xref: /linux/fs/squashfs/lzo_wrapper.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
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 
lzo_init(struct squashfs_sb_info * msblk,void * buff)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 
lzo_free(void * strm)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 
lzo_uncompress(struct squashfs_sb_info * msblk,void * strm,struct bio * bio,int offset,int length,struct squashfs_page_actor * output)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