| /* |
| * Copyright (C) 2014 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 <ctype.h> |
| #include <dirent.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/mount.h> |
| #include <unistd.h> |
| |
| #include <algorithm> |
| #include <array> |
| #include <utility> |
| #include <vector> |
| |
| #include <android-base/file.h> |
| #include <android-base/parseint.h> |
| #include <android-base/properties.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| #include <libgsi/libgsi.h> |
| |
| #include "fs_mgr_priv.h" |
| |
| using android::base::EndsWith; |
| using android::base::ParseByteCount; |
| using android::base::ParseInt; |
| using android::base::ReadFileToString; |
| using android::base::Readlink; |
| using android::base::Split; |
| using android::base::StartsWith; |
| |
| namespace android { |
| namespace fs_mgr { |
| namespace { |
| |
| constexpr char kDefaultAndroidDtDir[] = "/proc/device-tree/firmware/android"; |
| |
| struct FlagList { |
| const char *name; |
| uint64_t flag; |
| }; |
| |
| FlagList kMountFlagsList[] = { |
| {"noatime", MS_NOATIME}, |
| {"noexec", MS_NOEXEC}, |
| {"nosuid", MS_NOSUID}, |
| {"nodev", MS_NODEV}, |
| {"nodiratime", MS_NODIRATIME}, |
| {"ro", MS_RDONLY}, |
| {"rw", 0}, |
| {"sync", MS_SYNCHRONOUS}, |
| {"remount", MS_REMOUNT}, |
| {"bind", MS_BIND}, |
| {"rec", MS_REC}, |
| {"unbindable", MS_UNBINDABLE}, |
| {"private", MS_PRIVATE}, |
| {"slave", MS_SLAVE}, |
| {"shared", MS_SHARED}, |
| {"defaults", 0}, |
| }; |
| |
| off64_t CalculateZramSize(int percentage) { |
| off64_t total; |
| |
| total = sysconf(_SC_PHYS_PAGES); |
| total *= percentage; |
| total /= 100; |
| |
| total *= sysconf(_SC_PAGESIZE); |
| |
| return total; |
| } |
| |
| // Fills 'dt_value' with the underlying device tree value string without the trailing '\0'. |
| // Returns true if 'dt_value' has a valid string, 'false' otherwise. |
| bool ReadDtFile(const std::string& file_name, std::string* dt_value) { |
| if (android::base::ReadFileToString(file_name, dt_value)) { |
| if (!dt_value->empty()) { |
| // Trim the trailing '\0' out, otherwise the comparison will produce false-negatives. |
| dt_value->resize(dt_value->size() - 1); |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| void ParseFileEncryption(const std::string& arg, FstabEntry* entry) { |
| entry->fs_mgr_flags.file_encryption = true; |
| entry->encryption_options = arg; |
| } |
| |
| bool SetMountFlag(const std::string& flag, FstabEntry* entry) { |
| for (const auto& [name, value] : kMountFlagsList) { |
| if (flag == name) { |
| entry->flags |= value; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void ParseMountFlags(const std::string& flags, FstabEntry* entry) { |
| std::string fs_options; |
| for (const auto& flag : Split(flags, ",")) { |
| if (!SetMountFlag(flag, entry)) { |
| // Unknown flag, so it must be a filesystem specific option. |
| if (!fs_options.empty()) { |
| fs_options.append(","); // appends a comma if not the first |
| } |
| fs_options.append(flag); |
| |
| if (entry->fs_type == "f2fs" && StartsWith(flag, "reserve_root=")) { |
| std::string arg; |
| if (auto equal_sign = flag.find('='); equal_sign != std::string::npos) { |
| arg = flag.substr(equal_sign + 1); |
| } |
| if (!ParseInt(arg, &entry->reserved_size)) { |
| LWARNING << "Warning: reserve_root= flag malformed: " << arg; |
| } else { |
| entry->reserved_size <<= 12; |
| } |
| } |
| } |
| } |
| entry->fs_options = std::move(fs_options); |
| } |
| |
| void ParseFsMgrFlags(const std::string& flags, FstabEntry* entry) { |
| for (const auto& flag : Split(flags, ",")) { |
| if (flag.empty() || flag == "defaults") continue; |
| std::string arg; |
| if (auto equal_sign = flag.find('='); equal_sign != std::string::npos) { |
| arg = flag.substr(equal_sign + 1); |
| } |
| |
| // First handle flags that simply set a boolean. |
| #define CheckFlag(flag_name, value) \ |
| if (flag == flag_name) { \ |
| entry->fs_mgr_flags.value = true; \ |
| continue; \ |
| } |
| |
| CheckFlag("wait", wait); |
| CheckFlag("check", check); |
| CheckFlag("nonremovable", nonremovable); |
| CheckFlag("recoveryonly", recovery_only); |
| CheckFlag("noemulatedsd", no_emulated_sd); |
| CheckFlag("notrim", no_trim); |
| CheckFlag("verify", verify); |
| CheckFlag("formattable", formattable); |
| CheckFlag("slotselect", slot_select); |
| CheckFlag("latemount", late_mount); |
| CheckFlag("nofail", no_fail); |
| CheckFlag("verifyatboot", verify_at_boot); |
| CheckFlag("quota", quota); |
| CheckFlag("avb", avb); |
| CheckFlag("logical", logical); |
| CheckFlag("checkpoint=block", checkpoint_blk); |
| CheckFlag("checkpoint=fs", checkpoint_fs); |
| CheckFlag("first_stage_mount", first_stage_mount); |
| CheckFlag("slotselect_other", slot_select_other); |
| CheckFlag("fsverity", fs_verity); |
| CheckFlag("metadata_csum", ext_meta_csum); |
| CheckFlag("fscompress", fs_compress); |
| |
| #undef CheckFlag |
| |
| // Then handle flags that take an argument. |
| if (StartsWith(flag, "encryptable=")) { |
| // The encryptable flag is followed by an = and the location of the keys. |
| entry->fs_mgr_flags.crypt = true; |
| entry->key_loc = arg; |
| } else if (StartsWith(flag, "voldmanaged=")) { |
| // The voldmanaged flag is followed by an = and the label, a colon and the partition |
| // number or the word "auto", e.g. voldmanaged=sdcard:3 |
| entry->fs_mgr_flags.vold_managed = true; |
| auto parts = Split(arg, ":"); |
| if (parts.size() != 2) { |
| LWARNING << "Warning: voldmanaged= flag malformed: " << arg; |
| continue; |
| } |
| |
| entry->label = std::move(parts[0]); |
| if (parts[1] == "auto") { |
| entry->partnum = -1; |
| } else { |
| if (!ParseInt(parts[1], &entry->partnum)) { |
| entry->partnum = -1; |
| LWARNING << "Warning: voldmanaged= flag malformed: " << arg; |
| continue; |
| } |
| } |
| } else if (StartsWith(flag, "length=")) { |
| // The length flag is followed by an = and the size of the partition. |
| if (!ParseInt(arg, &entry->length)) { |
| LWARNING << "Warning: length= flag malformed: " << arg; |
| } |
| } else if (StartsWith(flag, "swapprio=")) { |
| if (!ParseInt(arg, &entry->swap_prio)) { |
| LWARNING << "Warning: swapprio= flag malformed: " << arg; |
| } |
| } else if (StartsWith(flag, "zramsize=")) { |
| if (!arg.empty() && arg.back() == '%') { |
| arg.pop_back(); |
| int val; |
| if (ParseInt(arg, &val, 0, 100)) { |
| entry->zram_size = CalculateZramSize(val); |
| } else { |
| LWARNING << "Warning: zramsize= flag malformed: " << arg; |
| } |
| } else { |
| if (!ParseInt(arg, &entry->zram_size)) { |
| LWARNING << "Warning: zramsize= flag malformed: " << arg; |
| } |
| } |
| } else if (StartsWith(flag, "forceencrypt=")) { |
| // The forceencrypt flag is followed by an = and the location of the keys. |
| entry->fs_mgr_flags.force_crypt = true; |
| entry->key_loc = arg; |
| } else if (StartsWith(flag, "fileencryption=")) { |
| ParseFileEncryption(arg, entry); |
| } else if (StartsWith(flag, "forcefdeorfbe=")) { |
| // The forcefdeorfbe flag is followed by an = and the location of the keys. Get it and |
| // return it. |
| entry->fs_mgr_flags.force_fde_or_fbe = true; |
| entry->key_loc = arg; |
| entry->encryption_options = "aes-256-xts:aes-256-cts"; |
| } else if (StartsWith(flag, "max_comp_streams=")) { |
| if (!ParseInt(arg, &entry->max_comp_streams)) { |
| LWARNING << "Warning: max_comp_streams= flag malformed: " << arg; |
| } |
| } else if (StartsWith(flag, "reservedsize=")) { |
| // The reserved flag is followed by an = and the reserved size of the partition. |
| uint64_t size; |
| if (!ParseByteCount(arg, &size)) { |
| LWARNING << "Warning: reservedsize= flag malformed: " << arg; |
| } else { |
| entry->reserved_size = static_cast<off64_t>(size); |
| } |
| } else if (StartsWith(flag, "eraseblk=")) { |
| // The erase block size flag is followed by an = and the flash erase block size. Get it, |
| // check that it is a power of 2 and at least 4096, and return it. |
| off64_t val; |
| if (!ParseInt(arg, &val) || val < 4096 || (val & (val - 1)) != 0) { |
| LWARNING << "Warning: eraseblk= flag malformed: " << arg; |
| } else { |
| entry->erase_blk_size = val; |
| } |
| } else if (StartsWith(flag, "logicalblk=")) { |
| // The logical block size flag is followed by an = and the flash logical block size. Get |
| // it, check that it is a power of 2 and at least 4096, and return it. |
| off64_t val; |
| if (!ParseInt(arg, &val) || val < 4096 || (val & (val - 1)) != 0) { |
| LWARNING << "Warning: logicalblk= flag malformed: " << arg; |
| } else { |
| entry->logical_blk_size = val; |
| } |
| } else if (StartsWith(flag, "avb_keys=")) { // must before the following "avb" |
| entry->avb_keys = arg; |
| } else if (StartsWith(flag, "avb")) { |
| entry->fs_mgr_flags.avb = true; |
| entry->vbmeta_partition = arg; |
| } else if (StartsWith(flag, "keydirectory=")) { |
| // The metadata flag is followed by an = and the directory for the keys. |
| entry->metadata_key_dir = arg; |
| } else if (StartsWith(flag, "metadata_encryption=")) { |
| // Specify the cipher and flags to use for metadata encryption |
| entry->metadata_encryption = arg; |
| } else if (StartsWith(flag, "sysfs_path=")) { |
| // The path to trigger device gc by idle-maint of vold. |
| entry->sysfs_path = arg; |
| } else if (StartsWith(flag, "zram_backingdev_size=")) { |
| if (!ParseByteCount(arg, &entry->zram_backingdev_size)) { |
| LWARNING << "Warning: zram_backingdev_size= flag malformed: " << arg; |
| } |
| } else { |
| LWARNING << "Warning: unknown flag: " << flag; |
| } |
| } |
| } |
| |
| std::string InitAndroidDtDir() { |
| std::string android_dt_dir; |
| // The platform may specify a custom Android DT path in kernel cmdline |
| if (!fs_mgr_get_boot_config_from_kernel_cmdline("android_dt_dir", &android_dt_dir)) { |
| // Fall back to the standard procfs-based path |
| android_dt_dir = kDefaultAndroidDtDir; |
| } |
| return android_dt_dir; |
| } |
| |
| bool IsDtFstabCompatible() { |
| std::string dt_value; |
| std::string file_name = get_android_dt_dir() + "/fstab/compatible"; |
| |
| if (ReadDtFile(file_name, &dt_value) && dt_value == "android,fstab") { |
| // If there's no status property or its set to "ok" or "okay", then we use the DT fstab. |
| std::string status_value; |
| std::string status_file_name = get_android_dt_dir() + "/fstab/status"; |
| return !ReadDtFile(status_file_name, &status_value) || status_value == "ok" || |
| status_value == "okay"; |
| } |
| |
| return false; |
| } |
| |
| std::string ReadFstabFromDt() { |
| if (!is_dt_compatible() || !IsDtFstabCompatible()) { |
| return {}; |
| } |
| |
| std::string fstabdir_name = get_android_dt_dir() + "/fstab"; |
| std::unique_ptr<DIR, int (*)(DIR*)> fstabdir(opendir(fstabdir_name.c_str()), closedir); |
| if (!fstabdir) return {}; |
| |
| dirent* dp; |
| // Each element in fstab_dt_entries is <mount point, the line format in fstab file>. |
| std::vector<std::pair<std::string, std::string>> fstab_dt_entries; |
| while ((dp = readdir(fstabdir.get())) != NULL) { |
| // skip over name, compatible and . |
| if (dp->d_type != DT_DIR || dp->d_name[0] == '.') continue; |
| |
| // create <dev> <mnt_point> <type> <mnt_flags> <fsmgr_flags>\n |
| std::vector<std::string> fstab_entry; |
| std::string file_name; |
| std::string value; |
| // skip a partition entry if the status property is present and not set to ok |
| file_name = android::base::StringPrintf("%s/%s/status", fstabdir_name.c_str(), dp->d_name); |
| if (ReadDtFile(file_name, &value)) { |
| if (value != "okay" && value != "ok") { |
| LINFO << "dt_fstab: Skip disabled entry for partition " << dp->d_name; |
| continue; |
| } |
| } |
| |
| file_name = android::base::StringPrintf("%s/%s/dev", fstabdir_name.c_str(), dp->d_name); |
| if (!ReadDtFile(file_name, &value)) { |
| LERROR << "dt_fstab: Failed to find device for partition " << dp->d_name; |
| return {}; |
| } |
| fstab_entry.push_back(value); |
| |
| std::string mount_point; |
| file_name = |
| android::base::StringPrintf("%s/%s/mnt_point", fstabdir_name.c_str(), dp->d_name); |
| if (ReadDtFile(file_name, &value)) { |
| LINFO << "dt_fstab: Using a specified mount point " << value << " for " << dp->d_name; |
| mount_point = value; |
| } else { |
| mount_point = android::base::StringPrintf("/%s", dp->d_name); |
| } |
| fstab_entry.push_back(mount_point); |
| |
| file_name = android::base::StringPrintf("%s/%s/type", fstabdir_name.c_str(), dp->d_name); |
| if (!ReadDtFile(file_name, &value)) { |
| LERROR << "dt_fstab: Failed to find type for partition " << dp->d_name; |
| return {}; |
| } |
| fstab_entry.push_back(value); |
| |
| file_name = android::base::StringPrintf("%s/%s/mnt_flags", fstabdir_name.c_str(), dp->d_name); |
| if (!ReadDtFile(file_name, &value)) { |
| LERROR << "dt_fstab: Failed to find type for partition " << dp->d_name; |
| return {}; |
| } |
| fstab_entry.push_back(value); |
| |
| file_name = android::base::StringPrintf("%s/%s/fsmgr_flags", fstabdir_name.c_str(), dp->d_name); |
| if (!ReadDtFile(file_name, &value)) { |
| LERROR << "dt_fstab: Failed to find type for partition " << dp->d_name; |
| return {}; |
| } |
| fstab_entry.push_back(value); |
| // Adds a fstab_entry to fstab_dt_entries, to be sorted by mount_point later. |
| fstab_dt_entries.emplace_back(mount_point, android::base::Join(fstab_entry, " ")); |
| } |
| |
| // Sort fstab_dt entries, to ensure /vendor is mounted before /vendor/abc is attempted. |
| std::sort(fstab_dt_entries.begin(), fstab_dt_entries.end(), |
| [](const auto& a, const auto& b) { return a.first < b.first; }); |
| |
| std::string fstab_result; |
| for (const auto& [_, dt_entry] : fstab_dt_entries) { |
| fstab_result += dt_entry + "\n"; |
| } |
| return fstab_result; |
| } |
| |
| // Identify path to fstab file. Lookup is based on pattern |
| // fstab.<fstab_suffix>, fstab.<hardware>, fstab.<hardware.platform> in |
| // folders /odm/etc, vendor/etc, or /. |
| std::string GetFstabPath() { |
| for (const char* prop : {"fstab_suffix", "hardware", "hardware.platform"}) { |
| std::string suffix; |
| |
| if (!fs_mgr_get_boot_config(prop, &suffix)) continue; |
| |
| for (const char* prefix : {"/odm/etc/fstab.", "/vendor/etc/fstab.", "/fstab."}) { |
| std::string fstab_path = prefix + suffix; |
| if (access(fstab_path.c_str(), F_OK) == 0) { |
| return fstab_path; |
| } |
| } |
| } |
| |
| return ""; |
| } |
| |
| bool ReadFstabFile(FILE* fstab_file, bool proc_mounts, Fstab* fstab_out) { |
| ssize_t len; |
| size_t alloc_len = 0; |
| char *line = NULL; |
| const char *delim = " \t"; |
| char *save_ptr, *p; |
| Fstab fstab; |
| |
| while ((len = getline(&line, &alloc_len, fstab_file)) != -1) { |
| /* if the last character is a newline, shorten the string by 1 byte */ |
| if (line[len - 1] == '\n') { |
| line[len - 1] = '\0'; |
| } |
| |
| /* Skip any leading whitespace */ |
| p = line; |
| while (isspace(*p)) { |
| p++; |
| } |
| /* ignore comments or empty lines */ |
| if (*p == '#' || *p == '\0') |
| continue; |
| |
| FstabEntry entry; |
| |
| if (!(p = strtok_r(line, delim, &save_ptr))) { |
| LERROR << "Error parsing mount source"; |
| goto err; |
| } |
| entry.blk_device = p; |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| LERROR << "Error parsing mount_point"; |
| goto err; |
| } |
| entry.mount_point = p; |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| LERROR << "Error parsing fs_type"; |
| goto err; |
| } |
| entry.fs_type = p; |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| LERROR << "Error parsing mount_flags"; |
| goto err; |
| } |
| |
| ParseMountFlags(p, &entry); |
| |
| // For /proc/mounts, ignore everything after mnt_freq and mnt_passno |
| if (proc_mounts) { |
| p += strlen(p); |
| } else if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| LERROR << "Error parsing fs_mgr_options"; |
| goto err; |
| } |
| |
| ParseFsMgrFlags(p, &entry); |
| |
| if (entry.fs_mgr_flags.logical) { |
| entry.logical_partition_name = entry.blk_device; |
| } |
| |
| fstab.emplace_back(std::move(entry)); |
| } |
| |
| if (fstab.empty()) { |
| LERROR << "No entries found in fstab"; |
| goto err; |
| } |
| |
| /* If an A/B partition, modify block device to be the real block device */ |
| if (!fs_mgr_update_for_slotselect(&fstab)) { |
| LERROR << "Error updating for slotselect"; |
| goto err; |
| } |
| free(line); |
| *fstab_out = std::move(fstab); |
| return true; |
| |
| err: |
| free(line); |
| return false; |
| } |
| |
| /* Extracts <device>s from the by-name symlinks specified in a fstab: |
| * /dev/block/<type>/<device>/by-name/<partition> |
| * |
| * <type> can be: platform, pci or vbd. |
| * |
| * For example, given the following entries in the input fstab: |
| * /dev/block/platform/soc/1da4000.ufshc/by-name/system |
| * /dev/block/pci/soc.0/f9824900.sdhci/by-name/vendor |
| * it returns a set { "soc/1da4000.ufshc", "soc.0/f9824900.sdhci" }. |
| */ |
| std::set<std::string> ExtraBootDevices(const Fstab& fstab) { |
| std::set<std::string> boot_devices; |
| |
| for (const auto& entry : fstab) { |
| std::string blk_device = entry.blk_device; |
| // Skips blk_device that doesn't conform to the format. |
| if (!android::base::StartsWith(blk_device, "/dev/block") || |
| android::base::StartsWith(blk_device, "/dev/block/by-name") || |
| android::base::StartsWith(blk_device, "/dev/block/bootdevice/by-name")) { |
| continue; |
| } |
| // Skips non-by_name blk_device. |
| // /dev/block/<type>/<device>/by-name/<partition> |
| // ^ slash_by_name |
| auto slash_by_name = blk_device.find("/by-name"); |
| if (slash_by_name == std::string::npos) continue; |
| blk_device.erase(slash_by_name); // erases /by-name/<partition> |
| |
| // Erases /dev/block/, now we have <type>/<device> |
| blk_device.erase(0, std::string("/dev/block/").size()); |
| |
| // <type>/<device> |
| // ^ first_slash |
| auto first_slash = blk_device.find('/'); |
| if (first_slash == std::string::npos) continue; |
| |
| auto boot_device = blk_device.substr(first_slash + 1); |
| if (!boot_device.empty()) boot_devices.insert(std::move(boot_device)); |
| } |
| |
| return boot_devices; |
| } |
| |
| FstabEntry BuildDsuUserdataFstabEntry() { |
| constexpr uint32_t kFlags = MS_NOATIME | MS_NOSUID | MS_NODEV; |
| |
| FstabEntry userdata = { |
| .blk_device = "userdata_gsi", |
| .mount_point = "/data", |
| .fs_type = "ext4", |
| .flags = kFlags, |
| .reserved_size = 128 * 1024 * 1024, |
| }; |
| userdata.fs_mgr_flags.wait = true; |
| userdata.fs_mgr_flags.check = true; |
| userdata.fs_mgr_flags.logical = true; |
| userdata.fs_mgr_flags.quota = true; |
| userdata.fs_mgr_flags.late_mount = true; |
| userdata.fs_mgr_flags.formattable = true; |
| return userdata; |
| } |
| |
| bool EraseFstabEntry(Fstab* fstab, const std::string& mount_point) { |
| auto iter = std::remove_if(fstab->begin(), fstab->end(), |
| [&](const auto& entry) { return entry.mount_point == mount_point; }); |
| if (iter != fstab->end()) { |
| fstab->erase(iter, fstab->end()); |
| return true; |
| } |
| return false; |
| } |
| |
| } // namespace |
| |
| void TransformFstabForDsu(Fstab* fstab, const std::vector<std::string>& dsu_partitions) { |
| static constexpr char kDsuKeysDir[] = "/avb"; |
| // Convert userdata |
| // Inherit fstab properties for userdata. |
| FstabEntry userdata; |
| if (FstabEntry* entry = GetEntryForMountPoint(fstab, "/data")) { |
| userdata = *entry; |
| userdata.blk_device = "userdata_gsi"; |
| userdata.fs_mgr_flags.logical = true; |
| userdata.fs_mgr_flags.formattable = true; |
| if (!userdata.metadata_key_dir.empty()) { |
| userdata.metadata_key_dir += "/gsi"; |
| } |
| } else { |
| userdata = BuildDsuUserdataFstabEntry(); |
| } |
| |
| if (EraseFstabEntry(fstab, "/data")) { |
| fstab->emplace_back(userdata); |
| } |
| |
| // Convert others |
| for (auto&& partition : dsu_partitions) { |
| if (!EndsWith(partition, gsi::kDsuPostfix)) { |
| continue; |
| } |
| // userdata has been handled |
| if (StartsWith(partition, "user")) { |
| continue; |
| } |
| // dsu_partition_name = corresponding_partition_name + kDsuPostfix |
| // e.g. |
| // system_gsi for system |
| // product_gsi for product |
| // vendor_gsi for vendor |
| std::string lp_name = partition.substr(0, partition.length() - strlen(gsi::kDsuPostfix)); |
| std::string mount_point = "/" + lp_name; |
| std::vector<FstabEntry*> entries = GetEntriesForMountPoint(fstab, mount_point); |
| if (entries.empty()) { |
| FstabEntry entry = { |
| .blk_device = partition, |
| // .logical_partition_name is required to look up AVB Hashtree descriptors. |
| .logical_partition_name = "system", |
| .mount_point = mount_point, |
| .fs_type = "ext4", |
| .flags = MS_RDONLY, |
| .fs_options = "barrier=1", |
| .avb_keys = kDsuKeysDir, |
| }; |
| entry.fs_mgr_flags.wait = true; |
| entry.fs_mgr_flags.logical = true; |
| entry.fs_mgr_flags.first_stage_mount = true; |
| fstab->emplace_back(entry); |
| } else { |
| // If the corresponding partition exists, transform all its Fstab |
| // by pointing .blk_device to the DSU partition. |
| for (auto&& entry : entries) { |
| entry->blk_device = partition; |
| // AVB keys for DSU should always be under kDsuKeysDir. |
| entry->avb_keys = kDsuKeysDir; |
| } |
| // Make sure the ext4 is included to support GSI. |
| auto partition_ext4 = |
| std::find_if(fstab->begin(), fstab->end(), [&](const auto& entry) { |
| return entry.mount_point == mount_point && entry.fs_type == "ext4"; |
| }); |
| if (partition_ext4 == fstab->end()) { |
| auto new_entry = *GetEntryForMountPoint(fstab, mount_point); |
| new_entry.fs_type = "ext4"; |
| fstab->emplace_back(new_entry); |
| } |
| } |
| } |
| } |
| |
| void EnableMandatoryFlags(Fstab* fstab) { |
| // Devices launched in R and after should enable fs_verity on userdata. The flag causes tune2fs |
| // to enable the feature. A better alternative would be to enable on mkfs at the beginning. |
| if (android::base::GetIntProperty("ro.product.first_api_level", 0) >= 30) { |
| std::vector<FstabEntry*> data_entries = GetEntriesForMountPoint(fstab, "/data"); |
| for (auto&& entry : data_entries) { |
| // Besides ext4, f2fs is also supported. But the image is already created with verity |
| // turned on when it was first introduced. |
| if (entry->fs_type == "ext4") { |
| entry->fs_mgr_flags.fs_verity = true; |
| } |
| } |
| } |
| } |
| |
| bool ReadFstabFromFile(const std::string& path, Fstab* fstab) { |
| auto fstab_file = std::unique_ptr<FILE, decltype(&fclose)>{fopen(path.c_str(), "re"), fclose}; |
| if (!fstab_file) { |
| PERROR << __FUNCTION__ << "(): cannot open file: '" << path << "'"; |
| return false; |
| } |
| |
| bool is_proc_mounts = path == "/proc/mounts"; |
| |
| if (!ReadFstabFile(fstab_file.get(), is_proc_mounts, fstab)) { |
| LERROR << __FUNCTION__ << "(): failed to load fstab from : '" << path << "'"; |
| return false; |
| } |
| if (!is_proc_mounts && !access(android::gsi::kGsiBootedIndicatorFile, F_OK)) { |
| std::string lp_names; |
| ReadFileToString(gsi::kGsiLpNamesFile, &lp_names); |
| TransformFstabForDsu(fstab, Split(lp_names, ",")); |
| } |
| |
| #ifndef NO_SKIP_MOUNT |
| SkipMountingPartitions(fstab); |
| #endif |
| EnableMandatoryFlags(fstab); |
| |
| return true; |
| } |
| |
| // Returns fstab entries parsed from the device tree if they exist |
| bool ReadFstabFromDt(Fstab* fstab, bool log) { |
| std::string fstab_buf = ReadFstabFromDt(); |
| if (fstab_buf.empty()) { |
| if (log) LINFO << __FUNCTION__ << "(): failed to read fstab from dt"; |
| return false; |
| } |
| |
| std::unique_ptr<FILE, decltype(&fclose)> fstab_file( |
| fmemopen(static_cast<void*>(const_cast<char*>(fstab_buf.c_str())), |
| fstab_buf.length(), "r"), fclose); |
| if (!fstab_file) { |
| if (log) PERROR << __FUNCTION__ << "(): failed to create a file stream for fstab dt"; |
| return false; |
| } |
| |
| if (!ReadFstabFile(fstab_file.get(), false, fstab)) { |
| if (log) { |
| LERROR << __FUNCTION__ << "(): failed to load fstab from kernel:" << std::endl |
| << fstab_buf; |
| } |
| return false; |
| } |
| |
| #ifndef NO_SKIP_MOUNT |
| SkipMountingPartitions(fstab); |
| #endif |
| |
| return true; |
| } |
| |
| #ifndef NO_SKIP_MOUNT |
| // For GSI to skip mounting /product and /system_ext, until there are well-defined interfaces |
| // between them and /system. Otherwise, the GSI flashed on /system might not be able to work with |
| // device-specific /product and /system_ext. skip_mount.cfg belongs to system_ext partition because |
| // only common files for all targets can be put into system partition. It is under |
| // /system/system_ext because GSI is a single system.img that includes the contents of system_ext |
| // partition and product partition under /system/system_ext and /system/product, respectively. |
| bool SkipMountingPartitions(Fstab* fstab) { |
| constexpr const char kSkipMountConfig[] = "/system/system_ext/etc/init/config/skip_mount.cfg"; |
| |
| std::string skip_config; |
| auto save_errno = errno; |
| if (!ReadFileToString(kSkipMountConfig, &skip_config)) { |
| errno = save_errno; // missing file is expected |
| return true; |
| } |
| |
| for (const auto& skip_mount_point : Split(skip_config, "\n")) { |
| if (skip_mount_point.empty()) { |
| continue; |
| } |
| auto it = std::remove_if(fstab->begin(), fstab->end(), |
| [&skip_mount_point](const auto& entry) { |
| return entry.mount_point == skip_mount_point; |
| }); |
| if (it == fstab->end()) continue; |
| fstab->erase(it, fstab->end()); |
| LOG(INFO) << "Skip mounting partition: " << skip_mount_point; |
| } |
| |
| return true; |
| } |
| #endif |
| |
| // Loads the fstab file and combines with fstab entries passed in from device tree. |
| bool ReadDefaultFstab(Fstab* fstab) { |
| Fstab dt_fstab; |
| ReadFstabFromDt(&dt_fstab, false); |
| |
| *fstab = std::move(dt_fstab); |
| |
| std::string default_fstab_path; |
| // Use different fstab paths for normal boot and recovery boot, respectively |
| if (access("/system/bin/recovery", F_OK) == 0) { |
| default_fstab_path = "/etc/recovery.fstab"; |
| } else { // normal boot |
| default_fstab_path = GetFstabPath(); |
| } |
| |
| Fstab default_fstab; |
| if (!default_fstab_path.empty()) { |
| ReadFstabFromFile(default_fstab_path, &default_fstab); |
| } else { |
| LINFO << __FUNCTION__ << "(): failed to find device default fstab"; |
| } |
| |
| for (auto&& entry : default_fstab) { |
| fstab->emplace_back(std::move(entry)); |
| } |
| |
| return !fstab->empty(); |
| } |
| |
| FstabEntry* GetEntryForMountPoint(Fstab* fstab, const std::string& path) { |
| if (fstab == nullptr) { |
| return nullptr; |
| } |
| |
| for (auto& entry : *fstab) { |
| if (entry.mount_point == path) { |
| return &entry; |
| } |
| } |
| |
| return nullptr; |
| } |
| |
| std::vector<FstabEntry*> GetEntriesForMountPoint(Fstab* fstab, const std::string& path) { |
| std::vector<FstabEntry*> entries; |
| if (fstab == nullptr) { |
| return entries; |
| } |
| |
| for (auto& entry : *fstab) { |
| if (entry.mount_point == path) { |
| entries.emplace_back(&entry); |
| } |
| } |
| |
| return entries; |
| } |
| |
| std::set<std::string> GetBootDevices() { |
| // First check the kernel commandline, then try the device tree otherwise |
| std::string dt_file_name = get_android_dt_dir() + "/boot_devices"; |
| std::string value; |
| if (fs_mgr_get_boot_config_from_kernel_cmdline("boot_devices", &value) || |
| ReadDtFile(dt_file_name, &value)) { |
| auto boot_devices = Split(value, ","); |
| return std::set<std::string>(boot_devices.begin(), boot_devices.end()); |
| } |
| |
| std::string cmdline; |
| if (android::base::ReadFileToString("/proc/cmdline", &cmdline)) { |
| std::set<std::string> boot_devices; |
| const std::string cmdline_key = "androidboot.boot_device"; |
| for (const auto& [key, value] : fs_mgr_parse_boot_config(cmdline)) { |
| if (key == cmdline_key) { |
| boot_devices.emplace(value); |
| } |
| } |
| if (!boot_devices.empty()) { |
| return boot_devices; |
| } |
| } |
| |
| // Fallback to extract boot devices from fstab. |
| Fstab fstab; |
| if (!ReadDefaultFstab(&fstab)) { |
| return {}; |
| } |
| |
| return ExtraBootDevices(fstab); |
| } |
| |
| std::string GetVerityDeviceName(const FstabEntry& entry) { |
| std::string base_device; |
| if (entry.mount_point == "/") { |
| // When using system-as-root, the device name is fixed as "vroot". |
| if (entry.fs_mgr_flags.avb) { |
| return "vroot"; |
| } |
| base_device = "system"; |
| } else { |
| base_device = android::base::Basename(entry.mount_point); |
| } |
| return base_device + "-verity"; |
| } |
| |
| } // namespace fs_mgr |
| } // namespace android |
| |
| // FIXME: The same logic is duplicated in system/core/init/ |
| const std::string& get_android_dt_dir() { |
| // Set once and saves time for subsequent calls to this function |
| static const std::string kAndroidDtDir = android::fs_mgr::InitAndroidDtDir(); |
| return kAndroidDtDir; |
| } |
| |
| bool is_dt_compatible() { |
| std::string file_name = get_android_dt_dir() + "/compatible"; |
| std::string dt_value; |
| if (android::fs_mgr::ReadDtFile(file_name, &dt_value)) { |
| if (dt_value == "android,firmware") { |
| return true; |
| } |
| } |
| |
| return false; |
| } |