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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
Hiroshi Shimamotoe4c570c2009-12-14 18:00:26 -08005 select FS_JOURNAL_INFO
Alexey Dobriyan6da0b382008-10-20 22:28:45 +04006 help
7 This is the next generation of the ext3 filesystem.
8
9 Unlike the change from ext2 filesystem to ext3 filesystem,
10 the on-disk format of ext4 is not forwards compatible with
11 ext3; it is based on extent maps and it supports 48-bit
12 physical block numbers. The ext4 filesystem also supports delayed
13 allocation, persistent preallocation, high resolution time stamps,
14 and a number of other features to improve performance and speed
15 up fsck time. For more information, please see the web pages at
16 http://ext4.wiki.kernel.org.
17
18 The ext4 filesystem will support mounting an ext3
19 filesystem; while there will be some performance gains from
20 the delayed allocation and inode table readahead, the best
21 performance gains will require enabling ext4 features in the
Matt LaPlante692105b2009-01-26 11:12:25 +010022 filesystem, or formatting a new filesystem as an ext4
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040023 filesystem initially.
24
25 To compile this file system support as a module, choose M here. The
26 module will be called ext4.
27
28 If unsure, say N.
29
Theodore Ts'o24b58422009-12-07 14:08:51 -050030config EXT4_USE_FOR_EXT23
31 bool "Use ext4 for ext2/ext3 file systems"
Theodore Ts'oa2142382009-12-09 21:09:58 -050032 depends on EXT3_FS=n || EXT2_FS=n
Theodore Ts'o24b58422009-12-07 14:08:51 -050033 default y
34 help
35 Allow the ext4 file system driver code to be used for ext2 or
36 ext3 file system mounts. This allows users to reduce their
37 compiled kernel size by using one file system driver for
38 ext2, ext3, and ext4 file systems.
39
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040040config EXT4_FS_XATTR
41 bool "Ext4 extended attributes"
42 depends on EXT4_FS
43 default y
44 help
45 Extended attributes are name:value pairs associated with inodes by
46 the kernel or by users (see the attr(5) manual page, or visit
47 <http://acl.bestbits.at/> for details).
48
49 If unsure, say N.
50
51 You need this for POSIX ACL support on ext4.
52
53config EXT4_FS_POSIX_ACL
54 bool "Ext4 POSIX Access Control Lists"
55 depends on EXT4_FS_XATTR
56 select FS_POSIX_ACL
57 help
58 POSIX Access Control Lists (ACLs) support permissions for users and
59 groups beyond the owner/group/world scheme.
60
61 To learn more about Access Control Lists, visit the POSIX ACLs for
62 Linux website <http://acl.bestbits.at/>.
63
64 If you don't know what Access Control Lists are, say N
65
66config EXT4_FS_SECURITY
67 bool "Ext4 Security Labels"
68 depends on EXT4_FS_XATTR
69 help
70 Security labels support alternative access control models
71 implemented by security modules like SELinux. This option
72 enables an extended attribute handler for file security
73 labels in the ext4 filesystem.
74
75 If you are not using a security module that requires using
76 extended attributes for file security labels, say N.
Theodore Ts'o6ba495e2009-09-18 13:38:55 -040077
78config EXT4_DEBUG
79 bool "EXT4 debugging support"
80 depends on EXT4_FS
81 help
82 Enables run-time debugging support for the ext4 filesystem.
83
84 If you select Y here, then you will be able to turn on debugging
85 with a command such as "echo 1 > /sys/kernel/debug/ext4/mballoc-debug"