# SPDX-License-Identifier: GPL-2.0-only config EROFS_FS tristate "EROFS filesystem support" depends on BLOCK select LIBCRC32C help EROFS (Enhanced Read-Only File System) is a lightweight read-only file system with modern designs (eg. page-sized blocks, inline xattrs/data, etc.) for scenarios which need high-performance read-only requirements, e.g. Android OS for mobile phones and LIVECDs. It also provides fixed-sized output compression support, which improves storage density, keeps relatively higher compression ratios, which is more useful to achieve high performance for embedded devices with limited memory. If unsure, say N. config EROFS_FS_DEBUG bool "EROFS debugging feature" depends on EROFS_FS help Print debugging messages and enable more BUG_ONs which check filesystem consistency and find potential issues aggressively, which can be used for Android eng build, for example. For daily use, say N. config EROFS_FS_XATTR bool "EROFS extended attributes" depends on EROFS_FS default y help Extended attributes are name:value pairs associated with inodes by the kernel or by users (see the attr(5) manual page, or visit for details). If unsure, say N. config EROFS_FS_POSIX_ACL bool "EROFS Access Control Lists" depends on EROFS_FS_XATTR select FS_POSIX_ACL default y help Posix Access Control Lists (ACLs) support permissions for users and groups beyond the owner/group/world scheme. To learn more about Access Control Lists, visit the POSIX ACLs for Linux website . If you don't know what Access Control Lists are, say N. config EROFS_FS_SECURITY bool "EROFS Security Labels" depends on EROFS_FS_XATTR default y help Security labels provide an access control facility to support Linux Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO Linux. This option enables an extended attribute handler for file security labels in the erofs filesystem, so that it requires enabling the extended attribute support in advance. If you are not using a security module, say N. config EROFS_FS_ZIP bool "EROFS Data Compression Support" depends on EROFS_FS select LZ4_DECOMPRESS default y help Enable fixed-sized output compression for EROFS. If you don't want to enable compression feature, say N. config EROFS_FS_CLUSTER_PAGE_LIMIT int "EROFS Cluster Pages Hard Limit" depends on EROFS_FS_ZIP range 1 256 default "1" help Indicates maximum # of pages of a compressed physical cluster. For example, if files in a image were compressed into 8k-unit, hard limit should not be configured less than 2. Otherwise, the image will be refused to mount on this kernel.