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