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/*
* Copyright (C) 2019 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 <libfiemap/split_fiemap_writer.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <memory>
#include <string>
#include <vector>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include "utility.h"
namespace android {
namespace fiemap {
using android::base::unique_fd;
// We use a four-digit suffix at the end of filenames.
static const size_t kMaxFilePieces = 500;
std::unique_ptr<SplitFiemap> SplitFiemap::Create(const std::string& file_path, uint64_t file_size,
uint64_t max_piece_size,
ProgressCallback progress) {
std::unique_ptr<SplitFiemap> ret;
if (!Create(file_path, file_size, max_piece_size, &ret, progress).is_ok()) {
return nullptr;
}
return ret;
}
FiemapStatus SplitFiemap::Create(const std::string& file_path, uint64_t file_size,
uint64_t max_piece_size, std::unique_ptr<SplitFiemap>* out_val,
ProgressCallback progress) {
out_val->reset();
if (!file_size) {
LOG(ERROR) << "Cannot create a fiemap for a 0-length file: " << file_path;
return FiemapStatus::Error();
}
if (!max_piece_size) {
auto status = DetermineMaximumFileSize(file_path, &max_piece_size);
if (!status.is_ok()) {
LOG(ERROR) << "Could not determine maximum file size for " << file_path;
return status;
}
}
// Remove any existing file.
RemoveSplitFiles(file_path);
// Call |progress| only when the total percentage would significantly change.
int permille = -1;
uint64_t total_bytes_written = 0;
auto on_progress = [&](uint64_t written, uint64_t) -> bool {
uint64_t actual_written = total_bytes_written + written;
int new_permille = (actual_written * 1000) / file_size;
if (new_permille != permille && actual_written < file_size) {
if (progress && !progress(actual_written, file_size)) {
return false;
}
permille = new_permille;
}
return true;
};
std::unique_ptr<SplitFiemap> out(new SplitFiemap());
out->creating_ = true;
out->list_file_ = file_path;
// Create the split files.
uint64_t remaining_bytes = file_size;
while (remaining_bytes) {
if (out->files_.size() >= kMaxFilePieces) {
LOG(ERROR) << "Requested size " << file_size << " created too many split files";
out.reset();
return FiemapStatus::Error();
}
std::string chunk_path =
android::base::StringPrintf("%s.%04d", file_path.c_str(), (int)out->files_.size());
uint64_t chunk_size = std::min(max_piece_size, remaining_bytes);
FiemapUniquePtr writer;
auto status = FiemapWriter::Open(chunk_path, chunk_size, &writer, true, on_progress);
if (!status.is_ok()) {
out.reset();
return status;
}
// To make sure the alignment doesn't create too much inconsistency, we
// account the *actual* size, not the requested size.
total_bytes_written += writer->size();
// writer->size() is block size aligned and could be bigger than remaining_bytes
// If remaining_bytes is bigger, set remaining_bytes to 0 to avoid underflow error.
remaining_bytes = remaining_bytes > writer->size() ? (remaining_bytes - writer->size()) : 0;
out->AddFile(std::move(writer));
}
// Create the split file list.
unique_fd fd(open(out->list_file_.c_str(), O_CREAT | O_WRONLY | O_CLOEXEC, 0660));
if (fd < 0) {
PLOG(ERROR) << "Failed to open " << file_path;
out.reset();
return FiemapStatus::FromErrno(errno);
}
for (const auto& writer : out->files_) {
std::string line = android::base::Basename(writer->file_path()) + "\n";
if (!android::base::WriteFully(fd, line.data(), line.size())) {
PLOG(ERROR) << "Write failed " << file_path;
out.reset();
return FiemapStatus::FromErrno(errno);
}
}
fsync(fd.get());
// Unset this bit, so we don't unlink on destruction.
out->creating_ = false;
*out_val = std::move(out);
return FiemapStatus::Ok();
}
std::unique_ptr<SplitFiemap> SplitFiemap::Open(const std::string& file_path) {
std::vector<std::string> files;
if (!GetSplitFileList(file_path, &files)) {
return nullptr;
}
std::unique_ptr<SplitFiemap> out(new SplitFiemap());
out->list_file_ = file_path;
for (const auto& file : files) {
auto writer = FiemapWriter::Open(file, 0, false);
if (!writer) {
// Error was logged in Open().
return nullptr;
}
out->AddFile(std::move(writer));
}
return out;
}
bool SplitFiemap::GetSplitFileList(const std::string& file_path, std::vector<std::string>* list) {
// This is not the most efficient thing, but it is simple and recovering
// the fiemap/fibmap is much more expensive.
std::string contents;
if (!android::base::ReadFileToString(file_path, &contents, true)) {
PLOG(ERROR) << "Error reading file: " << file_path;
return false;
}
std::vector<std::string> names = android::base::Split(contents, "\n");
std::string dir = android::base::Dirname(file_path);
for (const auto& name : names) {
if (!name.empty()) {
list->emplace_back(dir + "/" + name);
}
}
return true;
}
bool SplitFiemap::RemoveSplitFiles(const std::string& file_path, std::string* message) {
// Early exit if this does not exist, and do not report an error.
if (access(file_path.c_str(), F_OK) && errno == ENOENT) {
return true;
}
bool ok = true;
std::vector<std::string> files;
if (GetSplitFileList(file_path, &files)) {
for (const auto& file : files) {
if (access(file.c_str(), F_OK) != 0 && (errno == ENOENT || errno == ENAMETOOLONG)) {
continue;
}
ok &= android::base::RemoveFileIfExists(file, message);
}
}
ok &= android::base::RemoveFileIfExists(file_path, message);
return ok;
}
bool SplitFiemap::HasPinnedExtents() const {
for (const auto& file : files_) {
if (!FiemapWriter::HasPinnedExtents(file->file_path())) {
return false;
}
}
return true;
}
const std::vector<struct fiemap_extent>& SplitFiemap::extents() {
if (extents_.empty()) {
for (const auto& file : files_) {
const auto& extents = file->extents();
extents_.insert(extents_.end(), extents.begin(), extents.end());
}
}
return extents_;
}
bool SplitFiemap::Write(const void* data, uint64_t bytes) {
// Open the current file.
FiemapWriter* file = files_[cursor_index_].get();
const uint8_t* data_ptr = reinterpret_cast<const uint8_t*>(data);
uint64_t bytes_remaining = bytes;
while (bytes_remaining) {
// How many bytes can we write into the current file?
uint64_t file_bytes_left = file->size() - cursor_file_pos_;
if (!file_bytes_left) {
if (cursor_index_ == files_.size() - 1) {
LOG(ERROR) << "write past end of file requested";
return false;
}
// No space left in the current file, but we have more files to
// use, so prep the next one.
cursor_fd_ = {};
cursor_file_pos_ = 0;
file = files_[++cursor_index_].get();
file_bytes_left = file->size();
}
// Open the current file if it's not open.
if (cursor_fd_ < 0) {
cursor_fd_.reset(open(file->file_path().c_str(), O_CLOEXEC | O_WRONLY));
if (cursor_fd_ < 0) {
PLOG(ERROR) << "open failed: " << file->file_path();
return false;
}
CHECK(cursor_file_pos_ == 0);
}
if (!FiemapWriter::HasPinnedExtents(file->file_path())) {
LOG(ERROR) << "file is no longer pinned: " << file->file_path();
return false;
}
uint64_t bytes_to_write = std::min(file_bytes_left, bytes_remaining);
if (!android::base::WriteFully(cursor_fd_, data_ptr, bytes_to_write)) {
PLOG(ERROR) << "write failed: " << file->file_path();
return false;
}
data_ptr += bytes_to_write;
bytes_remaining -= bytes_to_write;
cursor_file_pos_ += bytes_to_write;
}
// If we've reached the end of the current file, close it.
if (cursor_file_pos_ == file->size()) {
cursor_fd_ = {};
}
return true;
}
bool SplitFiemap::Flush() {
for (const auto& file : files_) {
unique_fd fd(open(file->file_path().c_str(), O_RDONLY | O_CLOEXEC));
if (fd < 0) {
PLOG(ERROR) << "open failed: " << file->file_path();
return false;
}
if (fsync(fd)) {
PLOG(ERROR) << "fsync failed: " << file->file_path();
return false;
}
}
return true;
}
SplitFiemap::~SplitFiemap() {
if (!creating_) {
return;
}
// We failed to finish creating, so unlink everything.
unlink(list_file_.c_str());
for (auto&& file : files_) {
std::string path = file->file_path();
file = nullptr;
unlink(path.c_str());
}
}
void SplitFiemap::AddFile(FiemapUniquePtr&& file) {
total_size_ += file->size();
files_.emplace_back(std::move(file));
}
uint32_t SplitFiemap::block_size() const {
return files_[0]->block_size();
}
const std::string& SplitFiemap::bdev_path() const {
return files_[0]->bdev_path();
}
} // namespace fiemap
} // namespace android