From 4b676d2dbed3dadc6ef913d58f85360547fa071e Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 5 Aug 2010 23:42:54 +0100 Subject: [PATCH] Squashfs: update Kconfig and documentation for LZO 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 --- Documentation/filesystems/squashfs.txt | 2 +- fs/squashfs/Kconfig | 18 ++++++++++++++---- 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt index 203f7202cc9e..66699afd66ca 100644 --- a/Documentation/filesystems/squashfs.txt +++ b/Documentation/filesystems/squashfs.txt @@ -2,7 +2,7 @@ SQUASHFS 4.0 FILESYSTEM ======================= Squashfs is a compressed read-only filesystem for Linux. -It uses zlib compression to compress files, inodes and directories. +It uses zlib/lzo compression to compress 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 1Mbytes (default block size 128K). diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index 3da01108c44e..e5f63da64d04 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -5,13 +5,13 @@ config SQUASHFS 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 compression to compress both + 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. + 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 @@ -40,11 +40,21 @@ config SQUASHFS_XATTR 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" + bool "Additional option for memory-constrained systems" depends on SQUASHFS default n help