lockd: Introduce new-style XDR functions for NLMv3
[linux-2.6.git] / fs / jffs2 / compr_lzo.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2007 Nokia Corporation. All rights reserved.
5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6  *
7  * Created by Richard Purdie <rpurdie@openedhand.com>
8  *
9  * For licensing information, see the file 'LICENCE' in this directory.
10  *
11  */
12
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/vmalloc.h>
16 #include <linux/init.h>
17 #include <linux/lzo.h>
18 #include "compr.h"
19
20 static void *lzo_mem;
21 static void *lzo_compress_buf;
22 static DEFINE_MUTEX(deflate_mutex);     /* for lzo_mem and lzo_compress_buf */
23
24 static void free_workspace(void)
25 {
26         vfree(lzo_mem);
27         vfree(lzo_compress_buf);
28 }
29
30 static int __init alloc_workspace(void)
31 {
32         lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
33         lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
34
35         if (!lzo_mem || !lzo_compress_buf) {
36                 printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n");
37                 free_workspace();
38                 return -ENOMEM;
39         }
40
41         return 0;
42 }
43
44 static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
45                               uint32_t *sourcelen, uint32_t *dstlen)
46 {
47         size_t compress_size;
48         int ret;
49
50         mutex_lock(&deflate_mutex);
51         ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
52         if (ret != LZO_E_OK)
53                 goto fail;
54
55         if (compress_size > *dstlen)
56                 goto fail;
57
58         memcpy(cpage_out, lzo_compress_buf, compress_size);
59         mutex_unlock(&deflate_mutex);
60
61         *dstlen = compress_size;
62         return 0;
63
64  fail:
65         mutex_unlock(&deflate_mutex);
66         return -1;
67 }
68
69 static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
70                                  uint32_t srclen, uint32_t destlen)
71 {
72         size_t dl = destlen;
73         int ret;
74
75         ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
76
77         if (ret != LZO_E_OK || dl != destlen)
78                 return -1;
79
80         return 0;
81 }
82
83 static struct jffs2_compressor jffs2_lzo_comp = {
84         .priority = JFFS2_LZO_PRIORITY,
85         .name = "lzo",
86         .compr = JFFS2_COMPR_LZO,
87         .compress = &jffs2_lzo_compress,
88         .decompress = &jffs2_lzo_decompress,
89         .disabled = 0,
90 };
91
92 int __init jffs2_lzo_init(void)
93 {
94         int ret;
95
96         ret = alloc_workspace();
97         if (ret < 0)
98                 return ret;
99
100         ret = jffs2_register_compressor(&jffs2_lzo_comp);
101         if (ret)
102                 free_workspace();
103
104         return ret;
105 }
106
107 void jffs2_lzo_exit(void)
108 {
109         jffs2_unregister_compressor(&jffs2_lzo_comp);
110         free_workspace();
111 }