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Commit 2e007e03 authored by David Anderson's avatar David Anderson Committed by Gerrit Code Review
Browse files

Merge changes I7a9e07a4,I3ddab553,I212bdb0e 

* changes:
  remount: Remove the "backing" parameter to fs_mgr_overlayfs_setup.
  remount: Prevent error spam when remounting fails.
  remount: Move more stuff out of do_remount.
parents 693ac06a e9e3f6e0

fs_mgr/fs_mgr_overlayfs.cpp

+39 −26
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ bool fs_mgr_overlayfs_mount_all(Fstab*) { 
    return false;

}



bool fs_mgr_overlayfs_setup(const char*, const char*, bool* change, bool) {

bool fs_mgr_overlayfs_setup(const char*, bool* change, bool) {

    if (change) *change = false;

    return false;

}
@@ -370,28 +370,6 @@ bool fs_mgr_rw_access(const std::string& path) { 
    return ret;

}



bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only = true) {

    Fstab fstab;

    auto save_errno = errno;

    if (!ReadFstabFromFile("/proc/mounts", &fstab)) {

        return false;

    }

    errno = save_errno;

    const auto lowerdir = kLowerdirOption + mount_point;

    for (const auto& entry : fstab) {

        if (overlay_only && "overlay" != entry.fs_type && "overlayfs" != entry.fs_type) continue;

        if (mount_point != entry.mount_point) continue;

        if (!overlay_only) return true;

        const auto options = android::base::Split(entry.fs_options, ",");

        for (const auto& opt : options) {

            if (opt == lowerdir) {

                return true;

            }

        }

    }

    return false;

}



constexpr char kOverlayfsFileContext[] = "u:object_r:overlayfs_file:s0";



bool fs_mgr_overlayfs_setup_dir(const std::string& dir, std::string* overlay, bool* change) {
@@ -1290,8 +1268,23 @@ bool fs_mgr_wants_overlayfs(FstabEntry* entry) { 
}



Fstab fs_mgr_overlayfs_candidate_list(const Fstab& fstab) {

    android::fs_mgr::Fstab mounts;

    if (!android::fs_mgr::ReadFstabFromFile("/proc/mounts", &mounts)) {

        PLOG(ERROR) << "Failed to read /proc/mounts";

        return {};

    }



    Fstab candidates;

    for (const auto& entry : fstab) {

        // Filter out partitions whose type doesn't match what's mounted.

        // This avoids spammy behavior on devices which can mount different

        // filesystems for each partition.

        auto proc_mount_point = (entry.mount_point == "/system") ? "/" : entry.mount_point;

        auto mounted = GetEntryForMountPoint(&mounts, proc_mount_point);

        if (!mounted || mounted->fs_type != entry.fs_type) {

            continue;

        }



        FstabEntry new_entry = entry;

        if (!fs_mgr_overlayfs_already_mounted(entry.mount_point) &&

            !fs_mgr_wants_overlayfs(&new_entry)) {
@@ -1364,8 +1357,7 @@ bool fs_mgr_overlayfs_mount_all(Fstab* fstab) { 


// Returns false if setup not permitted, errno set to last error.

// If something is altered, set *change.

bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool* change,

                            bool force) {

bool fs_mgr_overlayfs_setup(const char* mount_point, bool* change, bool force) {

    if (change) *change = false;

    auto ret = false;

    if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) return ret;
@@ -1402,7 +1394,6 @@ bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool* 


    std::string dir;

    for (const auto& overlay_mount_point : OverlayMountPoints()) {

        if (backing && backing[0] && (overlay_mount_point != backing)) continue;

        if (overlay_mount_point == kScratchMountPoint) {

            if (!fs_mgr_overlayfs_setup_scratch(fstab, change)) continue;

        } else {
@@ -1698,6 +1689,28 @@ void TeardownAllOverlayForMountPoint(const std::string& mount_point) { 


#endif  // ALLOW_ADBD_DISABLE_VERITY != 0



bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only) {

    Fstab fstab;

    auto save_errno = errno;

    if (!ReadFstabFromFile("/proc/mounts", &fstab)) {

        return false;

    }

    errno = save_errno;

    const auto lowerdir = kLowerdirOption + mount_point;

    for (const auto& entry : fstab) {

        if (overlay_only && "overlay" != entry.fs_type && "overlayfs" != entry.fs_type) continue;

        if (mount_point != entry.mount_point) continue;

        if (!overlay_only) return true;

        const auto options = android::base::Split(entry.fs_options, ",");

        for (const auto& opt : options) {

            if (opt == lowerdir) {

                return true;

            }

        }

    }

    return false;

}



bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev) {

    struct statfs fs;

    if ((statfs((mount_point + "/lost+found").c_str(), &fs) == -1) ||

fs_mgr/fs_mgr_remount.cpp

+114 −102
Original line number Diff line number Diff line
@@ -91,12 +91,8 @@ void MyLogger(android::base::LogId id, android::base::LogSeverity severity, cons 
    logd(id, severity, tag, file, line, message);

}



[[noreturn]] void reboot(bool overlayfs = false) {

    if (overlayfs) {

        LOG(INFO) << "Successfully setup overlayfs\nrebooting device";

    } else {

        LOG(INFO) << "Successfully disabled verity\nrebooting device";

    }

[[noreturn]] void reboot() {

    LOG(INFO) << "Rebooting device for new settings to take effect";

    ::sync();

    android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot,remount");

    ::sleep(60);
@@ -136,7 +132,6 @@ enum RemountStatus { 
    BINDER_ERROR,

    CHECKPOINTING,

    GSID_ERROR,

    CLEAN_SCRATCH_FILES,

};



static bool ReadFstab(const char* fstab_file, android::fs_mgr::Fstab* fstab) {
@@ -191,8 +186,8 @@ static bool IsRemountable(Fstab& candidates, const FstabEntry& entry) { 
    if (entry.fs_type == "vfat") {

        return false;

    }

    if (GetEntryForMountPoint(&candidates, entry.mount_point)) {

        return true;

    if (auto candidate_entry = GetEntryForMountPoint(&candidates, entry.mount_point)) {

        return candidate_entry->fs_type == entry.fs_type;

    }

    if (GetWrappedEntry(candidates, entry)) {

        return false;
@@ -201,13 +196,22 @@ static bool IsRemountable(Fstab& candidates, const FstabEntry& entry) { 
}



static Fstab::const_iterator FindPartition(const Fstab& fstab, const std::string& partition) {

    Fstab mounts;

    if (!android::fs_mgr::ReadFstabFromFile("/proc/mounts", &mounts)) {

        LOG(ERROR) << "Failed to read /proc/mounts";

        return fstab.end();

    }



    for (auto iter = fstab.begin(); iter != fstab.end(); iter++) {

        const auto mount_point = system_mount_point(*iter);

        if (partition == mount_point) {

        if (partition == mount_point || partition == android::base::Basename(mount_point)) {

            // In case fstab has multiple entries, pick the one that matches the

            // actual mounted filesystem type.

            auto proc_mount_point = (iter->mount_point == "/system") ? "/" : iter->mount_point;

            auto mounted = GetEntryForMountPoint(&mounts, proc_mount_point);

            if (mounted && mounted->fs_type == iter->fs_type) {

                return iter;

            }

        if (partition == android::base::Basename(mount_point)) {

            return iter;

        }

    }

    return fstab.end();
@@ -248,7 +252,10 @@ static RemountStatus GetRemountList(const Fstab& fstab, const std::vector<std::s 
            entry = wrap;

        }



        if (!IsRemountable(candidates, *entry)) {

        // If it's already remounted, include it so it gets gracefully skipped

        // later on.

        if (!fs_mgr_overlayfs_already_mounted(entry->mount_point) &&

            !IsRemountable(candidates, *entry)) {

            LOG(ERROR) << "Invalid partition " << arg;

            return INVALID_PARTITION;

        }
@@ -266,6 +273,7 @@ struct RemountCheckResult { 
    bool setup_overlayfs = false;

    bool disabled_verity = false;

    bool verity_error = false;

    bool remounted_anything = false;

};



static RemountStatus CheckVerity(const FstabEntry& entry, RemountCheckResult* result) {
@@ -312,7 +320,7 @@ static RemountStatus CheckVerityAndOverlayfs(Fstab* partitions, RemountCheckResu 
        if (fs_mgr_wants_overlayfs(&entry)) {

            bool change = false;

            bool force = result->disabled_verity;

            if (!fs_mgr_overlayfs_setup(nullptr, mount_point.c_str(), &change, force)) {

            if (!fs_mgr_overlayfs_setup(mount_point.c_str(), &change, force)) {

                LOG(ERROR) << "Overlayfs setup for " << mount_point << " failed, skipping";

                status = BAD_OVERLAY;

                it = partitions->erase(it);
@@ -422,7 +430,69 @@ static RemountStatus RemountPartition(Fstab& fstab, Fstab& mounts, FstabEntry& e 
    return REMOUNT_FAILED;

}



static int do_remount(int argc, char* argv[]) {

static int do_remount(Fstab& fstab, const std::vector<std::string>& partition_args,

                      RemountCheckResult* check_result) {

    Fstab partitions;

    if (partition_args.empty()) {

        partitions = GetAllRemountablePartitions(fstab);

    } else {

        if (auto rv = GetRemountList(fstab, partition_args, &partitions); rv != REMOUNT_SUCCESS) {

            return rv;

        }

    }



    // Check verity and optionally setup overlayfs backing.

    auto retval = CheckVerityAndOverlayfs(&partitions, check_result);



    if (partitions.empty() || check_result->disabled_verity) {

        if (partitions.empty()) {

            LOG(WARNING) << "No remountable partitions were found.";

        }

        return retval;

    }



    // Mount overlayfs.

    errno = 0;

    if (!fs_mgr_overlayfs_mount_all(&partitions) && errno) {

        PLOG(ERROR) << "Can not mount overlayfs for partitions";

        return BAD_OVERLAY;

    }



    // Get actual mounts _after_ overlayfs has been added.

    android::fs_mgr::Fstab mounts;

    if (!android::fs_mgr::ReadFstabFromFile("/proc/mounts", &mounts) || mounts.empty()) {

        PLOG(ERROR) << "Failed to read /proc/mounts";

        return NO_MOUNTS;

    }



    // Remount selected partitions.

    for (auto& entry : partitions) {

        if (auto rv = RemountPartition(fstab, mounts, entry); rv != REMOUNT_SUCCESS) {

            retval = rv;

        } else {

            check_result->remounted_anything = true;

        }

    }

    return retval;

}



static int do_clean_scratch_files() {

    android::fs_mgr::CleanupOldScratchFiles();

    return 0;

}



int main(int argc, char* argv[]) {

    android::base::InitLogging(argv, MyLogger);

    if (argc > 0 && android::base::Basename(argv[0]) == "clean_scratch_files"s) {

        return do_clean_scratch_files();

    }



    // Make sure we are root.

    if (::getuid() != 0) {

        LOG(ERROR) << "Not running as root. Try \"adb root\" first.";

        return NOT_ROOT;

    }



    // If somehow this executable is delivered on a "user" build, it can

    // not function, so providing a clear message to the caller rather than

    // letting if fall through and provide a lot of confusing failure messages.
@@ -432,7 +502,7 @@ static int do_remount(int argc, char* argv[]) { 
    }



    const char* fstab_file = nullptr;

    auto can_reboot = false;

    auto auto_reboot = false;

    std::vector<std::string> partition_args;



    struct option longopts[] = {
@@ -449,7 +519,7 @@ static int do_remount(int argc, char* argv[]) { 
                usage(SUCCESS);

                break;

            case 'R':

                can_reboot = true;

                auto_reboot = true;

                break;

            case 'T':

                if (fstab_file) {
@@ -462,7 +532,7 @@ static int do_remount(int argc, char* argv[]) { 
                verbose = true;

                break;

            case 'C':

                return CLEAN_SCRATCH_FILES;

                return do_clean_scratch_files();

            default:

                LOG(ERROR) << "Bad Argument -" << char(opt);

                usage(BADARG);
@@ -474,10 +544,9 @@ static int do_remount(int argc, char* argv[]) { 
        partition_args.emplace_back(argv[optind]);

    }



    // Make sure we are root.

    if (::getuid() != 0) {

        LOG(ERROR) << "Not running as root. Try \"adb root\" first.";

        return NOT_ROOT;

    // Make sure checkpointing is disabled if necessary.

    if (auto rv = VerifyCheckpointing(); rv != REMOUNT_SUCCESS) {

        return rv;

    }



    // Read the selected fstab.
@@ -487,92 +556,35 @@ static int do_remount(int argc, char* argv[]) { 
        return NO_FSTAB;

    }



    if (auto rv = VerifyCheckpointing(); rv != REMOUNT_SUCCESS) {

        return rv;

    }



    Fstab partitions;

    if (partition_args.empty()) {

        partitions = GetAllRemountablePartitions(fstab);

    } else {

        if (auto rv = GetRemountList(fstab, partition_args, &partitions); rv != REMOUNT_SUCCESS) {

            return rv;

        }

    }



    // Check verity and optionally setup overlayfs backing.

    RemountCheckResult check_result;

    auto retval = CheckVerityAndOverlayfs(&partitions, &check_result);

    int result = do_remount(fstab, partition_args, &check_result);



    bool auto_reboot = check_result.reboot_later && can_reboot;

    if (check_result.disabled_verity && check_result.setup_overlayfs) {

        LOG(INFO) << "Verity disabled; overlayfs enabled.";

    } else if (check_result.disabled_verity) {

        LOG(INFO) << "Verity disabled.";

    } else if (check_result.setup_overlayfs) {

        LOG(INFO) << "Overlayfs enabled.";

    }



    if (check_result.reboot_later) {

        if (auto_reboot) {

            // If (1) remount requires a reboot to take effect, (2) system is currently

            // running a DSU guest and (3) DSU is disabled, then enable DSU so that the

            // next reboot would not take us back to the host system but stay within

            // the guest system.

    if (auto_reboot) {

            if (auto rv = EnableDsuIfNeeded(); rv != REMOUNT_SUCCESS) {

                LOG(ERROR) << "Unable to automatically enable DSU";

                return rv;

            }

    }



    if (partitions.empty() || check_result.disabled_verity) {

        if (auto_reboot) {

            reboot(check_result.setup_overlayfs);

        }

        if (check_result.reboot_later) {

            return MUST_REBOOT;

        }

        LOG(WARNING) << "No partitions to remount";

        return retval;

    }



    // Mount overlayfs.

    errno = 0;

    if (!fs_mgr_overlayfs_mount_all(&partitions) && errno) {

        PLOG(ERROR) << "Can not mount overlayfs for partitions";

        return BAD_OVERLAY;

    }



    // Get actual mounts _after_ overlayfs has been added.

    android::fs_mgr::Fstab mounts;

    if (!android::fs_mgr::ReadFstabFromFile("/proc/mounts", &mounts) || mounts.empty()) {

        PLOG(ERROR) << "Failed to read /proc/mounts";

        return NO_MOUNTS;

    }



    // Remount selected partitions.

    for (auto& entry : partitions) {

        if (auto rv = RemountPartition(fstab, mounts, entry); rv != REMOUNT_SUCCESS) {

            retval = rv;

        }

    }



    if (auto_reboot) reboot(check_result.setup_overlayfs);

    if (check_result.reboot_later) {

            reboot();

        } else {

            LOG(INFO) << "Now reboot your device for settings to take effect";

        }

    return retval;

}



static int do_clean_scratch_files() {

    android::fs_mgr::CleanupOldScratchFiles();

    return 0;

}



int main(int argc, char* argv[]) {

    android::base::InitLogging(argv, MyLogger);

    if (argc > 0 && android::base::Basename(argv[0]) == "clean_scratch_files"s) {

        return do_clean_scratch_files();

        return MUST_REBOOT;

    }

    int result = do_remount(argc, argv);

    if (result == MUST_REBOOT) {

        LOG(INFO) << "Now reboot your device for settings to take effect";

        result = 0;

    } else if (result == REMOUNT_SUCCESS) {

    if (result == REMOUNT_SUCCESS) {

        printf("remount succeeded\n");

    } else if (result == CLEAN_SCRATCH_FILES) {

        return do_clean_scratch_files();

    } else {

        printf("remount failed\n");

    }

fs_mgr/include/fs_mgr_overlayfs.h

+3 −2
Original line number Diff line number Diff line
@@ -28,11 +28,12 @@ android::fs_mgr::Fstab fs_mgr_overlayfs_candidate_list(const android::fs_mgr::Fs 


bool fs_mgr_wants_overlayfs(android::fs_mgr::FstabEntry* entry);

bool fs_mgr_overlayfs_mount_all(android::fs_mgr::Fstab* fstab);

bool fs_mgr_overlayfs_setup(const char* backing = nullptr, const char* mount_point = nullptr,

                            bool* change = nullptr, bool force = true);

bool fs_mgr_overlayfs_setup(const char* mount_point = nullptr, bool* change = nullptr,

                            bool force = true);

bool fs_mgr_overlayfs_teardown(const char* mount_point = nullptr, bool* change = nullptr);

bool fs_mgr_overlayfs_is_setup();

bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev);

bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only = true);

std::string fs_mgr_get_context(const std::string& mount_point);



enum class OverlayfsValidResult {

set-verity-state/set-verity-state.cpp

+1 −1
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ bool overlayfs_setup(bool enable) { 
  auto change = false;

  errno = 0;

  if (enable ? fs_mgr_overlayfs_teardown(nullptr, &change)

             : fs_mgr_overlayfs_setup(nullptr, nullptr, &change)) {

             : fs_mgr_overlayfs_setup(nullptr, &change)) {

    if (change) {

      LOG(INFO) << (enable ? "disabling" : "using") << " overlayfs";

    }