| /* |
| * 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/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 <limits> |
| #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> |
| #include <libdm/dm.h> |
| #include "utility.h" |
| |
| namespace android { |
| namespace fiemap { |
| |
| using namespace android::dm; |
| |
| // We cap the maximum number of extents as a robustness measure. |
| static constexpr uint32_t kMaxExtents = 50000; |
| |
| // 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; |
| |
| // Large file support must be enabled. |
| static_assert(sizeof(off_t) == sizeof(uint64_t)); |
| |
| static inline void cleanup(const std::string& file_path, bool created) { |
| if (created) { |
| unlink(file_path.c_str()); |
| } |
| } |
| |
| static bool ValidateDmTarget(const DeviceMapper::TargetInfo& target) { |
| const auto& entry = target.spec; |
| if (entry.sector_start != 0) { |
| LOG(INFO) << "Stopping at target with non-zero starting sector"; |
| return false; |
| } |
| |
| auto target_type = DeviceMapper::GetTargetType(entry); |
| if (target_type == "bow" || target_type == "default-key" || target_type == "crypt") { |
| return true; |
| } |
| if (target_type == "linear") { |
| auto pieces = android::base::Split(target.data, " "); |
| if (pieces[1] != "0") { |
| LOG(INFO) << "Stopping at complex linear target with non-zero starting sector: " |
| << pieces[1]; |
| return false; |
| } |
| return true; |
| } |
| |
| LOG(INFO) << "Stopping at complex target type " << target_type; |
| return false; |
| } |
| |
| static bool DeviceMapperStackPop(const std::string& bdev, std::string* bdev_raw) { |
| *bdev_raw = bdev; |
| |
| if (!::android::base::StartsWith(bdev, "dm-")) { |
| // We are at the bottom of the device mapper stack. |
| return true; |
| } |
| |
| // Get the device name. |
| auto dm_name_file = "/sys/block/" + bdev + "/dm/name"; |
| std::string dm_name; |
| if (!android::base::ReadFileToString(dm_name_file, &dm_name)) { |
| PLOG(ERROR) << "Could not read file: " << dm_name_file; |
| return false; |
| } |
| dm_name = android::base::Trim(dm_name); |
| |
| auto& dm = DeviceMapper::Instance(); |
| std::vector<DeviceMapper::TargetInfo> table; |
| if (!dm.GetTableInfo(dm_name, &table)) { |
| LOG(ERROR) << "Could not read device-mapper table for " << dm_name << " at " << bdev; |
| return false; |
| } |
| |
| // The purpose of libfiemap is to provide an extent-based view into |
| // a file. This is difficult if devices are not layered in a 1:1 manner; |
| // we would have to translate and break up extents based on the actual |
| // block mapping. Since this is too complex, we simply stop processing |
| // the device-mapper stack if we encounter a complex case. |
| // |
| // It is up to the caller to decide whether stopping at a virtual block |
| // device is allowable. In most cases it is not, because we want either |
| // "userdata" or an external volume. It is useful for tests however. |
| // Callers can check by comparing the device number to that of userdata, |
| // or by checking whether is a device-mapper node. |
| if (table.size() > 1) { |
| LOG(INFO) << "Stopping at complex table for " << dm_name << " at " << bdev; |
| return true; |
| } |
| if (!ValidateDmTarget(table[0])) { |
| return true; |
| } |
| |
| auto dm_leaf_dir = "/sys/block/" + bdev + "/slaves"; |
| 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); |
| } |
| |
| bool FiemapWriter::GetBlockDeviceForFile(const std::string& file_path, std::string* bdev_path, |
| bool* uses_dm) { |
| 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; |
| } |
| |
| if (uses_dm) { |
| *uses_dm = (bdev_raw != bdev); |
| } |
| |
| 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* 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 (!sfs.f_bsize) { |
| LOG(ERROR) << "Unsupported block size: " << sfs.f_bsize; |
| return false; |
| } |
| |
| // Check if the filesystem is of supported types. |
| // Only ext4, f2fs, and vfat are tested and supported. |
| switch (sfs.f_type) { |
| case EXT4_SUPER_MAGIC: |
| case F2FS_SUPER_MAGIC: |
| case MSDOS_SUPER_MAGIC: |
| break; |
| default: |
| LOG(ERROR) << "Unsupported file system type: 0x" << std::hex << sfs.f_type; |
| return false; |
| } |
| |
| *blocksz = sfs.f_bsize; |
| *fs_type = sfs.f_type; |
| return true; |
| } |
| |
| static FiemapStatus FallocateFallback(int file_fd, uint64_t block_size, uint64_t file_size, |
| const std::string& file_path, |
| const std::function<bool(uint64_t, uint64_t)>& on_progress) { |
| // Even though this is much faster than writing zeroes, it is still slow |
| // enough that we need to fire the progress callback periodically. To |
| // easily achieve this, we seek in chunks. We use 1000 chunks since |
| // normally we only fire the callback on 1/1000th increments. |
| uint64_t bytes_per_chunk = std::max(file_size / 1000, block_size); |
| |
| // Seek just to the end of each chunk and write a single byte, causing |
| // the filesystem to allocate blocks. |
| off_t cursor = 0; |
| off_t end = static_cast<off_t>(file_size); |
| while (cursor < end) { |
| cursor = std::min(static_cast<off_t>(cursor + bytes_per_chunk), end); |
| auto rv = TEMP_FAILURE_RETRY(lseek(file_fd, cursor - 1, SEEK_SET)); |
| if (rv < 0) { |
| PLOG(ERROR) << "Failed to lseek " << file_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| if (rv != cursor - 1) { |
| LOG(ERROR) << "Seek returned wrong offset " << rv << " for file " << file_path; |
| return FiemapStatus::Error(); |
| } |
| char buffer[] = {0}; |
| if (!android::base::WriteFully(file_fd, buffer, 1)) { |
| PLOG(ERROR) << "Write failed: " << file_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| if (on_progress && !on_progress(cursor, file_size)) { |
| return FiemapStatus::Error(); |
| } |
| } |
| return FiemapStatus::Ok(); |
| } |
| |
| // 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_GET_PIN_FILE _IOR(F2FS_IOCTL_MAGIC, 14, __u32) |
| #define F2FS_IOC_SET_PIN_FILE _IOW(F2FS_IOCTL_MAGIC, 13, __u32) |
| #endif |
| |
| static bool IsFilePinned(int file_fd, const std::string& file_path, uint32_t fs_type) { |
| if (fs_type != F2FS_SUPER_MAGIC) { |
| // No pinning necessary for ext4 or vfat. The blocks, once allocated, |
| // are expected to be fixed. |
| return true; |
| } |
| |
| // f2fs: export FS_NOCOW_FL flag to user |
| uint32_t flags; |
| int error = ioctl(file_fd, FS_IOC_GETFLAGS, &flags); |
| if (error < 0) { |
| if ((errno == ENOTTY) || (errno == ENOTSUP)) { |
| PLOG(ERROR) << "Failed to get flags, not supported by kernel: " << file_path; |
| } else { |
| PLOG(ERROR) << "Failed to get flags: " << file_path; |
| } |
| return false; |
| } |
| if (!(flags & FS_NOCOW_FL)) { |
| return false; |
| } |
| |
| // F2FS_IOC_GET_PIN_FILE returns the number of blocks moved. |
| uint32_t moved_blocks_nr; |
| 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(WARNING) << moved_blocks_nr << " blocks moved in file " << file_path; |
| } |
| return moved_blocks_nr == 0; |
| } |
| |
| static bool PinFile(int file_fd, const std::string& file_path, uint32_t fs_type) { |
| if (IsFilePinned(file_fd, file_path, fs_type)) { |
| return true; |
| } |
| if (fs_type != F2FS_SUPER_MAGIC) { |
| // No pinning necessary for ext4/msdos. The blocks, once allocated, are |
| // expected to be fixed. |
| return true; |
| } |
| |
| 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; |
| } |
| |
| // 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. |
| static FiemapStatus WriteZeroes(int file_fd, const std::string& file_path, size_t blocksz, |
| uint64_t file_size, |
| const std::function<bool(uint64_t, uint64_t)>& on_progress) { |
| 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 FiemapStatus::Error(); |
| } |
| |
| off64_t offset = lseek64(file_fd, 0, SEEK_SET); |
| if (offset < 0) { |
| PLOG(ERROR) << "Failed to seek at the beginning of : " << file_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| |
| int permille = -1; |
| while (offset < file_size) { |
| if (!::android::base::WriteFully(file_fd, buffer.get(), blocksz)) { |
| PLOG(ERROR) << "Failed to write" << blocksz << " bytes at offset" << offset |
| << " in file " << file_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| |
| offset += blocksz; |
| |
| // 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 && static_cast<uint64_t>(offset) != file_size) { |
| if (on_progress && !on_progress(offset, file_size)) { |
| return FiemapStatus::Error(); |
| } |
| permille = new_permille; |
| } |
| } |
| |
| if (lseek64(file_fd, 0, SEEK_SET) < 0) { |
| PLOG(ERROR) << "Failed to reset offset at the beginning of : " << file_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| return FiemapStatus::Ok(); |
| } |
| |
| // 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. |
| static FiemapStatus AllocateFile(int file_fd, const std::string& file_path, uint64_t blocksz, |
| uint64_t file_size, unsigned int fs_type, |
| std::function<bool(uint64_t, uint64_t)> on_progress) { |
| bool need_explicit_writes = true; |
| switch (fs_type) { |
| case EXT4_SUPER_MAGIC: |
| break; |
| case F2FS_SUPER_MAGIC: { |
| bool supported; |
| if (!F2fsPinBeforeAllocate(file_fd, &supported)) { |
| return FiemapStatus::Error(); |
| } |
| if (supported) { |
| if (!PinFile(file_fd, file_path, fs_type)) { |
| return FiemapStatus::Error(); |
| } |
| need_explicit_writes = false; |
| } |
| break; |
| } |
| case MSDOS_SUPER_MAGIC: |
| // fallocate() is not supported, and not needed, since VFAT does not support holes. |
| // Instead we can perform a much faster allocation. |
| return FallocateFallback(file_fd, blocksz, file_size, file_path, on_progress); |
| default: |
| LOG(ERROR) << "Missing fallocate() support for file system " << fs_type; |
| return FiemapStatus::Error(); |
| } |
| |
| if (fallocate(file_fd, 0, 0, file_size)) { |
| PLOG(ERROR) << "Failed to allocate space for file: " << file_path << " size: " << file_size; |
| return FiemapStatus::FromErrno(errno); |
| } |
| |
| if (need_explicit_writes) { |
| auto status = WriteZeroes(file_fd, file_path, blocksz, file_size, on_progress); |
| if (!status.is_ok()) { |
| return status; |
| } |
| } |
| |
| // flush all writes here .. |
| if (fsync(file_fd)) { |
| PLOG(ERROR) << "Failed to synchronize written file:" << file_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| |
| // Send one last progress notification. |
| if (on_progress && !on_progress(file_size, file_size)) { |
| return FiemapStatus::Error(); |
| } |
| return FiemapStatus::Ok(); |
| } |
| |
| 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 IsValidExtent(const fiemap_extent* extent, std::string_view file_path) { |
| if (extent->fe_flags & kUnsupportedExtentFlags) { |
| LOG(ERROR) << "Extent at location " << extent->fe_logical << " of file " << file_path |
| << " has unsupported flags"; |
| return false; |
| } |
| return true; |
| } |
| |
| static bool IsLastExtent(const fiemap_extent* extent) { |
| return !!(extent->fe_flags & FIEMAP_EXTENT_LAST); |
| } |
| |
| static bool FiemapToExtents(struct fiemap* fiemap, std::vector<struct fiemap_extent>* extents, |
| std::string_view file_path) { |
| uint32_t num_extents = fiemap->fm_mapped_extents; |
| if (num_extents == 0) { |
| LOG(ERROR) << "File " << file_path << " has zero extent"; |
| return false; |
| } |
| const struct fiemap_extent* last_extent = &fiemap->fm_extents[num_extents - 1]; |
| if (!IsLastExtent(last_extent)) { |
| LOG(ERROR) << "FIEMAP did not return a final extent for file: " << file_path |
| << " num_extents=" << num_extents << " max_extents=" << kMaxExtents; |
| return false; |
| } |
| |
| // Iterate through each extent, read and make sure its valid before adding it to the vector |
| // merging contiguous extents. |
| fiemap_extent* prev = &fiemap->fm_extents[0]; |
| if (!IsValidExtent(prev, file_path)) return false; |
| |
| for (uint32_t i = 1; i < num_extents; i++) { |
| fiemap_extent* next = &fiemap->fm_extents[i]; |
| |
| // Make sure extents are returned in order |
| if (next != last_extent && IsLastExtent(next)) { |
| LOG(ERROR) << "Extents are being received out-of-order"; |
| return false; |
| } |
| |
| // Check if extent's flags are valid |
| if (!IsValidExtent(next, file_path)) return false; |
| |
| // Check if the current extent is contiguous with the previous one. |
| // An extent can be combined with its predecessor only if: |
| // 1. There is no physical space between the previous and the current |
| // extent, and |
| // 2. The physical distance between the previous and current extent |
| // corresponds to their logical distance (contiguous mapping). |
| if (prev->fe_physical + prev->fe_length == next->fe_physical && |
| next->fe_physical - prev->fe_physical == next->fe_logical - prev->fe_logical) { |
| prev->fe_length += next->fe_length; |
| } else { |
| extents->emplace_back(*prev); |
| prev = next; |
| } |
| } |
| extents->emplace_back(*prev); |
| |
| return true; |
| } |
| |
| static bool ReadFiemap(int file_fd, const std::string& file_path, |
| std::vector<struct fiemap_extent>* extents) { |
| uint64_t fiemap_size = sizeof(struct fiemap) + 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; |
| } |
| return FiemapToExtents(fiemap, extents, file_path); |
| } |
| |
| static bool ReadFibmap(int file_fd, const std::string& file_path, |
| std::vector<struct fiemap_extent>* extents) { |
| struct stat s; |
| if (fstat(file_fd, &s)) { |
| PLOG(ERROR) << "Failed to stat " << file_path; |
| return false; |
| } |
| |
| unsigned int blksize; |
| if (ioctl(file_fd, FIGETBSZ, &blksize) < 0) { |
| PLOG(ERROR) << "Failed to get FIGETBSZ for " << file_path; |
| return false; |
| } |
| if (!blksize) { |
| LOG(ERROR) << "Invalid filesystem block size: " << blksize; |
| return false; |
| } |
| |
| uint64_t num_blocks = (s.st_size + blksize - 1) / blksize; |
| if (num_blocks > std::numeric_limits<uint32_t>::max()) { |
| LOG(ERROR) << "Too many blocks for FIBMAP (" << num_blocks << ")"; |
| return false; |
| } |
| |
| for (uint32_t last_block, block_number = 0; block_number < num_blocks; block_number++) { |
| uint32_t block = block_number; |
| if (ioctl(file_fd, FIBMAP, &block)) { |
| PLOG(ERROR) << "Failed to get FIBMAP for file " << file_path; |
| return false; |
| } |
| if (!block) { |
| LOG(ERROR) << "Logical block " << block_number << " is a hole, which is not supported"; |
| return false; |
| } |
| |
| if (!extents->empty() && block == last_block + 1) { |
| extents->back().fe_length += blksize; |
| } else { |
| extents->push_back(fiemap_extent{.fe_logical = block_number, |
| .fe_physical = static_cast<uint64_t>(block) * blksize, |
| .fe_length = static_cast<uint64_t>(blksize), |
| .fe_flags = 0}); |
| if (extents->size() > kMaxExtents) { |
| LOG(ERROR) << "File has more than " << kMaxExtents << "extents: " << file_path; |
| return false; |
| } |
| } |
| last_block = block; |
| } |
| return true; |
| } |
| |
| FiemapUniquePtr FiemapWriter::Open(const std::string& file_path, uint64_t file_size, bool create, |
| std::function<bool(uint64_t, uint64_t)> progress) { |
| FiemapUniquePtr ret; |
| if (!Open(file_path, file_size, &ret, create, progress).is_ok()) { |
| return nullptr; |
| } |
| return ret; |
| } |
| |
| FiemapStatus FiemapWriter::Open(const std::string& file_path, uint64_t file_size, |
| FiemapUniquePtr* out, bool create, |
| std::function<bool(uint64_t, uint64_t)> progress) { |
| out->reset(); |
| |
| // 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 FiemapStatus::FromErrno(errno); |
| } |
| |
| std::string abs_path; |
| if (!::android::base::Realpath(file_path, &abs_path)) { |
| int saved_errno = errno; |
| PLOG(ERROR) << "Invalid file path: " << file_path; |
| cleanup(file_path, create); |
| return FiemapStatus::FromErrno(saved_errno); |
| } |
| |
| std::string bdev_path; |
| if (!GetBlockDeviceForFile(abs_path, &bdev_path)) { |
| LOG(ERROR) << "Failed to get block dev path for file: " << file_path; |
| cleanup(abs_path, create); |
| return FiemapStatus::Error(); |
| } |
| |
| ::android::base::unique_fd bdev_fd( |
| TEMP_FAILURE_RETRY(open(bdev_path.c_str(), O_RDONLY | O_CLOEXEC))); |
| if (bdev_fd < 0) { |
| int saved_errno = errno; |
| PLOG(ERROR) << "Failed to open block device: " << bdev_path; |
| cleanup(file_path, create); |
| return FiemapStatus::FromErrno(saved_errno); |
| } |
| |
| uint64_t bdevsz; |
| if (!GetBlockDeviceSize(bdev_fd, bdev_path, &bdevsz)) { |
| int saved_errno = errno; |
| LOG(ERROR) << "Failed to get block device size for : " << bdev_path; |
| cleanup(file_path, create); |
| return FiemapStatus::FromErrno(saved_errno); |
| } |
| |
| if (!create) { |
| file_size = GetFileSize(abs_path); |
| if (file_size == 0) { |
| LOG(ERROR) << "Invalid file size of zero bytes for file: " << abs_path; |
| return FiemapStatus::FromErrno(errno); |
| } |
| } |
| |
| uint64_t blocksz; |
| uint32_t fs_type; |
| if (!PerformFileChecks(abs_path, &blocksz, &fs_type)) { |
| LOG(ERROR) << "Failed to validate file or file system for file:" << abs_path; |
| cleanup(abs_path, create); |
| return FiemapStatus::Error(); |
| } |
| |
| // Align up to the nearest block size. |
| if (file_size % blocksz) { |
| file_size += blocksz - (file_size % blocksz); |
| } |
| |
| if (create) { |
| auto status = |
| AllocateFile(file_fd, abs_path, blocksz, file_size, fs_type, std::move(progress)); |
| if (!status.is_ok()) { |
| LOG(ERROR) << "Failed to allocate file: " << abs_path << " of size: " << file_size |
| << " bytes"; |
| cleanup(abs_path, create); |
| return status; |
| } |
| } |
| |
| // 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 FiemapStatus::Error(); |
| } |
| |
| // now allocate the FiemapWriter and start setting it up |
| FiemapUniquePtr fmap(new FiemapWriter()); |
| switch (fs_type) { |
| case EXT4_SUPER_MAGIC: |
| case F2FS_SUPER_MAGIC: |
| if (!ReadFiemap(file_fd, abs_path, &fmap->extents_)) { |
| LOG(ERROR) << "Failed to read fiemap of file: " << abs_path; |
| cleanup(abs_path, create); |
| return FiemapStatus::Error(); |
| } |
| break; |
| case MSDOS_SUPER_MAGIC: |
| if (!ReadFibmap(file_fd, abs_path, &fmap->extents_)) { |
| LOG(ERROR) << "Failed to read fibmap of file: " << abs_path; |
| cleanup(abs_path, create); |
| return FiemapStatus::Error(); |
| } |
| break; |
| } |
| |
| fmap->file_path_ = abs_path; |
| fmap->bdev_path_ = bdev_path; |
| fmap->file_size_ = file_size; |
| fmap->bdev_size_ = bdevsz; |
| fmap->fs_type_ = fs_type; |
| fmap->block_size_ = blocksz; |
| |
| LOG(VERBOSE) << "Successfully created FiemapWriter for file " << abs_path << " on block device " |
| << bdev_path; |
| *out = std::move(fmap); |
| return FiemapStatus::Ok(); |
| } |
| |
| } // namespace fiemap |
| } // namespace android |
