From 62421645bb702c077ee5a462815525106cb53bcf Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 27 Nov 2014 18:48:44 +0000 Subject: [PATCH] Squashfs: Add LZ4 compression configuration option Add the glue code, and also update the documentation. Signed-off-by: Phillip Lougher --- Documentation/filesystems/squashfs.txt | 8 ++++---- fs/squashfs/Kconfig | 15 +++++++++++++++ fs/squashfs/Makefile | 1 + fs/squashfs/decompressor.c | 7 +++++++ fs/squashfs/decompressor.h | 4 ++++ 5 files changed, 31 insertions(+), 4 deletions(-) diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt index 403c090aca39..e5274f84dc56 100644 --- a/Documentation/filesystems/squashfs.txt +++ b/Documentation/filesystems/squashfs.txt @@ -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 diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index b6fa8657dcbc..ffb093e72b6c 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -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 diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile index 4132520b4ff2..246a6f329d89 100644 --- a/fs/squashfs/Makefile +++ b/fs/squashfs/Makefile @@ -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 diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c index ac22fe73b0ad..e9034bf6e5ae 100644 --- a/fs/squashfs/decompressor.c +++ b/fs/squashfs/decompressor.c @@ -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, diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h index af0985321808..a25713c031a5 100644 --- a/fs/squashfs/decompressor.h +++ b/fs/squashfs/decompressor.h @@ -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 -- 2.30.2