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 = bvec_virt(bvec);
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 if (!IS_ERR(data))
97 memcpy(data, buff, bytes);
98 break;
99 } else {
100 if (!IS_ERR(data))
101 memcpy(data, buff, PAGE_SIZE);
102 buff += PAGE_SIZE;
103 bytes -= PAGE_SIZE;
104 data = squashfs_next_page(output);
105 }
106 }
107 squashfs_finish_page(output);
108
109 return res;
110
111 failed:
112 return -EIO;
113 }
114
115 const struct squashfs_decompressor squashfs_lzo_comp_ops = {
116 .init = lzo_init,
117 .free = lzo_free,
118 .decompress = lzo_uncompress,
119 .id = LZO_COMPRESSION,
120 .name = "lzo",
121 .alloc_buffer = 0,
122 .supported = 1
123 };
124
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