Commit | Line | Data |
---|---|---|
68252eb5 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
81bb8deb PL |
2 | /* |
3 | * Squashfs - a compressed read only filesystem for Linux | |
4 | * | |
5 | * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 | |
d7f2ff67 | 6 | * Phillip Lougher <phillip@squashfs.org.uk> |
81bb8deb | 7 | * |
81bb8deb PL |
8 | * xz_wrapper.c |
9 | */ | |
10 | ||
11 | ||
12 | #include <linux/mutex.h> | |
13 | #include <linux/buffer_head.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/xz.h> | |
ff750311 | 16 | #include <linux/bitops.h> |
81bb8deb PL |
17 | |
18 | #include "squashfs_fs.h" | |
19 | #include "squashfs_fs_sb.h" | |
81bb8deb PL |
20 | #include "squashfs.h" |
21 | #include "decompressor.h" | |
846b730e | 22 | #include "page_actor.h" |
81bb8deb PL |
23 | |
24 | struct squashfs_xz { | |
25 | struct xz_dec *state; | |
26 | struct xz_buf buf; | |
27 | }; | |
28 | ||
9508c6b9 | 29 | struct disk_comp_opts { |
ff750311 PL |
30 | __le32 dictionary_size; |
31 | __le32 flags; | |
32 | }; | |
33 | ||
9508c6b9 PL |
34 | struct comp_opts { |
35 | int dict_size; | |
36 | }; | |
37 | ||
38 | static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk, | |
39 | void *buff, int len) | |
81bb8deb | 40 | { |
9508c6b9 PL |
41 | struct disk_comp_opts *comp_opts = buff; |
42 | struct comp_opts *opts; | |
43 | int err = 0, n; | |
44 | ||
45 | opts = kmalloc(sizeof(*opts), GFP_KERNEL); | |
46 | if (opts == NULL) { | |
47 | err = -ENOMEM; | |
48 | goto out2; | |
49 | } | |
ff750311 PL |
50 | |
51 | if (comp_opts) { | |
52 | /* check compressor options are the expected length */ | |
53 | if (len < sizeof(*comp_opts)) { | |
54 | err = -EIO; | |
9508c6b9 | 55 | goto out; |
ff750311 PL |
56 | } |
57 | ||
9508c6b9 | 58 | opts->dict_size = le32_to_cpu(comp_opts->dictionary_size); |
ff750311 PL |
59 | |
60 | /* the dictionary size should be 2^n or 2^n+2^(n+1) */ | |
9508c6b9 PL |
61 | n = ffs(opts->dict_size) - 1; |
62 | if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) + | |
ff750311 PL |
63 | (1 << (n + 1))) { |
64 | err = -EIO; | |
9508c6b9 | 65 | goto out; |
ff750311 | 66 | } |
9508c6b9 PL |
67 | } else |
68 | /* use defaults */ | |
69 | opts->dict_size = max_t(int, msblk->block_size, | |
70 | SQUASHFS_METADATA_SIZE); | |
ff750311 | 71 | |
9508c6b9 PL |
72 | return opts; |
73 | ||
74 | out: | |
75 | kfree(opts); | |
76 | out2: | |
77 | return ERR_PTR(err); | |
78 | } | |
79 | ||
80 | ||
81 | static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff) | |
82 | { | |
83 | struct comp_opts *comp_opts = buff; | |
84 | struct squashfs_xz *stream; | |
85 | int err; | |
81bb8deb | 86 | |
ff750311 PL |
87 | stream = kmalloc(sizeof(*stream), GFP_KERNEL); |
88 | if (stream == NULL) { | |
89 | err = -ENOMEM; | |
81bb8deb | 90 | goto failed; |
ff750311 | 91 | } |
81bb8deb | 92 | |
9508c6b9 | 93 | stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size); |
ff750311 PL |
94 | if (stream->state == NULL) { |
95 | kfree(stream); | |
96 | err = -ENOMEM; | |
81bb8deb | 97 | goto failed; |
ff750311 | 98 | } |
81bb8deb PL |
99 | |
100 | return stream; | |
101 | ||
102 | failed: | |
ff750311 PL |
103 | ERROR("Failed to initialise xz decompressor\n"); |
104 | return ERR_PTR(err); | |
81bb8deb PL |
105 | } |
106 | ||
107 | ||
108 | static void squashfs_xz_free(void *strm) | |
109 | { | |
110 | struct squashfs_xz *stream = strm; | |
111 | ||
112 | if (stream) { | |
113 | xz_dec_end(stream->state); | |
114 | kfree(stream); | |
115 | } | |
116 | } | |
117 | ||
118 | ||
9508c6b9 | 119 | static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, |
846b730e PL |
120 | struct buffer_head **bh, int b, int offset, int length, |
121 | struct squashfs_page_actor *output) | |
81bb8deb PL |
122 | { |
123 | enum xz_ret xz_err; | |
846b730e | 124 | int avail, total = 0, k = 0; |
9508c6b9 | 125 | struct squashfs_xz *stream = strm; |
81bb8deb PL |
126 | |
127 | xz_dec_reset(stream->state); | |
128 | stream->buf.in_pos = 0; | |
129 | stream->buf.in_size = 0; | |
130 | stream->buf.out_pos = 0; | |
09cbfeaf | 131 | stream->buf.out_size = PAGE_SIZE; |
846b730e | 132 | stream->buf.out = squashfs_first_page(output); |
81bb8deb PL |
133 | |
134 | do { | |
135 | if (stream->buf.in_pos == stream->buf.in_size && k < b) { | |
136 | avail = min(length, msblk->devblksize - offset); | |
137 | length -= avail; | |
81bb8deb PL |
138 | stream->buf.in = bh[k]->b_data + offset; |
139 | stream->buf.in_size = avail; | |
140 | stream->buf.in_pos = 0; | |
141 | offset = 0; | |
142 | } | |
143 | ||
846b730e PL |
144 | if (stream->buf.out_pos == stream->buf.out_size) { |
145 | stream->buf.out = squashfs_next_page(output); | |
146 | if (stream->buf.out != NULL) { | |
147 | stream->buf.out_pos = 0; | |
09cbfeaf | 148 | total += PAGE_SIZE; |
846b730e | 149 | } |
81bb8deb PL |
150 | } |
151 | ||
152 | xz_err = xz_dec_run(stream->state, &stream->buf); | |
153 | ||
154 | if (stream->buf.in_pos == stream->buf.in_size && k < b) | |
155 | put_bh(bh[k++]); | |
156 | } while (xz_err == XZ_OK); | |
157 | ||
846b730e PL |
158 | squashfs_finish_page(output); |
159 | ||
9508c6b9 PL |
160 | if (xz_err != XZ_STREAM_END || k < b) |
161 | goto out; | |
81bb8deb | 162 | |
9508c6b9 | 163 | return total + stream->buf.out_pos; |
81bb8deb | 164 | |
9508c6b9 | 165 | out: |
81bb8deb PL |
166 | for (; k < b; k++) |
167 | put_bh(bh[k]); | |
168 | ||
169 | return -EIO; | |
170 | } | |
171 | ||
172 | const struct squashfs_decompressor squashfs_xz_comp_ops = { | |
173 | .init = squashfs_xz_init, | |
9508c6b9 | 174 | .comp_opts = squashfs_xz_comp_opts, |
81bb8deb PL |
175 | .free = squashfs_xz_free, |
176 | .decompress = squashfs_xz_uncompress, | |
177 | .id = XZ_COMPRESSION, | |
178 | .name = "xz", | |
179 | .supported = 1 | |
180 | }; |