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/buffer_head.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 buffer_head **bh,
63	int b, int offset, int length, struct squashfs_page_actor *output)
64{
65	int res;
66	struct squashfs_stream *stream = msblk->stream;
67
68	mutex_lock(&stream->mutex);
69	res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
70		offset, length, output);
71	mutex_unlock(&stream->mutex);
72
73	if (res < 0)
74		ERROR("%s decompression failed, data probably corrupt\n",
75			msblk->decompressor->name);
76
77	return res;
78}
79
80int squashfs_max_decompressors(void)
81{
82	return 1;
83}