Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
1# SPDX-License-Identifier: GPL-2.0-only
2config EXT4_FS
3 tristate "The Extended 4 (ext4) filesystem"
4 select BUFFER_HEAD
5 select JBD2
6 select CRC16
7 select CRC32
8 select FS_IOMAP
9 select FS_ENCRYPTION_ALGS if FS_ENCRYPTION
10 help
11 This is the next generation of the ext3 filesystem.
12
13 Unlike the change from ext2 filesystem to ext3 filesystem,
14 the on-disk format of ext4 is not forwards compatible with
15 ext3; it is based on extent maps and it supports 48-bit
16 physical block numbers. The ext4 filesystem also supports delayed
17 allocation, persistent preallocation, high resolution time stamps,
18 and a number of other features to improve performance and speed
19 up fsck time. For more information, please see the web pages at
20 http://ext4.wiki.kernel.org.
21
22 The ext4 filesystem supports mounting an ext3 filesystem; while there
23 are some performance gains from the delayed allocation and inode
24 table readahead, the best performance gains require enabling ext4
25 features in the filesystem using tune2fs, or formatting a new
26 filesystem as an ext4 filesystem initially. Without explicit enabling
27 of ext4 features, the on disk filesystem format stays fully backward
28 compatible.
29
30 To compile this file system support as a module, choose M here. The
31 module will be called ext4.
32
33 If unsure, say N.
34
35config EXT4_USE_FOR_EXT2
36 bool "Use ext4 for ext2 file systems"
37 depends on EXT4_FS
38 depends on EXT2_FS=n
39 default y
40 help
41 Allow the ext4 file system driver code to be used for ext2
42 file system mounts. This allows users to reduce their
43 compiled kernel size by using one file system driver for
44 ext2, ext3, and ext4 file systems.
45
46config EXT4_FS_POSIX_ACL
47 bool "Ext4 POSIX Access Control Lists"
48 depends on EXT4_FS
49 select FS_POSIX_ACL
50 help
51 POSIX Access Control Lists (ACLs) support permissions for users and
52 groups beyond the owner/group/world scheme.
53
54 If you don't know what Access Control Lists are, say N
55
56config EXT4_FS_SECURITY
57 bool "Ext4 Security Labels"
58 depends on EXT4_FS
59 help
60 Security labels support alternative access control models
61 implemented by security modules like SELinux. This option
62 enables an extended attribute handler for file security
63 labels in the ext4 filesystem.
64
65 If you are not using a security module that requires using
66 extended attributes for file security labels, say N.
67
68config EXT4_DEBUG
69 bool "Ext4 debugging support"
70 depends on EXT4_FS
71 help
72 Enables run-time debugging support for the ext4 filesystem.
73
74 If you select Y here, then you will be able to turn on debugging
75 using dynamic debug control for mb_debug() / ext_debug() msgs.
76
77config EXT4_KUNIT_TESTS
78 tristate "KUnit tests for ext4" if !KUNIT_ALL_TESTS
79 depends on EXT4_FS && KUNIT
80 default KUNIT_ALL_TESTS
81 help
82 This builds the ext4 KUnit tests.
83
84 KUnit tests run during boot and output the results to the debug log
85 in TAP format (https://testanything.org/). Only useful for kernel devs
86 running KUnit test harness and are not for inclusion into a production
87 build.
88
89 For more information on KUnit and unit tests in general please refer
90 to the KUnit documentation in Documentation/dev-tools/kunit/.
91
92 If unsure, say N.