Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / fs / jffs2 / compr_lzo.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2007 Nokia Corporation. All rights reserved.
5  *
6  * Created by Richard Purdie <rpurdie@openedhand.com>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/slab.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);
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, void *model)
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         mutex_unlock(&deflate_mutex);
53
54         if (ret != LZO_E_OK)
55                 return -1;
56
57         if (compress_size > *dstlen)
58                 return -1;
59
60         memcpy(cpage_out, lzo_compress_buf, compress_size);
61         *dstlen = compress_size;
62
63         return 0;
64 }
65
66 static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
67                                  uint32_t srclen, uint32_t destlen, void *model)
68 {
69         size_t dl = destlen;
70         int ret;
71
72         ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
73
74         if (ret != LZO_E_OK || dl != destlen)
75                 return -1;
76
77         return 0;
78 }
79
80 static struct jffs2_compressor jffs2_lzo_comp = {
81         .priority = JFFS2_LZO_PRIORITY,
82         .name = "lzo",
83         .compr = JFFS2_COMPR_LZO,
84         .compress = &jffs2_lzo_compress,
85         .decompress = &jffs2_lzo_decompress,
86         .disabled = 0,
87 };
88
89 int __init jffs2_lzo_init(void)
90 {
91         int ret;
92
93         ret = alloc_workspace();
94         if (ret < 0)
95                 return ret;
96
97         ret = jffs2_register_compressor(&jffs2_lzo_comp);
98         if (ret)
99                 free_workspace();
100
101         return ret;
102 }
103
104 void jffs2_lzo_exit(void)
105 {
106         jffs2_unregister_compressor(&jffs2_lzo_comp);
107         free_workspace();
108 }