Commit | Line | Data |
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eb60ceac CM |
1 | #ifndef __CTREE__ |
2 | #define __CTREE__ | |
3 | ||
ed2ff2cb CM |
4 | #include "list.h" |
5 | ||
fec577fb | 6 | #define CTREE_BLOCKSIZE 1024 |
eb60ceac | 7 | |
fec577fb CM |
8 | /* |
9 | * the key defines the order in the tree, and so it also defines (optimal) | |
10 | * block layout. objectid corresonds to the inode number. The flags | |
11 | * tells us things about the object, and is a kind of stream selector. | |
12 | * so for a given inode, keys with flags of 1 might refer to the inode | |
13 | * data, flags of 2 may point to file data in the btree and flags == 3 | |
14 | * may point to extents. | |
15 | * | |
16 | * offset is the starting byte offset for this key in the stream. | |
17 | */ | |
eb60ceac CM |
18 | struct key { |
19 | u64 objectid; | |
20 | u32 flags; | |
21 | u64 offset; | |
22 | } __attribute__ ((__packed__)); | |
23 | ||
fec577fb CM |
24 | /* |
25 | * every tree block (leaf or node) starts with this header. | |
26 | */ | |
eb60ceac CM |
27 | struct header { |
28 | u64 fsid[2]; /* FS specific uuid */ | |
fec577fb CM |
29 | u64 blocknr; /* which block this node is supposed to live in */ |
30 | u64 parentid; /* objectid of the tree root */ | |
eb60ceac CM |
31 | u32 csum; |
32 | u32 ham; | |
33 | u16 nritems; | |
34 | u16 flags; | |
fec577fb | 35 | /* generation flags to be added */ |
eb60ceac CM |
36 | } __attribute__ ((__packed__)); |
37 | ||
38 | #define NODEPTRS_PER_BLOCK ((CTREE_BLOCKSIZE - sizeof(struct header)) / \ | |
39 | (sizeof(struct key) + sizeof(u64))) | |
40 | ||
d97e63b6 | 41 | #define MAX_LEVEL 8 |
eb60ceac CM |
42 | #define node_level(f) ((f) & (MAX_LEVEL-1)) |
43 | #define is_leaf(f) (node_level(f) == 0) | |
44 | ||
45 | struct tree_buffer; | |
d97e63b6 | 46 | |
fec577fb CM |
47 | /* |
48 | * in ram representation of the tree. extent_root is used for all allocations | |
49 | * and for the extent tree extent_root root. current_insert is used | |
50 | * only for the extent tree. | |
51 | */ | |
eb60ceac CM |
52 | struct ctree_root { |
53 | struct tree_buffer *node; | |
d97e63b6 | 54 | struct ctree_root *extent_root; |
9a8dd150 | 55 | struct key current_insert; |
eb60ceac CM |
56 | int fp; |
57 | struct radix_tree_root cache_radix; | |
ed2ff2cb CM |
58 | struct list_head trans; |
59 | struct list_head cache; | |
60 | int cache_size; | |
eb60ceac CM |
61 | }; |
62 | ||
fec577fb CM |
63 | /* |
64 | * describes a tree on disk | |
65 | */ | |
d97e63b6 CM |
66 | struct ctree_root_info { |
67 | u64 fsid[2]; /* FS specific uuid */ | |
68 | u64 blocknr; /* blocknr of this block */ | |
69 | u64 objectid; /* inode number of this root */ | |
fec577fb | 70 | u64 tree_root; /* the tree root block */ |
d97e63b6 CM |
71 | u32 csum; |
72 | u32 ham; | |
d97e63b6 CM |
73 | u64 snapuuid[2]; /* root specific uuid */ |
74 | } __attribute__ ((__packed__)); | |
75 | ||
fec577fb CM |
76 | /* |
77 | * the super block basically lists the main trees of the FS | |
78 | * it currently lacks any block count etc etc | |
79 | */ | |
cfaa7295 CM |
80 | struct ctree_super_block { |
81 | struct ctree_root_info root_info; | |
82 | struct ctree_root_info extent_info; | |
83 | } __attribute__ ((__packed__)); | |
84 | ||
fec577fb CM |
85 | /* |
86 | * A leaf is full of items. The exact type of item is defined by | |
87 | * the key flags parameter. offset and size tell us where to find | |
88 | * the item in the leaf (relative to the start of the data area) | |
89 | */ | |
eb60ceac CM |
90 | struct item { |
91 | struct key key; | |
92 | u16 offset; | |
93 | u16 size; | |
94 | } __attribute__ ((__packed__)); | |
95 | ||
fec577fb CM |
96 | /* |
97 | * leaves have an item area and a data area: | |
98 | * [item0, item1....itemN] [free space] [dataN...data1, data0] | |
99 | * | |
100 | * The data is separate from the items to get the keys closer together | |
101 | * during searches. | |
102 | */ | |
eb60ceac CM |
103 | #define LEAF_DATA_SIZE (CTREE_BLOCKSIZE - sizeof(struct header)) |
104 | struct leaf { | |
105 | struct header header; | |
106 | union { | |
107 | struct item items[LEAF_DATA_SIZE/sizeof(struct item)]; | |
108 | u8 data[CTREE_BLOCKSIZE-sizeof(struct header)]; | |
109 | }; | |
110 | } __attribute__ ((__packed__)); | |
111 | ||
fec577fb CM |
112 | /* |
113 | * all non-leaf blocks are nodes, they hold only keys and pointers to | |
114 | * other blocks | |
115 | */ | |
eb60ceac CM |
116 | struct node { |
117 | struct header header; | |
118 | struct key keys[NODEPTRS_PER_BLOCK]; | |
119 | u64 blockptrs[NODEPTRS_PER_BLOCK]; | |
120 | } __attribute__ ((__packed__)); | |
121 | ||
fec577fb CM |
122 | /* |
123 | * items in the extent btree are used to record the objectid of the | |
124 | * owner of the block and the number of references | |
125 | */ | |
d97e63b6 CM |
126 | struct extent_item { |
127 | u32 refs; | |
128 | u64 owner; | |
129 | } __attribute__ ((__packed__)); | |
130 | ||
fec577fb CM |
131 | /* |
132 | * ctree_paths remember the path taken from the root down to the leaf. | |
133 | * level 0 is always the leaf, and nodes[1...MAX_LEVEL] will point | |
134 | * to any other levels that are present. | |
135 | * | |
136 | * The slots array records the index of the item or block pointer | |
137 | * used while walking the tree. | |
138 | */ | |
eb60ceac CM |
139 | struct ctree_path { |
140 | struct tree_buffer *nodes[MAX_LEVEL]; | |
141 | int slots[MAX_LEVEL]; | |
142 | }; | |
5de08d7d CM |
143 | |
144 | struct tree_buffer *alloc_free_block(struct ctree_root *root); | |
02217ed2 | 145 | int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf); |
5de08d7d | 146 | int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks); |
02217ed2 | 147 | int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p, int ins_len, int cow); |
5de08d7d CM |
148 | void release_path(struct ctree_root *root, struct ctree_path *p); |
149 | void init_path(struct ctree_path *p); | |
150 | int del_item(struct ctree_root *root, struct ctree_path *path); | |
151 | int insert_item(struct ctree_root *root, struct key *key, void *data, int data_size); | |
152 | int next_leaf(struct ctree_root *root, struct ctree_path *path); | |
153 | int leaf_free_space(struct leaf *leaf); | |
eb60ceac | 154 | #endif |