fs/btrfs/ctree.h

   1 #ifndef __CTREE__
   2 #define __CTREE__
   3
   4 #define CTREE_BLOCKSIZE 256
   5
   6 struct key {
   7         u64 objectid;
   8         u32 flags;
   9         u64 offset;
  10 } __attribute__ ((__packed__));
  11
  12 struct header {
  13         u64 fsid[2]; /* FS specific uuid */
  14         u64 blocknr;
  15         u64 parentid;
  16         u32 csum;
  17         u32 ham;
  18         u16 nritems;
  19         u16 flags;
  20 } __attribute__ ((__packed__));
  21
  22 #define NODEPTRS_PER_BLOCK ((CTREE_BLOCKSIZE - sizeof(struct header)) / \
  23                             (sizeof(struct key) + sizeof(u64)))
  24
  25 #define MAX_LEVEL 8
  26 #define node_level(f) ((f) & (MAX_LEVEL-1))
  27 #define is_leaf(f) (node_level(f) == 0)
  28
  29 struct tree_buffer;
  30
  31 struct ctree_root {
  32         struct tree_buffer *node;
  33         struct ctree_root *extent_root;
  34         struct key current_insert;
  35         int fp;
  36         struct radix_tree_root cache_radix;
  37 };
  38
  39 struct ctree_root_info {
  40         u64 fsid[2]; /* FS specific uuid */
  41         u64 blocknr; /* blocknr of this block */
  42         u64 objectid; /* inode number of this root */
  43         u64 tree_root; /* the tree root */
  44         u32 csum;
  45         u32 ham;
  46         u64 snapuuid[2]; /* root specific uuid */
  47 } __attribute__ ((__packed__));
  48
  49 struct ctree_super_block {
  50         struct ctree_root_info root_info;
  51         struct ctree_root_info extent_info;
  52 } __attribute__ ((__packed__));
  53
  54 struct item {
  55         struct key key;
  56         u16 offset;
  57         u16 size;
  58 } __attribute__ ((__packed__));
  59
  60 #define LEAF_DATA_SIZE (CTREE_BLOCKSIZE - sizeof(struct header))
  61 struct leaf {
  62         struct header header;
  63         union {
  64                 struct item items[LEAF_DATA_SIZE/sizeof(struct item)];
  65                 u8 data[CTREE_BLOCKSIZE-sizeof(struct header)];
  66         };
  67 } __attribute__ ((__packed__));
  68
  69 struct node {
  70         struct header header;
  71         struct key keys[NODEPTRS_PER_BLOCK];
  72         u64 blockptrs[NODEPTRS_PER_BLOCK];
  73 } __attribute__ ((__packed__));
  74
  75 struct extent_item {
  76         u32 refs;
  77         u64 owner;
  78 } __attribute__ ((__packed__));
  79
  80 struct ctree_path {
  81         struct tree_buffer *nodes[MAX_LEVEL];
  82         int slots[MAX_LEVEL];
  83 };
  84 #endif