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