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. 4config 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 16config 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 25config 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 33config 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 select FS_IOMAP 41 help 42 This is the next generation of the ext3 filesystem. 43 44 Unlike the change from ext2 filesystem to ext3 filesystem, 45 the on-disk format of ext4 is not forwards compatible with 46 ext3; it is based on extent maps and it supports 48-bit 47 physical block numbers. The ext4 filesystem also supports delayed 48 allocation, persistent preallocation, high resolution time stamps, 49 and a number of other features to improve performance and speed 50 up fsck time. For more information, please see the web pages at 51 http://ext4.wiki.kernel.org. 52 53 The ext4 filesystem supports mounting an ext3 filesystem; while there 54 are some performance gains from the delayed allocation and inode 55 table readahead, the best performance gains require enabling ext4 56 features in the filesystem using tune2fs, or formatting a new 57 filesystem as an ext4 filesystem initially. Without explicit enabling 58 of ext4 features, the on disk filesystem format stays fully backward 59 compatible. 60 61 To compile this file system support as a module, choose M here. The 62 module will be called ext4. 63 64 If unsure, say N. 65 66config EXT4_USE_FOR_EXT2 67 bool "Use ext4 for ext2 file systems" 68 depends on EXT4_FS 69 depends on EXT2_FS=n 70 default y 71 help 72 Allow the ext4 file system driver code to be used for ext2 73 file system mounts. This allows users to reduce their 74 compiled kernel size by using one file system driver for 75 ext2, ext3, and ext4 file systems. 76 77config EXT4_FS_POSIX_ACL 78 bool "Ext4 POSIX Access Control Lists" 79 depends on EXT4_FS 80 select FS_POSIX_ACL 81 help 82 POSIX Access Control Lists (ACLs) support permissions for users and 83 groups beyond the owner/group/world scheme. 84 85 To learn more about Access Control Lists, visit the POSIX ACLs for 86 Linux website <http://acl.bestbits.at/>. 87 88 If you don't know what Access Control Lists are, say N 89 90config EXT4_FS_SECURITY 91 bool "Ext4 Security Labels" 92 depends on EXT4_FS 93 help 94 Security labels support alternative access control models 95 implemented by security modules like SELinux. This option 96 enables an extended attribute handler for file security 97 labels in the ext4 filesystem. 98 99 If you are not using a security module that requires using 100 extended attributes for file security labels, say N. 101 102config EXT4_ENCRYPTION 103 bool "Ext4 Encryption" 104 depends on EXT4_FS 105 select FS_ENCRYPTION 106 help 107 Enable encryption of ext4 files and directories. This 108 feature is similar to ecryptfs, but it is more memory 109 efficient since it avoids caching the encrypted and 110 decrypted pages in the page cache. 111 112config EXT4_FS_ENCRYPTION 113 bool 114 default y 115 depends on EXT4_ENCRYPTION 116 117config EXT4_DEBUG 118 bool "EXT4 debugging support" 119 depends on EXT4_FS 120 help 121 Enables run-time debugging support for the ext4 filesystem. 122 123 If you select Y here, then you will be able to turn on debugging 124 with a command such as: 125 echo 1 > /sys/module/ext4/parameters/mballoc_debug 126