projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 6da0b38f AD |
1 | config EXT4_FS |
| 2 | tristate "The Extended 4 (ext4) filesystem" | |
| 3 | select JBD2 | |
| 4 | select CRC16 | |
| 0441984a DW |
5 | select CRYPTO |
| 6 | select CRYPTO_CRC32C | |
| 6da0b38f AD |
7 | 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 | |
| 692105b8 | 23 | filesystem, or formatting a new filesystem as an ext4 |
| 6da0b38f AD |
24 | 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 | ||
| 24b58424 TT |
31 | config EXT4_USE_FOR_EXT23 |
| 32 | bool "Use ext4 for ext2/ext3 file systems" | |
| 84c66473 | 33 | depends on EXT4_FS |
| a214238d | 34 | depends on EXT3_FS=n || EXT2_FS=n |
| 24b58424 TT |
35 | 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 | ||
| 6da0b38f AD |
42 | config EXT4_FS_POSIX_ACL |
| 43 | bool "Ext4 POSIX Access Control Lists" | |
| 96465efe | 44 | depends on EXT4_FS |
| 6da0b38f AD |
45 | 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 | ||
| 55 | config EXT4_FS_SECURITY | |
| 56 | bool "Ext4 Security Labels" | |
| 96465efe | 57 | depends on EXT4_FS |
| 6da0b38f AD |
58 | 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. | |
| 6ba495e9 TT |
66 | |
| 67 | config EXT4_DEBUG | |
| 68 | bool "EXT4 debugging support" | |
| 69 | depends on EXT4_FS | |
| 70 | help | |
| 71 | Enables run-time debugging support for the ext4 filesystem. | |
| 72 | ||
| 73 | If you select Y here, then you will be able to turn on debugging | |
| 7f3e3c7c TT |
74 | with a command such as: |
| 75 | echo 1 > /sys/module/ext4/parameters/mballoc_debug |