xref: /openbmc/linux/fs/ext4/Kconfig (revision ba61bb17)
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	select FS_IOMAP
41	help
42	  This is the next generation of the ext3 filesystem.
43
44	  Unlike the change from ext2 filesystem to ext3 filesystem,
45	  the on-disk format of ext4 is not forwards compatible with
46	  ext3; it is based on extent maps and it supports 48-bit
47	  physical block numbers.  The ext4 filesystem also supports delayed
48	  allocation, persistent preallocation, high resolution time stamps,
49	  and a number of other features to improve performance and speed
50	  up fsck time.  For more information, please see the web pages at
51	  http://ext4.wiki.kernel.org.
52
53	  The ext4 filesystem supports mounting an ext3 filesystem; while there
54	  are some performance gains from the delayed allocation and inode
55	  table readahead, the best performance gains require enabling ext4
56	  features in the filesystem using tune2fs, or formatting a new
57	  filesystem as an ext4 filesystem initially. Without explicit enabling
58	  of ext4 features, the on disk filesystem format stays fully backward
59	  compatible.
60
61	  To compile this file system support as a module, choose M here. The
62	  module will be called ext4.
63
64	  If unsure, say N.
65
66config EXT4_USE_FOR_EXT2
67	bool "Use ext4 for ext2 file systems"
68	depends on EXT4_FS
69	depends on EXT2_FS=n
70	default y
71	help
72	  Allow the ext4 file system driver code to be used for ext2
73	  file system mounts.  This allows users to reduce their
74	  compiled kernel size by using one file system driver for
75	  ext2, ext3, and ext4 file systems.
76
77config EXT4_FS_POSIX_ACL
78	bool "Ext4 POSIX Access Control Lists"
79	depends on EXT4_FS
80	select FS_POSIX_ACL
81	help
82	  POSIX Access Control Lists (ACLs) support permissions for users and
83	  groups beyond the owner/group/world scheme.
84
85	  If you don't know what Access Control Lists are, say N
86
87config EXT4_FS_SECURITY
88	bool "Ext4 Security Labels"
89	depends on EXT4_FS
90	help
91	  Security labels support alternative access control models
92	  implemented by security modules like SELinux.  This option
93	  enables an extended attribute handler for file security
94	  labels in the ext4 filesystem.
95
96	  If you are not using a security module that requires using
97	  extended attributes for file security labels, say N.
98
99config EXT4_ENCRYPTION
100	bool "Ext4 Encryption"
101	depends on EXT4_FS
102	select FS_ENCRYPTION
103	help
104	  Enable encryption of ext4 files and directories.  This
105	  feature is similar to ecryptfs, but it is more memory
106	  efficient since it avoids caching the encrypted and
107	  decrypted pages in the page cache.
108
109config EXT4_FS_ENCRYPTION
110	bool
111	default y
112	depends on EXT4_ENCRYPTION
113
114config EXT4_DEBUG
115	bool "EXT4 debugging support"
116	depends on EXT4_FS
117	help
118	  Enables run-time debugging support for the ext4 filesystem.
119
120	  If you select Y here, then you will be able to turn on debugging
121	  with a command such as:
122		echo 1 > /sys/module/ext4/parameters/mballoc_debug
123