blob: 44bbfd249abc129ac7544be77b9cbd7a62b04e3e [file] [log] [blame]
Joern Engel5db53f32009-11-20 20:13:39 +01001/*
2 * fs/logfs/compr.c - compression routines
3 *
4 * As should be obvious for Linux kernel code, license is GPLv2
5 *
6 * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
7 */
8#include "logfs.h"
9#include <linux/vmalloc.h>
10#include <linux/zlib.h>
11
12#define COMPR_LEVEL 3
13
14static DEFINE_MUTEX(compr_mutex);
15static struct z_stream_s stream;
16
17int logfs_compress(void *in, void *out, size_t inlen, size_t outlen)
18{
19 int err, ret;
20
21 ret = -EIO;
22 mutex_lock(&compr_mutex);
23 err = zlib_deflateInit(&stream, COMPR_LEVEL);
24 if (err != Z_OK)
25 goto error;
26
27 stream.next_in = in;
28 stream.avail_in = inlen;
29 stream.total_in = 0;
30 stream.next_out = out;
31 stream.avail_out = outlen;
32 stream.total_out = 0;
33
34 err = zlib_deflate(&stream, Z_FINISH);
35 if (err != Z_STREAM_END)
36 goto error;
37
38 err = zlib_deflateEnd(&stream);
39 if (err != Z_OK)
40 goto error;
41
42 if (stream.total_out >= stream.total_in)
43 goto error;
44
45 ret = stream.total_out;
46error:
47 mutex_unlock(&compr_mutex);
48 return ret;
49}
50
51int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen)
52{
53 int err, ret;
54
55 ret = -EIO;
56 mutex_lock(&compr_mutex);
57 err = zlib_inflateInit(&stream);
58 if (err != Z_OK)
59 goto error;
60
61 stream.next_in = in;
62 stream.avail_in = inlen;
63 stream.total_in = 0;
64 stream.next_out = out;
65 stream.avail_out = outlen;
66 stream.total_out = 0;
67
68 err = zlib_inflate(&stream, Z_FINISH);
69 if (err != Z_STREAM_END)
70 goto error;
71
72 err = zlib_inflateEnd(&stream);
73 if (err != Z_OK)
74 goto error;
75
76 ret = 0;
77error:
78 mutex_unlock(&compr_mutex);
79 return ret;
80}
81
82int __init logfs_compr_init(void)
83{
84 size_t size = max(zlib_deflate_workspacesize(),
85 zlib_inflate_workspacesize());
86 stream.workspace = vmalloc(size);
87 if (!stream.workspace)
88 return -ENOMEM;
89 return 0;
90}
91
92void logfs_compr_exit(void)
93{
94 vfree(stream.workspace);
95}