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
23struct squashfs_lzo {
24	void	*input;
25	void	*output;
26};
27
28static 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
44failed2:
45	vfree(stream->input);
46failed:
47	ERROR("Failed to allocate lzo workspace\n");
48	kfree(stream);
49	return ERR_PTR(-ENOMEM);
50}
51
52
53static 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
65static 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 = page_address(bvec->bv_page) + bvec->bv_offset;
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			memcpy(data, buff, bytes);
97			break;
98		} else {
99			memcpy(data, buff, PAGE_SIZE);
100			buff += PAGE_SIZE;
101			bytes -= PAGE_SIZE;
102			data = squashfs_next_page(output);
103		}
104	}
105	squashfs_finish_page(output);
106
107	return res;
108
109failed:
110	return -EIO;
111}
112
113const struct squashfs_decompressor squashfs_lzo_comp_ops = {
114	.init = lzo_init,
115	.free = lzo_free,
116	.decompress = lzo_uncompress,
117	.id = LZO_COMPRESSION,
118	.name = "lzo",
119	.supported = 1
120};
121