core/fs/btrfs/btrfs.h

   1 #ifndef _BTRFS_H_
   2 #define _BTRFS_H_
   3
   4 #include <stdint.h>
   5 #include <zconf.h>
   6
   7 typedef uint8_t u8;
   8 typedef uint16_t u16;
   9 typedef uint32_t u32;
  10 typedef uint64_t u64;
  11 /* type that store on disk, but it is same as cpu type for i386 arch */
  12 typedef u16 __le16;
  13 typedef u32 __le32;
  14 typedef u64 __le64;
  15
  16 #include "crc32c.h"
  17 #define btrfs_crc32c crc32c_le
  18
  19 #define BTRFS_SUPER_INFO_OFFSET (64 * 1024)
  20 #define BTRFS_SUPER_INFO_SIZE 4096
  21 #define BTRFS_MAX_LEAF_SIZE 4096
  22 #define BTRFS_BLOCK_SHIFT 12
  23
  24 #define BTRFS_SUPER_MIRROR_MAX   3
  25 #define BTRFS_SUPER_MIRROR_SHIFT 12
  26 #define BTRFS_CSUM_SIZE 32
  27 #define BTRFS_FSID_SIZE 16
  28 #define BTRFS_LABEL_SIZE 256
  29 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
  30 #define BTRFS_UUID_SIZE 16
  31
  32 #define BTRFS_MAGIC "_BHRfS_M"
  33
  34 #define BTRFS_SUPER_FLAG_METADUMP       (1ULL << 33)
  35
  36 #define BTRFS_DEV_ITEM_KEY      216
  37 #define BTRFS_CHUNK_ITEM_KEY    228
  38 #define BTRFS_ROOT_REF_KEY      156
  39 #define BTRFS_ROOT_ITEM_KEY     132
  40 #define BTRFS_EXTENT_DATA_KEY   108
  41 #define BTRFS_DIR_ITEM_KEY      84
  42 #define BTRFS_INODE_ITEM_KEY    1
  43
  44 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
  45 #define BTRFS_FS_TREE_OBJECTID 5ULL
  46
  47 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
  48
  49 #define BTRFS_FILE_EXTENT_INLINE 0
  50 #define BTRFS_FILE_EXTENT_REG 1
  51 #define BTRFS_FILE_EXTENT_PREALLOC 2
  52
  53 #define BTRFS_MAX_LEVEL 8
  54 #define BTRFS_MAX_CHUNK_ENTRIES 256
  55
  56 #define BTRFS_FT_REG_FILE       1
  57 #define BTRFS_FT_DIR            2
  58 #define BTRFS_FT_SYMLINK        7
  59
  60 #define ROOT_DIR_WORD 0x002f
  61
  62 struct btrfs_dev_item {
  63         __le64 devid;
  64         __le64 total_bytes;
  65         __le64 bytes_used;
  66         __le32 io_align;
  67         __le32 io_width;
  68         __le32 sector_size;
  69         __le64 type;
  70         __le64 generation;
  71         __le64 start_offset;
  72         __le32 dev_group;
  73         u8 seek_speed;
  74         u8 bandwidth;
  75         u8 uuid[BTRFS_UUID_SIZE];
  76         u8 fsid[BTRFS_UUID_SIZE];
  77 } __attribute__ ((__packed__));
  78
  79 struct btrfs_super_block {
  80         u8 csum[BTRFS_CSUM_SIZE];
  81         /* the first 3 fields must match struct btrfs_header */
  82         u8 fsid[BTRFS_FSID_SIZE];    /* FS specific uuid */
  83         __le64 bytenr; /* this block number */
  84         __le64 flags;
  85
  86         /* allowed to be different from the btrfs_header from here own down */
  87         __le64 magic;
  88         __le64 generation;
  89         __le64 root;
  90         __le64 chunk_root;
  91         __le64 log_root;
  92
  93         /* this will help find the new super based on the log root */
  94         __le64 log_root_transid;
  95         __le64 total_bytes;
  96         __le64 bytes_used;
  97         __le64 root_dir_objectid;
  98         __le64 num_devices;
  99         __le32 sectorsize;
 100         __le32 nodesize;
 101         __le32 leafsize;
 102         __le32 stripesize;
 103         __le32 sys_chunk_array_size;
 104         __le64 chunk_root_generation;
 105         __le64 compat_flags;
 106         __le64 compat_ro_flags;
 107         __le64 incompat_flags;
 108         __le16 csum_type;
 109         u8 root_level;
 110         u8 chunk_root_level;
 111         u8 log_root_level;
 112         struct btrfs_dev_item dev_item;
 113
 114         char label[BTRFS_LABEL_SIZE];
 115
 116         /* future expansion */
 117         __le64 reserved[32];
 118         u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
 119 } __attribute__ ((__packed__));
 120
 121 struct btrfs_disk_key {
 122         __le64 objectid;
 123         u8 type;
 124         __le64 offset;
 125 } __attribute__ ((__packed__));
 126
 127 struct btrfs_stripe {
 128         __le64 devid;
 129         __le64 offset;
 130         u8 dev_uuid[BTRFS_UUID_SIZE];
 131 } __attribute__ ((__packed__));
 132
 133 struct btrfs_chunk {
 134         __le64 length;
 135         __le64 owner;
 136         __le64 stripe_len;
 137         __le64 type;
 138         __le32 io_align;
 139         __le32 io_width;
 140         __le32 sector_size;
 141         __le16 num_stripes;
 142         __le16 sub_stripes;
 143         struct btrfs_stripe stripe;
 144 } __attribute__ ((__packed__));
 145
 146 struct btrfs_header {
 147         /* these first four must match the super block */
 148         u8 csum[BTRFS_CSUM_SIZE];
 149         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
 150         __le64 bytenr; /* which block this node is supposed to live in */
 151         __le64 flags;
 152
 153         /* allowed to be different from the super from here on down */
 154         u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
 155         __le64 generation;
 156         __le64 owner;
 157         __le32 nritems;
 158         u8 level;
 159 } __attribute__ ((__packed__));
 160
 161 struct btrfs_item {
 162         struct btrfs_disk_key key;
 163         __le32 offset;
 164         __le32 size;
 165 } __attribute__ ((__packed__));
 166
 167 struct btrfs_leaf {
 168         struct btrfs_header header;
 169         struct btrfs_item items[];
 170 } __attribute__ ((__packed__));
 171
 172 struct btrfs_key_ptr {
 173         struct btrfs_disk_key key;
 174         __le64 blockptr;
 175         __le64 generation;
 176 } __attribute__ ((__packed__));
 177
 178 struct btrfs_node {
 179         struct btrfs_header header;
 180         struct btrfs_key_ptr ptrs[];
 181 } __attribute__ ((__packed__));
 182
 183 /* remember how we get to a node/leaf */
 184 struct btrfs_path {
 185         u64 offsets[BTRFS_MAX_LEVEL];
 186         int itemsnr[BTRFS_MAX_LEVEL];
 187         int slots[BTRFS_MAX_LEVEL];
 188         /* remember last slot's item and data */
 189         struct btrfs_item item;
 190         u8 data[BTRFS_MAX_LEAF_SIZE];
 191 };
 192
 193 /* store logical offset to physical offset mapping */
 194 struct btrfs_chunk_map_item {
 195         u64 logical;
 196         u64 length;
 197         u64 devid;
 198         u64 physical;
 199 };
 200
 201 struct btrfs_chunk_map {
 202         struct btrfs_chunk_map_item *map;
 203         u32 map_length;
 204         u32 cur_length;
 205 };
 206
 207 struct btrfs_timespec {
 208         __le64 sec;
 209         __le32 nsec;
 210 } __attribute__ ((__packed__));
 211
 212 struct btrfs_inode_item {
 213         /* nfs style generation number */
 214         __le64 generation;
 215         /* transid that last touched this inode */
 216         __le64 transid;
 217         __le64 size;
 218         __le64 nbytes;
 219         __le64 block_group;
 220         __le32 nlink;
 221         __le32 uid;
 222         __le32 gid;
 223         __le32 mode;
 224         __le64 rdev;
 225         __le64 flags;
 226
 227         /* modification sequence number for NFS */
 228         __le64 sequence;
 229
 230         /*
 231          * a little future expansion, for more than this we can
 232          * just grow the inode item and version it
 233          */
 234         __le64 reserved[4];
 235         struct btrfs_timespec atime;
 236         struct btrfs_timespec ctime;
 237         struct btrfs_timespec mtime;
 238         struct btrfs_timespec otime;
 239 } __attribute__ ((__packed__));
 240
 241 struct btrfs_root_item {
 242         struct btrfs_inode_item inode;
 243         __le64 generation;
 244         __le64 root_dirid;
 245         __le64 bytenr;
 246         __le64 byte_limit;
 247         __le64 bytes_used;
 248         __le64 last_snapshot;
 249         __le64 flags;
 250         __le32 refs;
 251         struct btrfs_disk_key drop_progress;
 252         u8 drop_level;
 253         u8 level;
 254 } __attribute__ ((__packed__));
 255
 256 struct btrfs_dir_item {
 257         struct btrfs_disk_key location;
 258         __le64 transid;
 259         __le16 data_len;
 260         __le16 name_len;
 261         u8 type;
 262 } __attribute__ ((__packed__));
 263
 264 struct btrfs_file_extent_item {
 265         __le64 generation;
 266         __le64 ram_bytes;
 267         u8 compression;
 268         u8 encryption;
 269         __le16 other_encoding; /* spare for later use */
 270         u8 type;
 271         __le64 disk_bytenr;
 272         __le64 disk_num_bytes;
 273         __le64 offset;
 274         __le64 num_bytes;
 275 } __attribute__ ((__packed__));
 276
 277 struct btrfs_root_ref {
 278         __le64 dirid;
 279         __le64 sequence;
 280         __le16 name_len;
 281 } __attribute__ ((__packed__));
 282
 283 /*
 284  * btrfs private inode information
 285  */
 286 struct btrfs_pvt_inode {
 287     uint64_t offset;
 288 };
 289
 290 #define PVT(i) ((struct btrfs_pvt_inode *)((i)->pvt))
 291
 292 #endif