Merge "Remove logic to fake /system in overlayfs" (d2ae1c91) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_overlayfs.cpp

+0 −20

Original line number	Diff line number	Diff line
		@@ -565,26 +565,6 @@ std::vector<std::string> fs_mgr_candidate_list(Fstab* fstab, const char* mount_p
		if (!duplicate_or_more_specific) mounts.emplace_back(new_mount_point);
		}

		// if not itemized /system or /, system as root, fake one up?

		// do we want or need to?
		if (mount_point && ("/system"s != mount_point)) return mounts;
		if (std::find(mounts.begin(), mounts.end(), "/system") != mounts.end()) return mounts;

		// fs_mgr_overlayfs_verity_enabled_list says not to?
		if (std::find(verity.begin(), verity.end(), "system") != verity.end()) return mounts;

		// confirm that fstab is missing system
		if (GetEntryForMountPoint(fstab, "/") != nullptr \|\|
		GetEntryForMountPoint(fstab, "/system") != nullptr) {
		return mounts;
		}

		// We have a stunted fstab (w/o system or / ) passed in by the caller,
		// verity claims are assumed accurate because they are collected internally
		// from fs_mgr_fstab_default() from within fs_mgr_update_verity_state(),
		// Can (re)evaluate /system with impunity since we know it is ever-present.
		mounts.emplace_back("/system");
		return mounts;
		}

init/first_stage_mount.cpp

+47 −1

Original line number	Diff line number	Diff line
		@@ -157,6 +157,37 @@ static Fstab ReadFirstStageFstab() {
		return fstab;
		}

		static bool GetRootEntry(FstabEntry* root_entry) {
		Fstab proc_mounts;
		if (!ReadFstabFromFile("/proc/mounts", &proc_mounts)) {
		LOG(ERROR) << "Could not read /proc/mounts and /system not in fstab, /system will not be "
		"available for overlayfs";
		return false;
		}

		auto entry = std::find_if(proc_mounts.begin(), proc_mounts.end(), [](const auto& entry) {
		return entry.mount_point == "/" && entry.fs_type != "rootfs";
		});

		if (entry == proc_mounts.end()) {
		LOG(ERROR) << "Could not get mount point for '/' in /proc/mounts, /system will not be "
		"available for overlayfs";
		return false;
		}

		root_entry = std::move(entry);

		// We don't know if we're avb or not, so we query device mapper as if we are avb. If we get a
		// success, then mark as avb, otherwise default to verify.
		auto& dm = android::dm::DeviceMapper::Instance();
		if (dm.GetState("vroot") != android::dm::DmDeviceState::INVALID) {
		root_entry->fs_mgr_flags.avb = true;
		} else {
		root_entry->fs_mgr_flags.verify = true;
		}
		return true;
		}

		// Class Definitions
		// -----------------
		FirstStageMount::FirstStageMount(Fstab fstab)
		@@ -443,7 +474,7 @@ bool FirstStageMount::TrySwitchSystemAsRoot() {

		if (system_partition == fstab_.end()) return true;

		if (MountPartition(system_partition, true /* erase_used_fstab_entry */)) {
		if (MountPartition(system_partition, false)) {
		SwitchRoot("/system");
		} else {
		PLOG(ERROR) << "Failed to mount /system";
		@@ -487,6 +518,12 @@ bool FirstStageMount::MountPartitions() {
		if (!TrySkipMountingPartitions()) return false;

		for (auto current = fstab_.begin(); current != fstab_.end();) {
		// We've already mounted /system above.
		if (current->mount_point == "/system") {
		++current;
		continue;
		}

		Fstab::iterator end;
		if (!MountPartition(current, false, &end)) {
		if (current->fs_mgr_flags.no_fail) {
		@@ -503,6 +540,15 @@ bool FirstStageMount::MountPartitions() {
		current = end;
		}

		// If we don't see /system or / in the fstab, then we need to create an root entry for
		// overlayfs.
		if (!GetEntryForMountPoint(&fstab_, "/system") && !GetEntryForMountPoint(&fstab_, "/")) {
		FstabEntry root_entry;
		if (GetRootEntry(&root_entry)) {
		fstab_.emplace_back(std::move(root_entry));
		}
		}

		// heads up for instantiating required device(s) for overlayfs logic
		const auto devices = fs_mgr_overlayfs_required_devices(&fstab_);
		for (auto const& device : devices) {