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 1.34 2004/11/16 20:36:14 dwmw2 Exp $
  12  *
  13  */
  14
  15 #ifndef __LINUX_JFFS2_H__
  16 #define __LINUX_JFFS2_H__
  17
  18 /* You must include something which defines the C99 uintXX_t types.
  19    We don't do it from here because this file is used in too many
  20    different environments. */
  21
  22 #define JFFS2_SUPER_MAGIC 0x72b6
  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 /* We only allow a single char for length, and 0xFF is empty flash so
  32    we don't want it confused with a real length. Hence max 254.
  33 */
  34 #define JFFS2_MAX_NAME_LEN 254
  35
  36 /* How small can we sensibly write nodes? */
  37 #define JFFS2_MIN_DATA_LEN 128
  38
  39 #define JFFS2_COMPR_NONE        0x00
  40 #define JFFS2_COMPR_ZERO        0x01
  41 #define JFFS2_COMPR_RTIME       0x02
  42 #define JFFS2_COMPR_RUBINMIPS   0x03
  43 #define JFFS2_COMPR_COPY        0x04
  44 #define JFFS2_COMPR_DYNRUBIN    0x05
  45 #define JFFS2_COMPR_ZLIB        0x06
  46 #define JFFS2_COMPR_LZO         0x07
  47 #define JFFS2_COMPR_LZARI       0x08
  48 /* Compatibility flags. */
  49 #define JFFS2_COMPAT_MASK 0xc000      /* What do to if an unknown nodetype is found */
  50 #define JFFS2_NODE_ACCURATE 0x2000
  51 /* INCOMPAT: Fail to mount the filesystem */
  52 #define JFFS2_FEATURE_INCOMPAT 0xc000
  53 /* ROCOMPAT: Mount read-only */
  54 #define JFFS2_FEATURE_ROCOMPAT 0x8000
  55 /* RWCOMPAT_COPY: Mount read/write, and copy the node when it's GC'd */
  56 #define JFFS2_FEATURE_RWCOMPAT_COPY 0x4000
  57 /* RWCOMPAT_DELETE: Mount read/write, and delete the node when it's GC'd */
  58 #define JFFS2_FEATURE_RWCOMPAT_DELETE 0x0000
  59
  60 #define JFFS2_NODETYPE_DIRENT (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 1)
  61 #define JFFS2_NODETYPE_INODE (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 2)
  62 #define JFFS2_NODETYPE_CLEANMARKER (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
  63 #define JFFS2_NODETYPE_PADDING (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 4)
  64
  65 // Maybe later...
  66 //#define JFFS2_NODETYPE_CHECKPOINT (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
  67 //#define JFFS2_NODETYPE_OPTIONS (JFFS2_FEATURE_RWCOMPAT_COPY | JFFS2_NODE_ACCURATE | 4)
  68
  69
  70 #define JFFS2_INO_FLAG_PREREAD    1     /* Do read_inode() for this one at
  71                                            mount time, don't wait for it to
  72                                            happen later */
  73 #define JFFS2_INO_FLAG_USERCOMPR  2     /* User has requested a specific
  74                                            compression type */
  75
  76
  77 /* These can go once we've made sure we've caught all uses without
  78    byteswapping */
  79
  80 typedef struct {
  81         uint32_t v32;
  82 } __attribute__((packed))  jint32_t;
  83
  84 typedef struct {
  85         uint32_t m;
  86 } __attribute__((packed))  jmode_t;
  87
  88 typedef struct {
  89         uint16_t v16;
  90 } __attribute__((packed)) jint16_t;
  91
  92 struct jffs2_unknown_node
  93 {
  94         /* All start like this */
  95         jint16_t magic;
  96         jint16_t nodetype;
  97         jint32_t totlen; /* So we can skip over nodes we don't grok */
  98         jint32_t hdr_crc;
  99 } __attribute__((packed));
 100
 101 struct jffs2_raw_dirent
 102 {
 103         jint16_t magic;
 104         jint16_t nodetype;      /* == JFFS_NODETYPE_DIRENT */
 105         jint32_t totlen;
 106         jint32_t hdr_crc;
 107         jint32_t pino;
 108         jint32_t version;
 109         jint32_t ino; /* == zero for unlink */
 110         jint32_t mctime;
 111         uint8_t nsize;
 112         uint8_t type;
 113         uint8_t unused[2];
 114         jint32_t node_crc;
 115         jint32_t name_crc;
 116         uint8_t name[0];
 117 } __attribute__((packed));
 118
 119 /* The JFFS2 raw inode structure: Used for storage on physical media.  */
 120 /* The uid, gid, atime, mtime and ctime members could be longer, but
 121    are left like this for space efficiency. If and when people decide
 122    they really need them extended, it's simple enough to add support for
 123    a new type of raw node.
 124 */
 125 struct jffs2_raw_inode
 126 {
 127         jint16_t magic;      /* A constant magic number.  */
 128         jint16_t nodetype;   /* == JFFS_NODETYPE_INODE */
 129         jint32_t totlen;     /* Total length of this node (inc data, etc.) */
 130         jint32_t hdr_crc;
 131         jint32_t ino;        /* Inode number.  */
 132         jint32_t version;    /* Version number.  */
 133         jmode_t mode;       /* The file's type or mode.  */
 134         jint16_t uid;        /* The file's owner.  */
 135         jint16_t gid;        /* The file's group.  */
 136         jint32_t isize;      /* Total resultant size of this inode (used for truncations)  */
 137         jint32_t atime;      /* Last access time.  */
 138         jint32_t mtime;      /* Last modification time.  */
 139         jint32_t ctime;      /* Change time.  */
 140         jint32_t offset;     /* Where to begin to write.  */
 141         jint32_t csize;      /* (Compressed) data size */
 142         jint32_t dsize;      /* Size of the node's data. (after decompression) */
 143         uint8_t compr;       /* Compression algorithm used */
 144         uint8_t usercompr;   /* Compression algorithm requested by the user */
 145         jint16_t flags;      /* See JFFS2_INO_FLAG_* */
 146         jint32_t data_crc;   /* CRC for the (compressed) data.  */
 147         jint32_t node_crc;   /* CRC for the raw inode (excluding data)  */
 148         uint8_t data[0];
 149 } __attribute__((packed));
 150
 151 union jffs2_node_union {
 152         struct jffs2_raw_inode i;
 153         struct jffs2_raw_dirent d;
 154         struct jffs2_unknown_node u;
 155 };
 156
 157 #endif /* __LINUX_JFFS2_H__ */