mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-14 07:44:21 +08:00
4b676d2dbe
Update compression types supported and add some help text for the LZO Kconfig option. Also add missing "default n" line and make some trivial whitespace cleanups too. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
78 lines
2.8 KiB
Plaintext
78 lines
2.8 KiB
Plaintext
config SQUASHFS
|
|
tristate "SquashFS 4.0 - Squashed file system support"
|
|
depends on BLOCK
|
|
select ZLIB_INFLATE
|
|
help
|
|
Saying Y here includes support for SquashFS 4.0 (a Compressed
|
|
Read-Only File System). Squashfs is a highly compressed read-only
|
|
filesystem for Linux. It uses zlib/lzo compression to compress both
|
|
files, inodes and directories. Inodes in the system are very small
|
|
and all blocks are packed to minimise data overhead. Block sizes
|
|
greater than 4K are supported up to a maximum of 1 Mbytes (default
|
|
block size 128K). SquashFS 4.0 supports 64 bit filesystems and files
|
|
(larger than 4GB), full uid/gid information, hard links and
|
|
timestamps.
|
|
|
|
Squashfs is intended for general read-only filesystem use, for
|
|
archival use (i.e. in cases where a .tar.gz file may be used), and in
|
|
embedded systems where low overhead is needed. Further information
|
|
and tools are available from http://squashfs.sourceforge.net.
|
|
|
|
If you want to compile this as a module ( = code which can be
|
|
inserted in and removed from the running kernel whenever you want),
|
|
say M here and read <file:Documentation/modules.txt>. The module
|
|
will be called squashfs. Note that the root file system (the one
|
|
containing the directory /) cannot be compiled as a module.
|
|
|
|
If unsure, say N.
|
|
|
|
config SQUASHFS_XATTR
|
|
bool "Squashfs XATTR support"
|
|
depends on SQUASHFS
|
|
default n
|
|
help
|
|
Saying Y here includes support for extended attributes (xattrs).
|
|
Xattrs are name:value pairs associated with inodes by
|
|
the kernel or by users (see the attr(5) manual page).
|
|
|
|
If unsure, say N.
|
|
|
|
config SQUASHFS_LZO
|
|
bool "Include support for LZO compressed file systems"
|
|
depends on SQUASHFS
|
|
default n
|
|
select LZO_DECOMPRESS
|
|
help
|
|
Saying Y here includes support for reading Squashfs file systems
|
|
compressed with LZO compresssion. LZO compression is mainly
|
|
aimed at embedded systems with slower CPUs where the overheads
|
|
of zlib are too high.
|
|
|
|
LZO is not the standard compression used in Squashfs and so most
|
|
file systems will be readable without selecting this option.
|
|
|
|
If unsure, say N.
|
|
|
|
config SQUASHFS_EMBEDDED
|
|
bool "Additional option for memory-constrained systems"
|
|
depends on SQUASHFS
|
|
default n
|
|
help
|
|
Saying Y here allows you to specify cache size.
|
|
|
|
If unsure, say N.
|
|
|
|
config SQUASHFS_FRAGMENT_CACHE_SIZE
|
|
int "Number of fragments cached" if SQUASHFS_EMBEDDED
|
|
depends on SQUASHFS
|
|
default "3"
|
|
help
|
|
By default SquashFS caches the last 3 fragments read from
|
|
the filesystem. Increasing this amount may mean SquashFS
|
|
has to re-read fragments less often from disk, at the expense
|
|
of extra system memory. Decreasing this amount will mean
|
|
SquashFS uses less memory at the expense of extra reads from disk.
|
|
|
|
Note there must be at least one cached fragment. Anything
|
|
much more than three will probably not make much difference.
|