LXR linux/fs/squashfs/lzo

   1/*
   2 * Squashfs - a compressed read only filesystem for Linux
   3 *
   4 * Copyright (c) 2010 LG Electronics
   5 * Chan Jeong <chan.jeong@lge.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; either version 2,
  10 * or (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20 *
  21 * lzo_wrapper.c
  22 */
  23
  24#include <linux/mutex.h>
  25#include <linux/buffer_head.h>
  26#include <linux/slab.h>
  27#include <linux/vmalloc.h>
  28#include <linux/lzo.h>
  29
  30#include "squashfs_fs.h"
  31#include "squashfs_fs_sb.h"
  32#include "squashfs.h"
  33#include "decompressor.h"
  34#include "page_actor.h"
  35
  36struct squashfs_lzo {
  37        void    *input;
  38        void    *output;
  39};
  40
  41static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
  42{
  43        int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
  44
  45        struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
  46        if (stream == NULL)
  47                goto failed;
  48        stream->input = vmalloc(block_size);
  49        if (stream->input == NULL)
  50                goto failed;
  51        stream->output = vmalloc(block_size);
  52        if (stream->output == NULL)
  53                goto failed2;
  54
  55        return stream;
  56
  57failed2:
  58        vfree(stream->input);
  59failed:
  60        ERROR("Failed to allocate lzo workspace\n");
  61        kfree(stream);
  62        return ERR_PTR(-ENOMEM);
  63}
  64
  65
  66static void lzo_free(void *strm)
  67{
  68        struct squashfs_lzo *stream = strm;
  69
  70        if (stream) {
  71                vfree(stream->input);
  72                vfree(stream->output);
  73        }
  74        kfree(stream);
  75}
  76
  77
  78static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
  79        struct buffer_head **bh, int b, int offset, int length,
  80        struct squashfs_page_actor *output)
  81{
  82        struct squashfs_lzo *stream = strm;
  83        void *buff = stream->input, *data;
  84        int avail, i, bytes = length, res;
  85        size_t out_len = output->length;
  86
  87        for (i = 0; i < b; i++) {
  88                avail = min(bytes, msblk->devblksize - offset);
  89                memcpy(buff, bh[i]->b_data + offset, avail);
  90                buff += avail;
  91                bytes -= avail;
  92                offset = 0;
  93                put_bh(bh[i]);
  94        }
  95
  96        res = lzo1x_decompress_safe(stream->input, (size_t)length,
  97                                        stream->output, &out_len);
  98        if (res != LZO_E_OK)
  99                goto failed;
 100
 101        res = bytes = (int)out_len;
 102        data = squashfs_first_page(output);
 103        buff = stream->output;
 104        while (data) {
 105                if (bytes <= PAGE_SIZE) {
 106                        memcpy(data, buff, bytes);
 107                        break;
 108                } else {
 109                        memcpy(data, buff, PAGE_SIZE);
 110                        buff += PAGE_SIZE;
 111                        bytes -= PAGE_SIZE;
 112                        data = squashfs_next_page(output);
 113                }
 114        }
 115        squashfs_finish_page(output);
 116
 117        return res;
 118
 119failed:
 120        return -EIO;
 121}
 122
 123const struct squashfs_decompressor squashfs_lzo_comp_ops = {
 124        .init = lzo_init,
 125        .free = lzo_free,
 126        .decompress = lzo_uncompress,
 127        .id = LZO_COMPRESSION,
 128        .name = "lzo",
 129        .supported = 1
 130};
 131