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.
146