1 # SPDX-License-Identifier: GPL-2.0-only
2 config SQUASHFS
3 tristate "SquashFS 4.0 - Squashed file
4 depends on BLOCK
5 help
6 Saying Y here includes support for S
7 Read-Only File System). Squashfs is
8 filesystem for Linux. It uses zlib,
9 compress both files, inodes and dire
10 are very small and all blocks are pa
11 Block sizes greater than 4K are supp
12 (default block size 128K). SquashFS
13 and files (larger than 4GB), full ui
14 timestamps.
15
16 Squashfs is intended for general rea
17 archival use (i.e. in cases where a
18 embedded systems where low overhead
19 and tools are available from http://
20
21 If you want to compile this as a mod
22 inserted in and removed from the run
23 say M here. The module will be call
24 file system (the one containing the
25 as a module.
26
27 If unsure, say N.
28
29 choice
30 prompt "File decompression options"
31 depends on SQUASHFS
32 help
33 Squashfs now supports two options fo
34 data. Traditionally Squashfs has de
35 intermediate buffer and then memcopi
36 Squashfs now supports the ability to
37 the page cache.
38
39 If unsure, select "Decompress file d
40
41 config SQUASHFS_FILE_CACHE
42 bool "Decompress file data into an int
43 help
44 Decompress file data into an interme
45 memcopy it into the page cache.
46
47 config SQUASHFS_FILE_DIRECT
48 bool "Decompress files directly into t
49 help
50 Directly decompress file data into t
51 Doing so can significantly improve p
52 it eliminates a memcpy and it also r
53 on the single buffer.
54
55 endchoice
56
57 config SQUASHFS_DECOMP_SINGLE
58 depends on SQUASHFS
59 def_bool n
60
61 config SQUASHFS_DECOMP_MULTI
62 depends on SQUASHFS
63 def_bool n
64
65 config SQUASHFS_DECOMP_MULTI_PERCPU
66 depends on SQUASHFS
67 def_bool n
68
69 config SQUASHFS_CHOICE_DECOMP_BY_MOUNT
70 bool "Select the parallel decompressio
71 depends on SQUASHFS
72 default n
73 select SQUASHFS_DECOMP_SINGLE
74 select SQUASHFS_DECOMP_MULTI
75 select SQUASHFS_DECOMP_MULTI_PERCPU
76 select SQUASHFS_MOUNT_DECOMP_THREADS
77 help
78 Compile all parallel decompression m
79 decompression mode by setting "threa
80 default Decompressor parallelisation
81
82 choice
83 prompt "Select decompression parallel
84 depends on SQUASHFS
85 depends on !SQUASHFS_CHOICE_DECOMP_BY_
86 help
87 Squashfs now supports three parallel
88 decompression. Each one exhibits va
89 decompression performance and CPU an
90
91 If in doubt, select "Single threaded
92
93 config SQUASHFS_COMPILE_DECOMP_SINGLE
94 bool "Single threaded compression"
95 select SQUASHFS_DECOMP_SINGLE
96 help
97 Traditionally Squashfs has used sing
98 Only one block (data or metadata) ca
99 one time. This limits CPU and memor
100
101 config SQUASHFS_COMPILE_DECOMP_MULTI
102 bool "Use multiple decompressors for p
103 select SQUASHFS_DECOMP_MULTI
104 help
105 By default Squashfs uses a single de
106 poor performance on parallel I/O wor
107 machines due to waiting on decompres
108
109 If you have a parallel I/O workload
110 using this option may improve overal
111
112 This decompressor implementation use
113 decompressors per core. It dynamica
114 on a demand basis.
115
116 config SQUASHFS_COMPILE_DECOMP_MULTI_PERCPU
117 bool "Use percpu multiple decompressor
118 select SQUASHFS_DECOMP_MULTI_PERCPU
119 help
120 By default Squashfs uses a single de
121 poor performance on parallel I/O wor
122 machines due to waiting on decompres
123
124 This decompressor implementation use
125 decompressor per core. It uses perc
126 decompression is load-balanced acros
127 endchoice
128
129 config SQUASHFS_MOUNT_DECOMP_THREADS
130 bool "Add the mount parameter 'threads
131 depends on SQUASHFS
132 depends on SQUASHFS_DECOMP_MULTI
133 default n
134 help
135 Use threads= to set the decompressio
136 If SQUASHFS_CHOICE_DECOMP_BY_MOUNT=y
137 threads=<single|multi|percpu|1|2
138 else
139 threads=<2|3|...>
140 The upper limit is num_online_cpus()
141
142 config SQUASHFS_XATTR
143 bool "Squashfs XATTR support"
144 depends on SQUASHFS
145 help
146 Saying Y here includes support for e
147 Xattrs are name:value pairs associat
148 the kernel or by users (see the attr
149
150 If unsure, say N.
151
152 config SQUASHFS_ZLIB
153 bool "Include support for ZLIB compres
154 depends on SQUASHFS
155 select ZLIB_INFLATE
156 default y
157 help
158 ZLIB compression is the standard com
159 file systems. It offers a good trad
160 achieved and the amount of CPU time
161 compress and decompress.
162
163 If unsure, say Y.
164
165 config SQUASHFS_LZ4
166 bool "Include support for LZ4 compress
167 depends on SQUASHFS
168 select LZ4_DECOMPRESS
169 help
170 Saying Y here includes support for r
171 compressed with LZ4 compression. LZ
172 aimed at embedded systems with slowe
173 of zlib are too high.
174
175 LZ4 is not the standard compression
176 file systems will be readable withou
177
178 If unsure, say N.
179
180 config SQUASHFS_LZO
181 bool "Include support for LZO compress
182 depends on SQUASHFS
183 select LZO_DECOMPRESS
184 help
185 Saying Y here includes support for r
186 compressed with LZO compression. LZ
187 aimed at embedded systems with slowe
188 of zlib are too high.
189
190 LZO is not the standard compression
191 file systems will be readable withou
192
193 If unsure, say N.
194
195 config SQUASHFS_XZ
196 bool "Include support for XZ compresse
197 depends on SQUASHFS
198 select XZ_DEC
199 help
200 Saying Y here includes support for r
201 compressed with XZ compression. XZ
202 the default zlib compression, at the
203 memory overhead.
204
205 XZ is not the standard compression u
206 file systems will be readable withou
207
208 If unsure, say N.
209
210 config SQUASHFS_ZSTD
211 bool "Include support for ZSTD compres
212 depends on SQUASHFS
213 select ZSTD_DECOMPRESS
214 help
215 Saying Y here includes support for r
216 compressed with ZSTD compression. Z
217 the default ZLIB compression, while
218
219 ZSTD is not the standard compression
220 file systems will be readable withou
221
222 If unsure, say N.
223
224 config SQUASHFS_4K_DEVBLK_SIZE
225 bool "Use 4K device block size?"
226 depends on SQUASHFS
227 help
228 By default Squashfs sets the dev blo
229 to 1K or the smallest block size sup
230 (if larger). This, because blocks a
231 unaligned in Squashfs, should reduce
232
233 This, however, gives poor performanc
234 the optimal I/O size is 4K (even tho
235 smaller block sizes).
236
237 Using a 4K device block size may als
238 performance for some file access pat
239 accesses of files in filesystem orde
240
241 Setting this option will force Squas
242 size by default.
243
244 If unsure, say N.
245
246 config SQUASHFS_EMBEDDED
247 bool "Additional option for memory-con
248 depends on SQUASHFS
249 help
250 Saying Y here allows you to specify
251
252 If unsure, say N.
253
254 config SQUASHFS_FRAGMENT_CACHE_SIZE
255 int "Number of fragments cached" if SQ
256 depends on SQUASHFS
257 default "3"
258 help
259 By default SquashFS caches the last
260 the filesystem. Increasing this amo
261 has to re-read fragments less often
262 of extra system memory. Decreasing
263 SquashFS uses less memory at the exp
264
265 Note there must be at least one cach
266 much more than three will probably n
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