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
free_workspace(void)24 static void free_workspace(void)
25 {
26 vfree(lzo_mem);
27 vfree(lzo_compress_buf);
28 }
29
alloc_workspace(void)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 free_workspace();
37 return -ENOMEM;
38 }
39
40 return 0;
41 }
42
jffs2_lzo_compress(unsigned char * data_in,unsigned char * cpage_out,uint32_t * sourcelen,uint32_t * dstlen)43 static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
44 uint32_t *sourcelen, uint32_t *dstlen)
45 {
46 size_t compress_size;
47 int ret;
48
49 mutex_lock(&deflate_mutex);
50 ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
51 if (ret != LZO_E_OK)
52 goto fail;
53
54 if (compress_size > *dstlen)
55 goto fail;
56
57 memcpy(cpage_out, lzo_compress_buf, compress_size);
58 mutex_unlock(&deflate_mutex);
59
60 *dstlen = compress_size;
61 return 0;
62
63 fail:
64 mutex_unlock(&deflate_mutex);
65 return -1;
66 }
67
jffs2_lzo_decompress(unsigned char * data_in,unsigned char * cpage_out,uint32_t srclen,uint32_t destlen)68 static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
69 uint32_t srclen, uint32_t destlen)
70 {
71 size_t dl = destlen;
72 int ret;
73
74 ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
75
76 if (ret != LZO_E_OK || dl != destlen)
77 return -1;
78
79 return 0;
80 }
81
82 static struct jffs2_compressor jffs2_lzo_comp = {
83 .priority = JFFS2_LZO_PRIORITY,
84 .name = "lzo",
85 .compr = JFFS2_COMPR_LZO,
86 .compress = &jffs2_lzo_compress,
87 .decompress = &jffs2_lzo_decompress,
88 .disabled = 0,
89 };
90
jffs2_lzo_init(void)91 int __init jffs2_lzo_init(void)
92 {
93 int ret;
94
95 ret = alloc_workspace();
96 if (ret < 0)
97 return ret;
98
99 ret = jffs2_register_compressor(&jffs2_lzo_comp);
100 if (ret)
101 free_workspace();
102
103 return ret;
104 }
105
jffs2_lzo_exit(void)106 void jffs2_lzo_exit(void)
107 {
108 jffs2_unregister_compressor(&jffs2_lzo_comp);
109 free_workspace();
110 }
111