LXR linux/fs/squashfs/decompressor

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2013
   4 * Phillip Lougher <phillip@squashfs.org.uk>
   5 */
   6
   7#include <linux/types.h>
   8#include <linux/mutex.h>
   9#include <linux/slab.h>
  10#include <linux/bio.h>
  11
  12#include "squashfs_fs.h"
  13#include "squashfs_fs_sb.h"
  14#include "decompressor.h"
  15#include "squashfs.h"
  16
  17/*
  18 * This file implements single-threaded decompression in the
  19 * decompressor framework
  20 */
  21
  22struct squashfs_stream {
  23        void            *stream;
  24        struct mutex    mutex;
  25};
  26
  27void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
  28                                                void *comp_opts)
  29{
  30        struct squashfs_stream *stream;
  31        int err = -ENOMEM;
  32
  33        stream = kmalloc(sizeof(*stream), GFP_KERNEL);
  34        if (stream == NULL)
  35                goto out;
  36
  37        stream->stream = msblk->decompressor->init(msblk, comp_opts);
  38        if (IS_ERR(stream->stream)) {
  39                err = PTR_ERR(stream->stream);
  40                goto out;
  41        }
  42
  43        kfree(comp_opts);
  44        mutex_init(&stream->mutex);
  45        return stream;
  46
  47out:
  48        kfree(stream);
  49        return ERR_PTR(err);
  50}
  51
  52void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
  53{
  54        struct squashfs_stream *stream = msblk->stream;
  55
  56        if (stream) {
  57                msblk->decompressor->free(stream->stream);
  58                kfree(stream);
  59        }
  60}
  61
  62int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
  63                        int offset, int length,
  64                        struct squashfs_page_actor *output)
  65{
  66        int res;
  67        struct squashfs_stream *stream = msblk->stream;
  68
  69        mutex_lock(&stream->mutex);
  70        res = msblk->decompressor->decompress(msblk, stream->stream, bio,
  71                offset, length, output);
  72        mutex_unlock(&stream->mutex);
  73
  74        if (res < 0)
  75                ERROR("%s decompression failed, data probably corrupt\n",
  76                        msblk->decompressor->name);
  77
  78        return res;
  79}
  80
  81int squashfs_max_decompressors(void)
  82{
  83        return 1;
  84}
  85