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 | |
| 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 | |
| 692105b8 | 21 | filesystem, or formatting a new filesystem as an ext4 |
| 6da0b38f AD |
22 | 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 | ||
| 24b58424 TT |
29 | config EXT4_USE_FOR_EXT23 |
| 30 | bool "Use ext4 for ext2/ext3 file systems" | |
| 84c66473 | 31 | depends on EXT4_FS |
| a214238d | 32 | depends on EXT3_FS=n || EXT2_FS=n |
| 24b58424 TT |
33 | 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 | ||
| 6da0b38f AD |
40 | config 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 | ||
| 53 | config 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 | ||
| 66 | config 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. | |
| 6ba495e9 TT |
77 | |
| 78 | config 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" |