1# SPDX-License-Identifier: GPL-2.0-only 2# Ext3 configs are here for backward compatibility with old configs which may 3# have EXT3_FS set but not EXT4_FS set and thus would result in non-bootable 4# kernels after the removal of ext3 driver. 5config EXT3_FS 6 tristate "The Extended 3 (ext3) filesystem" 7 select EXT4_FS 8 help 9 This config option is here only for backward compatibility. ext3 10 filesystem is now handled by the ext4 driver. 11 12config EXT3_FS_POSIX_ACL 13 bool "Ext3 POSIX Access Control Lists" 14 depends on EXT3_FS 15 select EXT4_FS_POSIX_ACL 16 select FS_POSIX_ACL 17 help 18 This config option is here only for backward compatibility. ext3 19 filesystem is now handled by the ext4 driver. 20 21config EXT3_FS_SECURITY 22 bool "Ext3 Security Labels" 23 depends on EXT3_FS 24 select EXT4_FS_SECURITY 25 help 26 This config option is here only for backward compatibility. ext3 27 filesystem is now handled by the ext4 driver. 28 29config EXT4_FS 30 tristate "The Extended 4 (ext4) filesystem" 31 select JBD2 32 select CRC16 33 select CRYPTO 34 select CRYPTO_CRC32C 35 select FS_IOMAP 36 help 37 This is the next generation of the ext3 filesystem. 38 39 Unlike the change from ext2 filesystem to ext3 filesystem, 40 the on-disk format of ext4 is not forwards compatible with 41 ext3; it is based on extent maps and it supports 48-bit 42 physical block numbers. The ext4 filesystem also supports delayed 43 allocation, persistent preallocation, high resolution time stamps, 44 and a number of other features to improve performance and speed 45 up fsck time. For more information, please see the web pages at 46 http://ext4.wiki.kernel.org. 47 48 The ext4 filesystem supports mounting an ext3 filesystem; while there 49 are some performance gains from the delayed allocation and inode 50 table readahead, the best performance gains require enabling ext4 51 features in the filesystem using tune2fs, or formatting a new 52 filesystem as an ext4 filesystem initially. Without explicit enabling 53 of ext4 features, the on disk filesystem format stays fully backward 54 compatible. 55 56 To compile this file system support as a module, choose M here. The 57 module will be called ext4. 58 59 If unsure, say N. 60 61config EXT4_USE_FOR_EXT2 62 bool "Use ext4 for ext2 file systems" 63 depends on EXT4_FS 64 depends on EXT2_FS=n 65 default y 66 help 67 Allow the ext4 file system driver code to be used for ext2 68 file system mounts. This allows users to reduce their 69 compiled kernel size by using one file system driver for 70 ext2, ext3, and ext4 file systems. 71 72config EXT4_FS_POSIX_ACL 73 bool "Ext4 POSIX Access Control Lists" 74 depends on EXT4_FS 75 select FS_POSIX_ACL 76 help 77 POSIX Access Control Lists (ACLs) support permissions for users and 78 groups beyond the owner/group/world scheme. 79 80 If you don't know what Access Control Lists are, say N 81 82config EXT4_FS_SECURITY 83 bool "Ext4 Security Labels" 84 depends on EXT4_FS 85 help 86 Security labels support alternative access control models 87 implemented by security modules like SELinux. This option 88 enables an extended attribute handler for file security 89 labels in the ext4 filesystem. 90 91 If you are not using a security module that requires using 92 extended attributes for file security labels, say N. 93 94config EXT4_DEBUG 95 bool "Ext4 debugging support" 96 depends on EXT4_FS 97 help 98 Enables run-time debugging support for the ext4 filesystem. 99 100 If you select Y here, then you will be able to turn on debugging 101 with a command such as: 102 echo 1 > /sys/module/ext4/parameters/mballoc_debug 103 104config EXT4_KUNIT_TESTS 105 bool "KUnit tests for ext4" 106 select EXT4_FS 107 depends on KUNIT 108 help 109 This builds the ext4 KUnit tests. 110 111 KUnit tests run during boot and output the results to the debug log 112 in TAP format (http://testanything.org/). Only useful for kernel devs 113 running KUnit test harness and are not for inclusion into a production 114 build. 115 116 For more information on KUnit and unit tests in general please refer 117 to the KUnit documentation in Documentation/dev-tools/kunit/. 118 119 If unsure, say N. 120