) && !fs_mgr_is_latemount(&fstab->recs[i])) ||
((mount_mode == MOUNT_MODE_EARLY) && fs_mgr_is_latemount(&fstab->recs[i]))) {
continue;
}
/* Skip swap and raw partition entries such as boot, recovery, etc */
if (!strcmp(fstab->recs[i].fs_type, "swap") ||
!strcmp(fstab->recs[i].fs_type, "emmc") ||
!strcmp(fstab->recs[i].fs_type, "mtd")) {
continue;
}
/* Skip mounting the root partition, as it will already have been mounted */
if (!strcmp(fstab->recs[i].mount_point, "/")) {
if ((fstab->recs[i].fs_mgr_flags & MS_RDONLY) != 0) {
fs_mgr_set_blk_ro(fstab->recs[i].blk_device);
}
continue;
}
/* Translate LABEL= file system labels into block devices */
if (is_extfs(fstab->recs[i].fs_type)) {
int tret = translate_ext_labels(&fstab->recs[i]);
if (tret < 0) {
LERROR << "Could not translate label to block device";
continue;
}
}
if ((fstab->recs[i].fs_mgr_flags & MF_LOGICAL)) {
if (!fs_mgr_update_logical_partition(&fstab->recs[i])) {
LERROR << "Could not set up logical partition, skipping!";
continue;
}
}
if (fstab->recs[i].fs_mgr_flags & MF_WAIT &&
!fs_mgr_wait_for_file(fstab->recs[i].blk_device, 20s)) {
LERROR << "Skipping '" << fstab->recs[i].blk_device << "' during mount_all";
continue;
}
if (fstab->recs[i].fs_mgr_flags & MF_AVB) {
if (!avb_handle) {
avb_handle = FsManagerAvbHandle::Open(*fstab);
if (!avb_handle) {
LERROR << "Failed to open FsManagerAvbHandle";
return FS_MGR_MNTALL_FAIL;
}
}
if (avb_handle->SetUpAvbHashtree(&fstab->recs[i], true /* wait_for_verity_dev */) ==
SetUpAvbHashtreeResult::kFail) {
LERROR << "Failed to set up AVB on partition: "
<< fstab->recs[i].mount_point << ", skipping!";
/* Skips mounting the device. */
continue;
}
} else if ((fstab->recs[i].fs_mgr_flags & MF_VERIFY)) {
int rc = fs_mgr_setup_verity(&fstab->recs[i], true);
if (__android_log_is_debuggable() &&
(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;
mret = mount_with_alternatives(fstab, i, &last_idx_inspected, &attempted_idx);
i = last_idx_inspected;
mount_errno = errno;
/* Deal with encryptability. */
if (!mret) {
int status = handle_encryptable(&fstab->recs[attempted_idx]);
if (status == FS_MGR_MNTALL_FAIL) {
/* Fatal error - no point continuing */
return status;
}
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", fstab->recs[attempted_idx].mount_point})) {
LERROR << "Encryption failed";
return FS_MGR_MNTALL_FAIL;
}
}
}
/* Success! Go get the next one */
continue;
}
bool wiped = partition_wiped(fstab->recs[top_idx].blk_device);
bool crypt_footer = false;
if (mret && mount_errno != EBUSY && mount_errno != EACCES &&
fs_mgr_is_formattable(&fstab->recs[top_idx]) && wiped) {
/* top_idx and attempted_idx point at the same partition, but sometimes
* at two different lines in the fstab. Use the top one for formatting
* as that is the preferred one.
*/
LERROR << __FUNCTION__ << "(): " << fstab->recs[top_idx].blk_device
<< " is wiped and " << fstab->recs[top_idx].mount_point
<< " " << fstab->recs[top_idx].fs_type
<< " is formattable. Format it.";
if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
int fd = open(fstab->recs[top_idx].key_loc, O_WRONLY);
if (fd >= 0) {
LINFO << __FUNCTION__ << "(): also wipe "
<< fstab->recs[top_idx].key_loc;
wipe_block_device(fd, get_file_size(fd));
close(fd);
} else {
PERROR << __FUNCTION__ << "(): "
<< fstab->recs[top_idx].key_loc << " wouldn't open";
}
} else if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
!strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
crypt_footer = true;
}
if (fs_mgr_do_format(&fstab->recs[top_idx], 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 (mret && mount_errno != EBUSY && mount_errno != EACCES &&
fs_mgr_is_encryptable(&fstab->recs[attempted_idx])) {
if (wiped) {
LERROR << __FUNCTION__ << "(): "
<< fstab->recs[attempted_idx].blk_device
<< " is wiped and "
<< fstab->recs[attempted_idx].mount_point << " "
<< fstab->recs[attempted_idx].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 "