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/*
* Copyright (C) 2018 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.
*/
#define LOG_TAG "Checkpoint"
#include "Checkpoint.h"
#include "VoldUtil.h"
#include "VolumeManager.h"
#include <fstream>
#include <list>
#include <memory>
#include <string>
#include <thread>
#include <vector>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/unique_fd.h>
#include <android/hardware/boot/1.0/IBootControl.h>
#include <cutils/android_reboot.h>
#include <fcntl.h>
#include <fs_mgr.h>
#include <linux/fs.h>
#include <mntent.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <unistd.h>
using android::base::GetBoolProperty;
using android::base::GetUintProperty;
using android::base::SetProperty;
using android::binder::Status;
using android::fs_mgr::Fstab;
using android::fs_mgr::ReadDefaultFstab;
using android::fs_mgr::ReadFstabFromFile;
using android::hardware::hidl_string;
using android::hardware::boot::V1_0::BoolResult;
using android::hardware::boot::V1_0::CommandResult;
using android::hardware::boot::V1_0::IBootControl;
using android::hardware::boot::V1_0::Slot;
namespace {
const std::string kMetadataCPFile = "/metadata/vold/checkpoint";
android::binder::Status error(const std::string& msg) {
PLOG(ERROR) << msg;
return android::binder::Status::fromServiceSpecificError(errno, android::String8(msg.c_str()));
}
android::binder::Status error(int error, const std::string& msg) {
LOG(ERROR) << msg;
return android::binder::Status::fromServiceSpecificError(error, android::String8(msg.c_str()));
}
bool setBowState(std::string const& block_device, std::string const& state) {
std::string bow_device = fs_mgr_find_bow_device(block_device);
if (bow_device.empty()) return false;
if (!android::base::WriteStringToFile(state, bow_device + "/bow/state")) {
PLOG(ERROR) << "Failed to write to file " << bow_device + "/bow/state";
return false;
}
return true;
}
} // namespace
Status cp_supportsCheckpoint(bool& result) {
result = false;
for (const auto& entry : fstab_default) {
if (entry.fs_mgr_flags.checkpoint_blk || entry.fs_mgr_flags.checkpoint_fs) {
result = true;
return Status::ok();
}
}
return Status::ok();
}
Status cp_supportsBlockCheckpoint(bool& result) {
result = false;
for (const auto& entry : fstab_default) {
if (entry.fs_mgr_flags.checkpoint_blk) {
result = true;
return Status::ok();
}
}
return Status::ok();
}
Status cp_supportsFileCheckpoint(bool& result) {
result = false;
for (const auto& entry : fstab_default) {
if (entry.fs_mgr_flags.checkpoint_fs) {
result = true;
return Status::ok();
}
}
return Status::ok();
}
Status cp_startCheckpoint(int retry) {
bool result;
if (!cp_supportsCheckpoint(result).isOk() || !result)
return error(ENOTSUP, "Checkpoints not supported");
if (retry < -1) return error(EINVAL, "Retry count must be more than -1");
std::string content = std::to_string(retry + 1);
if (retry == -1) {
android::sp<IBootControl> module = IBootControl::getService();
if (module) {
std::string suffix;
auto cb = [&suffix](hidl_string s) { suffix = s; };
if (module->getSuffix(module->getCurrentSlot(), cb).isOk()) content += " " + suffix;
}
}
if (!android::base::WriteStringToFile(content, kMetadataCPFile))
return error("Failed to write checkpoint file");
return Status::ok();
}
namespace {
volatile bool isCheckpointing = false;
volatile bool needsCheckpointWasCalled = false;
// Protects isCheckpointing, needsCheckpointWasCalled and code that makes decisions based on status
// of isCheckpointing
std::mutex isCheckpointingLock;
}
Status cp_commitChanges() {
std::lock_guard<std::mutex> lock(isCheckpointingLock);
if (!isCheckpointing) {
return Status::ok();
}
if (android::base::GetProperty("persist.vold.dont_commit_checkpoint", "0") == "1") {
LOG(WARNING)
<< "NOT COMMITTING CHECKPOINT BECAUSE persist.vold.dont_commit_checkpoint IS 1";
return Status::ok();
}
// TWRP should not mark errors on slots
// android::sp<IBootControl> module = IBootControl::getService();
// if (module) {
// CommandResult cr;
// module->markBootSuccessful([&cr](CommandResult result) { cr = result; });
// if (!cr.success)
// return error(EINVAL, "Error marking booted successfully: " + std::string(cr.errMsg));
// LOG(INFO) << "Marked slot as booted successfully.";
// // Clears the warm reset flag for next reboot.
// if (!SetProperty("ota.warm_reset", "0")) {
// LOG(WARNING) << "Failed to reset the warm reset flag";
// }
// }
// Must take action for list of mounted checkpointed things here
// To do this, we walk the list of mounted file systems.
// But we also need to get the matching fstab entries to see
// the original flags
std::string err_str;
Fstab mounts;
if (!ReadFstabFromFile("/proc/mounts", &mounts)) {
return error(EINVAL, "Failed to get /proc/mounts");
}
// Walk mounted file systems
for (const auto& mount_rec : mounts) {
const auto fstab_rec = GetEntryForMountPoint(&fstab_default, mount_rec.mount_point);
if (!fstab_rec) continue;
if (fstab_rec->fs_mgr_flags.checkpoint_fs) {
if (fstab_rec->fs_type == "f2fs") {
std::string options = mount_rec.fs_options + ",checkpoint=enable";
if (mount(mount_rec.blk_device.c_str(), mount_rec.mount_point.c_str(), "none",
MS_REMOUNT | fstab_rec->flags, options.c_str())) {
return error(EINVAL, "Failed to remount");
}
}
} else if (fstab_rec->fs_mgr_flags.checkpoint_blk) {
if (!setBowState(mount_rec.blk_device, "2"))
return error(EINVAL, "Failed to set bow state");
}
}
SetProperty("vold.checkpoint_committed", "1");
LOG(INFO) << "Checkpoint has been committed.";
isCheckpointing = false;
if (!android::base::RemoveFileIfExists(kMetadataCPFile, &err_str))
return error(err_str.c_str());
return Status::ok();
}
namespace {
void abort_metadata_file() {
std::string oldContent, newContent;
int retry = 0;
struct stat st;
int result = stat(kMetadataCPFile.c_str(), &st);
// If the file doesn't exist, we aren't managing a checkpoint retry counter
if (result != 0) return;
if (!android::base::ReadFileToString(kMetadataCPFile, &oldContent)) {
PLOG(ERROR) << "Failed to read checkpoint file";
return;
}
std::string retryContent = oldContent.substr(0, oldContent.find_first_of(" "));
if (!android::base::ParseInt(retryContent, &retry)) {
PLOG(ERROR) << "Could not parse retry count";
return;
}
if (retry > 0) {
newContent = "0";
if (!android::base::WriteStringToFile(newContent, kMetadataCPFile))
PLOG(ERROR) << "Could not write checkpoint file";
}
}
} // namespace
void cp_abortChanges(const std::string& message, bool retry) {
if (!cp_needsCheckpoint()) return;
if (!retry) abort_metadata_file();
android_reboot(ANDROID_RB_RESTART2, 0, message.c_str());
}
bool cp_needsRollback() {
std::string content;
bool ret;
ret = android::base::ReadFileToString(kMetadataCPFile, &content);
if (ret) {
if (content == "0") return true;
if (content.substr(0, 3) == "-1 ") {
std::string oldSuffix = content.substr(3);
android::sp<IBootControl> module = IBootControl::getService();
std::string newSuffix;
if (module) {
auto cb = [&newSuffix](hidl_string s) { newSuffix = s; };
module->getSuffix(module->getCurrentSlot(), cb);
if (oldSuffix == newSuffix) return true;
}
}
}
return false;
}
bool cp_needsCheckpoint() {
std::lock_guard<std::mutex> lock(isCheckpointingLock);
// Make sure we only return true during boot. See b/138952436 for discussion
if (needsCheckpointWasCalled) return isCheckpointing;
needsCheckpointWasCalled = true;
bool ret;
std::string content;
android::sp<IBootControl> module = IBootControl::getService();
if (isCheckpointing) return isCheckpointing;
if (module && module->isSlotMarkedSuccessful(module->getCurrentSlot()) == BoolResult::FALSE) {
isCheckpointing = true;
return true;
}
ret = android::base::ReadFileToString(kMetadataCPFile, &content);
if (ret) {
ret = content != "0";
isCheckpointing = ret;
return ret;
}
return false;
}
bool cp_isCheckpointing() {
return isCheckpointing;
}
namespace {
const std::string kSleepTimeProp = "ro.sys.cp_msleeptime";
const uint32_t msleeptime_default = 1000; // 1 s
const uint32_t max_msleeptime = 3600000; // 1 h
const std::string kMinFreeBytesProp = "ro.sys.cp_min_free_bytes";
const uint64_t min_free_bytes_default = 100 * (1 << 20); // 100 MiB
const std::string kCommitOnFullProp = "ro.sys.cp_commit_on_full";
const bool commit_on_full_default = true;
static void cp_healthDaemon(std::string mnt_pnt, std::string blk_device, bool is_fs_cp) {
struct statvfs data;
uint32_t msleeptime = GetUintProperty(kSleepTimeProp, msleeptime_default, max_msleeptime);
uint64_t min_free_bytes =
GetUintProperty(kMinFreeBytesProp, min_free_bytes_default, (uint64_t)-1);
bool commit_on_full = GetBoolProperty(kCommitOnFullProp, commit_on_full_default);
struct timespec req;
req.tv_sec = msleeptime / 1000;
msleeptime %= 1000;
req.tv_nsec = msleeptime * 1000000;
while (isCheckpointing) {
uint64_t free_bytes = 0;
if (is_fs_cp) {
statvfs(mnt_pnt.c_str(), &data);
free_bytes = ((uint64_t) data.f_bavail) * data.f_frsize;
} else {
std::string bow_device = fs_mgr_find_bow_device(blk_device);
if (!bow_device.empty()) {
std::string content;
if (android::base::ReadFileToString(bow_device + "/bow/free", &content)) {
free_bytes = std::strtoull(content.c_str(), NULL, 10);
}
}
}
if (free_bytes < min_free_bytes) {
if (commit_on_full) {
LOG(INFO) << "Low space for checkpointing. Commiting changes";
cp_commitChanges();
break;
} else {
LOG(INFO) << "Low space for checkpointing. Rebooting";
cp_abortChanges("checkpoint,low_space", false);
break;
}
}
nanosleep(&req, NULL);
}
}
} // namespace
Status cp_prepareCheckpoint() {
// Log to notify CTS - see b/137924328 for context
LOG(INFO) << "cp_prepareCheckpoint called";
std::lock_guard<std::mutex> lock(isCheckpointingLock);
if (!isCheckpointing) {
return Status::ok();
}
Fstab mounts;
if (!ReadFstabFromFile("/proc/mounts", &mounts)) {
return error(EINVAL, "Failed to get /proc/mounts");
}
for (const auto& mount_rec : mounts) {
const auto fstab_rec = GetEntryForMountPoint(&fstab_default, mount_rec.mount_point);
if (!fstab_rec) continue;
if (fstab_rec->fs_mgr_flags.checkpoint_blk) {
android::base::unique_fd fd(
TEMP_FAILURE_RETRY(open(mount_rec.mount_point.c_str(), O_RDONLY | O_CLOEXEC)));
if (fd == -1) {
PLOG(ERROR) << "Failed to open mount point" << mount_rec.mount_point;
continue;
}
struct fstrim_range range = {};
range.len = ULLONG_MAX;
nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
if (ioctl(fd, FITRIM, &range)) {
PLOG(ERROR) << "Failed to trim " << mount_rec.mount_point;
continue;
}
nsecs_t time = systemTime(SYSTEM_TIME_BOOTTIME) - start;
LOG(INFO) << "Trimmed " << range.len << " bytes on " << mount_rec.mount_point << " in "
<< nanoseconds_to_milliseconds(time) << "ms for checkpoint";
setBowState(mount_rec.blk_device, "1");
}
if (fstab_rec->fs_mgr_flags.checkpoint_blk || fstab_rec->fs_mgr_flags.checkpoint_fs) {
std::thread(cp_healthDaemon, std::string(mount_rec.mount_point),
std::string(mount_rec.blk_device),
fstab_rec->fs_mgr_flags.checkpoint_fs == 1)
.detach();
}
}
return Status::ok();
}
namespace {
const int kSectorSize = 512;
typedef uint64_t sector_t;
struct log_entry {
sector_t source; // in sectors of size kSectorSize
sector_t dest; // in sectors of size kSectorSize
uint32_t size; // in bytes
uint32_t checksum;
} __attribute__((packed));
struct log_sector_v1_0 {
uint32_t magic;
uint16_t header_version;
uint16_t header_size;
uint32_t block_size;
uint32_t count;
uint32_t sequence;
uint64_t sector0;
} __attribute__((packed));
// MAGIC is BOW in ascii
const int kMagic = 0x00574f42;
// Partially restored MAGIC is WOB in ascii
const int kPartialRestoreMagic = 0x00424f57;
void crc32(const void* data, size_t n_bytes, uint32_t* crc) {
static uint32_t table[0x100] = {
0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535,
0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,
0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D,
0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4,
0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC,
0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB,
0xB6662D3D,
0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5,
0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED,
0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074,
0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC,
0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C,
0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B,
0xC0BA6CAD,
0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615,
0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,
0x0A00AE27, 0x7D079EB1, 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D,
0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4,
0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C,
0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 0xCB61B38C,
0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B,
0x5BDEAE1D,
0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785,
0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,
0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD,
0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354,
0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 0xBDBDF21C,
0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B,
0x2D02EF8D};
for (size_t i = 0; i < n_bytes; ++i) {
*crc ^= ((uint8_t*)data)[i];
*crc = table[(uint8_t)*crc] ^ *crc >> 8;
}
}
// A map of relocations.
// The map must be initialized so that relocations[0] = 0
// During restore, we replay the log records in reverse, copying from dest to
// source
// To validate, we must be able to read the 'dest' sectors as though they had
// been copied but without actually copying. This map represents how the sectors
// would have been moved. To read a sector s, find the index <= s and read
// relocations[index] + s - index
typedef std::map<sector_t, sector_t> Relocations;
void relocate(Relocations& relocations, sector_t dest, sector_t source, int count) {
// Find first one we're equal to or greater than
auto s = --relocations.upper_bound(source);
// Take slice
Relocations slice;
slice[dest] = source - s->first + s->second;
++s;
// Add rest of elements
for (; s != relocations.end() && s->first < source + count; ++s)
slice[dest - source + s->first] = s->second;
// Split range at end of dest
auto dest_end = --relocations.upper_bound(dest + count);
relocations[dest + count] = dest + count - dest_end->first + dest_end->second;
// Remove all elements in [dest, dest + count)
relocations.erase(relocations.lower_bound(dest), relocations.lower_bound(dest + count));
// Add new elements
relocations.insert(slice.begin(), slice.end());
}
// A map of sectors that have been written to.
// The final entry must always be False.
// When we restart the restore after an interruption, we must take care that
// when we copy from dest to source, that the block we copy to was not
// previously copied from.
// i e. A->B C->A; If we replay this sequence, we end up copying C->B
// We must save our partial result whenever we finish a page, or when we copy
// to a location that was copied from earlier (our source is an earlier dest)
typedef std::map<sector_t, bool> Used_Sectors;
bool checkCollision(Used_Sectors& used_sectors, sector_t start, sector_t end) {
auto second_overlap = used_sectors.upper_bound(start);
auto first_overlap = --second_overlap;
if (first_overlap->second) {
return true;
} else if (second_overlap != used_sectors.end() && second_overlap->first < end) {
return true;
}
return false;
}
void markUsed(Used_Sectors& used_sectors, sector_t start, sector_t end) {
auto start_pos = used_sectors.insert_or_assign(start, true).first;
auto end_pos = used_sectors.insert_or_assign(end, false).first;
if (start_pos == used_sectors.begin() || !std::prev(start_pos)->second) {
start_pos++;
}
if (std::next(end_pos) != used_sectors.end() && !std::next(end_pos)->second) {
end_pos++;
}
if (start_pos->first < end_pos->first) {
used_sectors.erase(start_pos, end_pos);
}
}
// Restores the given log_entry's data from dest -> source
// If that entry is a log sector, set the magic to kPartialRestoreMagic and flush.
void restoreSector(int device_fd, Used_Sectors& used_sectors, std::vector<char>& ls_buffer,
log_entry* le, std::vector<char>& buffer) {
log_sector_v1_0& ls = *reinterpret_cast<log_sector_v1_0*>(&ls_buffer[0]);
uint32_t index = le - ((log_entry*)&ls_buffer[ls.header_size]);
int count = (le->size - 1) / kSectorSize + 1;
if (checkCollision(used_sectors, le->source, le->source + count)) {
fsync(device_fd);
lseek64(device_fd, 0, SEEK_SET);
ls.count = index + 1;
ls.magic = kPartialRestoreMagic;
write(device_fd, &ls_buffer[0], ls.block_size);
fsync(device_fd);
used_sectors.clear();
used_sectors[0] = false;
}
markUsed(used_sectors, le->dest, le->dest + count);
if (index == 0 && ls.sequence != 0) {
log_sector_v1_0* next = reinterpret_cast<log_sector_v1_0*>(&buffer[0]);
if (next->magic == kMagic) {
next->magic = kPartialRestoreMagic;
}
}
lseek64(device_fd, le->source * kSectorSize, SEEK_SET);
write(device_fd, &buffer[0], le->size);
if (index == 0) {
fsync(device_fd);
}
}
// Read from the device
// If we are validating, the read occurs as though the relocations had happened
std::vector<char> relocatedRead(int device_fd, Relocations const& relocations, bool validating,
sector_t sector, uint32_t size, uint32_t block_size) {
if (!validating) {
std::vector<char> buffer(size);
lseek64(device_fd, sector * kSectorSize, SEEK_SET);
read(device_fd, &buffer[0], size);
return buffer;
}
std::vector<char> buffer(size);
for (uint32_t i = 0; i < size; i += block_size, sector += block_size / kSectorSize) {
auto relocation = --relocations.upper_bound(sector);
lseek64(device_fd, (sector + relocation->second - relocation->first) * kSectorSize,
SEEK_SET);
read(device_fd, &buffer[i], block_size);
}
return buffer;
}
} // namespace
Status cp_restoreCheckpoint(const std::string& blockDevice, int restore_limit) {
bool validating = true;
std::string action = "Validating";
int restore_count = 0;
for (;;) {
Relocations relocations;
relocations[0] = 0;
Status status = Status::ok();
LOG(INFO) << action << " checkpoint on " << blockDevice;
android::base::unique_fd device_fd(open(blockDevice.c_str(), O_RDWR | O_CLOEXEC));
if (device_fd < 0) return error("Cannot open " + blockDevice);
log_sector_v1_0 original_ls;
read(device_fd, reinterpret_cast<char*>(&original_ls), sizeof(original_ls));
if (original_ls.magic == kPartialRestoreMagic) {
validating = false;
action = "Restoring";
} else if (original_ls.magic != kMagic) {
return error(EINVAL, "No magic");
}
LOG(INFO) << action << " " << original_ls.sequence << " log sectors";
for (int sequence = original_ls.sequence; sequence >= 0 && status.isOk(); sequence--) {
auto ls_buffer = relocatedRead(device_fd, relocations, validating, 0,
original_ls.block_size, original_ls.block_size);
log_sector_v1_0& ls = *reinterpret_cast<log_sector_v1_0*>(&ls_buffer[0]);
Used_Sectors used_sectors;
used_sectors[0] = false;
if (ls.magic != kMagic && (ls.magic != kPartialRestoreMagic || validating)) {
status = error(EINVAL, "No magic");
break;
}
if (ls.block_size != original_ls.block_size) {
status = error(EINVAL, "Block size mismatch");
break;
}
if ((int)ls.sequence != sequence) {
status = error(EINVAL, "Expecting log sector " + std::to_string(sequence) +
" but got " + std::to_string(ls.sequence));
break;
}
LOG(INFO) << action << " from log sector " << ls.sequence;
for (log_entry* le =
reinterpret_cast<log_entry*>(&ls_buffer[ls.header_size]) + ls.count - 1;
le >= reinterpret_cast<log_entry*>(&ls_buffer[ls.header_size]); --le) {
// This is very noisy - limit to DEBUG only
LOG(VERBOSE) << action << " " << le->size << " bytes from sector " << le->dest
<< " to " << le->source << " with checksum " << std::hex
<< le->checksum;
auto buffer = relocatedRead(device_fd, relocations, validating, le->dest, le->size,
ls.block_size);
uint32_t checksum = le->source / (ls.block_size / kSectorSize);
for (size_t i = 0; i < le->size; i += ls.block_size) {
crc32(&buffer[i], ls.block_size, &checksum);
}
if (le->checksum && checksum != le->checksum) {
status = error(EINVAL, "Checksums don't match");
break;
}
if (validating) {
relocate(relocations, le->source, le->dest, (le->size - 1) / kSectorSize + 1);
} else {
restoreSector(device_fd, used_sectors, ls_buffer, le, buffer);
restore_count++;
if (restore_limit && restore_count >= restore_limit) {
status = error(EAGAIN, "Hit the test limit");
break;
}
}
}
}
if (!status.isOk()) {
if (!validating) {
LOG(ERROR) << "Checkpoint restore failed even though checkpoint validation passed";
return status;
}
LOG(WARNING) << "Checkpoint validation failed - attempting to roll forward";
auto buffer = relocatedRead(device_fd, relocations, false, original_ls.sector0,
original_ls.block_size, original_ls.block_size);
lseek64(device_fd, 0, SEEK_SET);
write(device_fd, &buffer[0], original_ls.block_size);
return Status::ok();
}
if (!validating) break;
validating = false;
action = "Restoring";
}
return Status::ok();
}
Status cp_markBootAttempt() {
std::string oldContent, newContent;
int retry = 0;
struct stat st;
int result = stat(kMetadataCPFile.c_str(), &st);
// If the file doesn't exist, we aren't managing a checkpoint retry counter
if (result != 0) return Status::ok();
if (!android::base::ReadFileToString(kMetadataCPFile, &oldContent))
return error("Failed to read checkpoint file");
std::string retryContent = oldContent.substr(0, oldContent.find_first_of(" "));
if (!android::base::ParseInt(retryContent, &retry))
return error(EINVAL, "Could not parse retry count");
if (retry > 0) {
retry--;
newContent = std::to_string(retry);
if (!android::base::WriteStringToFile(newContent, kMetadataCPFile))
return error("Could not write checkpoint file");
}
return Status::ok();
}
void cp_resetCheckpoint() {
std::lock_guard<std::mutex> lock(isCheckpointingLock);
needsCheckpointWasCalled = false;
}