Root/fs/squashfs/Kconfig

1config SQUASHFS
2    tristate "SquashFS 4.0 - Squashed file system support"
3    depends on BLOCK
4    select ZLIB_INFLATE
5    help
6      Saying Y here includes support for SquashFS 4.0 (a Compressed
7      Read-Only File System). Squashfs is a highly compressed read-only
8      filesystem for Linux. It uses zlib, lzo or xz compression to
9      compress both files, inodes and directories. Inodes in the system
10      are very small and all blocks are packed to minimise data overhead.
11      Block sizes greater than 4K are supported up to a maximum of 1 Mbytes
12      (default block size 128K). SquashFS 4.0 supports 64 bit filesystems
13      and files (larger than 4GB), full uid/gid information, hard links and
14      timestamps.
15
16      Squashfs is intended for general read-only filesystem use, for
17      archival use (i.e. in cases where a .tar.gz file may be used), and in
18      embedded systems where low overhead is needed. Further information
19      and tools are available from http://squashfs.sourceforge.net.
20
21      If you want to compile this as a module ( = code which can be
22      inserted in and removed from the running kernel whenever you want),
23      say M here and read <file:Documentation/modules.txt>. The module
24      will be called squashfs. Note that the root file system (the one
25      containing the directory /) cannot be compiled as a module.
26
27      If unsure, say N.
28
29config SQUASHFS_XATTR
30    bool "Squashfs XATTR support"
31    depends on SQUASHFS
32    help
33      Saying Y here includes support for extended attributes (xattrs).
34      Xattrs are name:value pairs associated with inodes by
35      the kernel or by users (see the attr(5) manual page).
36
37      If unsure, say N.
38
39config SQUASHFS_LZO
40    bool "Include support for LZO compressed file systems"
41    depends on SQUASHFS
42    select LZO_DECOMPRESS
43    help
44      Saying Y here includes support for reading Squashfs file systems
45      compressed with LZO compression. LZO compression is mainly
46      aimed at embedded systems with slower CPUs where the overheads
47      of zlib are too high.
48
49      LZO is not the standard compression used in Squashfs and so most
50      file systems will be readable without selecting this option.
51
52      If unsure, say N.
53
54config SQUASHFS_XZ
55    bool "Include support for XZ compressed file systems"
56    depends on SQUASHFS
57    select XZ_DEC
58    help
59      Saying Y here includes support for reading Squashfs file systems
60      compressed with XZ compression. XZ gives better compression than
61      the default zlib compression, at the expense of greater CPU and
62      memory overhead.
63
64      XZ is not the standard compression used in Squashfs and so most
65      file systems will be readable without selecting this option.
66
67      If unsure, say N.
68
69config SQUASHFS_EMBEDDED
70    bool "Additional option for memory-constrained systems"
71    depends on SQUASHFS
72    help
73      Saying Y here allows you to specify cache size.
74
75      If unsure, say N.
76
77config SQUASHFS_FRAGMENT_CACHE_SIZE
78    int "Number of fragments cached" if SQUASHFS_EMBEDDED
79    depends on SQUASHFS
80    default "3"
81    help
82      By default SquashFS caches the last 3 fragments read from
83      the filesystem. Increasing this amount may mean SquashFS
84      has to re-read fragments less often from disk, at the expense
85      of extra system memory. Decreasing this amount will mean
86      SquashFS uses less memory at the expense of extra reads from disk.
87
88      Note there must be at least one cached fragment. Anything
89      much more than three will probably not make much difference.
90

Archive Download this file



interactive