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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
5 help
6 This is the next generation of the ext3 filesystem.
7
8 Unlike the change from ext2 filesystem to ext3 filesystem,
9 the on-disk format of ext4 is not forwards compatible with
10 ext3; it is based on extent maps and it supports 48-bit
11 physical block numbers. The ext4 filesystem also supports delayed
12 allocation, persistent preallocation, high resolution time stamps,
13 and a number of other features to improve performance and speed
14 up fsck time. For more information, please see the web pages at
15 http://ext4.wiki.kernel.org.
16
17 The ext4 filesystem will support mounting an ext3
18 filesystem; while there will be some performance gains from
19 the delayed allocation and inode table readahead, the best
20 performance gains will require enabling ext4 features in the
Matt LaPlante692105b2009-01-26 11:12:25 +010021 filesystem, or formatting a new filesystem as an ext4
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040022 filesystem initially.
23
24 To compile this file system support as a module, choose M here. The
25 module will be called ext4.
26
27 If unsure, say N.
28
29config EXT4DEV_COMPAT
30 bool "Enable ext4dev compatibility"
31 depends on EXT4_FS
32 help
33 Starting with 2.6.28, the name of the ext4 filesystem was
34 renamed from ext4dev to ext4. Unfortunately there are some
35 legacy userspace programs (such as klibc's fstype) have
36 "ext4dev" hardcoded.
37
38 To enable backwards compatibility so that systems that are
39 still expecting to mount ext4 filesystems using ext4dev,
Manish Katiyar43b38522009-07-27 21:38:17 -040040 choose Y here. This feature will go away by 2.6.31, so
Alexey Dobriyan6da0b382008-10-20 22:28:45 +040041 please arrange to get your userspace programs fixed!
42
43config EXT4_FS_XATTR
44 bool "Ext4 extended attributes"
45 depends on EXT4_FS
46 default y
47 help
48 Extended attributes are name:value pairs associated with inodes by
49 the kernel or by users (see the attr(5) manual page, or visit
50 <http://acl.bestbits.at/> for details).
51
52 If unsure, say N.
53
54 You need this for POSIX ACL support on ext4.
55
56config EXT4_FS_POSIX_ACL
57 bool "Ext4 POSIX Access Control Lists"
58 depends on EXT4_FS_XATTR
59 select FS_POSIX_ACL
60 help
61 POSIX Access Control Lists (ACLs) support permissions for users and
62 groups beyond the owner/group/world scheme.
63
64 To learn more about Access Control Lists, visit the POSIX ACLs for
65 Linux website <http://acl.bestbits.at/>.
66
67 If you don't know what Access Control Lists are, say N
68
69config EXT4_FS_SECURITY
70 bool "Ext4 Security Labels"
71 depends on EXT4_FS_XATTR
72 help
73 Security labels support alternative access control models
74 implemented by security modules like SELinux. This option
75 enables an extended attribute handler for file security
76 labels in the ext4 filesystem.
77
78 If you are not using a security module that requires using
79 extended attributes for file security labels, say N.
Theodore Ts'o6ba495e2009-09-18 13:38:55 -040080
81config EXT4_DEBUG
82 bool "EXT4 debugging support"
83 depends on EXT4_FS
84 help
85 Enables run-time debugging support for the ext4 filesystem.
86
87 If you select Y here, then you will be able to turn on debugging
88 with a command such as "echo 1 > /sys/kernel/debug/ext4/mballoc-debug"