Commit | Line | Data |
---|---|---|
20c8ccb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9c06a46f PL |
2 | /* |
3 | * Copyright (c) 2013, 2014 | |
4 | * Phillip Lougher <phillip@squashfs.org.uk> | |
9c06a46f PL |
5 | */ |
6 | ||
93e72b3c | 7 | #include <linux/bio.h> |
9c06a46f PL |
8 | #include <linux/mutex.h> |
9 | #include <linux/slab.h> | |
10 | #include <linux/vmalloc.h> | |
11 | #include <linux/lz4.h> | |
12 | ||
13 | #include "squashfs_fs.h" | |
14 | #include "squashfs_fs_sb.h" | |
15 | #include "squashfs.h" | |
16 | #include "decompressor.h" | |
17 | #include "page_actor.h" | |
18 | ||
19 | #define LZ4_LEGACY 1 | |
20 | ||
21 | struct lz4_comp_opts { | |
22 | __le32 version; | |
23 | __le32 flags; | |
24 | }; | |
25 | ||
26 | struct squashfs_lz4 { | |
27 | void *input; | |
28 | void *output; | |
29 | }; | |
30 | ||
31 | ||
32 | static void *lz4_comp_opts(struct squashfs_sb_info *msblk, | |
33 | void *buff, int len) | |
34 | { | |
35 | struct lz4_comp_opts *comp_opts = buff; | |
36 | ||
37 | /* LZ4 compressed filesystems always have compression options */ | |
38 | if (comp_opts == NULL || len < sizeof(*comp_opts)) | |
39 | return ERR_PTR(-EIO); | |
40 | ||
41 | if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) { | |
42 | /* LZ4 format currently used by the kernel is the 'legacy' | |
43 | * format */ | |
44 | ERROR("Unknown LZ4 version\n"); | |
45 | return ERR_PTR(-EINVAL); | |
46 | } | |
47 | ||
48 | return NULL; | |
49 | } | |
50 | ||
51 | ||
52 | static void *lz4_init(struct squashfs_sb_info *msblk, void *buff) | |
53 | { | |
54 | int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); | |
55 | struct squashfs_lz4 *stream; | |
56 | ||
57 | stream = kzalloc(sizeof(*stream), GFP_KERNEL); | |
58 | if (stream == NULL) | |
59 | goto failed; | |
60 | stream->input = vmalloc(block_size); | |
61 | if (stream->input == NULL) | |
62 | goto failed2; | |
63 | stream->output = vmalloc(block_size); | |
64 | if (stream->output == NULL) | |
65 | goto failed3; | |
66 | ||
67 | return stream; | |
68 | ||
69 | failed3: | |
70 | vfree(stream->input); | |
71 | failed2: | |
72 | kfree(stream); | |
73 | failed: | |
74 | ERROR("Failed to initialise LZ4 decompressor\n"); | |
75 | return ERR_PTR(-ENOMEM); | |
76 | } | |
77 | ||
78 | ||
79 | static void lz4_free(void *strm) | |
80 | { | |
81 | struct squashfs_lz4 *stream = strm; | |
82 | ||
83 | if (stream) { | |
84 | vfree(stream->input); | |
85 | vfree(stream->output); | |
86 | } | |
87 | kfree(stream); | |
88 | } | |
89 | ||
90 | ||
91 | static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, | |
93e72b3c | 92 | struct bio *bio, int offset, int length, |
9c06a46f PL |
93 | struct squashfs_page_actor *output) |
94 | { | |
93e72b3c PL |
95 | struct bvec_iter_all iter_all = {}; |
96 | struct bio_vec *bvec = bvec_init_iter_all(&iter_all); | |
9c06a46f PL |
97 | struct squashfs_lz4 *stream = strm; |
98 | void *buff = stream->input, *data; | |
93e72b3c | 99 | int bytes = length, res; |
9c06a46f | 100 | |
93e72b3c PL |
101 | while (bio_next_segment(bio, &iter_all)) { |
102 | int avail = min(bytes, ((int)bvec->bv_len) - offset); | |
103 | ||
fbc27241 | 104 | data = bvec_virt(bvec); |
93e72b3c | 105 | memcpy(buff, data + offset, avail); |
9c06a46f PL |
106 | buff += avail; |
107 | bytes -= avail; | |
108 | offset = 0; | |
9c06a46f PL |
109 | } |
110 | ||
d21b5ff1 SS |
111 | res = LZ4_decompress_safe(stream->input, stream->output, |
112 | length, output->length); | |
113 | ||
114 | if (res < 0) | |
9c06a46f PL |
115 | return -EIO; |
116 | ||
d21b5ff1 | 117 | bytes = res; |
9c06a46f PL |
118 | data = squashfs_first_page(output); |
119 | buff = stream->output; | |
120 | while (data) { | |
09cbfeaf | 121 | if (bytes <= PAGE_SIZE) { |
f268eedd PL |
122 | if (!IS_ERR(data)) |
123 | memcpy(data, buff, bytes); | |
9c06a46f PL |
124 | break; |
125 | } | |
f268eedd PL |
126 | if (!IS_ERR(data)) |
127 | memcpy(data, buff, PAGE_SIZE); | |
09cbfeaf KS |
128 | buff += PAGE_SIZE; |
129 | bytes -= PAGE_SIZE; | |
9c06a46f PL |
130 | data = squashfs_next_page(output); |
131 | } | |
132 | squashfs_finish_page(output); | |
133 | ||
d21b5ff1 | 134 | return res; |
9c06a46f PL |
135 | } |
136 | ||
137 | const struct squashfs_decompressor squashfs_lz4_comp_ops = { | |
138 | .init = lz4_init, | |
139 | .comp_opts = lz4_comp_opts, | |
140 | .free = lz4_free, | |
141 | .decompress = lz4_uncompress, | |
142 | .id = LZ4_COMPRESSION, | |
143 | .name = "lz4", | |
f268eedd | 144 | .alloc_buffer = 0, |
9c06a46f PL |
145 | .supported = 1 |
146 | }; |