include/linux/jffs2.h

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2001-2003 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in the
   9  * jffs2 directory.
  10  *
  11  * $Id: jffs2.h,v 1.38 2005/09/26 11:37:23 havasi Exp $
  12  *
  13  */
  14
  15 #ifndef __LINUX_JFFS2_H__
  16 #define __LINUX_JFFS2_H__
  17
  18 #include <linux/magic.h>
  19
  20 /* You must include something which defines the C99 uintXX_t types.
  21    We don't do it from here because this file is used in too many
  22    different environments. */
  23
  24 /* Values we may expect to find in the 'magic' field */
  25 #define JFFS2_OLD_MAGIC_BITMASK 0x1984
  26 #define JFFS2_MAGIC_BITMASK 0x1985
  27 #define KSAMTIB_CIGAM_2SFFJ 0x8519 /* For detecting wrong-endian fs */
  28 #define JFFS2_EMPTY_BITMASK 0xffff
  29 #define JFFS2_DIRTY_BITMASK 0x0000
  30
  31 /* Summary node MAGIC marker */
  32 #define JFFS2_SUM_MAGIC 0x02851885
  33
  34 /* We only allow a single char for length, and 0xFF is empty flash so
  35    we don't want it confused with a real length. Hence max 254.
  36 */
  37 #define JFFS2_MAX_NAME_LEN 254
  38
  39 /* How small can we sensibly write nodes? */
  40 #define JFFS2_MIN_DATA_LEN 128
  41
  42 #define JFFS2_COMPR_NONE        0x00
  43 #define JFFS2_COMPR_ZERO        0x01
  44 #define JFFS2_COMPR_RTIME       0x02
  45 #define JFFS2_COMPR_RUBINMIPS   0x03
  46 #define JFFS2_COMPR_COPY        0x04
  47 #define JFFS2_COMPR_DYNRUBIN    0x05
  48 #define JFFS2_COMPR_ZLIB        0x06
  49 #define JFFS2_COMPR_LZO         0x07
  50 /* Compatibility flags. */
  51 #define JFFS2_COMPAT_MASK 0xc000      /* What do to if an unknown nodetype is found */
  52 #define JFFS2_NODE_ACCURATE 0x2000
  53 /* INCOMPAT: Fail to mount the filesystem */
  54 #define JFFS2_FEATURE_INCOMPAT 0xc000
  55 /* ROCOMPAT: Mount read-only */
  56 #define JFFS2_FEATURE_ROCOMPAT 0x8000
  57 /* RWCOMPAT_COPY: Mount read/write, and copy the node when it's GC'd */
  58 #define JFFS2_FEATURE_RWCOMPAT_COPY 0x4000
  59 /* RWCOMPAT_DELETE: Mount read/write, and delete the node when it's GC'd */
  60 #define JFFS2_FEATURE_RWCOMPAT_DELETE 0x0000
  61
  62 #define JFFS2_NODETYPE_DIRENT (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 1)
  63 #define JFFS2_NODETYPE_INODE (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 2)
  64 #define JFFS2_NODETYPE_CLEANMARKER (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
  65 #define JFFS2_NODETYPE_PADDING (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 4)
  66
  67 #define JFFS2_NODETYPE_SUMMARY (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 6)
  68
  69 #define JFFS2_NODETYPE_XATTR (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 8)
  70 #define JFFS2_NODETYPE_XREF (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 9)
  71
  72 /* XATTR Related */
  73 #define JFFS2_XPREFIX_USER              1       /* for "user." */
  74 #define JFFS2_XPREFIX_SECURITY          2       /* for "security." */
  75 #define JFFS2_XPREFIX_ACL_ACCESS        3       /* for "system.posix_acl_access" */
  76 #define JFFS2_XPREFIX_ACL_DEFAULT       4       /* for "system.posix_acl_default" */
  77 #define JFFS2_XPREFIX_TRUSTED           5       /* for "trusted.*" */
  78
  79 #define JFFS2_ACL_VERSION               0x0001
  80
  81 // Maybe later...
  82 //#define JFFS2_NODETYPE_CHECKPOINT (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
  83 //#define JFFS2_NODETYPE_OPTIONS (JFFS2_FEATURE_RWCOMPAT_COPY | JFFS2_NODE_ACCURATE | 4)
  84
  85
  86 #define JFFS2_INO_FLAG_PREREAD    1     /* Do read_inode() for this one at
  87                                            mount time, don't wait for it to
  88                                            happen later */
  89 #define JFFS2_INO_FLAG_USERCOMPR  2     /* User has requested a specific
  90                                            compression type */
  91
  92
  93 /* These can go once we've made sure we've caught all uses without
  94    byteswapping */
  95
  96 typedef struct {
  97         uint32_t v32;
  98 } __attribute__((packed)) jint32_t;
  99
 100 typedef struct {
 101         uint32_t m;
 102 } __attribute__((packed)) jmode_t;
 103
 104 typedef struct {
 105         uint16_t v16;
 106 } __attribute__((packed)) jint16_t;
 107
 108 struct jffs2_unknown_node
 109 {
 110         /* All start like this */
 111         jint16_t magic;
 112         jint16_t nodetype;
 113         jint32_t totlen; /* So we can skip over nodes we don't grok */
 114         jint32_t hdr_crc;
 115 };
 116
 117 struct jffs2_raw_dirent
 118 {
 119         jint16_t magic;
 120         jint16_t nodetype;      /* == JFFS2_NODETYPE_DIRENT */
 121         jint32_t totlen;
 122         jint32_t hdr_crc;
 123         jint32_t pino;
 124         jint32_t version;
 125         jint32_t ino; /* == zero for unlink */
 126         jint32_t mctime;
 127         uint8_t nsize;
 128         uint8_t type;
 129         uint8_t unused[2];
 130         jint32_t node_crc;
 131         jint32_t name_crc;
 132         uint8_t name[0];
 133 };
 134
 135 /* The JFFS2 raw inode structure: Used for storage on physical media.  */
 136 /* The uid, gid, atime, mtime and ctime members could be longer, but
 137    are left like this for space efficiency. If and when people decide
 138    they really need them extended, it's simple enough to add support for
 139    a new type of raw node.
 140 */
 141 struct jffs2_raw_inode
 142 {
 143         jint16_t magic;      /* A constant magic number.  */
 144         jint16_t nodetype;   /* == JFFS2_NODETYPE_INODE */
 145         jint32_t totlen;     /* Total length of this node (inc data, etc.) */
 146         jint32_t hdr_crc;
 147         jint32_t ino;        /* Inode number.  */
 148         jint32_t version;    /* Version number.  */
 149         jmode_t mode;       /* The file's type or mode.  */
 150         jint16_t uid;        /* The file's owner.  */
 151         jint16_t gid;        /* The file's group.  */
 152         jint32_t isize;      /* Total resultant size of this inode (used for truncations)  */
 153         jint32_t atime;      /* Last access time.  */
 154         jint32_t mtime;      /* Last modification time.  */
 155         jint32_t ctime;      /* Change time.  */
 156         jint32_t offset;     /* Where to begin to write.  */
 157         jint32_t csize;      /* (Compressed) data size */
 158         jint32_t dsize;      /* Size of the node's data. (after decompression) */
 159         uint8_t compr;       /* Compression algorithm used */
 160         uint8_t usercompr;   /* Compression algorithm requested by the user */
 161         jint16_t flags;      /* See JFFS2_INO_FLAG_* */
 162         jint32_t data_crc;   /* CRC for the (compressed) data.  */
 163         jint32_t node_crc;   /* CRC for the raw inode (excluding data)  */
 164         uint8_t data[0];
 165 };
 166
 167 struct jffs2_raw_xattr {
 168         jint16_t magic;
 169         jint16_t nodetype;      /* = JFFS2_NODETYPE_XATTR */
 170         jint32_t totlen;
 171         jint32_t hdr_crc;
 172         jint32_t xid;           /* XATTR identifier number */
 173         jint32_t version;
 174         uint8_t xprefix;
 175         uint8_t name_len;
 176         jint16_t value_len;
 177         jint32_t data_crc;
 178         jint32_t node_crc;
 179         uint8_t data[0];
 180 } __attribute__((packed));
 181
 182 struct jffs2_raw_xref
 183 {
 184         jint16_t magic;
 185         jint16_t nodetype;      /* = JFFS2_NODETYPE_XREF */
 186         jint32_t totlen;
 187         jint32_t hdr_crc;
 188         jint32_t ino;           /* inode number */
 189         jint32_t xid;           /* XATTR identifier number */
 190         jint32_t xseqno;        /* xref sequencial number */
 191         jint32_t node_crc;
 192 } __attribute__((packed));
 193
 194 struct jffs2_raw_summary
 195 {
 196         jint16_t magic;
 197         jint16_t nodetype;      /* = JFFS2_NODETYPE_SUMMARY */
 198         jint32_t totlen;
 199         jint32_t hdr_crc;
 200         jint32_t sum_num;       /* number of sum entries*/
 201         jint32_t cln_mkr;       /* clean marker size, 0 = no cleanmarker */
 202         jint32_t padded;        /* sum of the size of padding nodes */
 203         jint32_t sum_crc;       /* summary information crc */
 204         jint32_t node_crc;      /* node crc */
 205         jint32_t sum[0];        /* inode summary info */
 206 };
 207
 208 union jffs2_node_union
 209 {
 210         struct jffs2_raw_inode i;
 211         struct jffs2_raw_dirent d;
 212         struct jffs2_raw_xattr x;
 213         struct jffs2_raw_xref r;
 214         struct jffs2_raw_summary s;
 215         struct jffs2_unknown_node u;
 216 };
 217
 218 /* Data payload for device nodes. */
 219 union jffs2_device_node {
 220         jint16_t old;
 221         jint32_t new;
 222 };
 223
 224 #endif /* __LINUX_JFFS2_H__ */