1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
5 * University of Szeged, Hungary
6 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12#ifndef __JFFS2_COMPR_H__
13#define __JFFS2_COMPR_H__
14
15#include <linux/kernel.h>
16#include <linux/vmalloc.h>
17#include <linux/list.h>
18#include <linux/types.h>
19#include <linux/string.h>
20#include <linux/slab.h>
21#include <linux/errno.h>
22#include <linux/fs.h>
23#include <linux/jffs2.h>
24#include "jffs2_fs_i.h"
25#include "jffs2_fs_sb.h"
26#include "nodelist.h"
27
28#define JFFS2_RUBINMIPS_PRIORITY 10
29#define JFFS2_DYNRUBIN_PRIORITY 20
30#define JFFS2_LZARI_PRIORITY 30
31#define JFFS2_RTIME_PRIORITY 50
32#define JFFS2_ZLIB_PRIORITY 60
33#define JFFS2_LZO_PRIORITY 80
34
35
36#define JFFS2_RUBINMIPS_DISABLED /* RUBINs will be used only */
37#define JFFS2_DYNRUBIN_DISABLED /* for decompression */
38
39#define JFFS2_COMPR_MODE_NONE 0
40#define JFFS2_COMPR_MODE_PRIORITY 1
41#define JFFS2_COMPR_MODE_SIZE 2
42#define JFFS2_COMPR_MODE_FAVOURLZO 3
43#define JFFS2_COMPR_MODE_FORCELZO 4
44#define JFFS2_COMPR_MODE_FORCEZLIB 5
45
46#define FAVOUR_LZO_PERCENT 80
47
48struct jffs2_compressor {
49 struct list_head list;
50 int priority; /* used by prirority comr. mode */
51 char *name;
52 char compr; /* JFFS2_COMPR_XXX */
53 int (*compress)(unsigned char *data_in, unsigned char *cpage_out,
54 uint32_t *srclen, uint32_t *destlen);
55 int (*decompress)(unsigned char *cdata_in, unsigned char *data_out,
56 uint32_t cdatalen, uint32_t datalen);
57 int usecount;
58 int disabled; /* if set the compressor won't compress */
59 unsigned char *compr_buf; /* used by size compr. mode */
60 uint32_t compr_buf_size; /* used by size compr. mode */
61 uint32_t stat_compr_orig_size;
62 uint32_t stat_compr_new_size;
63 uint32_t stat_compr_blocks;
64 uint32_t stat_decompr_blocks;
65};
66
67int jffs2_register_compressor(struct jffs2_compressor *comp);
68int jffs2_unregister_compressor(struct jffs2_compressor *comp);
69
70int jffs2_compressors_init(void);
71int jffs2_compressors_exit(void);
72
73uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
74 unsigned char *data_in, unsigned char **cpage_out,
75 uint32_t *datalen, uint32_t *cdatalen);
76
77int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
78 uint16_t comprtype, unsigned char *cdata_in,
79 unsigned char *data_out, uint32_t cdatalen, uint32_t datalen);
80
81void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig);
82
83/* Compressor modules */
84/* These functions will be called by jffs2_compressors_init/exit */
85
86#ifdef CONFIG_JFFS2_RUBIN
87int jffs2_rubinmips_init(void);
88void jffs2_rubinmips_exit(void);
89int jffs2_dynrubin_init(void);
90void jffs2_dynrubin_exit(void);
91#else
92static inline int jffs2_rubinmips_init(void) { return 0; }
93static inline void jffs2_rubinmips_exit(void) {}
94static inline int jffs2_dynrubin_init(void) { return 0; }
95static inline void jffs2_dynrubin_exit(void) {}
96#endif
97#ifdef CONFIG_JFFS2_RTIME
98extern int jffs2_rtime_init(void);
99extern void jffs2_rtime_exit(void);
100#else
101static inline int jffs2_rtime_init(void) { return 0; }
102static inline void jffs2_rtime_exit(void) {}
103#endif
104#ifdef CONFIG_JFFS2_ZLIB
105extern int jffs2_zlib_init(void);
106extern void jffs2_zlib_exit(void);
107#else
108static inline int jffs2_zlib_init(void) { return 0; }
109static inline void jffs2_zlib_exit(void) {}
110#endif
111#ifdef CONFIG_JFFS2_LZO
112extern int jffs2_lzo_init(void);
113extern void jffs2_lzo_exit(void);
114#else
115static inline int jffs2_lzo_init(void) { return 0; }
116static inline void jffs2_lzo_exit(void) {}
117#endif
118
119#endif /* __JFFS2_COMPR_H__ */
120

source code of linux/fs/jffs2/compr.h