136 строки
3.2 KiB
C
136 строки
3.2 KiB
C
/*
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* Squashfs - a compressed read only filesystem for Linux
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*
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* Copyright (c) 2010 LG Electronics
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* Chan Jeong <chan.jeong@lge.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2,
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* or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* lzo_wrapper.c
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*/
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#include <linux/mutex.h>
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#include <linux/buffer_head.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/lzo.h>
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#include "squashfs_fs.h"
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#include "squashfs_fs_sb.h"
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#include "squashfs.h"
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#include "decompressor.h"
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struct squashfs_lzo {
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void *input;
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void *output;
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};
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static void *lzo_init(struct squashfs_sb_info *msblk, void *buff, int len)
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{
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int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
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struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
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if (stream == NULL)
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goto failed;
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stream->input = vmalloc(block_size);
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if (stream->input == NULL)
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goto failed;
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stream->output = vmalloc(block_size);
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if (stream->output == NULL)
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goto failed2;
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return stream;
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failed2:
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vfree(stream->input);
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failed:
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ERROR("Failed to allocate lzo workspace\n");
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kfree(stream);
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return ERR_PTR(-ENOMEM);
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}
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static void lzo_free(void *strm)
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{
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struct squashfs_lzo *stream = strm;
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if (stream) {
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vfree(stream->input);
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vfree(stream->output);
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}
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kfree(stream);
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}
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static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer,
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struct buffer_head **bh, int b, int offset, int length, int srclength,
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int pages)
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{
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struct squashfs_lzo *stream = msblk->stream;
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void *buff = stream->input;
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int avail, i, bytes = length, res;
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size_t out_len = srclength;
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mutex_lock(&msblk->read_data_mutex);
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for (i = 0; i < b; i++) {
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wait_on_buffer(bh[i]);
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if (!buffer_uptodate(bh[i]))
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goto block_release;
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avail = min(bytes, msblk->devblksize - offset);
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memcpy(buff, bh[i]->b_data + offset, avail);
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buff += avail;
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bytes -= avail;
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offset = 0;
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put_bh(bh[i]);
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}
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res = lzo1x_decompress_safe(stream->input, (size_t)length,
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stream->output, &out_len);
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if (res != LZO_E_OK)
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goto failed;
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res = bytes = (int)out_len;
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for (i = 0, buff = stream->output; bytes && i < pages; i++) {
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avail = min_t(int, bytes, PAGE_CACHE_SIZE);
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memcpy(buffer[i], buff, avail);
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buff += avail;
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bytes -= avail;
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}
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mutex_unlock(&msblk->read_data_mutex);
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return res;
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block_release:
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for (; i < b; i++)
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put_bh(bh[i]);
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failed:
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mutex_unlock(&msblk->read_data_mutex);
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ERROR("lzo decompression failed, data probably corrupt\n");
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return -EIO;
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}
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const struct squashfs_decompressor squashfs_lzo_comp_ops = {
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.init = lzo_init,
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.free = lzo_free,
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.decompress = lzo_uncompress,
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.id = LZO_COMPRESSION,
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.name = "lzo",
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.supported = 1
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};
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