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22635ec9 AD |
1 | config 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 | |
4b676d2d | 8 | filesystem for Linux. It uses zlib/lzo compression to compress both |
22635ec9 AD |
9 | files, inodes and directories. Inodes in the system are very small |
10 | and all blocks are packed to minimise data overhead. Block sizes | |
11 | greater than 4K are supported up to a maximum of 1 Mbytes (default | |
12 | block size 128K). SquashFS 4.0 supports 64 bit filesystems and files | |
13 | (larger than 4GB), full uid/gid information, hard links and | |
4b676d2d | 14 | timestamps. |
22635ec9 AD |
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 | ||
637d5c9a | 29 | config SQUASHFS_XATTR |
01e5b4e4 PL |
30 | bool "Squashfs XATTR support" |
31 | depends on SQUASHFS | |
32 | default n | |
33 | help | |
34 | Saying Y here includes support for extended attributes (xattrs). | |
35 | Xattrs are name:value pairs associated with inodes by | |
36 | the kernel or by users (see the attr(5) manual page). | |
37 | ||
38 | If unsure, say N. | |
39 | ||
79cb8ced CJ |
40 | config SQUASHFS_LZO |
41 | bool "Include support for LZO compressed file systems" | |
42 | depends on SQUASHFS | |
4b676d2d | 43 | default n |
79cb8ced | 44 | select LZO_DECOMPRESS |
4b676d2d PL |
45 | help |
46 | Saying Y here includes support for reading Squashfs file systems | |
47 | compressed with LZO compresssion. LZO compression is mainly | |
48 | aimed at embedded systems with slower CPUs where the overheads | |
49 | of zlib are too high. | |
79cb8ced | 50 | |
4b676d2d PL |
51 | LZO is not the standard compression used in Squashfs and so most |
52 | file systems will be readable without selecting this option. | |
22635ec9 | 53 | |
4b676d2d PL |
54 | If unsure, say N. |
55 | ||
56 | config SQUASHFS_EMBEDDED | |
57 | bool "Additional option for memory-constrained systems" | |
22635ec9 AD |
58 | depends on SQUASHFS |
59 | default n | |
60 | help | |
61 | Saying Y here allows you to specify cache size. | |
62 | ||
63 | If unsure, say N. | |
64 | ||
65 | config SQUASHFS_FRAGMENT_CACHE_SIZE | |
66 | int "Number of fragments cached" if SQUASHFS_EMBEDDED | |
67 | depends on SQUASHFS | |
68 | default "3" | |
69 | help | |
70 | By default SquashFS caches the last 3 fragments read from | |
71 | the filesystem. Increasing this amount may mean SquashFS | |
72 | has to re-read fragments less often from disk, at the expense | |
73 | of extra system memory. Decreasing this amount will mean | |
74 | SquashFS uses less memory at the expense of extra reads from disk. | |
75 | ||
76 | Note there must be at least one cached fragment. Anything | |
77 | much more than three will probably not make much difference. |