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Alexey Dobriyan6da0b382008-10-20 22:28:45 +04001config EXT4_FS
2 tristate "The Extended 4 (ext4) filesystem"
3 select JBD2
4 select CRC16
Darrick J. Wong04419842012-04-29 18:27:10 -04005 select CRYPTO
6 select CRYPTO_CRC32C
Alexey Dobriyan6da0b382008-10-20 22:28:45 +04007 help
8 This is the next generation of the ext3 filesystem.
9
10 Unlike the change from ext2 filesystem to ext3 filesystem,
11 the on-disk format of ext4 is not forwards compatible with
12 ext3; it is based on extent maps and it supports 48-bit
13 physical block numbers. The ext4 filesystem also supports delayed
14 allocation, persistent preallocation, high resolution time stamps,
15 and a number of other features to improve performance and speed
16 up fsck time. For more information, please see the web pages at
17 http://ext4.wiki.kernel.org.
18
19 The ext4 filesystem will support mounting an ext3
20 filesystem; while there will be some performance gains from
21 the delayed allocation and inode table readahead, the best
22 performance gains will require enabling ext4 features in the
Matt LaPlante692105b2009-01-26 11:12:25 +010023 filesystem, or formatting a new filesystem as an ext4
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040024 filesystem initially.
25
26 To compile this file system support as a module, choose M here. The
27 module will be called ext4.
28
29 If unsure, say N.
30
Theodore Ts'o24b58422009-12-07 14:08:51 -050031config EXT4_USE_FOR_EXT23
32 bool "Use ext4 for ext2/ext3 file systems"
David Howells84c66472009-12-21 10:54:09 -050033 depends on EXT4_FS
Theodore Ts'oa2142382009-12-09 21:09:58 -050034 depends on EXT3_FS=n || EXT2_FS=n
Theodore Ts'o24b58422009-12-07 14:08:51 -050035 default y
36 help
37 Allow the ext4 file system driver code to be used for ext2 or
38 ext3 file system mounts. This allows users to reduce their
39 compiled kernel size by using one file system driver for
40 ext2, ext3, and ext4 file systems.
41
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040042config EXT4_FS_POSIX_ACL
43 bool "Ext4 POSIX Access Control Lists"
Valerie Aurora96465ef2013-01-06 23:38:44 -050044 depends on EXT4_FS
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040045 select FS_POSIX_ACL
46 help
47 POSIX Access Control Lists (ACLs) support permissions for users and
48 groups beyond the owner/group/world scheme.
49
50 To learn more about Access Control Lists, visit the POSIX ACLs for
51 Linux website <http://acl.bestbits.at/>.
52
53 If you don't know what Access Control Lists are, say N
54
55config EXT4_FS_SECURITY
56 bool "Ext4 Security Labels"
Valerie Aurora96465ef2013-01-06 23:38:44 -050057 depends on EXT4_FS
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040058 help
59 Security labels support alternative access control models
60 implemented by security modules like SELinux. This option
61 enables an extended attribute handler for file security
62 labels in the ext4 filesystem.
63
64 If you are not using a security module that requires using
65 extended attributes for file security labels, say N.
Theodore Ts'o6ba495e2009-09-18 13:38:55 -040066
Herbert Xufb63e542015-05-02 10:29:19 -040067config EXT4_ENCRYPTION
68 tristate "Ext4 Encryption"
Theodore Ts'ob17655f2015-04-11 07:46:47 -040069 depends on EXT4_FS
70 select CRYPTO_AES
71 select CRYPTO_CBC
72 select CRYPTO_ECB
73 select CRYPTO_XTS
74 select CRYPTO_CTS
Theodore Ts'o71dea012015-05-31 13:31:37 -040075 select CRYPTO_CTR
Theodore Ts'ob17655f2015-04-11 07:46:47 -040076 select CRYPTO_SHA256
77 select KEYS
78 select ENCRYPTED_KEYS
79 help
80 Enable encryption of ext4 files and directories. This
81 feature is similar to ecryptfs, but it is more memory
82 efficient since it avoids caching the encrypted and
83 decrypted pages in the page cache.
84
Herbert Xufb63e542015-05-02 10:29:19 -040085config EXT4_FS_ENCRYPTION
86 bool
87 default y
88 depends on EXT4_ENCRYPTION
89
Theodore Ts'o6ba495e2009-09-18 13:38:55 -040090config EXT4_DEBUG
91 bool "EXT4 debugging support"
92 depends on EXT4_FS
93 help
94 Enables run-time debugging support for the ext4 filesystem.
95
96 If you select Y here, then you will be able to turn on debugging
Theodore Ts'o7f3e3c72013-04-21 20:32:03 -040097 with a command such as:
98 echo 1 > /sys/module/ext4/parameters/mballoc_debug