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_BACKED_BY_FILE <<
78 bool "File-backed EROFS filesystem sup <<
79 depends on EROFS_FS <<
80 default y <<
81 help <<
82 This allows EROFS to use filesystem <<
83 the intercession of loopback block d <<
84 particularly useful for container im <<
85 other sandboxes, where loop devices <<
86 be used to simplify error-prone life <<
87 virtual block devices. <<
88 <<
89 Note that this feature, along with o <<
90 hooks, will eventually replace "EROF <<
91 <<
92 If you don't want to enable this fea <<
93 <<
94 config EROFS_FS_ZIP 76 config EROFS_FS_ZIP
95 bool "EROFS Data Compression Support" 77 bool "EROFS Data Compression Support"
96 depends on EROFS_FS 78 depends on EROFS_FS
97 select LZ4_DECOMPRESS 79 select LZ4_DECOMPRESS
98 default y 80 default y
99 help 81 help
100 Enable fixed-sized output compressio 82 Enable fixed-sized output compression for EROFS.
101 83
102 If you don't want to enable compress 84 If you don't want to enable compression feature, say N.
103 85
104 config EROFS_FS_ZIP_LZMA 86 config EROFS_FS_ZIP_LZMA
105 bool "EROFS LZMA compressed data suppo 87 bool "EROFS LZMA compressed data support"
106 depends on EROFS_FS_ZIP 88 depends on EROFS_FS_ZIP
107 select XZ_DEC 89 select XZ_DEC
108 select XZ_DEC_MICROLZMA 90 select XZ_DEC_MICROLZMA
109 help 91 help
110 Saying Y here includes support for r 92 Saying Y here includes support for reading EROFS file systems
111 containing LZMA compressed data, spe !! 93 containing LZMA compressed data, specifically called microLZMA. it
112 gives better compression ratios than !! 94 gives better compression ratios than the LZ4 algorithm, at the
113 expense of more CPU overhead. 95 expense of more CPU overhead.
114 96
115 If unsure, say N. !! 97 LZMA support is an experimental feature for now and so most file
116 !! 98 systems will be readable without selecting this option.
117 config EROFS_FS_ZIP_DEFLATE <<
118 bool "EROFS DEFLATE compressed data su <<
119 depends on EROFS_FS_ZIP <<
120 select ZLIB_INFLATE <<
121 help <<
122 Saying Y here includes support for r <<
123 containing DEFLATE compressed data. <<
124 ratios than the default LZ4 format, <<
125 overhead. <<
126 <<
127 DEFLATE support is an experimental f <<
128 file systems will be readable withou <<
129 <<
130 If unsure, say N. <<
131 <<
132 config EROFS_FS_ZIP_ZSTD <<
133 bool "EROFS Zstandard compressed data <<
134 depends on EROFS_FS_ZIP <<
135 select ZSTD_DECOMPRESS <<
136 help <<
137 Saying Y here includes support for r <<
138 containing Zstandard compressed data <<
139 ratios than the default LZ4 format, <<
140 overhead. <<
141 <<
142 Zstandard support is an experimental <<
143 file systems will be readable withou <<
144 99
145 If unsure, say N. 100 If unsure, say N.
146 101
147 config EROFS_FS_ONDEMAND 102 config EROFS_FS_ONDEMAND
148 bool "EROFS fscache-based on-demand re !! 103 bool "EROFS fscache-based on-demand read support"
149 depends on EROFS_FS !! 104 depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
150 select NETFS_SUPPORT !! 105 default n
151 select FSCACHE <<
152 select CACHEFILES <<
153 select CACHEFILES_ONDEMAND <<
154 help 106 help
155 This permits EROFS to use fscache-ba 107 This permits EROFS to use fscache-backed data blobs with on-demand
156 read support. 108 read support.
157 <<
158 It is now deprecated and scheduled t <<
159 after fanotify pre-content hooks are <<
160 <<
161 If unsure, say N. <<
162 <<
163 config EROFS_FS_PCPU_KTHREAD <<
164 bool "EROFS per-cpu decompression kthr <<
165 depends on EROFS_FS_ZIP <<
166 help <<
167 Saying Y here enables per-CPU kthrea <<
168 async decompression for low latencie <<
169 <<
170 If unsure, say N. <<
171 <<
172 config EROFS_FS_PCPU_KTHREAD_HIPRI <<
173 bool "EROFS high priority per-CPU kthr <<
174 depends on EROFS_FS_ZIP && EROFS_FS_PC <<
175 default y <<
176 help <<
177 This permits EROFS to configure per- <<
178 at higher priority. <<
179 109
180 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.