1config UBIFS_FS 2 tristate "UBIFS file system support" 3 select CRC16 4 select CRC32 5 select CRYPTO if UBIFS_FS_ADVANCED_COMPR 6 select CRYPTO if UBIFS_FS_LZO 7 select CRYPTO if UBIFS_FS_ZLIB 8 select CRYPTO_LZO if UBIFS_FS_LZO 9 select CRYPTO_DEFLATE if UBIFS_FS_ZLIB 10 select CRYPTO_HASH_INFO 11 depends on MTD_UBI 12 help 13 UBIFS is a file system for flash devices which works on top of UBI. 14 15config UBIFS_FS_ADVANCED_COMPR 16 bool "Advanced compression options" 17 depends on UBIFS_FS 18 help 19 This option allows to explicitly choose which compressions, if any, 20 are enabled in UBIFS. Removing compressors means inability to read 21 existing file systems. 22 23 If unsure, say 'N'. 24 25config UBIFS_FS_LZO 26 bool "LZO compression support" if UBIFS_FS_ADVANCED_COMPR 27 depends on UBIFS_FS 28 default y 29 help 30 LZO compressor is generally faster than zlib but compresses worse. 31 Say 'Y' if unsure. 32 33config UBIFS_FS_ZLIB 34 bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR 35 depends on UBIFS_FS 36 default y 37 help 38 Zlib compresses better than LZO but it is slower. Say 'Y' if unsure. 39 40config UBIFS_ATIME_SUPPORT 41 bool "Access time support" if UBIFS_FS 42 depends on UBIFS_FS 43 default n 44 help 45 Originally UBIFS did not support atime, because it looked like a bad idea due 46 increased flash wear. This option adds atime support and it is disabled by default 47 to preserve the old behavior. If you enable this option, UBIFS starts updating atime, 48 which means that file-system read operations will cause writes (inode atime 49 updates). This may affect file-system performance and increase flash device wear, 50 so be careful. How often atime is updated depends on the selected strategy: 51 strictatime is the "heavy", relatime is "lighter", etc. 52 53 If unsure, say 'N' 54 55config UBIFS_FS_XATTR 56 bool "UBIFS XATTR support" 57 depends on UBIFS_FS 58 default y 59 help 60 Saying Y here includes support for extended attributes (xattrs). 61 Xattrs are name:value pairs associated with inodes by 62 the kernel or by users (see the attr(5) manual page). 63 64 If unsure, say Y. 65 66config UBIFS_FS_ENCRYPTION 67 bool "UBIFS Encryption" 68 depends on UBIFS_FS && UBIFS_FS_XATTR && BLOCK 69 select FS_ENCRYPTION 70 default n 71 help 72 Enable encryption of UBIFS files and directories. This 73 feature is similar to ecryptfs, but it is more memory 74 efficient since it avoids caching the encrypted and 75 decrypted pages in the page cache. 76 77config UBIFS_FS_SECURITY 78 bool "UBIFS Security Labels" 79 depends on UBIFS_FS && UBIFS_FS_XATTR 80 default y 81 help 82 Security labels provide an access control facility to support Linux 83 Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO 84 Linux. This option enables an extended attribute handler for file 85 security labels in the ubifs filesystem, so that it requires enabling 86 the extended attribute support in advance. 87 88 If you are not using a security module, say N. 89 90config UBIFS_FS_AUTHENTICATION 91 bool "UBIFS authentication support" 92 select CRYPTO_HMAC 93 help 94 Enable authentication support for UBIFS. This feature offers protection 95 against offline changes for both data and metadata of the filesystem. 96 If you say yes here you should also select a hashing algorithm such as 97 sha256, these are not selected automatically since there are many 98 different options. 99