fs/squashfs/lzo_wrapper.c

   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
  23 struct squashfs_lzo {
  24         void    *input;
  25         void    *output;
  26 };
  27
  28 static 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
  44 failed2:
  45         vfree(stream->input);
  46 failed:
  47         ERROR("Failed to allocate lzo workspace\n");
  48         kfree(stream);
  49         return ERR_PTR(-ENOMEM);
  50 }
  51
  52
  53 static 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
  65 static 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
 109 failed:
 110         return -EIO;
 111 }
 112
 113 const 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 };