include/linux/jffs2.h

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 2001-2007 Red Hat, Inc.
   5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
   6  *
   7  * Created by David Woodhouse <dwmw2@infradead.org>
   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
 107 struct jffs2_unknown_node
 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 };
 115
 116 struct jffs2_raw_dirent
 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;
 126         __u8 nsize;
 127         __u8 type;
 128         __u8 unused[2];
 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 */
 140 struct jffs2_raw_inode
 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 };
 165
 166 struct jffs2_raw_xattr {
 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;
 173         __u8 xprefix;
 174         __u8 name_len;
 175         jint16_t value_len;
 176         jint32_t data_crc;
 177         jint32_t node_crc;
 178         __u8 data[0];
 179 } __attribute__((packed));
 180
 181 struct jffs2_raw_xref
 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));
 192
 193 struct jffs2_raw_summary
 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 };
 206
 207 union jffs2_node_union
 208 {
 209         struct jffs2_raw_inode i;
 210         struct jffs2_raw_dirent d;
 211         struct jffs2_raw_xattr x;
 212         struct jffs2_raw_xref r;
 213         struct jffs2_raw_summary s;
 214         struct jffs2_unknown_node u;
 215 };
 216
 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__ */