Commit 7a02d089 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next 

Pull squashfs update from Phillip Lougher:
 "These patches optionally add LZ4 compression support to Squashfs.

  LZ4 is a lightweight compression algorithm which can be used on
  embedded systems to reduce CPU and memory overhead (in comparison to
  the standard zlib compression).

  These patches add the wrapper code to allow Squashfs to use the
  existing LZ4 decompression code, and the necessary configuration
  option"

* tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
  Squashfs: Add LZ4 compression configuration option
  Squashfs: add LZ4 compression support
parents 980f3c34 62421645

Documentation/filesystems/squashfs.txt

+4 −4
Original line number Diff line number Diff line
@@ -2,10 +2,10 @@ SQUASHFS 4.0 FILESYSTEM 
=======================



Squashfs is a compressed read-only filesystem for Linux.

It uses zlib/lzo/xz 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).

It uses zlib, lz4, lzo, or xz 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).



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 constrained

fs/squashfs/Kconfig

+15 −0
Original line number Diff line number Diff line
@@ -120,6 +120,21 @@ config SQUASHFS_ZLIB 


	  If unsure, say Y.



config SQUASHFS_LZ4

	bool "Include support for LZ4 compressed file systems"

	depends on SQUASHFS

	select LZ4_DECOMPRESS

	help

	  Saying Y here includes support for reading Squashfs file systems

	  compressed with LZ4 compression.  LZ4 compression is mainly

	  aimed at embedded systems with slower CPUs where the overheads

	  of zlib are too high.



	  LZ4 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_LZO

	bool "Include support for LZO compressed file systems"

	depends on SQUASHFS

fs/squashfs/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ squashfs-$(CONFIG_SQUASHFS_DECOMP_SINGLE) += decompressor_single.o 
squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI) += decompressor_multi.o

squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) += decompressor_multi_percpu.o

squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o

squashfs-$(CONFIG_SQUASHFS_LZ4) += lz4_wrapper.o

squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o

squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o

squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o

fs/squashfs/decompressor.c

+7 −0
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { 
	NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0

};



#ifndef CONFIG_SQUASHFS_LZ4

static const struct squashfs_decompressor squashfs_lz4_comp_ops = {

	NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0

};

#endif



#ifndef CONFIG_SQUASHFS_LZO

static const struct squashfs_decompressor squashfs_lzo_comp_ops = {

	NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
@@ -65,6 +71,7 @@ static const struct squashfs_decompressor squashfs_unknown_comp_ops = { 


static const struct squashfs_decompressor *decompressor[] = {

	&squashfs_zlib_comp_ops,

	&squashfs_lz4_comp_ops,

	&squashfs_lzo_comp_ops,

	&squashfs_xz_comp_ops,

	&squashfs_lzma_unsupported_comp_ops,

fs/squashfs/decompressor.h

+4 −0
Original line number Diff line number Diff line
@@ -46,6 +46,10 @@ static inline void *squashfs_comp_opts(struct squashfs_sb_info *msblk, 
extern const struct squashfs_decompressor squashfs_xz_comp_ops;

#endif



#ifdef CONFIG_SQUASHFS_LZ4

extern const struct squashfs_decompressor squashfs_lz4_comp_ops;

#endif



#ifdef CONFIG_SQUASHFS_LZO

extern const struct squashfs_decompressor squashfs_lzo_comp_ops;

#endif

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