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authorPhillip Lougher <phillip@lougher.demon.co.uk>2009-09-22 14:25:24 -0400
committerPhillip Lougher <phillip@lougher.demon.co.uk>2010-01-20 16:47:46 -0500
commite6a6d3795565b8ccb957afc6ca0e50db40b2d899 (patch)
tree5ab7020e28652f3db91dffcce06d5ec1723a4394 /fs/squashfs/zlib_wrapper.c
parent7284ce6c9f6153d1777df5f310c959724d1bd446 (diff)
Squashfs: move zlib decompression wrapper code into a separate file
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Diffstat (limited to 'fs/squashfs/zlib_wrapper.c')
-rw-r--r--fs/squashfs/zlib_wrapper.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 000000000000..3be99642d6af
--- /dev/null
+++ b/fs/squashfs/zlib_wrapper.c
@@ -0,0 +1,109 @@
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
34int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
35 struct buffer_head **bh, int b, int offset, int length, int srclength,
36 int pages)
37{
38 int zlib_err = 0, zlib_init = 0;
39 int avail, bytes, k = 0, page = 0;
40
41 mutex_lock(&msblk->read_data_mutex);
42
43 msblk->stream.avail_out = 0;
44 msblk->stream.avail_in = 0;
45
46 bytes = length;
47 do {
48 if (msblk->stream.avail_in == 0 && k < b) {
49 avail = min(bytes, msblk->devblksize - offset);
50 bytes -= avail;
51 wait_on_buffer(bh[k]);
52 if (!buffer_uptodate(bh[k]))
53 goto release_mutex;
54
55 if (avail == 0) {
56 offset = 0;
57 put_bh(bh[k++]);
58 continue;
59 }
60
61 msblk->stream.next_in = bh[k]->b_data + offset;
62 msblk->stream.avail_in = avail;
63 offset = 0;
64 }
65
66 if (msblk->stream.avail_out == 0 && page < pages) {
67 msblk->stream.next_out = buffer[page++];
68 msblk->stream.avail_out = PAGE_CACHE_SIZE;
69 }
70
71 if (!zlib_init) {
72 zlib_err = zlib_inflateInit(&msblk->stream);
73 if (zlib_err != Z_OK) {
74 ERROR("zlib_inflateInit returned unexpected "
75 "result 0x%x, srclength %d\n",
76 zlib_err, srclength);
77 goto release_mutex;
78 }
79 zlib_init = 1;
80 }
81
82 zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
83
84 if (msblk->stream.avail_in == 0 && k < b)
85 put_bh(bh[k++]);
86 } while (zlib_err == Z_OK);
87
88 if (zlib_err != Z_STREAM_END) {
89 ERROR("zlib_inflate error, data probably corrupt\n");
90 goto release_mutex;
91 }
92
93 zlib_err = zlib_inflateEnd(&msblk->stream);
94 if (zlib_err != Z_OK) {
95 ERROR("zlib_inflate error, data probably corrupt\n");
96 goto release_mutex;
97 }
98
99 mutex_unlock(&msblk->read_data_mutex);
100 return msblk->stream.total_out;
101
102release_mutex:
103 mutex_unlock(&msblk->read_data_mutex);
104
105 for (; k < b; k++)
106 put_bh(bh[k]);
107
108 return -EIO;
109}