Signed-off-by: Enrico Jorns <ejo@xxxxxxxxxxxxxx> --- fs/squashfs/Kconfig | 13 +++++ fs/squashfs/Makefile | 1 + fs/squashfs/lz4_wrapper.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 154 insertions(+) create mode 100644 fs/squashfs/lz4_wrapper.c diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index d8ee554..d2de168 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -17,6 +17,19 @@ menuconfig FS_SQUASHFS embedded systems where low overhead is needed. Further information and tools are available from http://squashfs.sourceforge.net. +config SQUASHFS_LZ4 + bool "Include support for LZ4 compressed file systems" + depends on FS_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. + config SQUASHFS_LZO bool "Include support for LZO compressed file systems" default y diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile index 447e15e..8590b09 100644 --- a/fs/squashfs/Makefile +++ b/fs/squashfs/Makefile @@ -12,3 +12,4 @@ obj-y += namei.o obj-y += super.o obj-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o obj-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o +obj-$(CONFIG_SQUASHFS_LZ4) += lz4_wrapper.o diff --git a/fs/squashfs/lz4_wrapper.c b/fs/squashfs/lz4_wrapper.c new file mode 100644 index 0000000..6ca6a32 --- /dev/null +++ b/fs/squashfs/lz4_wrapper.c @@ -0,0 +1,140 @@ +/* + * Copyright (c) 2013, 2014 + * Phillip Lougher <phillip@xxxxxxxxxxxxxxx> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include <types.h> +#include <linux/mutex.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, + char **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] + offset, avail); + buff += avail; + bytes -= avail; + offset = 0; + kfree(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 +}; -- 2.9.3 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
