fs/ext4/Kconfig

   1 # Ext3 configs are here for backward compatibility with old configs which may
   2 # have EXT3_FS set but not EXT4_FS set and thus would result in non-bootable
   3 # kernels after the removal of ext3 driver.
   4 config EXT3_FS
   5         tristate "The Extended 3 (ext3) filesystem"
   6         # These must match EXT4_FS selects...
   7         select EXT4_FS
   8         select JBD2
   9         select CRC16
  10         select CRYPTO
  11         select CRYPTO_CRC32C
  12         help
  13           This config option is here only for backward compatibility. ext3
  14           filesystem is now handled by the ext4 driver.
  15
  16 config EXT3_FS_POSIX_ACL
  17         bool "Ext3 POSIX Access Control Lists"
  18         depends on EXT3_FS
  19         select EXT4_FS_POSIX_ACL
  20         select FS_POSIX_ACL
  21         help
  22           This config option is here only for backward compatibility. ext3
  23           filesystem is now handled by the ext4 driver.
  24
  25 config EXT3_FS_SECURITY
  26         bool "Ext3 Security Labels"
  27         depends on EXT3_FS
  28         select EXT4_FS_SECURITY
  29         help
  30           This config option is here only for backward compatibility. ext3
  31           filesystem is now handled by the ext4 driver.
  32
  33 config EXT4_FS
  34         tristate "The Extended 4 (ext4) filesystem"
  35         # Please update EXT3_FS selects when changing these
  36         select JBD2
  37         select CRC16
  38         select CRYPTO
  39         select CRYPTO_CRC32C
  40         help
  41           This is the next generation of the ext3 filesystem.
  42
  43           Unlike the change from ext2 filesystem to ext3 filesystem,
  44           the on-disk format of ext4 is not forwards compatible with
  45           ext3; it is based on extent maps and it supports 48-bit
  46           physical block numbers.  The ext4 filesystem also supports delayed
  47           allocation, persistent preallocation, high resolution time stamps,
  48           and a number of other features to improve performance and speed
  49           up fsck time.  For more information, please see the web pages at
  50           http://ext4.wiki.kernel.org.
  51
  52           The ext4 filesystem supports mounting an ext3 filesystem; while there
  53           are some performance gains from the delayed allocation and inode
  54           table readahead, the best performance gains require enabling ext4
  55           features in the filesystem using tune2fs, or formatting a new
  56           filesystem as an ext4 filesystem initially. Without explicit enabling
  57           of ext4 features, the on disk filesystem format stays fully backward
  58           compatible.
  59
  60           To compile this file system support as a module, choose M here. The
  61           module will be called ext4.
  62
  63           If unsure, say N.
  64
  65 config EXT4_USE_FOR_EXT2
  66         bool "Use ext4 for ext2 file systems"
  67         depends on EXT4_FS
  68         depends on EXT2_FS=n
  69         default y
  70         help
  71           Allow the ext4 file system driver code to be used for ext2
  72           file system mounts.  This allows users to reduce their
  73           compiled kernel size by using one file system driver for
  74           ext2, ext3, and ext4 file systems.
  75
  76 config EXT4_FS_POSIX_ACL
  77         bool "Ext4 POSIX Access Control Lists"
  78         depends on EXT4_FS
  79         select FS_POSIX_ACL
  80         help
  81           POSIX Access Control Lists (ACLs) support permissions for users and
  82           groups beyond the owner/group/world scheme.
  83
  84           To learn more about Access Control Lists, visit the POSIX ACLs for
  85           Linux website <http://acl.bestbits.at/>.
  86
  87           If you don't know what Access Control Lists are, say N
  88
  89 config EXT4_FS_SECURITY
  90         bool "Ext4 Security Labels"
  91         depends on EXT4_FS
  92         help
  93           Security labels support alternative access control models
  94           implemented by security modules like SELinux.  This option
  95           enables an extended attribute handler for file security
  96           labels in the ext4 filesystem.
  97
  98           If you are not using a security module that requires using
  99           extended attributes for file security labels, say N.
 100
 101 config EXT4_ENCRYPTION
 102         bool "Ext4 Encryption"
 103         depends on EXT4_FS
 104         select FS_ENCRYPTION
 105         help
 106           Enable encryption of ext4 files and directories.  This
 107           feature is similar to ecryptfs, but it is more memory
 108           efficient since it avoids caching the encrypted and
 109           decrypted pages in the page cache.
 110
 111 config EXT4_FS_ENCRYPTION
 112         bool
 113         default y
 114         depends on EXT4_ENCRYPTION
 115
 116 config EXT4_DEBUG
 117         bool "EXT4 debugging support"
 118         depends on EXT4_FS
 119         help
 120           Enables run-time debugging support for the ext4 filesystem.
 121
 122           If you select Y here, then you will be able to turn on debugging
 123           with a command such as:
 124                 echo 1 > /sys/module/ext4/parameters/mballoc_debug