LXR linux/fs/squashfs/lzo

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Squashfs - a compressed read only filesystem for Linux
   4 *
   5 * Copyright (c) 2010 LG Electronics
   6 * Chan Jeong <chan.jeong@lge.com>
   7 *
   8 * lzo_wrapper.c
   9 */
  10
  11#include <linux/mutex.h>
  12#include <linux/bio.h>
  13#include <linux/slab.h>
  14#include <linux/vmalloc.h>
  15#include <linux/lzo.h>
  16
  17#include "squashfs_fs.h"
  18#include "squashfs_fs_sb.h"
  19#include "squashfs.h"
  20#include "decompressor.h"
  21#include "page_actor.h"
  22
  23struct squashfs_lzo {
  24        void    *input;
  25        void    *output;
  26};
  27
  28static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
  29{
  30        int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
  31
  32        struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
  33        if (stream == NULL)
  34                goto failed;
  35        stream->input = vmalloc(block_size);
  36        if (stream->input == NULL)
  37                goto failed;
  38        stream->output = vmalloc(block_size);
  39        if (stream->output == NULL)
  40                goto failed2;
  41
  42        return stream;
  43
  44failed2:
  45        vfree(stream->input);
  46failed:
  47        ERROR("Failed to allocate lzo workspace\n");
  48        kfree(stream);
  49        return ERR_PTR(-ENOMEM);
  50}
  51
  52
  53static void lzo_free(void *strm)
  54{
  55        struct squashfs_lzo *stream = strm;
  56
  57        if (stream) {
  58                vfree(stream->input);
  59                vfree(stream->output);
  60        }
  61        kfree(stream);
  62}
  63
  64
  65static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
  66        struct bio *bio, int offset, int length,
  67        struct squashfs_page_actor *output)
  68{
  69        struct bvec_iter_all iter_all = {};
  70        struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
  71        struct squashfs_lzo *stream = strm;
  72        void *buff = stream->input, *data;
  73        int bytes = length, res;
  74        size_t out_len = output->length;
  75
  76        while (bio_next_segment(bio, &iter_all)) {
  77                int avail = min(bytes, ((int)bvec->bv_len) - offset);
  78
  79                data = page_address(bvec->bv_page) + bvec->bv_offset;
  80                memcpy(buff, data + offset, avail);
  81                buff += avail;
  82                bytes -= avail;
  83                offset = 0;
  84        }
  85
  86        res = lzo1x_decompress_safe(stream->input, (size_t)length,
  87                                        stream->output, &out_len);
  88        if (res != LZO_E_OK)
  89                goto failed;
  90
  91        res = bytes = (int)out_len;
  92        data = squashfs_first_page(output);
  93        buff = stream->output;
  94        while (data) {
  95                if (bytes <= PAGE_SIZE) {
  96                        memcpy(data, buff, bytes);
  97                        break;
  98                } else {
  99                        memcpy(data, buff, PAGE_SIZE);
 100                        buff += PAGE_SIZE;
 101                        bytes -= PAGE_SIZE;
 102                        data = squashfs_next_page(output);
 103                }
 104        }
 105        squashfs_finish_page(output);
 106
 107        return res;
 108
 109failed:
 110        return -EIO;
 111}
 112
 113const struct squashfs_decompressor squashfs_lzo_comp_ops = {
 114        .init = lzo_init,
 115        .free = lzo_free,
 116        .decompress = lzo_uncompress,
 117        .id = LZO_COMPRESSION,
 118        .name = "lzo",
 119        .supported = 1
 120};
 121