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 * the super block basically lists the main trees of the FS
63 * it currently lacks any block count etc etc
65 struct btrfs_super_block {
66 u8 fsid[16]; /* FS specific uuid */
67 __le64 blocknr; /* this block number */
75 } __attribute__ ((__packed__));
78 * A leaf is full of items. offset and size tell us where to find
79 * the item in the leaf (relative to the start of the data area)
82 struct btrfs_disk_key key;
85 } __attribute__ ((__packed__));
88 * leaves have an item area and a data area:
89 * [item0, item1....itemN] [free space] [dataN...data1, data0]
91 * The data is separate from the items to get the keys closer together
95 struct btrfs_header header;
96 struct btrfs_item items[];
97 } __attribute__ ((__packed__));
100 * all non-leaf blocks are nodes, they hold only keys and pointers to
103 struct btrfs_key_ptr {
104 struct btrfs_disk_key key;
106 } __attribute__ ((__packed__));
109 struct btrfs_header header;
110 struct btrfs_key_ptr ptrs[];
111 } __attribute__ ((__packed__));
114 * btrfs_paths remember the path taken from the root down to the leaf.
115 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
116 * to any other levels that are present.
118 * The slots array records the index of the item or block pointer
119 * used while walking the tree.
122 struct btrfs_buffer *nodes[BTRFS_MAX_LEVEL];
123 int slots[BTRFS_MAX_LEVEL];
127 * items in the extent btree are used to record the objectid of the
128 * owner of the block and the number of references
130 struct btrfs_extent_item {
133 } __attribute__ ((__packed__));
135 struct btrfs_dir_item {
139 } __attribute__ ((__packed__));
141 struct btrfs_root_item {
150 * in ram representation of the tree. extent_root is used for all allocations
151 * and for the extent tree extent_root root. current_insert is used
152 * only for the extent tree.
155 struct btrfs_buffer *node;
156 struct btrfs_buffer *commit_root;
157 struct btrfs_root *extent_root;
158 struct btrfs_root *tree_root;
159 struct btrfs_key current_insert;
160 struct btrfs_key last_insert;
162 struct radix_tree_root cache_radix;
163 struct radix_tree_root pinned_radix;
164 struct list_head trans;
165 struct list_head cache;
168 struct btrfs_root_item root_item;
169 struct btrfs_key root_key;
174 /* the lower bits in the key flags defines the item type */
175 #define BTRFS_KEY_TYPE_MAX 256
176 #define BTRFS_KEY_TYPE_MASK (BTRFS_KEY_TYPE_MAX - 1)
177 #define BTRFS_INODE_ITEM_KEY 1
178 #define BTRFS_DIR_ITEM_KEY 2
179 #define BTRFS_ROOT_ITEM_KEY 3
180 #define BTRFS_EXTENT_ITEM_KEY 4
181 #define BTRFS_STRING_ITEM_KEY 5
183 static inline u64 btrfs_dir_objectid(struct btrfs_dir_item *d)
185 return le64_to_cpu(d->objectid);
188 static inline void btrfs_set_dir_objectid(struct btrfs_dir_item *d, u64 val)
190 d->objectid = cpu_to_le64(val);
193 static inline u16 btrfs_dir_flags(struct btrfs_dir_item *d)
195 return le16_to_cpu(d->flags);
198 static inline void btrfs_set_dir_flags(struct btrfs_dir_item *d, u16 val)
200 d->flags = cpu_to_le16(val);
203 static inline u8 btrfs_dir_type(struct btrfs_dir_item *d)
208 static inline void btrfs_set_dir_type(struct btrfs_dir_item *d, u8 val)
214 static inline u64 btrfs_extent_owner(struct btrfs_extent_item *ei)
216 return le64_to_cpu(ei->owner);
219 static inline void btrfs_set_extent_owner(struct btrfs_extent_item *ei, u64 val)
221 ei->owner = cpu_to_le64(val);
224 static inline u32 btrfs_extent_refs(struct btrfs_extent_item *ei)
226 return le32_to_cpu(ei->refs);
229 static inline void btrfs_set_extent_refs(struct btrfs_extent_item *ei, u32 val)
231 ei->refs = cpu_to_le32(val);
234 static inline u64 btrfs_node_blockptr(struct btrfs_node *n, int nr)
236 return le64_to_cpu(n->ptrs[nr].blockptr);
239 static inline void btrfs_set_node_blockptr(struct btrfs_node *n, int nr,
242 n->ptrs[nr].blockptr = cpu_to_le64(val);
245 static inline u32 btrfs_item_offset(struct btrfs_item *item)
247 return le32_to_cpu(item->offset);
250 static inline void btrfs_set_item_offset(struct btrfs_item *item, u32 val)
252 item->offset = cpu_to_le32(val);
255 static inline u32 btrfs_item_end(struct btrfs_item *item)
257 return le32_to_cpu(item->offset) + le16_to_cpu(item->size);
260 static inline u16 btrfs_item_size(struct btrfs_item *item)
262 return le16_to_cpu(item->size);
265 static inline void btrfs_set_item_size(struct btrfs_item *item, u16 val)
267 item->size = cpu_to_le16(val);
270 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
271 struct btrfs_disk_key *disk)
273 cpu->offset = le64_to_cpu(disk->offset);
274 cpu->flags = le32_to_cpu(disk->flags);
275 cpu->objectid = le64_to_cpu(disk->objectid);
278 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
279 struct btrfs_key *cpu)
281 disk->offset = cpu_to_le64(cpu->offset);
282 disk->flags = cpu_to_le32(cpu->flags);
283 disk->objectid = cpu_to_le64(cpu->objectid);
286 static inline u64 btrfs_disk_key_objectid(struct btrfs_disk_key *disk)
288 return le64_to_cpu(disk->objectid);
291 static inline void btrfs_set_disk_key_objectid(struct btrfs_disk_key *disk,
294 disk->objectid = cpu_to_le64(val);
297 static inline u64 btrfs_disk_key_offset(struct btrfs_disk_key *disk)
299 return le64_to_cpu(disk->offset);
302 static inline void btrfs_set_disk_key_offset(struct btrfs_disk_key *disk,
305 disk->offset = cpu_to_le64(val);
308 static inline u32 btrfs_disk_key_flags(struct btrfs_disk_key *disk)
310 return le32_to_cpu(disk->flags);
313 static inline void btrfs_set_disk_key_flags(struct btrfs_disk_key *disk,
316 disk->flags = cpu_to_le32(val);
319 static inline u32 btrfs_key_type(struct btrfs_key *key)
321 return key->flags & BTRFS_KEY_TYPE_MASK;
324 static inline u32 btrfs_disk_key_type(struct btrfs_disk_key *key)
326 return le32_to_cpu(key->flags) & BTRFS_KEY_TYPE_MASK;
329 static inline void btrfs_set_key_type(struct btrfs_key *key, u32 type)
331 BUG_ON(type >= BTRFS_KEY_TYPE_MAX);
332 key->flags = (key->flags & ~((u64)BTRFS_KEY_TYPE_MASK)) | type;
335 static inline void btrfs_set_disk_key_type(struct btrfs_disk_key *key, u32 type)
337 u32 flags = btrfs_disk_key_flags(key);
338 BUG_ON(type >= BTRFS_KEY_TYPE_MAX);
339 flags = (flags & ~((u64)BTRFS_KEY_TYPE_MASK)) | type;
340 btrfs_set_disk_key_flags(key, flags);
345 static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
347 return le64_to_cpu(h->blocknr);
350 static inline void btrfs_set_header_blocknr(struct btrfs_header *h, u64 blocknr)
352 h->blocknr = cpu_to_le64(blocknr);
355 static inline u64 btrfs_header_parentid(struct btrfs_header *h)
357 return le64_to_cpu(h->parentid);
360 static inline void btrfs_set_header_parentid(struct btrfs_header *h,
363 h->parentid = cpu_to_le64(parentid);
366 static inline u16 btrfs_header_nritems(struct btrfs_header *h)
368 return le16_to_cpu(h->nritems);
371 static inline void btrfs_set_header_nritems(struct btrfs_header *h, u16 val)
373 h->nritems = cpu_to_le16(val);
376 static inline u16 btrfs_header_flags(struct btrfs_header *h)
378 return le16_to_cpu(h->flags);
381 static inline void btrfs_set_header_flags(struct btrfs_header *h, u16 val)
383 h->flags = cpu_to_le16(val);
386 static inline int btrfs_header_level(struct btrfs_header *h)
388 return btrfs_header_flags(h) & (BTRFS_MAX_LEVEL - 1);
391 static inline void btrfs_set_header_level(struct btrfs_header *h, int level)
394 BUG_ON(level > BTRFS_MAX_LEVEL);
395 flags = btrfs_header_flags(h) & ~(BTRFS_MAX_LEVEL - 1);
396 btrfs_set_header_flags(h, flags | level);
399 static inline int btrfs_is_leaf(struct btrfs_node *n)
401 return (btrfs_header_level(&n->header) == 0);
404 static inline u64 btrfs_root_blocknr(struct btrfs_root_item *item)
406 return le64_to_cpu(item->blocknr);
409 static inline void btrfs_set_root_blocknr(struct btrfs_root_item *item, u64 val)
411 item->blocknr = cpu_to_le64(val);
414 static inline u32 btrfs_root_refs(struct btrfs_root_item *item)
416 return le32_to_cpu(item->refs);
419 static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val)
421 item->refs = cpu_to_le32(val);
424 static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)
426 return le64_to_cpu(s->blocknr);
429 static inline void btrfs_set_super_blocknr(struct btrfs_super_block *s, u64 val)
431 s->blocknr = cpu_to_le64(val);
434 static inline u64 btrfs_super_root(struct btrfs_super_block *s)
436 return le64_to_cpu(s->root);
439 static inline void btrfs_set_super_root(struct btrfs_super_block *s, u64 val)
441 s->root = cpu_to_le64(val);
444 static inline u64 btrfs_super_total_blocks(struct btrfs_super_block *s)
446 return le64_to_cpu(s->total_blocks);
449 static inline void btrfs_set_super_total_blocks(struct btrfs_super_block *s,
452 s->total_blocks = cpu_to_le64(val);
455 static inline u64 btrfs_super_blocks_used(struct btrfs_super_block *s)
457 return le64_to_cpu(s->blocks_used);
460 static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s,
463 s->blocks_used = cpu_to_le64(val);
466 static inline u32 btrfs_super_blocksize(struct btrfs_super_block *s)
468 return le32_to_cpu(s->blocksize);
471 static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s,
474 s->blocksize = cpu_to_le32(val);
477 static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l)
479 return (u8 *)l->items;
481 /* helper function to cast into the data area of the leaf. */
482 #define btrfs_item_ptr(leaf, slot, type) \
483 ((type *)(btrfs_leaf_data(leaf) + \
484 btrfs_item_offset((leaf)->items + (slot))))
486 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root);
487 int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf);
488 int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks);
489 int btrfs_search_slot(struct btrfs_root *root, struct btrfs_key *key,
490 struct btrfs_path *p, int ins_len, int cow);
491 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
492 void btrfs_init_path(struct btrfs_path *p);
493 int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path);
494 int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *key,
495 void *data, u32 data_size);
496 int btrfs_insert_empty_item(struct btrfs_root *root, struct btrfs_path *path,
497 struct btrfs_key *cpu_key, u32 data_size);
498 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
499 int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf);
500 int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap);
501 int btrfs_finish_extent_commit(struct btrfs_root *root);
502 int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key);
503 int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key,
504 struct btrfs_root_item *item);
505 int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key,
506 struct btrfs_root_item *item);
507 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
508 struct btrfs_root_item *item, struct btrfs_key *key);