xref: /linux/fs/ext4/Kconfig (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
1# Ext3 configs are here for backward compatibility with old configs which may
2# have EXT3_FS set but not EXT4_FS set and thus would result in non-bootable
3# kernels after the removal of ext3 driver.
4config EXT3_FS
5	tristate "The Extended 3 (ext3) filesystem"
6	# These must match EXT4_FS selects...
7	select EXT4_FS
8	select JBD2
9	select CRC16
10	select CRYPTO
11	select CRYPTO_CRC32C
12	help
13	  This config option is here only for backward compatibility. ext3
14	  filesystem is now handled by the ext4 driver.
15
16config EXT3_FS_POSIX_ACL
17	bool "Ext3 POSIX Access Control Lists"
18	depends on EXT3_FS
19	select EXT4_FS_POSIX_ACL
20	select FS_POSIX_ACL
21	help
22	  This config option is here only for backward compatibility. ext3
23	  filesystem is now handled by the ext4 driver.
24
25config EXT3_FS_SECURITY
26	bool "Ext3 Security Labels"
27	depends on EXT3_FS
28	select EXT4_FS_SECURITY
29	help
30	  This config option is here only for backward compatibility. ext3
31	  filesystem is now handled by the ext4 driver.
32
33config EXT4_FS
34	tristate "The Extended 4 (ext4) filesystem"
35	# Please update EXT3_FS selects when changing these
36	select JBD2
37	select CRC16
38	select CRYPTO
39	select CRYPTO_CRC32C
40	help
41	  This is the next generation of the ext3 filesystem.
42
43	  Unlike the change from ext2 filesystem to ext3 filesystem,
44	  the on-disk format of ext4 is not forwards compatible with
45	  ext3; it is based on extent maps and it supports 48-bit
46	  physical block numbers.  The ext4 filesystem also supports delayed
47	  allocation, persistent preallocation, high resolution time stamps,
48	  and a number of other features to improve performance and speed
49	  up fsck time.  For more information, please see the web pages at
50	  http://ext4.wiki.kernel.org.
51
52	  The ext4 filesystem supports mounting an ext3 filesystem; while there
53	  are some performance gains from the delayed allocation and inode
54	  table readahead, the best performance gains require enabling ext4
55	  features in the filesystem using tune2fs, or formatting a new
56	  filesystem as an ext4 filesystem initially. Without explicit enabling
57	  of ext4 features, the on disk filesystem format stays fully backward
58	  compatible.
59
60	  To compile this file system support as a module, choose M here. The
61	  module will be called ext4.
62
63	  If unsure, say N.
64
65config EXT4_USE_FOR_EXT2
66	bool "Use ext4 for ext2 file systems"
67	depends on EXT4_FS
68	depends on EXT2_FS=n
69	default y
70	help
71	  Allow the ext4 file system driver code to be used for ext2
72	  file system mounts.  This allows users to reduce their
73	  compiled kernel size by using one file system driver for
74	  ext2, ext3, and ext4 file systems.
75
76config EXT4_FS_POSIX_ACL
77	bool "Ext4 POSIX Access Control Lists"
78	depends on EXT4_FS
79	select FS_POSIX_ACL
80	help
81	  POSIX Access Control Lists (ACLs) support permissions for users and
82	  groups beyond the owner/group/world scheme.
83
84	  To learn more about Access Control Lists, visit the POSIX ACLs for
85	  Linux website <http://acl.bestbits.at/>.
86
87	  If you don't know what Access Control Lists are, say N
88
89config EXT4_FS_SECURITY
90	bool "Ext4 Security Labels"
91	depends on EXT4_FS
92	help
93	  Security labels support alternative access control models
94	  implemented by security modules like SELinux.  This option
95	  enables an extended attribute handler for file security
96	  labels in the ext4 filesystem.
97
98	  If you are not using a security module that requires using
99	  extended attributes for file security labels, say N.
100
101config EXT4_ENCRYPTION
102	tristate "Ext4 Encryption"
103	depends on EXT4_FS
104	select CRYPTO_AES
105	select CRYPTO_CBC
106	select CRYPTO_ECB
107	select CRYPTO_XTS
108	select CRYPTO_CTS
109	select CRYPTO_CTR
110	select CRYPTO_SHA256
111	select KEYS
112	select ENCRYPTED_KEYS
113	help
114	  Enable encryption of ext4 files and directories.  This
115	  feature is similar to ecryptfs, but it is more memory
116	  efficient since it avoids caching the encrypted and
117	  decrypted pages in the page cache.
118
119config EXT4_FS_ENCRYPTION
120	bool
121	default y
122	depends on EXT4_ENCRYPTION
123
124config EXT4_DEBUG
125	bool "EXT4 debugging support"
126	depends on EXT4_FS
127	help
128	  Enables run-time debugging support for the ext4 filesystem.
129
130	  If you select Y here, then you will be able to turn on debugging
131	  with a command such as:
132		echo 1 > /sys/module/ext4/parameters/mballoc_debug
133