From 79cb8ced7eef53856b5a877db0544acf52e00c80 Mon Sep 17 00:00:00 2001 From: Chan Jeong Date: Thu, 5 Aug 2010 02:29:59 +0100 Subject: Squashfs: Add LZO compression support Signed-off-by: Chan Jeong Signed-off-by: Phillip Lougher --- fs/squashfs/lzo_wrapper.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 fs/squashfs/lzo_wrapper.c (limited to 'fs/squashfs/lzo_wrapper.c') diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c new file mode 100644 index 0000000..e1f86de --- /dev/null +++ b/fs/squashfs/lzo_wrapper.c @@ -0,0 +1,134 @@ +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2010 LG Electronics + * Chan Jeong + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2, + * or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * lzo_wrapper.c + */ + +#include +#include +#include +#include +#include + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "decompressor.h" + +struct squashfs_lzo { + void *input; + void *output; +}; + +static void *lzo_init(struct squashfs_sb_info *msblk) +{ + struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) + goto failed; + stream->input = vmalloc(msblk->block_size); + if (stream->input == NULL) + goto failed; + stream->output = vmalloc(msblk->block_size); + if (stream->output == NULL) + goto failed2; + + return stream; + +failed2: + vfree(stream->input); +failed: + ERROR("Failed to allocate lzo workspace\n"); + kfree(stream); + return NULL; +} + + +static void lzo_free(void *strm) +{ + struct squashfs_lzo *stream = strm; + + if (stream) { + vfree(stream->input); + vfree(stream->output); + } + kfree(stream); +} + + +static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer, + struct buffer_head **bh, int b, int offset, int length, int srclength, + int pages) +{ + struct squashfs_lzo *stream = msblk->stream; + void *buff = stream->input; + int avail, i, bytes = length, res; + size_t out_len = msblk->block_size; + + mutex_lock(&msblk->read_data_mutex); + + for (i = 0; i < b; i++) { + wait_on_buffer(bh[i]); + if (!buffer_uptodate(bh[i])) + goto block_release; + + 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 = lzo1x_decompress_safe(stream->input, (size_t)length, + stream->output, &out_len); + if (res != LZO_E_OK) + goto failed; + + res = bytes = (int)out_len; + for (i = 0, buff = stream->output; bytes && i < pages; i++) { + avail = min_t(int, bytes, PAGE_CACHE_SIZE); + memcpy(buffer[i], buff, avail); + buff += avail; + bytes -= avail; + } + + mutex_unlock(&msblk->read_data_mutex); + return res; + +block_release: + for (; i < b; i++) + put_bh(bh[i]); + +failed: + mutex_unlock(&msblk->read_data_mutex); + + ERROR("lzo decompression failed, data probably corrupt\n"); + return -EIO; +} + +const struct squashfs_decompressor squashfs_lzo_comp_ops = { + .init = lzo_init, + .free = lzo_free, + .decompress = lzo_uncompress, + .id = LZO_COMPRESSION, + .name = "lzo", + .supported = 1 +}; -- cgit v1.1