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authorRichard Purdie <rpurdie@openedhand.com>2007-07-10 05:28:36 -0400
committerDavid Woodhouse <dwmw2@infradead.org>2007-07-11 10:03:53 -0400
commitc799aca31bfe61ba3a91133acf5a13a0773087d4 (patch)
treed05f44fbec08e26fd52b8b1f4c7b5d162cfe3c31 /fs/jffs2/compr_lzo.c
parent8691a729a2a3d739ee40a577053157393450aabd (diff)
[JFFS2] Add LZO compression support.
Add LZO1X compression/decompression support to jffs2. LZO's interface doesn't entirely match that required by jffs2 so a buffer and memcpy is unavoidable. Signed-off-by: Richard Purdie <rpurdie@openedhand.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'fs/jffs2/compr_lzo.c')
-rw-r--r--fs/jffs2/compr_lzo.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c
new file mode 100644
index 000000000000..47b045797e42
--- /dev/null
+++ b/fs/jffs2/compr_lzo.c
@@ -0,0 +1,108 @@
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
20static void *lzo_mem;
21static void *lzo_compress_buf;
22static DEFINE_MUTEX(deflate_mutex);
23
24static void free_workspace(void)
25{
26 vfree(lzo_mem);
27 vfree(lzo_compress_buf);
28}
29
30static 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
44static 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
66static 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
80static 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
89int __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
104void jffs2_lzo_exit(void)
105{
106 jffs2_unregister_compressor(&jffs2_lzo_comp);
107 free_workspace();
108}