xref: /openbmc/linux/fs/erofs/Kconfig (revision d6f1e0bfe532b2ec725d9f768ca305af7aa1029a)
1 # SPDX-License-Identifier: GPL-2.0-only
2 
3 config 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 	  for more details.
25 
26 	  If unsure, say N.
27 
28 config 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 
38 config EROFS_FS_XATTR
39 	bool "EROFS extended attributes"
40 	depends on EROFS_FS
41 	default y
42 	help
43 	  Extended attributes are name:value pairs associated with inodes by
44 	  the kernel or by users (see the attr(5) manual page, or visit
45 	  <http://acl.bestbits.at/> for details).
46 
47 	  If unsure, say N.
48 
49 config EROFS_FS_POSIX_ACL
50 	bool "EROFS Access Control Lists"
51 	depends on EROFS_FS_XATTR
52 	select FS_POSIX_ACL
53 	default y
54 	help
55 	  Posix Access Control Lists (ACLs) support permissions for users and
56 	  groups beyond the owner/group/world scheme.
57 
58 	  To learn more about Access Control Lists, visit the POSIX ACLs for
59 	  Linux website <http://acl.bestbits.at/>.
60 
61 	  If you don't know what Access Control Lists are, say N.
62 
63 config EROFS_FS_SECURITY
64 	bool "EROFS Security Labels"
65 	depends on EROFS_FS_XATTR
66 	default y
67 	help
68 	  Security labels provide an access control facility to support Linux
69 	  Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
70 	  Linux. This option enables an extended attribute handler for file
71 	  security labels in the erofs filesystem, so that it requires enabling
72 	  the extended attribute support in advance.
73 
74 	  If you are not using a security module, say N.
75 
76 config EROFS_FS_ZIP
77 	bool "EROFS Data Compression Support"
78 	depends on EROFS_FS
79 	select LZ4_DECOMPRESS
80 	default y
81 	help
82 	  Enable fixed-sized output compression for EROFS.
83 
84 	  If you don't want to enable compression feature, say N.
85 
86 config EROFS_FS_ZIP_LZMA
87 	bool "EROFS LZMA compressed data support"
88 	depends on EROFS_FS_ZIP
89 	select XZ_DEC
90 	select XZ_DEC_MICROLZMA
91 	help
92 	  Saying Y here includes support for reading EROFS file systems
93 	  containing LZMA compressed data, specifically called microLZMA. it
94 	  gives better compression ratios than the LZ4 algorithm, at the
95 	  expense of more CPU overhead.
96 
97 	  LZMA support is an experimental feature for now and so most file
98 	  systems will be readable without selecting this option.
99 
100 	  If unsure, say N.
101 
102 config EROFS_FS_ONDEMAND
103 	bool "EROFS fscache-based on-demand read support"
104 	depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
105 	default n
106 	help
107 	  This permits EROFS to use fscache-backed data blobs with on-demand
108 	  read support.
109 
110 	  If unsure, say N.
111 
112 config EROFS_FS_PCPU_KTHREAD
113 	bool "EROFS per-cpu decompression kthread workers"
114 	depends on EROFS_FS_ZIP
115 	help
116 	  Saying Y here enables per-CPU kthread workers pool to carry out
117 	  async decompression for low latencies on some architectures.
118 
119 	  If unsure, say N.
120 
121 config EROFS_FS_PCPU_KTHREAD_HIPRI
122 	bool "EROFS high priority per-CPU kthread workers"
123 	depends on EROFS_FS_ZIP && EROFS_FS_PCPU_KTHREAD
124 	default y
125 	help
126 	  This permits EROFS to configure per-CPU kthread workers to run
127 	  at higher priority.
128 
129 	  If unsure, say N.
130