| /* |
| * 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 <dirent.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/fs.h> |
| #include <stdlib.h> |
| #include <sys/stat.h> |
| #include <sys/statvfs.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include <algorithm> |
| #include <memory> |
| #include <optional> |
| #include <string> |
| #include <vector> |
| |
| #include <android-base/file.h> |
| #include <android-base/properties.h> |
| #include <android-base/strings.h> |
| #include <fs_mgr.h> |
| #include <fs_mgr_dm_linear.h> |
| #include <fs_mgr_overlayfs.h> |
| #include <fstab/fstab.h> |
| #include <libdm/dm.h> |
| #include <libfiemap/image_manager.h> |
| #include <libgsi/libgsi.h> |
| #include <liblp/builder.h> |
| #include <liblp/liblp.h> |
| #include <storage_literals/storage_literals.h> |
| |
| #include "fs_mgr_overlayfs_control.h" |
| #include "fs_mgr_overlayfs_mount.h" |
| #include "fs_mgr_priv.h" |
| #include "libfiemap/utility.h" |
| |
| using namespace std::literals; |
| using namespace android::dm; |
| using namespace android::fs_mgr; |
| using namespace android::storage_literals; |
| using android::fiemap::FilesystemHasReliablePinning; |
| using android::fiemap::IImageManager; |
| |
| namespace { |
| |
| constexpr char kDataScratchSizeMbProp[] = "fs_mgr.overlayfs.data_scratch_size_mb"; |
| |
| constexpr char kPhysicalDevice[] = "/dev/block/by-name/"; |
| constexpr char kScratchImageMetadata[] = "/metadata/gsi/remount/lp_metadata"; |
| |
| constexpr char kMkF2fs[] = "/system/bin/make_f2fs"; |
| constexpr char kMkExt4[] = "/system/bin/mke2fs"; |
| |
| // Return true if everything is mounted, but before adb is started. Right |
| // after 'trigger load_persist_props_action' is done. |
| static bool fs_mgr_boot_completed() { |
| return android::base::GetBoolProperty("ro.persistent_properties.ready", false); |
| } |
| |
| // Note: this is meant only for recovery/first-stage init. |
| static bool ScratchIsOnData() { |
| // The scratch partition of DSU is managed by gsid. |
| if (fs_mgr_is_dsu_running()) { |
| return false; |
| } |
| return access(kScratchImageMetadata, F_OK) == 0; |
| } |
| |
| static bool fs_mgr_rm_all(const std::string& path, bool* change = nullptr, int level = 0) { |
| std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(path.c_str()), closedir); |
| if (!dir) { |
| if (errno == ENOENT) { |
| return true; |
| } |
| PERROR << "opendir " << path << " depth=" << level; |
| if ((errno == EPERM) && (level != 0)) { |
| return true; |
| } |
| return false; |
| } |
| dirent* entry; |
| auto ret = true; |
| while ((entry = readdir(dir.get()))) { |
| if (("."s == entry->d_name) || (".."s == entry->d_name)) continue; |
| auto file = path + "/" + entry->d_name; |
| if (entry->d_type == DT_UNKNOWN) { |
| struct stat st; |
| if (!lstat(file.c_str(), &st) && (st.st_mode & S_IFDIR)) entry->d_type = DT_DIR; |
| } |
| if (entry->d_type == DT_DIR) { |
| ret &= fs_mgr_rm_all(file, change, level + 1); |
| if (!rmdir(file.c_str())) { |
| if (change) *change = true; |
| } else { |
| if (errno != ENOENT) ret = false; |
| PERROR << "rmdir " << file << " depth=" << level; |
| } |
| continue; |
| } |
| if (!unlink(file.c_str())) { |
| if (change) *change = true; |
| } else { |
| if (errno != ENOENT) ret = false; |
| PERROR << "rm " << file << " depth=" << level; |
| } |
| } |
| return ret; |
| } |
| |
| std::string fs_mgr_overlayfs_setup_dir(const std::string& dir) { |
| auto top = dir + "/" + kOverlayTopDir; |
| |
| AutoSetFsCreateCon createcon(kOverlayfsFileContext); |
| if (!createcon.Ok()) { |
| return {}; |
| } |
| if (mkdir(top.c_str(), 0755) != 0 && errno != EEXIST) { |
| PERROR << "mkdir " << top; |
| return {}; |
| } |
| if (!createcon.Restore()) { |
| return {}; |
| } |
| return top; |
| } |
| |
| bool fs_mgr_overlayfs_setup_one(const std::string& overlay, const std::string& mount_point, |
| bool* want_reboot) { |
| if (fs_mgr_overlayfs_already_mounted(mount_point)) { |
| return true; |
| } |
| const auto base = GetEncodedBaseDirForMountPoint(mount_point); |
| auto fsrec_mount_point = overlay + "/" + base + "/"; |
| |
| AutoSetFsCreateCon createcon(kOverlayfsFileContext); |
| if (!createcon.Ok()) { |
| return false; |
| } |
| if (mkdir(fsrec_mount_point.c_str(), 0755) != 0 && errno != EEXIST) { |
| PERROR << "mkdir " << fsrec_mount_point; |
| return false; |
| } |
| if (mkdir((fsrec_mount_point + kWorkName).c_str(), 0755) != 0 && errno != EEXIST) { |
| PERROR << "mkdir " << fsrec_mount_point << kWorkName; |
| return false; |
| } |
| if (!createcon.Restore()) { |
| return false; |
| } |
| |
| createcon = {}; |
| |
| auto new_context = fs_mgr_get_context(mount_point); |
| if (new_context.empty() || !createcon.Set(new_context)) { |
| return false; |
| } |
| |
| auto upper = fsrec_mount_point + kUpperName; |
| if (mkdir(upper.c_str(), 0755) != 0 && errno != EEXIST) { |
| PERROR << "mkdir " << upper; |
| return false; |
| } |
| if (!createcon.Restore()) { |
| return false; |
| } |
| |
| if (want_reboot) *want_reboot = true; |
| |
| return true; |
| } |
| |
| static uint32_t fs_mgr_overlayfs_slot_number() { |
| return SlotNumberForSlotSuffix(fs_mgr_get_slot_suffix()); |
| } |
| |
| static bool fs_mgr_overlayfs_has_logical(const Fstab& fstab) { |
| for (const auto& entry : fstab) { |
| if (entry.fs_mgr_flags.logical) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| OverlayfsTeardownResult TeardownDataScratch(IImageManager* images, |
| const std::string& partition_name, bool was_mounted) { |
| if (!images) { |
| return OverlayfsTeardownResult::Error; |
| } |
| if (!images->DisableImage(partition_name)) { |
| return OverlayfsTeardownResult::Error; |
| } |
| if (was_mounted) { |
| // If overlayfs was mounted, don't bother trying to unmap since |
| // it'll fail and create error spam. |
| return OverlayfsTeardownResult::Busy; |
| } |
| if (!images->UnmapImageIfExists(partition_name)) { |
| return OverlayfsTeardownResult::Busy; |
| } |
| if (!images->DeleteBackingImage(partition_name)) { |
| return OverlayfsTeardownResult::Busy; |
| } |
| return OverlayfsTeardownResult::Ok; |
| } |
| |
| bool GetOverlaysActiveFlag() { |
| auto slot_number = fs_mgr_overlayfs_slot_number(); |
| const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name(); |
| |
| auto metadata = ReadMetadata(super_device, slot_number); |
| if (!metadata) { |
| return false; |
| } |
| return !!(metadata->header.flags & LP_HEADER_FLAG_OVERLAYS_ACTIVE); |
| } |
| |
| bool SetOverlaysActiveFlag(bool flag) { |
| // Mark overlays as active in the partition table, to detect re-flash. |
| auto slot_number = fs_mgr_overlayfs_slot_number(); |
| const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name(); |
| auto builder = MetadataBuilder::New(super_device, slot_number); |
| if (!builder) { |
| LERROR << "open " << super_device << " metadata"; |
| return false; |
| } |
| builder->SetOverlaysActiveFlag(flag); |
| auto metadata = builder->Export(); |
| if (!metadata || !UpdatePartitionTable(super_device, *metadata.get(), slot_number)) { |
| LERROR << "update super metadata"; |
| return false; |
| } |
| return true; |
| } |
| |
| OverlayfsTeardownResult fs_mgr_overlayfs_teardown_scratch(const std::string& overlay, |
| bool* change) { |
| // umount and delete kScratchMountPoint storage if we have logical partitions |
| if (overlay != kScratchMountPoint) { |
| return OverlayfsTeardownResult::Ok; |
| } |
| |
| // Validation check. |
| if (fs_mgr_is_dsu_running()) { |
| LERROR << "Destroying DSU scratch is not allowed."; |
| return OverlayfsTeardownResult::Error; |
| } |
| |
| // Note: we don't care if SetOverlaysActiveFlag fails, since |
| // the overlays are removed no matter what. |
| SetOverlaysActiveFlag(false); |
| |
| bool was_mounted = fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false); |
| if (was_mounted) { |
| fs_mgr_overlayfs_umount_scratch(); |
| } |
| |
| const auto partition_name = android::base::Basename(kScratchMountPoint); |
| |
| auto images = IImageManager::Open("remount", 10s); |
| if (images && images->BackingImageExists(partition_name)) { |
| // No need to check super partition, if we knew we had a scratch device |
| // in /data. |
| return TeardownDataScratch(images.get(), partition_name, was_mounted); |
| } |
| |
| auto slot_number = fs_mgr_overlayfs_slot_number(); |
| const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name(); |
| if (access(super_device.c_str(), R_OK | W_OK)) { |
| return OverlayfsTeardownResult::Ok; |
| } |
| |
| auto builder = MetadataBuilder::New(super_device, slot_number); |
| if (!builder) { |
| return OverlayfsTeardownResult::Ok; |
| } |
| if (builder->FindPartition(partition_name) == nullptr) { |
| return OverlayfsTeardownResult::Ok; |
| } |
| builder->RemovePartition(partition_name); |
| auto metadata = builder->Export(); |
| if (metadata && UpdatePartitionTable(super_device, *metadata.get(), slot_number)) { |
| if (change) *change = true; |
| if (!DestroyLogicalPartition(partition_name)) { |
| return OverlayfsTeardownResult::Error; |
| } |
| } else { |
| LERROR << "delete partition " << overlay; |
| return OverlayfsTeardownResult::Error; |
| } |
| |
| if (was_mounted) { |
| return OverlayfsTeardownResult::Busy; |
| } |
| return OverlayfsTeardownResult::Ok; |
| } |
| |
| bool fs_mgr_overlayfs_teardown_one(const std::string& overlay, const std::string& mount_point, |
| bool* change, bool* should_destroy_scratch = nullptr) { |
| const auto top = overlay + "/" + kOverlayTopDir; |
| |
| if (access(top.c_str(), F_OK)) { |
| if (should_destroy_scratch) *should_destroy_scratch = true; |
| return true; |
| } |
| |
| auto cleanup_all = mount_point.empty(); |
| const auto base = GetEncodedBaseDirForMountPoint(mount_point); |
| const auto oldpath = top + (cleanup_all ? "" : ("/" + base)); |
| const auto newpath = cleanup_all ? overlay + "/." + kOverlayTopDir + ".teardown" |
| : top + "/." + base + ".teardown"; |
| auto ret = fs_mgr_rm_all(newpath); |
| if (!rename(oldpath.c_str(), newpath.c_str())) { |
| if (change) *change = true; |
| } else if (errno != ENOENT) { |
| ret = false; |
| PERROR << "mv " << oldpath << " " << newpath; |
| } |
| ret &= fs_mgr_rm_all(newpath, change); |
| if (!rmdir(newpath.c_str())) { |
| if (change) *change = true; |
| } else if (errno != ENOENT) { |
| ret = false; |
| PERROR << "rmdir " << newpath; |
| } |
| if (!cleanup_all) { |
| if (!rmdir(top.c_str())) { |
| if (change) *change = true; |
| cleanup_all = true; |
| } else if (errno == ENOTEMPTY) { |
| cleanup_all = true; |
| // cleanup all if the content is all hidden (leading .) |
| std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(top.c_str()), closedir); |
| if (!dir) { |
| PERROR << "opendir " << top; |
| } else { |
| dirent* entry; |
| while ((entry = readdir(dir.get()))) { |
| if (entry->d_name[0] != '.') { |
| cleanup_all = false; |
| break; |
| } |
| } |
| } |
| } else if (errno == ENOENT) { |
| cleanup_all = true; |
| } else { |
| ret = false; |
| PERROR << "rmdir " << top; |
| } |
| } |
| if (should_destroy_scratch) *should_destroy_scratch = cleanup_all; |
| return ret; |
| } |
| |
| // Note: The scratch partition of DSU is managed by gsid, and should be initialized during |
| // first-stage-mount. Just check if the DM device for DSU scratch partition is created or not. |
| static std::string GetDsuScratchDevice() { |
| auto& dm = DeviceMapper::Instance(); |
| std::string device; |
| if (dm.GetState(android::gsi::kDsuScratch) != DmDeviceState::INVALID && |
| dm.GetDmDevicePathByName(android::gsi::kDsuScratch, &device)) { |
| return device; |
| } |
| return ""; |
| } |
| |
| bool MakeScratchFilesystem(const std::string& scratch_device) { |
| // Force mkfs by design for overlay support of adb remount, simplify and |
| // thus do not rely on fsck to correct problems that could creep in. |
| auto fs_type = ""s; |
| auto command = ""s; |
| if (!access(kMkF2fs, X_OK) && fs_mgr_filesystem_available("f2fs")) { |
| fs_type = "f2fs"; |
| command = kMkF2fs + " -w "s; |
| command += std::to_string(getpagesize()); |
| command = kMkF2fs + " -b "s; |
| command += std::to_string(getpagesize()); |
| command += " -f -d1 -l" + android::base::Basename(kScratchMountPoint); |
| } else if (!access(kMkExt4, X_OK) && fs_mgr_filesystem_available("ext4")) { |
| fs_type = "ext4"; |
| command = kMkExt4 + " -F -b 4096 -t ext4 -m 0 -O has_journal -M "s + kScratchMountPoint; |
| } else { |
| LERROR << "No supported mkfs command or filesystem driver available, supported filesystems " |
| "are: f2fs, ext4"; |
| return false; |
| } |
| command += " " + scratch_device + " >/dev/null 2>/dev/null </dev/null"; |
| fs_mgr_set_blk_ro(scratch_device, false); |
| auto ret = system(command.c_str()); |
| if (ret) { |
| LERROR << "make " << fs_type << " filesystem on " << scratch_device << " return=" << ret; |
| return false; |
| } |
| return true; |
| } |
| |
| static void TruncatePartitionsWithSuffix(MetadataBuilder* builder, const std::string& suffix) { |
| auto& dm = DeviceMapper::Instance(); |
| |
| // Remove <other> partitions |
| for (const auto& group : builder->ListGroups()) { |
| for (const auto& part : builder->ListPartitionsInGroup(group)) { |
| const auto& name = part->name(); |
| if (!android::base::EndsWith(name, suffix)) { |
| continue; |
| } |
| if (dm.GetState(name) != DmDeviceState::INVALID && !DestroyLogicalPartition(name)) { |
| continue; |
| } |
| builder->ResizePartition(builder->FindPartition(name), 0); |
| } |
| } |
| } |
| |
| // Create or update a scratch partition within super. |
| static bool CreateDynamicScratch(std::string* scratch_device, bool* partition_exists) { |
| const auto partition_name = android::base::Basename(kScratchMountPoint); |
| |
| auto& dm = DeviceMapper::Instance(); |
| *partition_exists = dm.GetState(partition_name) != DmDeviceState::INVALID; |
| |
| auto partition_create = !*partition_exists; |
| auto slot_number = fs_mgr_overlayfs_slot_number(); |
| const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name(); |
| auto builder = MetadataBuilder::New(super_device, slot_number); |
| if (!builder) { |
| LERROR << "open " << super_device << " metadata"; |
| return false; |
| } |
| auto partition = builder->FindPartition(partition_name); |
| *partition_exists = partition != nullptr; |
| auto changed = false; |
| if (!*partition_exists) { |
| partition = builder->AddPartition(partition_name, LP_PARTITION_ATTR_NONE); |
| if (!partition) { |
| LERROR << "create " << partition_name; |
| return false; |
| } |
| changed = true; |
| } |
| // Take half of free space, minimum 512MB or maximum free - margin. |
| static constexpr auto kMinimumSize = uint64_t(512 * 1024 * 1024); |
| if (partition->size() < kMinimumSize) { |
| auto partition_size = |
| builder->AllocatableSpace() - builder->UsedSpace() + partition->size(); |
| if ((partition_size > kMinimumSize) || !partition->size()) { |
| partition_size = std::max(std::min(kMinimumSize, partition_size), partition_size / 2); |
| if (partition_size > partition->size()) { |
| if (!builder->ResizePartition(partition, partition_size)) { |
| // Try to free up space by deallocating partitions in the other slot. |
| TruncatePartitionsWithSuffix(builder.get(), fs_mgr_get_other_slot_suffix()); |
| |
| partition_size = |
| builder->AllocatableSpace() - builder->UsedSpace() + partition->size(); |
| partition_size = |
| std::max(std::min(kMinimumSize, partition_size), partition_size / 2); |
| if (!builder->ResizePartition(partition, partition_size)) { |
| LERROR << "resize " << partition_name; |
| return false; |
| } |
| } |
| if (!partition_create) DestroyLogicalPartition(partition_name); |
| changed = true; |
| *partition_exists = false; |
| } |
| } |
| } |
| |
| // land the update back on to the partition |
| if (changed) { |
| auto metadata = builder->Export(); |
| if (!metadata || !UpdatePartitionTable(super_device, *metadata.get(), slot_number)) { |
| LERROR << "add partition " << partition_name; |
| return false; |
| } |
| } |
| |
| if (changed || partition_create) { |
| CreateLogicalPartitionParams params = { |
| .block_device = super_device, |
| .metadata_slot = slot_number, |
| .partition_name = partition_name, |
| .force_writable = true, |
| .timeout_ms = 10s, |
| }; |
| if (!CreateLogicalPartition(params, scratch_device)) { |
| return false; |
| } |
| } else if (scratch_device->empty()) { |
| *scratch_device = GetBootScratchDevice(); |
| } |
| return true; |
| } |
| |
| static inline uint64_t GetIdealDataScratchSize() { |
| BlockDeviceInfo super_info; |
| PartitionOpener opener; |
| if (!opener.GetInfo(fs_mgr_get_super_partition_name(), &super_info)) { |
| LERROR << "could not get block device info for super"; |
| return 0; |
| } |
| |
| struct statvfs s; |
| if (statvfs("/data", &s) < 0) { |
| PERROR << "could not statfs /data"; |
| return 0; |
| } |
| |
| auto ideal_size = std::min(super_info.size, uint64_t(uint64_t(s.f_frsize) * s.f_bfree * 0.85)); |
| |
| // Align up to the filesystem block size. |
| if (auto remainder = ideal_size % s.f_bsize; remainder > 0) { |
| ideal_size += s.f_bsize - remainder; |
| } |
| return ideal_size; |
| } |
| |
| static bool CreateScratchOnData(std::string* scratch_device, bool* partition_exists) { |
| *partition_exists = false; |
| |
| auto images = IImageManager::Open("remount", 10s); |
| if (!images) { |
| return false; |
| } |
| |
| auto partition_name = android::base::Basename(kScratchMountPoint); |
| if (images->GetMappedImageDevice(partition_name, scratch_device)) { |
| *partition_exists = true; |
| return true; |
| } |
| |
| // Note: calling RemoveDisabledImages here ensures that we do not race with |
| // clean_scratch_files and accidentally try to map an image that will be |
| // deleted. |
| if (!images->RemoveDisabledImages()) { |
| return false; |
| } |
| if (!images->BackingImageExists(partition_name)) { |
| auto size = android::base::GetUintProperty<uint64_t>(kDataScratchSizeMbProp, 0) * 1_MiB; |
| if (!size) { |
| size = GetIdealDataScratchSize(); |
| } |
| if (!size) { |
| size = 2_GiB; |
| } |
| |
| auto flags = IImageManager::CREATE_IMAGE_DEFAULT; |
| |
| if (!images->CreateBackingImage(partition_name, size, flags)) { |
| LERROR << "could not create scratch image of " << size << " bytes"; |
| return false; |
| } |
| } |
| if (!images->MapImageDevice(partition_name, 10s, scratch_device)) { |
| LERROR << "could not map scratch image"; |
| // If we cannot use this image, then remove it. |
| TeardownDataScratch(images.get(), partition_name, false /* was_mounted */); |
| return false; |
| } |
| return true; |
| } |
| |
| static bool CanUseSuperPartition(const Fstab& fstab) { |
| auto slot_number = fs_mgr_overlayfs_slot_number(); |
| const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name(); |
| if (access(super_device.c_str(), R_OK | W_OK) || !fs_mgr_overlayfs_has_logical(fstab)) { |
| return false; |
| } |
| auto metadata = ReadMetadata(super_device, slot_number); |
| if (!metadata) { |
| return false; |
| } |
| return true; |
| } |
| |
| bool fs_mgr_overlayfs_create_scratch(const Fstab& fstab, std::string* scratch_device, |
| bool* partition_exists) { |
| // Use the DSU scratch device managed by gsid if within a DSU system. |
| if (fs_mgr_is_dsu_running()) { |
| *scratch_device = GetDsuScratchDevice(); |
| *partition_exists = !scratch_device->empty(); |
| return *partition_exists; |
| } |
| |
| // Try ImageManager on /data first. |
| bool can_use_data = false; |
| if (FilesystemHasReliablePinning("/data", &can_use_data) && can_use_data) { |
| if (CreateScratchOnData(scratch_device, partition_exists)) { |
| return true; |
| } |
| LOG(WARNING) << "Failed to allocate scratch on /data, fallback to use free space on super"; |
| } |
| // If that fails, see if we can land on super. |
| if (CanUseSuperPartition(fstab)) { |
| return CreateDynamicScratch(scratch_device, partition_exists); |
| } |
| return false; |
| } |
| |
| // Create and mount kScratchMountPoint storage if we have logical partitions |
| bool fs_mgr_overlayfs_setup_scratch(const Fstab& fstab) { |
| if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) { |
| return true; |
| } |
| |
| std::string scratch_device; |
| bool partition_exists; |
| if (!fs_mgr_overlayfs_create_scratch(fstab, &scratch_device, &partition_exists)) { |
| LOG(ERROR) << "Failed to create scratch partition"; |
| return false; |
| } |
| |
| if (!SetOverlaysActiveFlag(true)) { |
| LOG(ERROR) << "Failed to update dynamic partition data"; |
| fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, nullptr); |
| return false; |
| } |
| |
| // If the partition exists, assume first that it can be mounted. |
| if (partition_exists) { |
| if (MountScratch(scratch_device)) { |
| const auto top = kScratchMountPoint + "/"s + kOverlayTopDir; |
| if (access(top.c_str(), F_OK) == 0 || fs_mgr_filesystem_has_space(kScratchMountPoint)) { |
| return true; |
| } |
| // declare it useless, no overrides and no free space |
| if (!fs_mgr_overlayfs_umount_scratch()) { |
| LOG(ERROR) << "Unable to unmount scratch partition"; |
| return false; |
| } |
| } |
| } |
| |
| if (!MakeScratchFilesystem(scratch_device)) { |
| LOG(ERROR) << "Failed to format scratch partition"; |
| return false; |
| } |
| |
| return MountScratch(scratch_device); |
| } |
| |
| constexpr bool OverlayfsTeardownAllowed() { |
| // Never allow on non-debuggable build. |
| return kAllowOverlayfs; |
| } |
| |
| } // namespace |
| |
| bool fs_mgr_overlayfs_setup(const Fstab& fstab, const char* mount_point, bool* want_reboot, |
| bool just_disabled_verity) { |
| if (!OverlayfsSetupAllowed(/*verbose=*/true)) { |
| return false; |
| } |
| |
| if (!fs_mgr_boot_completed()) { |
| LOG(ERROR) << "Cannot setup overlayfs before persistent properties are ready"; |
| return false; |
| } |
| |
| auto candidates = fs_mgr_overlayfs_candidate_list(fstab); |
| for (auto it = candidates.begin(); it != candidates.end();) { |
| if (mount_point && |
| (fs_mgr_mount_point(it->mount_point) != fs_mgr_mount_point(mount_point))) { |
| it = candidates.erase(it); |
| continue; |
| } |
| |
| auto verity_enabled = !just_disabled_verity && fs_mgr_is_verity_enabled(*it); |
| if (verity_enabled) { |
| it = candidates.erase(it); |
| continue; |
| } |
| ++it; |
| } |
| |
| if (candidates.empty()) { |
| if (mount_point) { |
| LOG(ERROR) << "No overlayfs candidate was found for " << mount_point; |
| return false; |
| } |
| return true; |
| } |
| |
| std::string dir; |
| for (const auto& overlay_mount_point : OverlayMountPoints()) { |
| if (overlay_mount_point == kScratchMountPoint) { |
| if (!fs_mgr_overlayfs_setup_scratch(fstab)) { |
| continue; |
| } |
| } else { |
| if (!fs_mgr_overlayfs_already_mounted(overlay_mount_point, false /* overlay */)) { |
| continue; |
| } |
| } |
| dir = overlay_mount_point; |
| break; |
| } |
| if (dir.empty()) { |
| LOG(ERROR) << "Could not allocate backing storage for overlays"; |
| return false; |
| } |
| |
| const auto overlay = fs_mgr_overlayfs_setup_dir(dir); |
| if (overlay.empty()) { |
| return false; |
| } |
| |
| bool ok = true; |
| for (const auto& entry : candidates) { |
| auto fstab_mount_point = fs_mgr_mount_point(entry.mount_point); |
| ok &= fs_mgr_overlayfs_setup_one(overlay, fstab_mount_point, want_reboot); |
| } |
| return ok; |
| } |
| |
| struct MapInfo { |
| // If set, partition is owned by ImageManager. |
| std::unique_ptr<IImageManager> images; |
| // If set, and images is null, this is a DAP partition. |
| std::string name; |
| // If set, and images and name are empty, this is a non-dynamic partition. |
| std::string device; |
| |
| MapInfo() = default; |
| MapInfo(MapInfo&&) = default; |
| ~MapInfo() { |
| if (images) { |
| images->UnmapImageDevice(name); |
| } else if (!name.empty()) { |
| DestroyLogicalPartition(name); |
| } |
| } |
| }; |
| |
| // Note: This function never returns the DSU scratch device in recovery or fastbootd, |
| // because the DSU scratch is created in the first-stage-mount, which is not run in recovery. |
| static std::optional<MapInfo> EnsureScratchMapped() { |
| MapInfo info; |
| info.device = GetBootScratchDevice(); |
| if (!info.device.empty()) { |
| return {std::move(info)}; |
| } |
| if (!InRecovery()) { |
| return {}; |
| } |
| |
| auto partition_name = android::base::Basename(kScratchMountPoint); |
| |
| // Check for scratch on /data first, before looking for a modified super |
| // partition. We should only reach this code in recovery, because scratch |
| // would otherwise always be mapped. |
| auto images = IImageManager::Open("remount", 10s); |
| if (images && images->BackingImageExists(partition_name)) { |
| if (images->IsImageDisabled(partition_name)) { |
| return {}; |
| } |
| if (!images->MapImageDevice(partition_name, 10s, &info.device)) { |
| return {}; |
| } |
| info.name = partition_name; |
| info.images = std::move(images); |
| return {std::move(info)}; |
| } |
| |
| // Avoid uart spam by first checking for a scratch partition. |
| const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name(); |
| auto metadata = ReadCurrentMetadata(super_device); |
| if (!metadata) { |
| return {}; |
| } |
| |
| auto partition = FindPartition(*metadata.get(), partition_name); |
| if (!partition) { |
| return {}; |
| } |
| |
| CreateLogicalPartitionParams params = { |
| .block_device = super_device, |
| .metadata = metadata.get(), |
| .partition = partition, |
| .force_writable = true, |
| .timeout_ms = 10s, |
| }; |
| if (!CreateLogicalPartition(params, &info.device)) { |
| return {}; |
| } |
| info.name = partition_name; |
| return {std::move(info)}; |
| } |
| |
| // This should only be reachable in recovery, where DSU scratch is not |
| // automatically mapped. |
| static bool MapDsuScratchDevice(std::string* device) { |
| std::string dsu_slot; |
| if (!android::gsi::IsGsiInstalled() || !android::gsi::GetActiveDsu(&dsu_slot) || |
| dsu_slot.empty()) { |
| // Nothing to do if no DSU installation present. |
| return false; |
| } |
| |
| auto images = IImageManager::Open("dsu/" + dsu_slot, 10s); |
| if (!images || !images->BackingImageExists(android::gsi::kDsuScratch)) { |
| // Nothing to do if DSU scratch device doesn't exist. |
| return false; |
| } |
| |
| images->UnmapImageDevice(android::gsi::kDsuScratch); |
| if (!images->MapImageDevice(android::gsi::kDsuScratch, 10s, device)) { |
| return false; |
| } |
| return true; |
| } |
| |
| static OverlayfsTeardownResult TeardownMountsAndScratch(const char* mount_point, |
| bool* want_reboot) { |
| bool should_destroy_scratch = false; |
| auto rv = OverlayfsTeardownResult::Ok; |
| for (const auto& overlay_mount_point : OverlayMountPoints()) { |
| auto ok = fs_mgr_overlayfs_teardown_one( |
| overlay_mount_point, mount_point ? fs_mgr_mount_point(mount_point) : "", |
| want_reboot, |
| overlay_mount_point == kScratchMountPoint ? &should_destroy_scratch : nullptr); |
| if (!ok) { |
| rv = OverlayfsTeardownResult::Error; |
| } |
| } |
| |
| // Do not attempt to destroy DSU scratch if within a DSU system, |
| // because DSU scratch partition is managed by gsid. |
| if (should_destroy_scratch && !fs_mgr_is_dsu_running()) { |
| auto rv = fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, want_reboot); |
| if (rv != OverlayfsTeardownResult::Ok) { |
| return rv; |
| } |
| } |
| // And now that we did what we could, lets inform |
| // caller that there may still be more to do. |
| if (!fs_mgr_boot_completed()) { |
| LOG(ERROR) << "Cannot teardown overlayfs before persistent properties are ready"; |
| return OverlayfsTeardownResult::Error; |
| } |
| return rv; |
| } |
| |
| // Returns false if teardown not permitted. If something is altered, set *want_reboot. |
| OverlayfsTeardownResult fs_mgr_overlayfs_teardown(const char* mount_point, bool* want_reboot) { |
| if (!OverlayfsTeardownAllowed()) { |
| // Nothing to teardown. |
| return OverlayfsTeardownResult::Ok; |
| } |
| // If scratch exists, but is not mounted, lets gain access to clean |
| // specific override entries. |
| auto mount_scratch = false; |
| if ((mount_point != nullptr) && !fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) { |
| std::string scratch_device = GetBootScratchDevice(); |
| if (!scratch_device.empty()) { |
| mount_scratch = MountScratch(scratch_device); |
| } |
| } |
| |
| auto rv = TeardownMountsAndScratch(mount_point, want_reboot); |
| |
| if (mount_scratch) { |
| if (!fs_mgr_overlayfs_umount_scratch()) { |
| return OverlayfsTeardownResult::Busy; |
| } |
| } |
| return rv; |
| } |
| |
| namespace android { |
| namespace fs_mgr { |
| |
| void MapScratchPartitionIfNeeded(Fstab* fstab, |
| const std::function<bool(const std::set<std::string>&)>& init) { |
| if (!OverlayfsSetupAllowed()) { |
| return; |
| } |
| if (GetEntryForMountPoint(fstab, kScratchMountPoint) != nullptr) { |
| return; |
| } |
| |
| if (!GetOverlaysActiveFlag()) { |
| return; |
| } |
| if (ScratchIsOnData()) { |
| if (auto images = IImageManager::Open("remount", 0ms)) { |
| images->MapAllImages(init); |
| } |
| } |
| |
| // Physical or logical partitions will have already been mapped here, |
| // so just ensure /dev/block symlinks exist. |
| auto device = GetBootScratchDevice(); |
| if (!device.empty()) { |
| init({android::base::Basename(device)}); |
| } |
| } |
| |
| void CleanupOldScratchFiles() { |
| if (!OverlayfsTeardownAllowed()) { |
| return; |
| } |
| if (!ScratchIsOnData()) { |
| return; |
| } |
| if (auto images = IImageManager::Open("remount", 0ms)) { |
| images->RemoveDisabledImages(); |
| if (!GetOverlaysActiveFlag()) { |
| fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, nullptr); |
| } |
| } |
| } |
| |
| // This returns the scratch device that was detected during early boot (first- |
| // stage init). If the device was created later, for example during setup for |
| // the adb remount command, it can return an empty string since it does not |
| // query ImageManager. (Note that ImageManager in first-stage init will always |
| // use device-mapper, since /data is not available to use loop devices.) |
| std::string GetBootScratchDevice() { |
| // Note: fs_mgr_is_dsu_running() always returns false in recovery or fastbootd. |
| if (fs_mgr_is_dsu_running()) { |
| return GetDsuScratchDevice(); |
| } |
| |
| auto& dm = DeviceMapper::Instance(); |
| |
| // If there is a scratch partition allocated in /data or on super, we |
| // automatically prioritize that over super_other or system_other. |
| // Some devices, for example, have a write-protected eMMC and the |
| // super partition cannot be used even if it exists. |
| std::string device; |
| auto partition_name = android::base::Basename(kScratchMountPoint); |
| if (dm.GetState(partition_name) != DmDeviceState::INVALID && |
| dm.GetDmDevicePathByName(partition_name, &device)) { |
| return device; |
| } |
| |
| return ""; |
| } |
| |
| void TeardownAllOverlayForMountPoint(const std::string& mount_point) { |
| if (!OverlayfsTeardownAllowed()) { |
| return; |
| } |
| if (!InRecovery()) { |
| LERROR << __FUNCTION__ << "(): must be called within recovery."; |
| return; |
| } |
| |
| // Empty string means teardown everything. |
| const std::string teardown_dir = mount_point.empty() ? "" : fs_mgr_mount_point(mount_point); |
| constexpr bool* ignore_change = nullptr; |
| |
| // Teardown legacy overlay mount points that's not backed by a scratch device. |
| for (const auto& overlay_mount_point : OverlayMountPoints()) { |
| if (overlay_mount_point == kScratchMountPoint) { |
| continue; |
| } |
| fs_mgr_overlayfs_teardown_one(overlay_mount_point, teardown_dir, ignore_change); |
| } |
| |
| if (mount_point.empty()) { |
| // Throw away the entire partition. |
| auto partition_name = android::base::Basename(kScratchMountPoint); |
| auto images = IImageManager::Open("remount", 10s); |
| if (images && images->BackingImageExists(partition_name)) { |
| if (images->DisableImage(partition_name)) { |
| LOG(INFO) << "Disabled scratch partition for: " << kScratchMountPoint; |
| } else { |
| LOG(ERROR) << "Unable to disable scratch partition for " << kScratchMountPoint; |
| } |
| } |
| } |
| |
| // Note if we just disabled scratch, this mount will fail. |
| if (auto info = EnsureScratchMapped(); info.has_value()) { |
| // Map scratch device, mount kScratchMountPoint and teardown kScratchMountPoint. |
| fs_mgr_overlayfs_umount_scratch(); |
| if (MountScratch(info->device)) { |
| bool should_destroy_scratch = false; |
| fs_mgr_overlayfs_teardown_one(kScratchMountPoint, teardown_dir, ignore_change, |
| &should_destroy_scratch); |
| fs_mgr_overlayfs_umount_scratch(); |
| if (should_destroy_scratch) { |
| fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, nullptr); |
| } |
| } |
| } |
| |
| // Teardown DSU overlay if present. |
| std::string scratch_device; |
| if (MapDsuScratchDevice(&scratch_device)) { |
| fs_mgr_overlayfs_umount_scratch(); |
| if (MountScratch(scratch_device)) { |
| fs_mgr_overlayfs_teardown_one(kScratchMountPoint, teardown_dir, ignore_change); |
| fs_mgr_overlayfs_umount_scratch(); |
| } |
| DestroyLogicalPartition(android::gsi::kDsuScratch); |
| } |
| } |
| |
| } // namespace fs_mgr |
| } // namespace android |
