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/types.h>
  16 #include <linux/magic.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 /* Values we may expect to find in the 'magic' field */
  23 #define JFFS2_OLD_MAGIC_BITMASK 0x1984
  24 #define JFFS2_MAGIC_BITMASK 0x1985
  25 #define KSAMTIB_CIGAM_2SFFJ 0x8519 /* For detecting wrong-endian fs */
  26 #define JFFS2_EMPTY_BITMASK 0xffff
  27 #define JFFS2_DIRTY_BITMASK 0x0000
  28
  29 /* Summary node MAGIC marker */
  30 #define JFFS2_SUM_MAGIC 0x02851885
  31
  32 /* We only allow a single char for length, and 0xFF is empty flash so
  33    we don't want it confused with a real length. Hence max 254.
  34 */
  35 #define JFFS2_MAX_NAME_LEN 254
  36
  37 /* How small can we sensibly write nodes? */
  38 #define JFFS2_MIN_DATA_LEN 128
  39
  40 #define JFFS2_COMPR_NONE        0x00
  41 #define JFFS2_COMPR_ZERO        0x01
  42 #define JFFS2_COMPR_RTIME       0x02
  43 #define JFFS2_COMPR_RUBINMIPS   0x03
  44 #define JFFS2_COMPR_COPY        0x04
  45 #define JFFS2_COMPR_DYNRUBIN    0x05
  46 #define JFFS2_COMPR_ZLIB        0x06
  47 #define JFFS2_COMPR_LZO         0x07
  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 #define JFFS2_NODETYPE_SUMMARY (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 6)
  66
  67 #define JFFS2_NODETYPE_XATTR (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 8)
  68 #define JFFS2_NODETYPE_XREF (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 9)
  69
  70 /* XATTR Related */
  71 #define JFFS2_XPREFIX_USER              1       /* for "user." */
  72 #define JFFS2_XPREFIX_SECURITY          2       /* for "security." */
  73 #define JFFS2_XPREFIX_ACL_ACCESS        3       /* for "system.posix_acl_access" */
  74 #define JFFS2_XPREFIX_ACL_DEFAULT       4       /* for "system.posix_acl_default" */
  75 #define JFFS2_XPREFIX_TRUSTED           5       /* for "trusted.*" */
  76
  77 #define JFFS2_ACL_VERSION               0x0001
  78
  79 // Maybe later...
  80 //#define JFFS2_NODETYPE_CHECKPOINT (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
  81 //#define JFFS2_NODETYPE_OPTIONS (JFFS2_FEATURE_RWCOMPAT_COPY | JFFS2_NODE_ACCURATE | 4)
  82
  83
  84 #define JFFS2_INO_FLAG_PREREAD    1     /* Do read_inode() for this one at
  85                                            mount time, don't wait for it to
  86                                            happen later */
  87 #define JFFS2_INO_FLAG_USERCOMPR  2     /* User has requested a specific
  88                                            compression type */
  89
  90
  91 /* These can go once we've made sure we've caught all uses without
  92    byteswapping */
  93
  94 typedef struct {
  95         __u32 v32;
  96 } __attribute__((packed)) jint32_t;
  97
  98 typedef struct {
  99         __u32 m;
 100 } __attribute__((packed)) jmode_t;
 101
 102 typedef struct {
 103         __u16 v16;
 104 } __attribute__((packed)) jint16_t;
 105
 106 struct jffs2_unknown_node
 107 {
 108         /* All start like this */
 109         jint16_t magic;
 110         jint16_t nodetype;
 111         jint32_t totlen; /* So we can skip over nodes we don't grok */
 112         jint32_t hdr_crc;
 113 };
 114
 115 struct jffs2_raw_dirent
 116 {
 117         jint16_t magic;
 118         jint16_t nodetype;      /* == JFFS2_NODETYPE_DIRENT */
 119         jint32_t totlen;
 120         jint32_t hdr_crc;
 121         jint32_t pino;
 122         jint32_t version;
 123         jint32_t ino; /* == zero for unlink */
 124         jint32_t mctime;
 125         __u8 nsize;
 126         __u8 type;
 127         __u8 unused[2];
 128         jint32_t node_crc;
 129         jint32_t name_crc;
 130         __u8 name[0];
 131 };
 132
 133 /* The JFFS2 raw inode structure: Used for storage on physical media.  */
 134 /* The uid, gid, atime, mtime and ctime members could be longer, but
 135    are left like this for space efficiency. If and when people decide
 136    they really need them extended, it's simple enough to add support for
 137    a new type of raw node.
 138 */
 139 struct jffs2_raw_inode
 140 {
 141         jint16_t magic;      /* A constant magic number.  */
 142         jint16_t nodetype;   /* == JFFS2_NODETYPE_INODE */
 143         jint32_t totlen;     /* Total length of this node (inc data, etc.) */
 144         jint32_t hdr_crc;
 145         jint32_t ino;        /* Inode number.  */
 146         jint32_t version;    /* Version number.  */
 147         jmode_t mode;       /* The file's type or mode.  */
 148         jint16_t uid;        /* The file's owner.  */
 149         jint16_t gid;        /* The file's group.  */
 150         jint32_t isize;      /* Total resultant size of this inode (used for truncations)  */
 151         jint32_t atime;      /* Last access time.  */
 152         jint32_t mtime;      /* Last modification time.  */
 153         jint32_t ctime;      /* Change time.  */
 154         jint32_t offset;     /* Where to begin to write.  */
 155         jint32_t csize;      /* (Compressed) data size */
 156         jint32_t dsize;      /* Size of the node's data. (after decompression) */
 157         __u8 compr;       /* Compression algorithm used */
 158         __u8 usercompr;   /* Compression algorithm requested by the user */
 159         jint16_t flags;      /* See JFFS2_INO_FLAG_* */
 160         jint32_t data_crc;   /* CRC for the (compressed) data.  */
 161         jint32_t node_crc;   /* CRC for the raw inode (excluding data)  */
 162         __u8 data[0];
 163 };
 164
 165 struct jffs2_raw_xattr {
 166         jint16_t magic;
 167         jint16_t nodetype;      /* = JFFS2_NODETYPE_XATTR */
 168         jint32_t totlen;
 169         jint32_t hdr_crc;
 170         jint32_t xid;           /* XATTR identifier number */
 171         jint32_t version;
 172         __u8 xprefix;
 173         __u8 name_len;
 174         jint16_t value_len;
 175         jint32_t data_crc;
 176         jint32_t node_crc;
 177         __u8 data[0];
 178 } __attribute__((packed));
 179
 180 struct jffs2_raw_xref
 181 {
 182         jint16_t magic;
 183         jint16_t nodetype;      /* = JFFS2_NODETYPE_XREF */
 184         jint32_t totlen;
 185         jint32_t hdr_crc;
 186         jint32_t ino;           /* inode number */
 187         jint32_t xid;           /* XATTR identifier number */
 188         jint32_t xseqno;        /* xref sequencial number */
 189         jint32_t node_crc;
 190 } __attribute__((packed));
 191
 192 struct jffs2_raw_summary
 193 {
 194         jint16_t magic;
 195         jint16_t nodetype;      /* = JFFS2_NODETYPE_SUMMARY */
 196         jint32_t totlen;
 197         jint32_t hdr_crc;
 198         jint32_t sum_num;       /* number of sum entries*/
 199         jint32_t cln_mkr;       /* clean marker size, 0 = no cleanmarker */
 200         jint32_t padded;        /* sum of the size of padding nodes */
 201         jint32_t sum_crc;       /* summary information crc */
 202         jint32_t node_crc;      /* node crc */
 203         jint32_t sum[0];        /* inode summary info */
 204 };
 205
 206 union jffs2_node_union
 207 {
 208         struct jffs2_raw_inode i;
 209         struct jffs2_raw_dirent d;
 210         struct jffs2_raw_xattr x;
 211         struct jffs2_raw_xref r;
 212         struct jffs2_raw_summary s;
 213         struct jffs2_unknown_node u;
 214 };
 215
 216 /* Data payload for device nodes. */
 217 union jffs2_device_node {
 218         jint16_t old;
 219         jint32_t new;
 220 };
 221
 222 #endif /* __LINUX_JFFS2_H__ */