| /* |
| * 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. |
| */ |
| |
| #include <libfiemap_writer/fiemap_writer.h> |
| |
| #include <dirent.h> |
| #include <fcntl.h> |
| #include <linux/fs.h> |
| #include <stdio.h> |
| #include <sys/ioctl.h> |
| #include <sys/stat.h> |
| #include <sys/sysmacros.h> |
| #include <sys/types.h> |
| #include <sys/vfs.h> |
| #include <unistd.h> |
| |
| #include <string> |
| #include <utility> |
| #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> |
| |
| namespace android { |
| namespace fiemap_writer { |
| |
| // We are expecting no more than 512 extents in a fiemap of the file we create. |
| // If we find more, then it is treated as error for now. |
| static constexpr const uint32_t kMaxExtents = 512; |
| |
| // TODO: Fallback to using fibmap if FIEMAP_EXTENT_MERGED is set. |
| static constexpr const uint32_t kUnsupportedExtentFlags = |
| FIEMAP_EXTENT_UNKNOWN | FIEMAP_EXTENT_UNWRITTEN | FIEMAP_EXTENT_DELALLOC | |
| FIEMAP_EXTENT_NOT_ALIGNED | FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_DATA_TAIL | |
| FIEMAP_EXTENT_UNWRITTEN | FIEMAP_EXTENT_SHARED | FIEMAP_EXTENT_MERGED; |
| |
| static inline void cleanup(const std::string& file_path, bool created) { |
| if (created) { |
| unlink(file_path.c_str()); |
| } |
| } |
| |
| static bool BlockDeviceToName(uint32_t major, uint32_t minor, std::string* bdev_name) { |
| // The symlinks in /sys/dev/block point to the block device node under /sys/device/.. |
| // The directory name in the target corresponds to the name of the block device. We use |
| // that to extract the block device name. |
| // e.g for block device name 'ram0', there exists a symlink named '1:0' in /sys/dev/block as |
| // follows. |
| // 1:0 -> ../../devices/virtual/block/ram0 |
| std::string sysfs_path = ::android::base::StringPrintf("/sys/dev/block/%u:%u", major, minor); |
| std::string sysfs_bdev; |
| |
| if (!::android::base::Readlink(sysfs_path, &sysfs_bdev)) { |
| PLOG(ERROR) << "Failed to read link at: " << sysfs_path; |
| return false; |
| } |
| |
| *bdev_name = ::android::base::Basename(sysfs_bdev); |
| // Paranoid sanity check to make sure we just didn't get the |
| // input in return as-is. |
| if (sysfs_bdev == *bdev_name) { |
| LOG(ERROR) << "Malformed symlink for block device: " << sysfs_bdev; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool DeviceMapperStackPop(const std::string& bdev, std::string* bdev_raw) { |
| // TODO: Stop popping the device mapper stack if dm-linear target is found |
| if (!::android::base::StartsWith(bdev, "dm-")) { |
| // We are at the bottom of the device mapper stack. |
| *bdev_raw = bdev; |
| return true; |
| } |
| |
| std::string dm_leaf_dir = ::android::base::StringPrintf("/sys/block/%s/slaves", bdev.c_str()); |
| auto d = std::unique_ptr<DIR, decltype(&closedir)>(opendir(dm_leaf_dir.c_str()), closedir); |
| if (d == nullptr) { |
| PLOG(ERROR) << "Failed to open: " << dm_leaf_dir; |
| return false; |
| } |
| |
| struct dirent* de; |
| uint32_t num_leaves = 0; |
| std::string bdev_next = ""; |
| while ((de = readdir(d.get())) != nullptr) { |
| if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) { |
| continue; |
| } |
| |
| // We set the first name we find here |
| if (bdev_next.empty()) { |
| bdev_next = de->d_name; |
| } |
| num_leaves++; |
| } |
| |
| // if we have more than one leaves, we return immediately. We can't continue to create the |
| // file since we don't know how to write it out using fiemap, so it will be readable via the |
| // underlying block devices later. The reader will also have to construct the same device mapper |
| // target in order read the file out. |
| if (num_leaves > 1) { |
| LOG(ERROR) << "Found " << num_leaves << " leaf block devices under device mapper device " |
| << bdev; |
| return false; |
| } |
| |
| // recursively call with the block device we found in order to pop the device mapper stack. |
| return DeviceMapperStackPop(bdev_next, bdev_raw); |
| } |
| |
| static bool FileToBlockDevicePath(const std::string& file_path, std::string* bdev_path) { |
| struct stat sb; |
| if (stat(file_path.c_str(), &sb)) { |
| PLOG(ERROR) << "Failed to get stat for: " << file_path; |
| return false; |
| } |
| |
| std::string bdev; |
| if (!BlockDeviceToName(major(sb.st_dev), minor(sb.st_dev), &bdev)) { |
| LOG(ERROR) << "Failed to get block device name for " << major(sb.st_dev) << ":" |
| << minor(sb.st_dev); |
| return false; |
| } |
| |
| std::string bdev_raw; |
| if (!DeviceMapperStackPop(bdev, &bdev_raw)) { |
| LOG(ERROR) << "Failed to get the bottom of the device mapper stack for device: " << bdev; |
| return false; |
| } |
| |
| LOG(DEBUG) << "Popped device (" << bdev_raw << ") from device mapper stack starting with (" |
| << bdev << ")"; |
| |
| *bdev_path = ::android::base::StringPrintf("/dev/block/%s", bdev_raw.c_str()); |
| |
| // Make sure we are talking to a block device before calling it a success. |
| if (stat(bdev_path->c_str(), &sb)) { |
| PLOG(ERROR) << "Failed to get stat for block device: " << *bdev_path; |
| return false; |
| } |
| |
| if ((sb.st_mode & S_IFMT) != S_IFBLK) { |
| PLOG(ERROR) << "File: " << *bdev_path << " is not a block device"; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool GetBlockDeviceSize(int bdev_fd, const std::string& bdev_path, uint64_t* bdev_size) { |
| uint64_t size_in_bytes = 0; |
| if (ioctl(bdev_fd, BLKGETSIZE64, &size_in_bytes)) { |
| PLOG(ERROR) << "Failed to get total size for: " << bdev_path; |
| return false; |
| } |
| |
| *bdev_size = size_in_bytes; |
| |
| return true; |
| } |
| |
| static uint64_t GetFileSize(const std::string& file_path) { |
| struct stat sb; |
| if (stat(file_path.c_str(), &sb)) { |
| PLOG(ERROR) << "Failed to get size for file: " << file_path; |
| return 0; |
| } |
| |
| return sb.st_size; |
| } |
| |
| static bool PerformFileChecks(const std::string& file_path, uint64_t file_size, uint64_t* blocksz, |
| uint32_t* fs_type) { |
| struct statfs64 sfs; |
| if (statfs64(file_path.c_str(), &sfs)) { |
| PLOG(ERROR) << "Failed to read file system status at: " << file_path; |
| return false; |
| } |
| |
| if (file_size % sfs.f_bsize) { |
| LOG(ERROR) << "File size " << file_size << " is not aligned to optimal block size " |
| << sfs.f_bsize << " for file " << file_path; |
| return false; |
| } |
| |
| // Check if the filesystem is of supported types. |
| // Only ext4 and f2fs are tested and supported. |
| if ((sfs.f_type != EXT4_SUPER_MAGIC) && (sfs.f_type != F2FS_SUPER_MAGIC)) { |
| LOG(ERROR) << "Unsupported file system type: 0x" << std::hex << sfs.f_type; |
| return false; |
| } |
| |
| uint64_t available_bytes = sfs.f_bsize * sfs.f_bavail; |
| if (available_bytes <= file_size) { |
| LOG(ERROR) << "Not enough free space in file system to create file of size : " << file_size; |
| return false; |
| } |
| |
| *blocksz = sfs.f_bsize; |
| *fs_type = sfs.f_type; |
| return true; |
| } |
| |
| static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blocksz, |
| uint64_t file_size, std::function<bool(uint64_t, uint64_t)> on_progress) { |
| // Reserve space for the file on the file system and write it out to make sure the extents |
| // don't come back unwritten. Return from this function with the kernel file offset set to 0. |
| // If the filesystem is f2fs, then we also PIN the file on disk to make sure the blocks |
| // aren't moved around. |
| if (fallocate(file_fd, FALLOC_FL_ZERO_RANGE, 0, file_size)) { |
| PLOG(ERROR) << "Failed to allocate space for file: " << file_path << " size: " << file_size; |
| return false; |
| } |
| |
| // write zeroes in 'blocksz' byte increments until we reach file_size to make sure the data |
| // blocks are actually written to by the file system and thus getting rid of the holes in the |
| // file. |
| auto buffer = std::unique_ptr<void, decltype(&free)>(calloc(1, blocksz), free); |
| if (buffer == nullptr) { |
| LOG(ERROR) << "failed to allocate memory for writing file"; |
| return false; |
| } |
| |
| off64_t offset = lseek64(file_fd, 0, SEEK_SET); |
| if (offset < 0) { |
| PLOG(ERROR) << "Failed to seek at the beginning of : " << file_path; |
| return false; |
| } |
| |
| int permille = -1; |
| for (; offset < file_size; offset += blocksz) { |
| if (!::android::base::WriteFully(file_fd, buffer.get(), blocksz)) { |
| PLOG(ERROR) << "Failed to write" << blocksz << " bytes at offset" << offset |
| << " in file " << file_path; |
| return false; |
| } |
| // Don't invoke the callback every iteration - wait until a significant |
| // chunk (here, 1/1000th) of the data has been processed. |
| int new_permille = (static_cast<uint64_t>(offset) * 1000) / file_size; |
| if (new_permille != permille) { |
| if (on_progress && !on_progress(offset, file_size)) { |
| return false; |
| } |
| permille = new_permille; |
| } |
| } |
| |
| if (lseek64(file_fd, 0, SEEK_SET) < 0) { |
| PLOG(ERROR) << "Failed to reset offset at the beginning of : " << file_path; |
| return false; |
| } |
| |
| // flush all writes here .. |
| if (fsync(file_fd)) { |
| PLOG(ERROR) << "Failed to synchronize written file:" << file_path; |
| return false; |
| } |
| |
| // Send one last progress notification. |
| if (on_progress && !on_progress(file_size, file_size)) { |
| return false; |
| } |
| return true; |
| } |
| |
| static bool PinFile(int file_fd, const std::string& file_path, uint32_t fs_type) { |
| if (fs_type == EXT4_SUPER_MAGIC) { |
| // No pinning necessary for ext4. The blocks, once allocated, are expected |
| // to be fixed. |
| return true; |
| } |
| |
| // F2FS-specific ioctl |
| // It requires the below kernel commit merged in v4.16-rc1. |
| // 1ad71a27124c ("f2fs: add an ioctl to disable GC for specific file") |
| // In android-4.4, |
| // 56ee1e817908 ("f2fs: updates on v4.16-rc1") |
| // In android-4.9, |
| // 2f17e34672a8 ("f2fs: updates on v4.16-rc1") |
| // In android-4.14, |
| // ce767d9a55bc ("f2fs: updates on v4.16-rc1") |
| #ifndef F2FS_IOC_SET_PIN_FILE |
| #ifndef F2FS_IOCTL_MAGIC |
| #define F2FS_IOCTL_MAGIC 0xf5 |
| #endif |
| #define F2FS_IOC_SET_PIN_FILE _IOW(F2FS_IOCTL_MAGIC, 13, __u32) |
| #endif |
| |
| uint32_t pin_status = 1; |
| int error = ioctl(file_fd, F2FS_IOC_SET_PIN_FILE, &pin_status); |
| if (error < 0) { |
| if ((errno == ENOTTY) || (errno == ENOTSUP)) { |
| PLOG(ERROR) << "Failed to pin file, not supported by kernel: " << file_path; |
| } else { |
| PLOG(ERROR) << "Failed to pin file: " << file_path; |
| } |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool IsFilePinned(int file_fd, const std::string& file_path, uint32_t fs_type) { |
| if (fs_type == EXT4_SUPER_MAGIC) { |
| // No pinning necessary for ext4. The blocks, once allocated, are expected |
| // to be fixed. |
| return true; |
| } |
| |
| // F2FS-specific ioctl |
| // It requires the below kernel commit merged in v4.16-rc1. |
| // 1ad71a27124c ("f2fs: add an ioctl to disable GC for specific file") |
| // In android-4.4, |
| // 56ee1e817908 ("f2fs: updates on v4.16-rc1") |
| // In android-4.9, |
| // 2f17e34672a8 ("f2fs: updates on v4.16-rc1") |
| // In android-4.14, |
| // ce767d9a55bc ("f2fs: updates on v4.16-rc1") |
| #ifndef F2FS_IOC_GET_PIN_FILE |
| #ifndef F2FS_IOCTL_MAGIC |
| #define F2FS_IOCTL_MAGIC 0xf5 |
| #endif |
| #define F2FS_IOC_GET_PIN_FILE _IOR(F2FS_IOCTL_MAGIC, 14, __u32) |
| #endif |
| |
| // F2FS_IOC_GET_PIN_FILE returns the number of blocks moved. |
| uint32_t moved_blocks_nr; |
| int error = ioctl(file_fd, F2FS_IOC_GET_PIN_FILE, &moved_blocks_nr); |
| if (error < 0) { |
| if ((errno == ENOTTY) || (errno == ENOTSUP)) { |
| PLOG(ERROR) << "Failed to get file pin status, not supported by kernel: " << file_path; |
| } else { |
| PLOG(ERROR) << "Failed to get file pin status: " << file_path; |
| } |
| return false; |
| } |
| |
| if (moved_blocks_nr) { |
| LOG(ERROR) << moved_blocks_nr << " blocks moved in file " << file_path; |
| } |
| return moved_blocks_nr == 0; |
| } |
| |
| bool FiemapWriter::HasPinnedExtents(const std::string& file_path) { |
| android::base::unique_fd fd(open(file_path.c_str(), O_NOFOLLOW | O_CLOEXEC | O_RDONLY)); |
| if (fd < 0) { |
| PLOG(ERROR) << "open: " << file_path; |
| return false; |
| } |
| |
| struct statfs64 sfs; |
| if (fstatfs64(fd, &sfs)) { |
| PLOG(ERROR) << "fstatfs64: " << file_path; |
| return false; |
| } |
| return IsFilePinned(fd, file_path, sfs.f_type); |
| } |
| |
| static bool ReadFiemap(int file_fd, const std::string& file_path, |
| std::vector<struct fiemap_extent>* extents) { |
| uint64_t fiemap_size = |
| sizeof(struct fiemap_extent) + kMaxExtents * sizeof(struct fiemap_extent); |
| auto buffer = std::unique_ptr<void, decltype(&free)>(calloc(1, fiemap_size), free); |
| if (buffer == nullptr) { |
| LOG(ERROR) << "Failed to allocate memory for fiemap"; |
| return false; |
| } |
| |
| struct fiemap* fiemap = reinterpret_cast<struct fiemap*>(buffer.get()); |
| fiemap->fm_start = 0; |
| fiemap->fm_length = UINT64_MAX; |
| // make sure file is synced to disk before we read the fiemap |
| fiemap->fm_flags = FIEMAP_FLAG_SYNC; |
| fiemap->fm_extent_count = kMaxExtents; |
| |
| if (ioctl(file_fd, FS_IOC_FIEMAP, fiemap)) { |
| PLOG(ERROR) << "Failed to get FIEMAP from the kernel for file: " << file_path; |
| return false; |
| } |
| |
| if (fiemap->fm_mapped_extents == 0) { |
| LOG(ERROR) << "File " << file_path << " has zero extents"; |
| return false; |
| } |
| |
| // Iterate through each extent read and make sure its valid before adding it to the vector |
| bool last_extent_seen = false; |
| struct fiemap_extent* extent = &fiemap->fm_extents[0]; |
| for (uint32_t i = 0; i < fiemap->fm_mapped_extents; i++, extent++) { |
| // LogExtent(i + 1, *extent); |
| if (extent->fe_flags & kUnsupportedExtentFlags) { |
| LOG(ERROR) << "Extent " << i + 1 << " of file " << file_path |
| << " has unsupported flags"; |
| extents->clear(); |
| return false; |
| } |
| |
| if (extent->fe_flags & FIEMAP_EXTENT_LAST) { |
| last_extent_seen = true; |
| if (i != (fiemap->fm_mapped_extents - 1)) { |
| LOG(WARNING) << "Extents are being received out-of-order"; |
| } |
| } |
| extents->emplace_back(std::move(*extent)); |
| } |
| |
| if (!last_extent_seen) { |
| // The file is possibly too fragmented. |
| if (fiemap->fm_mapped_extents == kMaxExtents) { |
| LOG(ERROR) << "File is too fragmented, needs more than " << kMaxExtents << " extents."; |
| } |
| extents->clear(); |
| } |
| |
| return last_extent_seen; |
| } |
| |
| FiemapUniquePtr FiemapWriter::Open(const std::string& file_path, uint64_t file_size, bool create, |
| std::function<bool(uint64_t, uint64_t)> progress) { |
| // if 'create' is false, open an existing file and do not truncate. |
| int open_flags = O_RDWR | O_CLOEXEC; |
| if (create) { |
| if (access(file_path.c_str(), F_OK) == 0) { |
| LOG(WARNING) << "File " << file_path << " already exists, truncating"; |
| } |
| open_flags |= O_CREAT | O_TRUNC; |
| } |
| ::android::base::unique_fd file_fd( |
| TEMP_FAILURE_RETRY(open(file_path.c_str(), open_flags, S_IRUSR | S_IWUSR))); |
| if (file_fd < 0) { |
| PLOG(ERROR) << "Failed to create file at: " << file_path; |
| return nullptr; |
| } |
| |
| std::string abs_path; |
| if (!::android::base::Realpath(file_path, &abs_path)) { |
| PLOG(ERROR) << "Invalid file path: " << file_path; |
| cleanup(file_path, create); |
| return nullptr; |
| } |
| |
| std::string bdev_path; |
| if (!FileToBlockDevicePath(abs_path, &bdev_path)) { |
| LOG(ERROR) << "Failed to get block dev path for file: " << file_path; |
| cleanup(abs_path, create); |
| return nullptr; |
| } |
| |
| ::android::base::unique_fd bdev_fd( |
| TEMP_FAILURE_RETRY(open(bdev_path.c_str(), O_RDONLY | O_CLOEXEC))); |
| if (bdev_fd < 0) { |
| PLOG(ERROR) << "Failed to open block device: " << bdev_path; |
| cleanup(file_path, create); |
| return nullptr; |
| } |
| |
| uint64_t bdevsz; |
| if (!GetBlockDeviceSize(bdev_fd, bdev_path, &bdevsz)) { |
| LOG(ERROR) << "Failed to get block device size for : " << bdev_path; |
| cleanup(file_path, create); |
| return nullptr; |
| } |
| |
| if (!create) { |
| file_size = GetFileSize(abs_path); |
| if (file_size == 0) { |
| LOG(ERROR) << "Invalid file size of zero bytes for file: " << abs_path; |
| return nullptr; |
| } |
| } |
| |
| uint64_t blocksz; |
| uint32_t fs_type; |
| if (!PerformFileChecks(abs_path, file_size, &blocksz, &fs_type)) { |
| LOG(ERROR) << "Failed to validate file or file system for file:" << abs_path; |
| cleanup(abs_path, create); |
| return nullptr; |
| } |
| |
| if (create) { |
| if (!AllocateFile(file_fd, abs_path, blocksz, file_size, std::move(progress))) { |
| LOG(ERROR) << "Failed to allocate file: " << abs_path << " of size: " << file_size |
| << " bytes"; |
| cleanup(abs_path, create); |
| return nullptr; |
| } |
| } |
| |
| // f2fs may move the file blocks around. |
| if (!PinFile(file_fd, abs_path, fs_type)) { |
| cleanup(abs_path, create); |
| LOG(ERROR) << "Failed to pin the file in storage"; |
| return nullptr; |
| } |
| |
| // now allocate the FiemapWriter and start setting it up |
| FiemapUniquePtr fmap(new FiemapWriter()); |
| if (!ReadFiemap(file_fd, abs_path, &fmap->extents_)) { |
| LOG(ERROR) << "Failed to read fiemap of file: " << abs_path; |
| cleanup(abs_path, create); |
| return nullptr; |
| } |
| |
| fmap->file_path_ = abs_path; |
| fmap->bdev_path_ = bdev_path; |
| fmap->file_fd_ = std::move(file_fd); |
| fmap->file_size_ = file_size; |
| fmap->bdev_size_ = bdevsz; |
| fmap->fs_type_ = fs_type; |
| fmap->block_size_ = blocksz; |
| |
| LOG(INFO) << "Successfully created FiemapWriter for file " << abs_path << " on block device " |
| << bdev_path; |
| return fmap; |
| } |
| |
| bool FiemapWriter::Read(off64_t off, uint8_t* buffer, uint64_t size) { |
| return false; |
| } |
| |
| } // namespace fiemap_writer |
| } // namespace android |
