tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2
3config EROFS_FS
4 tristate "EROFS filesystem support"
5 depends on BLOCK
6 help
7 EROFS(Enhanced Read-Only File System) is a lightweight
8 read-only file system with modern designs (eg. page-sized
9 blocks, inline xattrs/data, etc.) for scenarios which need
10 high-performance read-only requirements, eg. firmwares in
11 mobile phone or LIVECDs.
12
13 It also provides VLE compression support, focusing on
14 random read improvements, keeping relatively lower
15 compression ratios, which is useful for high-performance
16 devices with limited memory and ROM space.
17
18 If unsure, say N.
19
20config EROFS_FS_DEBUG
21 bool "EROFS debugging feature"
22 depends on EROFS_FS
23 help
24 Print EROFS debugging messages and enable more BUG_ONs
25 which check the filesystem consistency aggressively.
26
27 For daily use, say N.
28
29config EROFS_FS_XATTR
30 bool "EROFS extended attributes"
31 depends on EROFS_FS
32 default y
33 help
34 Extended attributes are name:value pairs associated with inodes by
35 the kernel or by users (see the attr(5) manual page, or visit
36 <http://acl.bestbits.at/> for details).
37
38 If unsure, say N.
39
40config EROFS_FS_POSIX_ACL
41 bool "EROFS Access Control Lists"
42 depends on EROFS_FS_XATTR
43 select FS_POSIX_ACL
44 default y
45 help
46 Posix Access Control Lists (ACLs) support permissions for users and
47 groups beyond the owner/group/world scheme.
48
49 To learn more about Access Control Lists, visit the POSIX ACLs for
50 Linux website <http://acl.bestbits.at/>.
51
52 If you don't know what Access Control Lists are, say N.
53
54config EROFS_FS_SECURITY
55 bool "EROFS Security Labels"
56 depends on EROFS_FS_XATTR
57 help
58 Security labels provide an access control facility to support Linux
59 Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
60 Linux. This option enables an extended attribute handler for file
61 security labels in the erofs filesystem, so that it requires enabling
62 the extended attribute support in advance.
63
64 If you are not using a security module, say N.
65
66config EROFS_FS_USE_VM_MAP_RAM
67 bool "EROFS VM_MAP_RAM Support"
68 depends on EROFS_FS
69 help
70 use vm_map_ram/vm_unmap_ram instead of vmap/vunmap.
71
72 If you don't know what these are, say N.
73
74config EROFS_FAULT_INJECTION
75 bool "EROFS fault injection facility"
76 depends on EROFS_FS
77 help
78 Test EROFS to inject faults such as ENOMEM, EIO, and so on.
79 If unsure, say N.
80
81config EROFS_FS_IO_MAX_RETRIES
82 int "EROFS IO Maximum Retries"
83 depends on EROFS_FS
84 default "5"
85 help
86 Maximum retry count of IO Errors.
87
88 If unsure, leave the default value (5 retries, 6 IOs at most).
89
90config EROFS_FS_ZIP
91 bool "EROFS Data Compresssion Support"
92 depends on EROFS_FS
93 select LZ4_DECOMPRESS
94 help
95 Currently we support LZ4 VLE Compression only.
96 Play at your own risk.
97
98 If you don't want to use compression feature, say N.
99
100config EROFS_FS_CLUSTER_PAGE_LIMIT
101 int "EROFS Cluster Pages Hard Limit"
102 depends on EROFS_FS_ZIP
103 range 1 256
104 default "1"
105 help
106 Indicates VLE compressed pages hard limit of a
107 compressed cluster.
108
109 For example, if files of a image are compressed
110 into 8k-unit, the hard limit should not be less
111 than 2. Otherwise, the image cannot be mounted
112 correctly on this kernel.
113
114choice
115 prompt "EROFS VLE Data Decompression mode"
116 depends on EROFS_FS_ZIP
117 default EROFS_FS_ZIP_CACHE_BIPOLAR
118 help
119 EROFS supports three options for VLE decompression.
120 "In-place Decompression Only" consumes the minimum memory
121 with lowest random read.
122
123 "Bipolar Cached Decompression" consumes the maximum memory
124 with highest random read.
125
126 If unsure, select "Bipolar Cached Decompression"
127
128config EROFS_FS_ZIP_NO_CACHE
129 bool "In-place Decompression Only"
130 help
131 Read compressed data into page cache and do in-place
132 decompression directly.
133
134config EROFS_FS_ZIP_CACHE_UNIPOLAR
135 bool "Unipolar Cached Decompression"
136 help
137 For each request, it caches the last compressed page
138 for further reading.
139 It still decompresses in place for the rest compressed pages.
140
141config EROFS_FS_ZIP_CACHE_BIPOLAR
142 bool "Bipolar Cached Decompression"
143 help
144 For each request, it caches the both end compressed pages
145 for further reading.
146 It still decompresses in place for the rest compressed pages.
147
148 Recommended for performance priority.
149
150endchoice
151