decompressor_single.c revision 846b730e
1/*
2 * Copyright (c) 2013
3 * Phillip Lougher <phillip@squashfs.org.uk>
4 *
5 * This work is licensed under the terms of the GNU GPL, version 2. See
6 * the COPYING file in the top-level directory.
7 */
8
9#include <linux/types.h>
10#include <linux/mutex.h>
11#include <linux/slab.h>
12#include <linux/buffer_head.h>
13
14#include "squashfs_fs.h"
15#include "squashfs_fs_sb.h"
16#include "decompressor.h"
17#include "squashfs.h"
18
19/*
20 * This file implements single-threaded decompression in the
21 * decompressor framework
22 */
23
24struct squashfs_stream {
25	void		*stream;
26	struct mutex	mutex;
27};
28
29void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
30						void *comp_opts)
31{
32	struct squashfs_stream *stream;
33	int err = -ENOMEM;
34
35	stream = kmalloc(sizeof(*stream), GFP_KERNEL);
36	if (stream == NULL)
37		goto out;
38
39	stream->stream = msblk->decompressor->init(msblk, comp_opts);
40	if (IS_ERR(stream->stream)) {
41		err = PTR_ERR(stream->stream);
42		goto out;
43	}
44
45	kfree(comp_opts);
46	mutex_init(&stream->mutex);
47	return stream;
48
49out:
50	kfree(stream);
51	return ERR_PTR(err);
52}
53
54void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
55{
56	struct squashfs_stream *stream = msblk->stream;
57
58	if (stream) {
59		msblk->decompressor->free(stream->stream);
60		kfree(stream);
61	}
62}
63
64int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
65	int b, int offset, int length, struct squashfs_page_actor *output)
66{
67	int res;
68	struct squashfs_stream *stream = msblk->stream;
69
70	mutex_lock(&stream->mutex);
71	res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
72		offset, length, output);
73	mutex_unlock(&stream->mutex);
74
75	if (res < 0)
76		ERROR("%s decompression failed, data probably corrupt\n",
77			msblk->decompressor->name);
78
79	return res;
80}
81
82int squashfs_max_decompressors(void)
83{
84	return 1;
85}
86