Commit | Line | Data |
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e6a6d379 PL |
1 | /* |
2 | * Squashfs - a compressed read only filesystem for Linux | |
3 | * | |
4 | * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 | |
5 | * Phillip Lougher <phillip@lougher.demon.co.uk> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version 2, | |
10 | * or (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. | |
20 | * | |
21 | * zlib_wrapper.c | |
22 | */ | |
23 | ||
24 | ||
25 | #include <linux/mutex.h> | |
26 | #include <linux/buffer_head.h> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
e6a6d379 PL |
28 | #include <linux/zlib.h> |
29 | ||
30 | #include "squashfs_fs.h" | |
31 | #include "squashfs_fs_sb.h" | |
32 | #include "squashfs_fs_i.h" | |
33 | #include "squashfs.h" | |
4c0f0bb2 | 34 | #include "decompressor.h" |
e6a6d379 | 35 | |
4c0f0bb2 | 36 | static void *zlib_init(struct squashfs_sb_info *dummy) |
f1a40359 PL |
37 | { |
38 | z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); | |
39 | if (stream == NULL) | |
40 | goto failed; | |
41 | stream->workspace = kmalloc(zlib_inflate_workspacesize(), | |
42 | GFP_KERNEL); | |
43 | if (stream->workspace == NULL) | |
44 | goto failed; | |
45 | ||
46 | return stream; | |
47 | ||
48 | failed: | |
49 | ERROR("Failed to allocate zlib workspace\n"); | |
50 | kfree(stream); | |
51 | return NULL; | |
52 | } | |
53 | ||
54 | ||
4c0f0bb2 | 55 | static void zlib_free(void *strm) |
f1a40359 PL |
56 | { |
57 | z_stream *stream = strm; | |
58 | ||
59 | if (stream) | |
60 | kfree(stream->workspace); | |
61 | kfree(stream); | |
62 | } | |
63 | ||
64 | ||
4c0f0bb2 | 65 | static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer, |
e6a6d379 PL |
66 | struct buffer_head **bh, int b, int offset, int length, int srclength, |
67 | int pages) | |
68 | { | |
69 | int zlib_err = 0, zlib_init = 0; | |
70 | int avail, bytes, k = 0, page = 0; | |
f1a40359 | 71 | z_stream *stream = msblk->stream; |
e6a6d379 PL |
72 | |
73 | mutex_lock(&msblk->read_data_mutex); | |
74 | ||
f1a40359 PL |
75 | stream->avail_out = 0; |
76 | stream->avail_in = 0; | |
e6a6d379 PL |
77 | |
78 | bytes = length; | |
79 | do { | |
f1a40359 | 80 | if (stream->avail_in == 0 && k < b) { |
e6a6d379 PL |
81 | avail = min(bytes, msblk->devblksize - offset); |
82 | bytes -= avail; | |
83 | wait_on_buffer(bh[k]); | |
84 | if (!buffer_uptodate(bh[k])) | |
85 | goto release_mutex; | |
86 | ||
87 | if (avail == 0) { | |
88 | offset = 0; | |
89 | put_bh(bh[k++]); | |
90 | continue; | |
91 | } | |
92 | ||
f1a40359 PL |
93 | stream->next_in = bh[k]->b_data + offset; |
94 | stream->avail_in = avail; | |
e6a6d379 PL |
95 | offset = 0; |
96 | } | |
97 | ||
f1a40359 PL |
98 | if (stream->avail_out == 0 && page < pages) { |
99 | stream->next_out = buffer[page++]; | |
100 | stream->avail_out = PAGE_CACHE_SIZE; | |
e6a6d379 PL |
101 | } |
102 | ||
103 | if (!zlib_init) { | |
f1a40359 | 104 | zlib_err = zlib_inflateInit(stream); |
e6a6d379 PL |
105 | if (zlib_err != Z_OK) { |
106 | ERROR("zlib_inflateInit returned unexpected " | |
107 | "result 0x%x, srclength %d\n", | |
108 | zlib_err, srclength); | |
109 | goto release_mutex; | |
110 | } | |
111 | zlib_init = 1; | |
112 | } | |
113 | ||
f1a40359 | 114 | zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); |
e6a6d379 | 115 | |
f1a40359 | 116 | if (stream->avail_in == 0 && k < b) |
e6a6d379 PL |
117 | put_bh(bh[k++]); |
118 | } while (zlib_err == Z_OK); | |
119 | ||
120 | if (zlib_err != Z_STREAM_END) { | |
121 | ERROR("zlib_inflate error, data probably corrupt\n"); | |
122 | goto release_mutex; | |
123 | } | |
124 | ||
f1a40359 | 125 | zlib_err = zlib_inflateEnd(stream); |
e6a6d379 PL |
126 | if (zlib_err != Z_OK) { |
127 | ERROR("zlib_inflate error, data probably corrupt\n"); | |
128 | goto release_mutex; | |
129 | } | |
130 | ||
792590c7 | 131 | length = stream->total_out; |
e6a6d379 | 132 | mutex_unlock(&msblk->read_data_mutex); |
792590c7 | 133 | return length; |
e6a6d379 PL |
134 | |
135 | release_mutex: | |
136 | mutex_unlock(&msblk->read_data_mutex); | |
137 | ||
138 | for (; k < b; k++) | |
139 | put_bh(bh[k]); | |
140 | ||
141 | return -EIO; | |
142 | } | |
4c0f0bb2 PL |
143 | |
144 | const struct squashfs_decompressor squashfs_zlib_comp_ops = { | |
145 | .init = zlib_init, | |
146 | .free = zlib_free, | |
147 | .decompress = zlib_uncompress, | |
148 | .id = ZLIB_COMPRESSION, | |
149 | .name = "zlib", | |
150 | .supported = 1 | |
151 | }; | |
152 |