5 #include "kerncompat.h"
7 #define BTRFS_MAGIC "_BtRfS_M"
9 #define BTRFS_ROOT_TREE_OBJECTID 1
10 #define BTRFS_EXTENT_TREE_OBJECTID 2
11 #define BTRFS_FS_TREE_OBJECTID 3
14 * the key defines the order in the tree, and so it also defines (optimal)
15 * block layout. objectid corresonds to the inode number. The flags
16 * tells us things about the object, and is a kind of stream selector.
17 * so for a given inode, keys with flags of 1 might refer to the inode
18 * data, flags of 2 may point to file data in the btree and flags == 3
19 * may point to extents.
21 * offset is the starting byte offset for this key in the stream.
23 * btrfs_disk_key is in disk byte order. struct btrfs_key is always
24 * in cpu native order. Otherwise they are identical and their sizes
25 * should be the same (ie both packed)
27 struct btrfs_disk_key {
31 } __attribute__ ((__packed__));
37 } __attribute__ ((__packed__));
40 * every tree block (leaf or node) starts with this header.
43 u8 fsid[16]; /* FS specific uuid */
44 __le64 blocknr; /* which block this node is supposed to live in */
45 __le64 parentid; /* objectid of the tree root */
50 /* generation flags to be added */
51 } __attribute__ ((__packed__));
53 #define BTRFS_MAX_LEVEL 8
54 #define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->blocksize - \
55 sizeof(struct btrfs_header)) / \
56 (sizeof(struct btrfs_disk_key) + sizeof(u64)))
57 #define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
58 #define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->blocksize))
62 struct btrfs_root_item {
71 * in ram representation of the tree. extent_root is used for all allocations
72 * and for the extent tree extent_root root. current_insert is used
73 * only for the extent tree.
76 struct btrfs_buffer *node;
77 struct btrfs_buffer *commit_root;
78 struct btrfs_root *extent_root;
79 struct btrfs_root *tree_root;
80 struct btrfs_key current_insert;
81 struct btrfs_key last_insert;
83 struct radix_tree_root cache_radix;
84 struct radix_tree_root pinned_radix;
85 struct list_head trans;
86 struct list_head cache;
89 struct btrfs_root_item root_item;
90 struct btrfs_key root_key;
95 * the super block basically lists the main trees of the FS
96 * it currently lacks any block count etc etc
98 struct btrfs_super_block {
99 u8 fsid[16]; /* FS specific uuid */
100 __le64 blocknr; /* this block number */
108 } __attribute__ ((__packed__));
111 * A leaf is full of items. The exact type of item is defined by
112 * the key flags parameter. offset and size tell us where to find
113 * the item in the leaf (relative to the start of the data area)
116 struct btrfs_disk_key key;
119 } __attribute__ ((__packed__));
122 * leaves have an item area and a data area:
123 * [item0, item1....itemN] [free space] [dataN...data1, data0]
125 * The data is separate from the items to get the keys closer together
129 struct btrfs_header header;
130 struct btrfs_item items[];
131 } __attribute__ ((__packed__));
134 * all non-leaf blocks are nodes, they hold only keys and pointers to
137 struct btrfs_key_ptr {
138 struct btrfs_disk_key key;
140 } __attribute__ ((__packed__));
143 struct btrfs_header header;
144 struct btrfs_key_ptr ptrs[];
145 } __attribute__ ((__packed__));
148 * items in the extent btree are used to record the objectid of the
149 * owner of the block and the number of references
151 struct btrfs_extent_item {
154 } __attribute__ ((__packed__));
157 * btrfs_paths remember the path taken from the root down to the leaf.
158 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
159 * to any other levels that are present.
161 * The slots array records the index of the item or block pointer
162 * used while walking the tree.
165 struct btrfs_buffer *nodes[BTRFS_MAX_LEVEL];
166 int slots[BTRFS_MAX_LEVEL];
169 static inline u64 btrfs_extent_owner(struct btrfs_extent_item *ei)
171 return le64_to_cpu(ei->owner);
174 static inline void btrfs_set_extent_owner(struct btrfs_extent_item *ei, u64 val)
176 ei->owner = cpu_to_le64(val);
179 static inline u32 btrfs_extent_refs(struct btrfs_extent_item *ei)
181 return le32_to_cpu(ei->refs);
184 static inline void btrfs_set_extent_refs(struct btrfs_extent_item *ei, u32 val)
186 ei->refs = cpu_to_le32(val);
189 static inline u64 btrfs_node_blockptr(struct btrfs_node *n, int nr)
191 return le64_to_cpu(n->ptrs[nr].blockptr);
194 static inline void btrfs_set_node_blockptr(struct btrfs_node *n, int nr,
197 n->ptrs[nr].blockptr = cpu_to_le64(val);
200 static inline u32 btrfs_item_offset(struct btrfs_item *item)
202 return le32_to_cpu(item->offset);
205 static inline void btrfs_set_item_offset(struct btrfs_item *item, u32 val)
207 item->offset = cpu_to_le32(val);
210 static inline u32 btrfs_item_end(struct btrfs_item *item)
212 return le32_to_cpu(item->offset) + le16_to_cpu(item->size);
215 static inline u16 btrfs_item_size(struct btrfs_item *item)
217 return le16_to_cpu(item->size);
220 static inline void btrfs_set_item_size(struct btrfs_item *item, u16 val)
222 item->size = cpu_to_le16(val);
225 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
226 struct btrfs_disk_key *disk)
228 cpu->offset = le64_to_cpu(disk->offset);
229 cpu->flags = le32_to_cpu(disk->flags);
230 cpu->objectid = le64_to_cpu(disk->objectid);
233 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
234 struct btrfs_key *cpu)
236 disk->offset = cpu_to_le64(cpu->offset);
237 disk->flags = cpu_to_le32(cpu->flags);
238 disk->objectid = cpu_to_le64(cpu->objectid);
241 static inline u64 btrfs_key_objectid(struct btrfs_disk_key *disk)
243 return le64_to_cpu(disk->objectid);
246 static inline void btrfs_set_key_objectid(struct btrfs_disk_key *disk,
249 disk->objectid = cpu_to_le64(val);
252 static inline u64 btrfs_key_offset(struct btrfs_disk_key *disk)
254 return le64_to_cpu(disk->offset);
257 static inline void btrfs_set_key_offset(struct btrfs_disk_key *disk,
260 disk->offset = cpu_to_le64(val);
263 static inline u32 btrfs_key_flags(struct btrfs_disk_key *disk)
265 return le32_to_cpu(disk->flags);
268 static inline void btrfs_set_key_flags(struct btrfs_disk_key *disk,
271 disk->flags = cpu_to_le32(val);
274 static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
276 return le64_to_cpu(h->blocknr);
279 static inline void btrfs_set_header_blocknr(struct btrfs_header *h, u64 blocknr)
281 h->blocknr = cpu_to_le64(blocknr);
284 static inline u64 btrfs_header_parentid(struct btrfs_header *h)
286 return le64_to_cpu(h->parentid);
289 static inline void btrfs_set_header_parentid(struct btrfs_header *h,
292 h->parentid = cpu_to_le64(parentid);
295 static inline u16 btrfs_header_nritems(struct btrfs_header *h)
297 return le16_to_cpu(h->nritems);
300 static inline void btrfs_set_header_nritems(struct btrfs_header *h, u16 val)
302 h->nritems = cpu_to_le16(val);
305 static inline u16 btrfs_header_flags(struct btrfs_header *h)
307 return le16_to_cpu(h->flags);
310 static inline void btrfs_set_header_flags(struct btrfs_header *h, u16 val)
312 h->flags = cpu_to_le16(val);
315 static inline int btrfs_header_level(struct btrfs_header *h)
317 return btrfs_header_flags(h) & (BTRFS_MAX_LEVEL - 1);
320 static inline void btrfs_set_header_level(struct btrfs_header *h, int level)
323 BUG_ON(level > BTRFS_MAX_LEVEL);
324 flags = btrfs_header_flags(h) & ~(BTRFS_MAX_LEVEL - 1);
325 btrfs_set_header_flags(h, flags | level);
328 static inline int btrfs_is_leaf(struct btrfs_node *n)
330 return (btrfs_header_level(&n->header) == 0);
333 static inline u64 btrfs_root_blocknr(struct btrfs_root_item *item)
335 return le64_to_cpu(item->blocknr);
338 static inline void btrfs_set_root_blocknr(struct btrfs_root_item *item, u64 val)
340 item->blocknr = cpu_to_le64(val);
343 static inline u32 btrfs_root_refs(struct btrfs_root_item *item)
345 return le32_to_cpu(item->refs);
348 static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val)
350 item->refs = cpu_to_le32(val);
353 static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)
355 return le64_to_cpu(s->blocknr);
358 static inline void btrfs_set_super_blocknr(struct btrfs_super_block *s, u64 val)
360 s->blocknr = cpu_to_le64(val);
363 static inline u64 btrfs_super_root(struct btrfs_super_block *s)
365 return le64_to_cpu(s->root);
368 static inline void btrfs_set_super_root(struct btrfs_super_block *s, u64 val)
370 s->root = cpu_to_le64(val);
373 static inline u64 btrfs_super_total_blocks(struct btrfs_super_block *s)
375 return le64_to_cpu(s->total_blocks);
378 static inline void btrfs_set_super_total_blocks(struct btrfs_super_block *s,
381 s->total_blocks = cpu_to_le64(val);
384 static inline u64 btrfs_super_blocks_used(struct btrfs_super_block *s)
386 return le64_to_cpu(s->blocks_used);
389 static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s,
392 s->blocks_used = cpu_to_le64(val);
395 static inline u32 btrfs_super_blocksize(struct btrfs_super_block *s)
397 return le32_to_cpu(s->blocksize);
400 static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s,
403 s->blocksize = cpu_to_le32(val);
406 static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l)
408 return (u8 *)l->items;
411 /* helper function to cast into the data area of the leaf. */
412 #define btrfs_item_ptr(leaf, slot, type) \
413 ((type *)(btrfs_leaf_data(leaf) + \
414 btrfs_item_offset((leaf)->items + (slot))))
416 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root);
417 int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf);
418 int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks);
419 int btrfs_search_slot(struct btrfs_root *root, struct btrfs_key *key,
420 struct btrfs_path *p, int ins_len, int cow);
421 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
422 void btrfs_init_path(struct btrfs_path *p);
423 int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path);
424 int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *key,
425 void *data, int data_size);
426 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
427 int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf);
428 int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap);
429 int btrfs_finish_extent_commit(struct btrfs_root *root);
430 int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key);
431 int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key,
432 struct btrfs_root_item *item);
433 int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key,
434 struct btrfs_root_item *item);
435 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
436 struct btrfs_root_item *item, struct btrfs_key *key);