| Alexey Dobriyan | 6da0b38 | 2008-10-20 22:28:45 +0400 | [diff] [blame] | 1 | config EXT4_FS |
| 2 | tristate "The Extended 4 (ext4) filesystem" |
| 3 | select JBD2 |
| 4 | select CRC16 |
| Darrick J. Wong | 0441984 | 2012-04-29 18:27:10 -0400 | [diff] [blame] | 5 | select CRYPTO |
| 6 | select CRYPTO_CRC32C |
| Alexey Dobriyan | 6da0b38 | 2008-10-20 22:28:45 +0400 | [diff] [blame] | 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 |
| Matt LaPlante | 692105b | 2009-01-26 11:12:25 +0100 | [diff] [blame] | 23 | filesystem, or formatting a new filesystem as an ext4 |
| Alexey Dobriyan | 6da0b38 | 2008-10-20 22:28:45 +0400 | [diff] [blame] | 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 | |
| Theodore Ts'o | 24b5842 | 2009-12-07 14:08:51 -0500 | [diff] [blame] | 31 | config EXT4_USE_FOR_EXT23 |
| 32 | bool "Use ext4 for ext2/ext3 file systems" |
| David Howells | 84c6647 | 2009-12-21 10:54:09 -0500 | [diff] [blame] | 33 | depends on EXT4_FS |
| Theodore Ts'o | a214238 | 2009-12-09 21:09:58 -0500 | [diff] [blame] | 34 | depends on EXT3_FS=n || EXT2_FS=n |
| Theodore Ts'o | 24b5842 | 2009-12-07 14:08:51 -0500 | [diff] [blame] | 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 | |
| Alexey Dobriyan | 6da0b38 | 2008-10-20 22:28:45 +0400 | [diff] [blame] | 42 | config EXT4_FS_POSIX_ACL |
| 43 | bool "Ext4 POSIX Access Control Lists" |
| Valerie Aurora | 96465ef | 2013-01-06 23:38:44 -0500 | [diff] [blame] | 44 | depends on EXT4_FS |
| Alexey Dobriyan | 6da0b38 | 2008-10-20 22:28:45 +0400 | [diff] [blame] | 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" |
| Valerie Aurora | 96465ef | 2013-01-06 23:38:44 -0500 | [diff] [blame] | 57 | depends on EXT4_FS |
| Alexey Dobriyan | 6da0b38 | 2008-10-20 22:28:45 +0400 | [diff] [blame] | 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. |
| Theodore Ts'o | 6ba495e | 2009-09-18 13:38:55 -0400 | [diff] [blame] | 66 | |
| Herbert Xu | fb63e54 | 2015-05-02 10:29:19 -0400 | [diff] [blame] | 67 | config EXT4_ENCRYPTION |
| 68 | tristate "Ext4 Encryption" |
| Theodore Ts'o | b17655f | 2015-04-11 07:46:47 -0400 | [diff] [blame] | 69 | 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'o | 71dea01 | 2015-05-31 13:31:37 -0400 | [diff] [blame] | 75 | select CRYPTO_CTR |
| Theodore Ts'o | b17655f | 2015-04-11 07:46:47 -0400 | [diff] [blame] | 76 | 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 Xu | fb63e54 | 2015-05-02 10:29:19 -0400 | [diff] [blame] | 85 | config EXT4_FS_ENCRYPTION |
| 86 | bool |
| 87 | default y |
| 88 | depends on EXT4_ENCRYPTION |
| 89 | |
| Theodore Ts'o | 6ba495e | 2009-09-18 13:38:55 -0400 | [diff] [blame] | 90 | config 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'o | 7f3e3c7 | 2013-04-21 20:32:03 -0400 | [diff] [blame] | 97 | with a command such as: |
| 98 | echo 1 > /sys/module/ext4/parameters/mballoc_debug |