diff options
| -rw-r--r-- | Documentation/filesystems/squashfs.txt | 8 | ||||
| -rw-r--r-- | fs/squashfs/Kconfig | 15 | ||||
| -rw-r--r-- | fs/squashfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/squashfs/decompressor.c | 7 | ||||
| -rw-r--r-- | fs/squashfs/decompressor.h | 4 | ||||
| -rw-r--r-- | fs/squashfs/lz4_wrapper.c | 142 | ||||
| -rw-r--r-- | fs/squashfs/squashfs_fs.h | 1 |
7 files changed, 174 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 diff --git a/fs/squashfs/lz4_wrapper.c b/fs/squashfs/lz4_wrapper.c new file mode 100644 index 000000000000..c31e2bc9c081 --- /dev/null +++ b/fs/squashfs/lz4_wrapper.c @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2013, 2014 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include <linux/buffer_head.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/lz4.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +#define LZ4_LEGACY 1 + +struct lz4_comp_opts { + __le32 version; + __le32 flags; +}; + +struct squashfs_lz4 { + void *input; + void *output; +}; + + +static void *lz4_comp_opts(struct squashfs_sb_info *msblk, + void *buff, int len) +{ + struct lz4_comp_opts *comp_opts = buff; + + /* LZ4 compressed filesystems always have compression options */ + if (comp_opts == NULL || len < sizeof(*comp_opts)) + return ERR_PTR(-EIO); + + if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) { + /* LZ4 format currently used by the kernel is the 'legacy' + * format */ + ERROR("Unknown LZ4 version\n"); + return ERR_PTR(-EINVAL); + } + + return NULL; +} + + +static void *lz4_init(struct squashfs_sb_info *msblk, void *buff) +{ + int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); + struct squashfs_lz4 *stream; + + stream = kzalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) + goto failed; + stream->input = vmalloc(block_size); + if (stream->input == NULL) + goto failed2; + stream->output = vmalloc(block_size); + if (stream->output == NULL) + goto failed3; + + return stream; + +failed3: + vfree(stream->input); +failed2: + kfree(stream); +failed: + ERROR("Failed to initialise LZ4 decompressor\n"); + return ERR_PTR(-ENOMEM); +} + + +static void lz4_free(void *strm) +{ + struct squashfs_lz4 *stream = strm; + + if (stream) { + vfree(stream->input); + vfree(stream->output); + } + kfree(stream); +} + + +static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct buffer_head **bh, int b, int offset, int length, + struct squashfs_page_actor *output) +{ + struct squashfs_lz4 *stream = strm; + void *buff = stream->input, *data; + int avail, i, bytes = length, res; + size_t dest_len = output->length; + + for (i = 0; i < b; i++) { + avail = min(bytes, msblk->devblksize - offset); + memcpy(buff, bh[i]->b_data + offset, avail); + buff += avail; + bytes -= avail; + offset = 0; + put_bh(bh[i]); + } + + res = lz4_decompress_unknownoutputsize(stream->input, length, + stream->output, &dest_len); + if (res) + return -EIO; + + bytes = dest_len; + data = squashfs_first_page(output); + buff = stream->output; + while (data) { + if (bytes <= PAGE_CACHE_SIZE) { + memcpy(data, buff, bytes); + break; + } + memcpy(data, buff, PAGE_CACHE_SIZE); + buff += PAGE_CACHE_SIZE; + bytes -= PAGE_CACHE_SIZE; + data = squashfs_next_page(output); + } + squashfs_finish_page(output); + + return dest_len; +} + +const struct squashfs_decompressor squashfs_lz4_comp_ops = { + .init = lz4_init, + .comp_opts = lz4_comp_opts, + .free = lz4_free, + .decompress = lz4_uncompress, + .id = LZ4_COMPRESSION, + .name = "lz4", + .supported = 1 +}; diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h index 4b2beda49498..506f4ba5b983 100644 --- a/fs/squashfs/squashfs_fs.h +++ b/fs/squashfs/squashfs_fs.h @@ -240,6 +240,7 @@ struct meta_index { #define LZMA_COMPRESSION 2 #define LZO_COMPRESSION 3 #define XZ_COMPRESSION 4 +#define LZ4_COMPRESSION 5 struct squashfs_super_block { __le32 s_magic; |
