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
22 struct squashfs_stream {
23 void *stream;
24 struct mutex mutex;
25 };
26
27 static void *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
47 out:
48 kfree(stream);
49 return ERR_PTR(err);
50 }
51
52 static void 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
62 static int 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
81 static int squashfs_max_decompressors(void)
82 {
83 return 1;
84 }
85
86 const struct squashfs_decompressor_thread_ops squashfs_decompressor_single = {
87 .create = squashfs_decompressor_create,
88 .destroy = squashfs_decompressor_destroy,
89 .decompress = squashfs_decompress,
90 .max_decompressors = squashfs_max_decompressors,
91 };
92
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