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1# SPDX-License-Identifier: GPL-2.0-only
2
3config EROFS_FS
4 tristate "EROFS filesystem support"
5 depends on BLOCK
6 select FS_IOMAP
7 select LIBCRC32C
8 help
9 EROFS (Enhanced Read-Only File System) is a lightweight read-only
10 file system with modern designs (e.g. no buffer heads, inline
11 xattrs/data, chunk-based deduplication, multiple devices, etc.) for
12 scenarios which need high-performance read-only solutions, e.g.
13 smartphones with Android OS, LiveCDs and high-density hosts with
14 numerous containers;
15
16 It also provides fixed-sized output compression support in order to
17 improve storage density as well as keep relatively higher compression
18 ratios and implements in-place decompression to reuse the file page
19 for compressed data temporarily with proper strategies, which is
20 quite useful to ensure guaranteed end-to-end runtime decompression
21 performance under extremely memory pressure without extra cost.
22
23 See the documentation at <file:Documentation/filesystems/erofs.rst>
24 and the web pages at <https://erofs.docs.kernel.org> for more details.
25
26 If unsure, say N.
27
28config EROFS_FS_DEBUG
29 bool "EROFS debugging feature"
30 depends on EROFS_FS
31 help
32 Print debugging messages and enable more BUG_ONs which check
33 filesystem consistency and find potential issues aggressively,
34 which can be used for Android eng build, for example.
35
36 For daily use, say N.
37
38config EROFS_FS_XATTR
39 bool "EROFS extended attributes"
40 depends on EROFS_FS
41 select XXHASH
42 default y
43 help
44 Extended attributes are name:value pairs associated with inodes by
45 the kernel or by users (see the attr(5) manual page, or visit
46 <http://acl.bestbits.at/> for details).
47
48 If unsure, say N.
49
50config EROFS_FS_POSIX_ACL
51 bool "EROFS Access Control Lists"
52 depends on EROFS_FS_XATTR
53 select FS_POSIX_ACL
54 default y
55 help
56 Posix Access Control Lists (ACLs) support permissions for users and
57 groups beyond the owner/group/world scheme.
58
59 To learn more about Access Control Lists, visit the POSIX ACLs for
60 Linux website <http://acl.bestbits.at/>.
61
62 If you don't know what Access Control Lists are, say N.
63
64config EROFS_FS_SECURITY
65 bool "EROFS Security Labels"
66 depends on EROFS_FS_XATTR
67 default y
68 help
69 Security labels provide an access control facility to support Linux
70 Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
71 Linux. This option enables an extended attribute handler for file
72 security labels in the erofs filesystem, so that it requires enabling
73 the extended attribute support in advance.
74
75 If you are not using a security module, say N.
76
77config EROFS_FS_ZIP
78 bool "EROFS Data Compression Support"
79 depends on EROFS_FS
80 select LZ4_DECOMPRESS
81 default y
82 help
83 Enable fixed-sized output compression for EROFS.
84
85 If you don't want to enable compression feature, say N.
86
87config EROFS_FS_ZIP_LZMA
88 bool "EROFS LZMA compressed data support"
89 depends on EROFS_FS_ZIP
90 select XZ_DEC
91 select XZ_DEC_MICROLZMA
92 help
93 Saying Y here includes support for reading EROFS file systems
94 containing LZMA compressed data, specifically called microLZMA. It
95 gives better compression ratios than the default LZ4 format, at the
96 expense of more CPU overhead.
97
98 If unsure, say N.
99
100config EROFS_FS_ZIP_DEFLATE
101 bool "EROFS DEFLATE compressed data support"
102 depends on EROFS_FS_ZIP
103 select ZLIB_INFLATE
104 help
105 Saying Y here includes support for reading EROFS file systems
106 containing DEFLATE compressed data. It gives better compression
107 ratios than the default LZ4 format, while it costs more CPU
108 overhead.
109
110 DEFLATE support is an experimental feature for now and so most
111 file systems will be readable without selecting this option.
112
113 If unsure, say N.
114
115config EROFS_FS_ONDEMAND
116 bool "EROFS fscache-based on-demand read support"
117 depends on EROFS_FS
118 select NETFS_SUPPORT
119 select FSCACHE
120 select CACHEFILES
121 select CACHEFILES_ONDEMAND
122 help
123 This permits EROFS to use fscache-backed data blobs with on-demand
124 read support.
125
126 If unsure, say N.
127
128config EROFS_FS_PCPU_KTHREAD
129 bool "EROFS per-cpu decompression kthread workers"
130 depends on EROFS_FS_ZIP
131 help
132 Saying Y here enables per-CPU kthread workers pool to carry out
133 async decompression for low latencies on some architectures.
134
135 If unsure, say N.
136
137config EROFS_FS_PCPU_KTHREAD_HIPRI
138 bool "EROFS high priority per-CPU kthread workers"
139 depends on EROFS_FS_ZIP && EROFS_FS_PCPU_KTHREAD
140 default y
141 help
142 This permits EROFS to configure per-CPU kthread workers to run
143 at higher priority.
144
145 If unsure, say N.
1# SPDX-License-Identifier: GPL-2.0-only
2
3config EROFS_FS
4 tristate "EROFS filesystem support"
5 depends on BLOCK
6 select FS_IOMAP
7 select LIBCRC32C
8 help
9 EROFS (Enhanced Read-Only File System) is a lightweight read-only
10 file system with modern designs (e.g. no buffer heads, inline
11 xattrs/data, chunk-based deduplication, multiple devices, etc.) for
12 scenarios which need high-performance read-only solutions, e.g.
13 smartphones with Android OS, LiveCDs and high-density hosts with
14 numerous containers;
15
16 It also provides fixed-sized output compression support in order to
17 improve storage density as well as keep relatively higher compression
18 ratios and implements in-place decompression to reuse the file page
19 for compressed data temporarily with proper strategies, which is
20 quite useful to ensure guaranteed end-to-end runtime decompression
21 performance under extremely memory pressure without extra cost.
22
23 See the documentation at <file:Documentation/filesystems/erofs.rst>
24 and the web pages at <https://erofs.docs.kernel.org> for more details.
25
26 If unsure, say N.
27
28config EROFS_FS_DEBUG
29 bool "EROFS debugging feature"
30 depends on EROFS_FS
31 help
32 Print debugging messages and enable more BUG_ONs which check
33 filesystem consistency and find potential issues aggressively,
34 which can be used for Android eng build, for example.
35
36 For daily use, say N.
37
38config EROFS_FS_XATTR
39 bool "EROFS extended attributes"
40 depends on EROFS_FS
41 select XXHASH
42 default y
43 help
44 Extended attributes are name:value pairs associated with inodes by
45 the kernel or by users (see the attr(5) manual page, or visit
46 <http://acl.bestbits.at/> for details).
47
48 If unsure, say N.
49
50config EROFS_FS_POSIX_ACL
51 bool "EROFS Access Control Lists"
52 depends on EROFS_FS_XATTR
53 select FS_POSIX_ACL
54 default y
55 help
56 Posix Access Control Lists (ACLs) support permissions for users and
57 groups beyond the owner/group/world scheme.
58
59 To learn more about Access Control Lists, visit the POSIX ACLs for
60 Linux website <http://acl.bestbits.at/>.
61
62 If you don't know what Access Control Lists are, say N.
63
64config EROFS_FS_SECURITY
65 bool "EROFS Security Labels"
66 depends on EROFS_FS_XATTR
67 default y
68 help
69 Security labels provide an access control facility to support Linux
70 Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
71 Linux. This option enables an extended attribute handler for file
72 security labels in the erofs filesystem, so that it requires enabling
73 the extended attribute support in advance.
74
75 If you are not using a security module, say N.
76
77config EROFS_FS_BACKED_BY_FILE
78 bool "File-backed EROFS filesystem support"
79 depends on EROFS_FS
80 default y
81 help
82 This allows EROFS to use filesystem image files directly, without
83 the intercession of loopback block devices or likewise. It is
84 particularly useful for container images with numerous blobs and
85 other sandboxes, where loop devices behave intricately. It can also
86 be used to simplify error-prone lifetime management of unnecessary
87 virtual block devices.
88
89 Note that this feature, along with ongoing fanotify pre-content
90 hooks, will eventually replace "EROFS over fscache."
91
92 If you don't want to enable this feature, say N.
93
94config EROFS_FS_ZIP
95 bool "EROFS Data Compression Support"
96 depends on EROFS_FS
97 select LZ4_DECOMPRESS
98 default y
99 help
100 Enable fixed-sized output compression for EROFS.
101
102 If you don't want to enable compression feature, say N.
103
104config EROFS_FS_ZIP_LZMA
105 bool "EROFS LZMA compressed data support"
106 depends on EROFS_FS_ZIP
107 select XZ_DEC
108 select XZ_DEC_MICROLZMA
109 help
110 Saying Y here includes support for reading EROFS file systems
111 containing LZMA compressed data, specifically called microLZMA. It
112 gives better compression ratios than the default LZ4 format, at the
113 expense of more CPU overhead.
114
115 If unsure, say N.
116
117config EROFS_FS_ZIP_DEFLATE
118 bool "EROFS DEFLATE compressed data support"
119 depends on EROFS_FS_ZIP
120 select ZLIB_INFLATE
121 help
122 Saying Y here includes support for reading EROFS file systems
123 containing DEFLATE compressed data. It gives better compression
124 ratios than the default LZ4 format, while it costs more CPU
125 overhead.
126
127 DEFLATE support is an experimental feature for now and so most
128 file systems will be readable without selecting this option.
129
130 If unsure, say N.
131
132config EROFS_FS_ZIP_ZSTD
133 bool "EROFS Zstandard compressed data support"
134 depends on EROFS_FS_ZIP
135 select ZSTD_DECOMPRESS
136 help
137 Saying Y here includes support for reading EROFS file systems
138 containing Zstandard compressed data. It gives better compression
139 ratios than the default LZ4 format, while it costs more CPU
140 overhead.
141
142 Zstandard support is an experimental feature for now and so most
143 file systems will be readable without selecting this option.
144
145 If unsure, say N.
146
147config EROFS_FS_ONDEMAND
148 bool "EROFS fscache-based on-demand read support (deprecated)"
149 depends on EROFS_FS
150 select NETFS_SUPPORT
151 select FSCACHE
152 select CACHEFILES
153 select CACHEFILES_ONDEMAND
154 help
155 This permits EROFS to use fscache-backed data blobs with on-demand
156 read support.
157
158 It is now deprecated and scheduled to be removed from the kernel
159 after fanotify pre-content hooks are landed.
160
161 If unsure, say N.
162
163config EROFS_FS_PCPU_KTHREAD
164 bool "EROFS per-cpu decompression kthread workers"
165 depends on EROFS_FS_ZIP
166 help
167 Saying Y here enables per-CPU kthread workers pool to carry out
168 async decompression for low latencies on some architectures.
169
170 If unsure, say N.
171
172config EROFS_FS_PCPU_KTHREAD_HIPRI
173 bool "EROFS high priority per-CPU kthread workers"
174 depends on EROFS_FS_ZIP && EROFS_FS_PCPU_KTHREAD
175 default y
176 help
177 This permits EROFS to configure per-CPU kthread workers to run
178 at higher priority.
179
180 If unsure, say N.