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jffs2.h
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1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  * Copyright © 2004-2010 David Woodhouse <[email protected]>
6  *
7  * Created by David Woodhouse <[email protected]>
8  *
9  * For licensing information, see the file 'LICENCE' in the
10  * jffs2 directory.
11  */
12 
13 #ifndef __LINUX_JFFS2_H__
14 #define __LINUX_JFFS2_H__
15 
16 #include <linux/types.h>
17 #include <linux/magic.h>
18 
19 /* You must include something which defines the C99 uintXX_t types.
20  We don't do it from here because this file is used in too many
21  different environments. */
22 
23 /* Values we may expect to find in the 'magic' field */
24 #define JFFS2_OLD_MAGIC_BITMASK 0x1984
25 #define JFFS2_MAGIC_BITMASK 0x1985
26 #define KSAMTIB_CIGAM_2SFFJ 0x8519 /* For detecting wrong-endian fs */
27 #define JFFS2_EMPTY_BITMASK 0xffff
28 #define JFFS2_DIRTY_BITMASK 0x0000
29 
30 /* Summary node MAGIC marker */
31 #define JFFS2_SUM_MAGIC 0x02851885
32 
33 /* We only allow a single char for length, and 0xFF is empty flash so
34  we don't want it confused with a real length. Hence max 254.
35 */
36 #define JFFS2_MAX_NAME_LEN 254
37 
38 /* How small can we sensibly write nodes? */
39 #define JFFS2_MIN_DATA_LEN 128
40 
41 #define JFFS2_COMPR_NONE 0x00
42 #define JFFS2_COMPR_ZERO 0x01
43 #define JFFS2_COMPR_RTIME 0x02
44 #define JFFS2_COMPR_RUBINMIPS 0x03
45 #define JFFS2_COMPR_COPY 0x04
46 #define JFFS2_COMPR_DYNRUBIN 0x05
47 #define JFFS2_COMPR_ZLIB 0x06
48 #define JFFS2_COMPR_LZO 0x07
49 /* Compatibility flags. */
50 #define JFFS2_COMPAT_MASK 0xc000 /* What do to if an unknown nodetype is found */
51 #define JFFS2_NODE_ACCURATE 0x2000
52 /* INCOMPAT: Fail to mount the filesystem */
53 #define JFFS2_FEATURE_INCOMPAT 0xc000
54 /* ROCOMPAT: Mount read-only */
55 #define JFFS2_FEATURE_ROCOMPAT 0x8000
56 /* RWCOMPAT_COPY: Mount read/write, and copy the node when it's GC'd */
57 #define JFFS2_FEATURE_RWCOMPAT_COPY 0x4000
58 /* RWCOMPAT_DELETE: Mount read/write, and delete the node when it's GC'd */
59 #define JFFS2_FEATURE_RWCOMPAT_DELETE 0x0000
60 
61 #define JFFS2_NODETYPE_DIRENT (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 1)
62 #define JFFS2_NODETYPE_INODE (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 2)
63 #define JFFS2_NODETYPE_CLEANMARKER (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
64 #define JFFS2_NODETYPE_PADDING (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 4)
65 
66 #define JFFS2_NODETYPE_SUMMARY (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 6)
67 
68 #define JFFS2_NODETYPE_XATTR (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 8)
69 #define JFFS2_NODETYPE_XREF (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 9)
70 
71 /* XATTR Related */
72 #define JFFS2_XPREFIX_USER 1 /* for "user." */
73 #define JFFS2_XPREFIX_SECURITY 2 /* for "security." */
74 #define JFFS2_XPREFIX_ACL_ACCESS 3 /* for "system.posix_acl_access" */
75 #define JFFS2_XPREFIX_ACL_DEFAULT 4 /* for "system.posix_acl_default" */
76 #define JFFS2_XPREFIX_TRUSTED 5 /* for "trusted.*" */
77 
78 #define JFFS2_ACL_VERSION 0x0001
79 
80 // Maybe later...
81 //#define JFFS2_NODETYPE_CHECKPOINT (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
82 //#define JFFS2_NODETYPE_OPTIONS (JFFS2_FEATURE_RWCOMPAT_COPY | JFFS2_NODE_ACCURATE | 4)
83 
84 
85 #define JFFS2_INO_FLAG_PREREAD 1 /* Do read_inode() for this one at
86  mount time, don't wait for it to
87  happen later */
88 #define JFFS2_INO_FLAG_USERCOMPR 2 /* User has requested a specific
89  compression type */
90 
91 
92 /* These can go once we've made sure we've caught all uses without
93  byteswapping */
94 
95 typedef struct {
96  __u32 v32;
97 } __attribute__((packed)) jint32_t;
98 
99 typedef struct {
100  __u32 m;
101 } __attribute__((packed)) jmode_t;
102 
103 typedef struct {
104  __u16 v16;
105 } __attribute__((packed)) jint16_t;
106 
108 {
109  /* All start like this */
110  jint16_t magic;
111  jint16_t nodetype;
112  jint32_t totlen; /* So we can skip over nodes we don't grok */
113  jint32_t hdr_crc;
114 };
117 {
118  jint16_t magic;
119  jint16_t nodetype; /* == JFFS2_NODETYPE_DIRENT */
120  jint32_t totlen;
121  jint32_t hdr_crc;
122  jint32_t pino;
123  jint32_t version;
124  jint32_t ino; /* == zero for unlink */
125  jint32_t mctime;
129  jint32_t node_crc;
130  jint32_t name_crc;
131  __u8 name[0];
132 };
133 
134 /* The JFFS2 raw inode structure: Used for storage on physical media. */
135 /* The uid, gid, atime, mtime and ctime members could be longer, but
136  are left like this for space efficiency. If and when people decide
137  they really need them extended, it's simple enough to add support for
138  a new type of raw node.
139 */
141 {
142  jint16_t magic; /* A constant magic number. */
143  jint16_t nodetype; /* == JFFS2_NODETYPE_INODE */
144  jint32_t totlen; /* Total length of this node (inc data, etc.) */
145  jint32_t hdr_crc;
146  jint32_t ino; /* Inode number. */
147  jint32_t version; /* Version number. */
148  jmode_t mode; /* The file's type or mode. */
149  jint16_t uid; /* The file's owner. */
150  jint16_t gid; /* The file's group. */
151  jint32_t isize; /* Total resultant size of this inode (used for truncations) */
152  jint32_t atime; /* Last access time. */
153  jint32_t mtime; /* Last modification time. */
154  jint32_t ctime; /* Change time. */
155  jint32_t offset; /* Where to begin to write. */
156  jint32_t csize; /* (Compressed) data size */
157  jint32_t dsize; /* Size of the node's data. (after decompression) */
158  __u8 compr; /* Compression algorithm used */
159  __u8 usercompr; /* Compression algorithm requested by the user */
160  jint16_t flags; /* See JFFS2_INO_FLAG_* */
161  jint32_t data_crc; /* CRC for the (compressed) data. */
162  jint32_t node_crc; /* CRC for the raw inode (excluding data) */
163  __u8 data[0];
164 };
167  jint16_t magic;
168  jint16_t nodetype; /* = JFFS2_NODETYPE_XATTR */
169  jint32_t totlen;
170  jint32_t hdr_crc;
171  jint32_t xid; /* XATTR identifier number */
172  jint32_t version;
175  jint16_t value_len;
176  jint32_t data_crc;
177  jint32_t node_crc;
178  __u8 data[0];
179 } __attribute__((packed));
182 {
183  jint16_t magic;
184  jint16_t nodetype; /* = JFFS2_NODETYPE_XREF */
185  jint32_t totlen;
186  jint32_t hdr_crc;
187  jint32_t ino; /* inode number */
188  jint32_t xid; /* XATTR identifier number */
189  jint32_t xseqno; /* xref sequential number */
190  jint32_t node_crc;
191 } __attribute__((packed));
194 {
195  jint16_t magic;
196  jint16_t nodetype; /* = JFFS2_NODETYPE_SUMMARY */
197  jint32_t totlen;
198  jint32_t hdr_crc;
199  jint32_t sum_num; /* number of sum entries*/
200  jint32_t cln_mkr; /* clean marker size, 0 = no cleanmarker */
201  jint32_t padded; /* sum of the size of padding nodes */
202  jint32_t sum_crc; /* summary information crc */
203  jint32_t node_crc; /* node crc */
204  jint32_t sum[0]; /* inode summary info */
205 };
208 {
212  struct jffs2_raw_xref r;
213  struct jffs2_raw_summary s;
214  struct jffs2_unknown_node u;
215 };
217 /* Data payload for device nodes. */
218 union jffs2_device_node {
219  jint16_t old_id;
220  jint32_t new_id;
221 };
222 
223 #endif /* __LINUX_JFFS2_H__ */