Squashfs: Add LZ4 compression configuration option (62421645) · Commits · 戴 / test

Documentation/filesystems/squashfs.txt

+4 −4

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		@@ -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

+15 −0

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		@@ -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

+1 −0

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		@@ -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

+7 −0

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		@@ -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,

+4 −0

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		@@ -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