Merge "fs_mgr: overlayfs skip mount points that are more specific" (d2b29eb3) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_overlayfs.cpp

+32 −18

Original line number	Diff line number	Diff line
		@@ -360,6 +360,34 @@ bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point) {
		return false;
		}

		std::vector<std::string> fs_mgr_candidate_list(const fstab* fstab,
		const char* mount_point = nullptr) {
		std::vector<std::string> mounts;
		if (!fstab) return mounts;

		for (auto i = 0; i < fstab->num_entries; i++) {
		const auto fsrec = &fstab->recs[i];
		if (!fs_mgr_wants_overlayfs(fsrec)) continue;
		std::string new_mount_point(fs_mgr_mount_point(fstab, fsrec->mount_point));
		if (mount_point && (new_mount_point != mount_point)) continue;
		auto duplicate_or_more_specific = false;
		for (auto it = mounts.begin(); it != mounts.end();) {
		if ((*it == new_mount_point) \|\|
		(android::base::StartsWith(new_mount_point, *it + "/"))) {
		duplicate_or_more_specific = true;
		break;
		}
		if (android::base::StartsWith(*it, new_mount_point + "/")) {
		it = mounts.erase(it);
		} else {
		++it;
		}
		}
		if (!duplicate_or_more_specific) mounts.emplace_back(new_mount_point);
		}
		return mounts;
		}

		} // namespace

		bool fs_mgr_overlayfs_mount_all() {
		@@ -371,10 +399,7 @@ bool fs_mgr_overlayfs_mount_all() {
		fs_mgr_free_fstab);
		if (!fstab) return ret;

		for (auto i = 0; i < fstab->num_entries; i++) {
		const auto fsrec = &fstab->recs[i];
		if (!fs_mgr_wants_overlayfs(fsrec)) continue;
		std::string mount_point(fs_mgr_mount_point(fstab.get(), fsrec->mount_point));
		for (const auto& mount_point : fs_mgr_candidate_list(fstab.get())) {
		if (fs_mgr_overlayfs_already_mounted(mount_point)) continue;
		if (fs_mgr_overlayfs_mount(mount_point)) ret = true;
		}
		@@ -399,20 +424,9 @@ bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool*

		std::unique_ptr<struct fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
		fs_mgr_free_fstab);
		std::vector<std::string> mounts;
		mount_point = fs_mgr_mount_point(fstab.get(), mount_point);
		if (fstab) {
		if (!fs_mgr_get_entry_for_mount_point(fstab.get(), kOverlayMountPoint)) return ret;
		for (auto i = 0; i < fstab->num_entries; i++) {
		const auto fsrec = &fstab->recs[i];
		auto fsrec_mount_point = fs_mgr_mount_point(fstab.get(), fsrec->mount_point);
		if (!fsrec_mount_point) continue;
		if (mount_point && strcmp(fsrec_mount_point, mount_point)) continue;
		if (!fs_mgr_wants_overlayfs(fsrec)) continue;
		mounts.emplace_back(fsrec_mount_point);
		}
		if (mounts.empty()) return ret;
		}
		if (fstab && !fs_mgr_get_entry_for_mount_point(fstab.get(), kOverlayMountPoint)) return ret;
		auto mounts = fs_mgr_candidate_list(fstab.get(), fs_mgr_mount_point(fstab.get(), mount_point));
		if (fstab && mounts.empty()) return ret;

		auto overlay = kOverlayMountPoint + "/overlay/";
		auto save_errno = errno;