Commit cc6d3497 authored by Phillip Lougher's avatar Phillip Lougher
Browse files

Squashfs: Make ZLIB compression support optional 



Squashfs now supports XZ and LZO compression in addition to ZLIB.
As such it no longer makes sense to always include ZLIB support.
In particular embedded systems may only use LZO or XZ compression, and
the ability to exclude ZLIB support will reduce kernel size.

Signed-off-by: default avatarPhillip Lougher <phillip@squashfs.org.uk>
parent 812753d6

fs/squashfs/Kconfig

+13 −1
Original line number Diff line number Diff line 
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
@@ -36,6 +35,19 @@ config SQUASHFS_XATTR 


	  If unsure, say N.



config SQUASHFS_ZLIB

	bool "Include support for ZLIB compressed file systems"

	depends on SQUASHFS

	select ZLIB_INFLATE

	default y

	help

	  ZLIB compression is the standard compression used by Squashfs

	  file systems.  It offers a good trade-off between compression

	  achieved and the amount of CPU time and memory necessary to

	  compress and decompress.



	  If unsure, say Y.



config SQUASHFS_LZO

	bool "Include support for LZO compressed file systems"

	depends on SQUASHFS

fs/squashfs/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -4,7 +4,8 @@ 


obj-$(CONFIG_SQUASHFS) += squashfs.o

squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o

squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o

squashfs-y += namei.o super.o symlink.o decompressor.o

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

+6 −0
Original line number Diff line number Diff line
@@ -52,6 +52,12 @@ static const struct squashfs_decompressor squashfs_xz_comp_ops = { 
};

#endif



#ifndef CONFIG_SQUASHFS_ZLIB

static const struct squashfs_decompressor squashfs_zlib_comp_ops = {

	NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0

};

#endif



static const struct squashfs_decompressor squashfs_unknown_comp_ops = {

	NULL, NULL, NULL, 0, "unknown", 0

};

fs/squashfs/decompressor.h

+4 −0
Original line number Diff line number Diff line
@@ -56,4 +56,8 @@ extern const struct squashfs_decompressor squashfs_xz_comp_ops; 
extern const struct squashfs_decompressor squashfs_lzo_comp_ops;

#endif



#ifdef CONFIG_SQUASHFS_ZLIB

extern const struct squashfs_decompressor squashfs_zlib_comp_ops;

#endif



#endif

fs/squashfs/squashfs.h

+0 −3
Original line number Diff line number Diff line
@@ -97,6 +97,3 @@ extern const struct inode_operations squashfs_symlink_inode_ops; 


/* xattr.c */

extern const struct xattr_handler *squashfs_xattr_handlers[];
 


/* zlib_wrapper.c */

extern const struct squashfs_decompressor squashfs_zlib_comp_ops;

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