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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/vmalloc.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/lzo.h> | |
17 | #include "compr.h" | |
18 | ||
19 | static void *lzo_mem; | |
20 | static void *lzo_compress_buf; | |
21 | static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */ | |
22 | ||
23 | static void free_workspace(void) | |
24 | { | |
25 | vfree(lzo_mem); | |
26 | vfree(lzo_compress_buf); | |
27 | } | |
28 | ||
29 | static int __init alloc_workspace(void) | |
30 | { | |
31 | lzo_mem = vmalloc(LZO1X_MEM_COMPRESS); | |
32 | lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE)); | |
33 | ||
34 | if (!lzo_mem || !lzo_compress_buf) { | |
35 | printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n"); | |
36 | free_workspace(); | |
37 | return -ENOMEM; | |
38 | } | |
39 | ||
40 | return 0; | |
41 | } | |
42 | ||
43 | static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out, | |
44 | uint32_t *sourcelen, uint32_t *dstlen, void *model) | |
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 | ||
68 | static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, | |
69 | uint32_t srclen, uint32_t destlen, void *model) | |
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 | ||
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 | ||
106 | void jffs2_lzo_exit(void) | |
107 | { | |
108 | jffs2_unregister_compressor(&jffs2_lzo_comp); | |
109 | free_workspace(); | |
110 | } |