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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> | |
27 | #include <linux/zlib.h> | |
28 | ||
29 | #include "squashfs_fs.h" | |
30 | #include "squashfs_fs_sb.h" | |
31 | #include "squashfs_fs_i.h" | |
32 | #include "squashfs.h" | |
33 | ||
f1a40359 PL |
34 | void *squashfs_zlib_init() |
35 | { | |
36 | z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); | |
37 | if (stream == NULL) | |
38 | goto failed; | |
39 | stream->workspace = kmalloc(zlib_inflate_workspacesize(), | |
40 | GFP_KERNEL); | |
41 | if (stream->workspace == NULL) | |
42 | goto failed; | |
43 | ||
44 | return stream; | |
45 | ||
46 | failed: | |
47 | ERROR("Failed to allocate zlib workspace\n"); | |
48 | kfree(stream); | |
49 | return NULL; | |
50 | } | |
51 | ||
52 | ||
53 | void squashfs_zlib_free(void *strm) | |
54 | { | |
55 | z_stream *stream = strm; | |
56 | ||
57 | if (stream) | |
58 | kfree(stream->workspace); | |
59 | kfree(stream); | |
60 | } | |
61 | ||
62 | ||
e6a6d379 PL |
63 | int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer, |
64 | struct buffer_head **bh, int b, int offset, int length, int srclength, | |
65 | int pages) | |
66 | { | |
67 | int zlib_err = 0, zlib_init = 0; | |
68 | int avail, bytes, k = 0, page = 0; | |
f1a40359 | 69 | z_stream *stream = msblk->stream; |
e6a6d379 PL |
70 | |
71 | mutex_lock(&msblk->read_data_mutex); | |
72 | ||
f1a40359 PL |
73 | stream->avail_out = 0; |
74 | stream->avail_in = 0; | |
e6a6d379 PL |
75 | |
76 | bytes = length; | |
77 | do { | |
f1a40359 | 78 | if (stream->avail_in == 0 && k < b) { |
e6a6d379 PL |
79 | avail = min(bytes, msblk->devblksize - offset); |
80 | bytes -= avail; | |
81 | wait_on_buffer(bh[k]); | |
82 | if (!buffer_uptodate(bh[k])) | |
83 | goto release_mutex; | |
84 | ||
85 | if (avail == 0) { | |
86 | offset = 0; | |
87 | put_bh(bh[k++]); | |
88 | continue; | |
89 | } | |
90 | ||
f1a40359 PL |
91 | stream->next_in = bh[k]->b_data + offset; |
92 | stream->avail_in = avail; | |
e6a6d379 PL |
93 | offset = 0; |
94 | } | |
95 | ||
f1a40359 PL |
96 | if (stream->avail_out == 0 && page < pages) { |
97 | stream->next_out = buffer[page++]; | |
98 | stream->avail_out = PAGE_CACHE_SIZE; | |
e6a6d379 PL |
99 | } |
100 | ||
101 | if (!zlib_init) { | |
f1a40359 | 102 | zlib_err = zlib_inflateInit(stream); |
e6a6d379 PL |
103 | if (zlib_err != Z_OK) { |
104 | ERROR("zlib_inflateInit returned unexpected " | |
105 | "result 0x%x, srclength %d\n", | |
106 | zlib_err, srclength); | |
107 | goto release_mutex; | |
108 | } | |
109 | zlib_init = 1; | |
110 | } | |
111 | ||
f1a40359 | 112 | zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); |
e6a6d379 | 113 | |
f1a40359 | 114 | if (stream->avail_in == 0 && k < b) |
e6a6d379 PL |
115 | put_bh(bh[k++]); |
116 | } while (zlib_err == Z_OK); | |
117 | ||
118 | if (zlib_err != Z_STREAM_END) { | |
119 | ERROR("zlib_inflate error, data probably corrupt\n"); | |
120 | goto release_mutex; | |
121 | } | |
122 | ||
f1a40359 | 123 | zlib_err = zlib_inflateEnd(stream); |
e6a6d379 PL |
124 | if (zlib_err != Z_OK) { |
125 | ERROR("zlib_inflate error, data probably corrupt\n"); | |
126 | goto release_mutex; | |
127 | } | |
128 | ||
129 | mutex_unlock(&msblk->read_data_mutex); | |
f1a40359 | 130 | return stream->total_out; |
e6a6d379 PL |
131 | |
132 | release_mutex: | |
133 | mutex_unlock(&msblk->read_data_mutex); | |
134 | ||
135 | for (; k < b; k++) | |
136 | put_bh(bh[k]); | |
137 | ||
138 | return -EIO; | |
139 | } |