1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 2
3 config EROFS_FS 3 config EROFS_FS
4 tristate "EROFS filesystem support" 4 tristate "EROFS filesystem support"
5 depends on BLOCK 5 depends on BLOCK
6 select FS_IOMAP 6 select FS_IOMAP
7 select LIBCRC32C 7 select LIBCRC32C
8 help 8 help
9 EROFS (Enhanced Read-Only File Syste 9 EROFS (Enhanced Read-Only File System) is a lightweight read-only
10 file system with modern designs (e.g 10 file system with modern designs (e.g. no buffer heads, inline
11 xattrs/data, chunk-based deduplicati 11 xattrs/data, chunk-based deduplication, multiple devices, etc.) for
12 scenarios which need high-performanc 12 scenarios which need high-performance read-only solutions, e.g.
13 smartphones with Android OS, LiveCDs 13 smartphones with Android OS, LiveCDs and high-density hosts with
14 numerous containers; 14 numerous containers;
15 15
16 It also provides fixed-sized output 16 It also provides fixed-sized output compression support in order to
17 improve storage density as well as k 17 improve storage density as well as keep relatively higher compression
18 ratios and implements in-place decom 18 ratios and implements in-place decompression to reuse the file page
19 for compressed data temporarily with 19 for compressed data temporarily with proper strategies, which is
20 quite useful to ensure guaranteed en 20 quite useful to ensure guaranteed end-to-end runtime decompression
21 performance under extremely memory p 21 performance under extremely memory pressure without extra cost.
22 22
23 See the documentation at <file:Docum 23 See the documentation at <file:Documentation/filesystems/erofs.rst>
24 and the web pages at <https://erofs. !! 24 for more details.
25 25
26 If unsure, say N. 26 If unsure, say N.
27 27
28 config EROFS_FS_DEBUG 28 config EROFS_FS_DEBUG
29 bool "EROFS debugging feature" 29 bool "EROFS debugging feature"
30 depends on EROFS_FS 30 depends on EROFS_FS
31 help 31 help
32 Print debugging messages and enable 32 Print debugging messages and enable more BUG_ONs which check
33 filesystem consistency and find pote 33 filesystem consistency and find potential issues aggressively,
34 which can be used for Android eng bu 34 which can be used for Android eng build, for example.
35 35
36 For daily use, say N. 36 For daily use, say N.
37 37
38 config EROFS_FS_XATTR 38 config EROFS_FS_XATTR
39 bool "EROFS extended attributes" 39 bool "EROFS extended attributes"
40 depends on EROFS_FS 40 depends on EROFS_FS
41 select XXHASH <<
42 default y 41 default y
43 help 42 help
44 Extended attributes are name:value p 43 Extended attributes are name:value pairs associated with inodes by
45 the kernel or by users (see the attr 44 the kernel or by users (see the attr(5) manual page, or visit
46 <http://acl.bestbits.at/> for detail 45 <http://acl.bestbits.at/> for details).
47 46
48 If unsure, say N. 47 If unsure, say N.
49 48
50 config EROFS_FS_POSIX_ACL 49 config EROFS_FS_POSIX_ACL
51 bool "EROFS Access Control Lists" 50 bool "EROFS Access Control Lists"
52 depends on EROFS_FS_XATTR 51 depends on EROFS_FS_XATTR
53 select FS_POSIX_ACL 52 select FS_POSIX_ACL
54 default y 53 default y
55 help 54 help
56 Posix Access Control Lists (ACLs) su 55 Posix Access Control Lists (ACLs) support permissions for users and
57 groups beyond the owner/group/world 56 groups beyond the owner/group/world scheme.
58 57
59 To learn more about Access Control L 58 To learn more about Access Control Lists, visit the POSIX ACLs for
60 Linux website <http://acl.bestbits.a 59 Linux website <http://acl.bestbits.at/>.
61 60
62 If you don't know what Access Contro 61 If you don't know what Access Control Lists are, say N.
63 62
64 config EROFS_FS_SECURITY 63 config EROFS_FS_SECURITY
65 bool "EROFS Security Labels" 64 bool "EROFS Security Labels"
66 depends on EROFS_FS_XATTR 65 depends on EROFS_FS_XATTR
67 default y 66 default y
68 help 67 help
69 Security labels provide an access co 68 Security labels provide an access control facility to support Linux
70 Security Models (LSMs) accepted by A 69 Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
71 Linux. This option enables an extend 70 Linux. This option enables an extended attribute handler for file
72 security labels in the erofs filesys 71 security labels in the erofs filesystem, so that it requires enabling
73 the extended attribute support in ad 72 the extended attribute support in advance.
74 73
75 If you are not using a security modu 74 If you are not using a security module, say N.
76 75
77 config EROFS_FS_ZIP 76 config EROFS_FS_ZIP
78 bool "EROFS Data Compression Support" 77 bool "EROFS Data Compression Support"
79 depends on EROFS_FS 78 depends on EROFS_FS
80 select LZ4_DECOMPRESS 79 select LZ4_DECOMPRESS
81 default y 80 default y
82 help 81 help
83 Enable fixed-sized output compressio 82 Enable fixed-sized output compression for EROFS.
84 83
85 If you don't want to enable compress 84 If you don't want to enable compression feature, say N.
86 85
87 config EROFS_FS_ZIP_LZMA 86 config EROFS_FS_ZIP_LZMA
88 bool "EROFS LZMA compressed data suppo 87 bool "EROFS LZMA compressed data support"
89 depends on EROFS_FS_ZIP 88 depends on EROFS_FS_ZIP
90 select XZ_DEC 89 select XZ_DEC
91 select XZ_DEC_MICROLZMA 90 select XZ_DEC_MICROLZMA
92 help 91 help
93 Saying Y here includes support for r 92 Saying Y here includes support for reading EROFS file systems
94 containing LZMA compressed data, spe !! 93 containing LZMA compressed data, specifically called microLZMA. it
95 gives better compression ratios than !! 94 gives better compression ratios than the LZ4 algorithm, at the
96 expense of more CPU overhead. 95 expense of more CPU overhead.
97 96
98 If unsure, say N. !! 97 LZMA support is an experimental feature for now and so most file
99 !! 98 systems will be readable without selecting this option.
100 config EROFS_FS_ZIP_DEFLATE <<
101 bool "EROFS DEFLATE compressed data su <<
102 depends on EROFS_FS_ZIP <<
103 select ZLIB_INFLATE <<
104 help <<
105 Saying Y here includes support for r <<
106 containing DEFLATE compressed data. <<
107 ratios than the default LZ4 format, <<
108 overhead. <<
109 <<
110 DEFLATE support is an experimental f <<
111 file systems will be readable withou <<
112 <<
113 If unsure, say N. <<
114 <<
115 config EROFS_FS_ZIP_ZSTD <<
116 bool "EROFS Zstandard compressed data <<
117 depends on EROFS_FS_ZIP <<
118 select ZSTD_DECOMPRESS <<
119 help <<
120 Saying Y here includes support for r <<
121 containing Zstandard compressed data <<
122 ratios than the default LZ4 format, <<
123 overhead. <<
124 <<
125 Zstandard support is an experimental <<
126 file systems will be readable withou <<
127 99
128 If unsure, say N. 100 If unsure, say N.
129 101
130 config EROFS_FS_ONDEMAND 102 config EROFS_FS_ONDEMAND
131 bool "EROFS fscache-based on-demand re 103 bool "EROFS fscache-based on-demand read support"
132 depends on EROFS_FS !! 104 depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
133 select NETFS_SUPPORT !! 105 default n
134 select FSCACHE <<
135 select CACHEFILES <<
136 select CACHEFILES_ONDEMAND <<
137 help 106 help
138 This permits EROFS to use fscache-ba 107 This permits EROFS to use fscache-backed data blobs with on-demand
139 read support. 108 read support.
140 <<
141 If unsure, say N. <<
142 <<
143 config EROFS_FS_PCPU_KTHREAD <<
144 bool "EROFS per-cpu decompression kthr <<
145 depends on EROFS_FS_ZIP <<
146 help <<
147 Saying Y here enables per-CPU kthrea <<
148 async decompression for low latencie <<
149 <<
150 If unsure, say N. <<
151 <<
152 config EROFS_FS_PCPU_KTHREAD_HIPRI <<
153 bool "EROFS high priority per-CPU kthr <<
154 depends on EROFS_FS_ZIP && EROFS_FS_PC <<
155 default y <<
156 help <<
157 This permits EROFS to configure per- <<
158 at higher priority. <<
159 109
160 If unsure, say N. 110 If unsure, say N.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.