1config EXT4_FS
   2        tristate "The Extended 4 (ext4) filesystem"
   3        select JBD2
   4        select CRC16
   5        select CRYPTO
   6        select CRYPTO_CRC32C
   7        help
   8          This is the next generation of the ext3 filesystem.
  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
  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
  23          filesystem, or formatting a new filesystem as an ext4
  24          filesystem initially.
  26          To compile this file system support as a module, choose M here. The
  27          module will be called ext4.
  29          If unsure, say N.
  31config EXT4_USE_FOR_EXT23
  32        bool "Use ext4 for ext2/ext3 file systems"
  33        depends on EXT4_FS
  34        depends on EXT3_FS=n || EXT2_FS=n
  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.
  42config EXT4_FS_XATTR
  43        bool "Ext4 extended attributes"
  44        depends on EXT4_FS
  45        default y
  46        help
  47          Extended attributes are name:value pairs associated with inodes by
  48          the kernel or by users (see the attr(5) manual page, or visit
  49          <> for details).
  51          If unsure, say N.
  53          You need this for POSIX ACL support on ext4.
  55config EXT4_FS_POSIX_ACL
  56        bool "Ext4 POSIX Access Control Lists"
  57        depends on EXT4_FS_XATTR
  58        select FS_POSIX_ACL
  59        help
  60          POSIX Access Control Lists (ACLs) support permissions for users and
  61          groups beyond the owner/group/world scheme.
  63          To learn more about Access Control Lists, visit the POSIX ACLs for
  64          Linux website <>.
  66          If you don't know what Access Control Lists are, say N
  68config EXT4_FS_SECURITY
  69        bool "Ext4 Security Labels"
  70        depends on EXT4_FS_XATTR
  71        help
  72          Security labels support alternative access control models
  73          implemented by security modules like SELinux.  This option
  74          enables an extended attribute handler for file security
  75          labels in the ext4 filesystem.
  77          If you are not using a security module that requires using
  78          extended attributes for file security labels, say N.
  80config EXT4_DEBUG
  81        bool "EXT4 debugging support"
  82        depends on EXT4_FS
  83        help
  84          Enables run-time debugging support for the ext4 filesystem.
  86          If you select Y here, then you will be able to turn on debugging
  87          with a command such as "echo 1 > /sys/kernel/debug/ext4/mballoc-debug"
  88 kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.