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_extent_owner(struct btrfs_extent_item *ei)
185 return le64_to_cpu(ei->owner);
188 static inline void btrfs_set_extent_owner(struct btrfs_extent_item *ei, u64 val)
190 ei->owner = cpu_to_le64(val);
193 static inline u32 btrfs_extent_refs(struct btrfs_extent_item *ei)
195 return le32_to_cpu(ei->refs);
198 static inline void btrfs_set_extent_refs(struct btrfs_extent_item *ei, u32 val)
200 ei->refs = cpu_to_le32(val);
203 static inline u64 btrfs_node_blockptr(struct btrfs_node *n, int nr)
205 return le64_to_cpu(n->ptrs[nr].blockptr);
208 static inline void btrfs_set_node_blockptr(struct btrfs_node *n, int nr,
211 n->ptrs[nr].blockptr = cpu_to_le64(val);
214 static inline u32 btrfs_item_offset(struct btrfs_item *item)
216 return le32_to_cpu(item->offset);
219 static inline void btrfs_set_item_offset(struct btrfs_item *item, u32 val)
221 item->offset = cpu_to_le32(val);
224 static inline u32 btrfs_item_end(struct btrfs_item *item)
226 return le32_to_cpu(item->offset) + le16_to_cpu(item->size);
229 static inline u16 btrfs_item_size(struct btrfs_item *item)
231 return le16_to_cpu(item->size);
234 static inline void btrfs_set_item_size(struct btrfs_item *item, u16 val)
236 item->size = cpu_to_le16(val);
239 static inline u64 btrfs_dir_objectid(struct btrfs_dir_item *d)
241 return le64_to_cpu(d->objectid);
244 static inline void btrfs_set_dir_objectid(struct btrfs_dir_item *d, u64 val)
246 d->objectid = cpu_to_le64(val);
249 static inline u16 btrfs_dir_flags(struct btrfs_dir_item *d)
251 return le16_to_cpu(d->flags);
254 static inline void btrfs_set_dir_flags(struct btrfs_dir_item *d, u16 val)
256 d->flags = cpu_to_le16(val);
259 static inline u8 btrfs_dir_type(struct btrfs_dir_item *d)
264 static inline void btrfs_set_dir_type(struct btrfs_dir_item *d, u8 val)
269 static inline u32 btrfs_dir_name_len(struct btrfs_item *i)
271 return btrfs_item_size(i) - sizeof(struct btrfs_dir_item);
274 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
275 struct btrfs_disk_key *disk)
277 cpu->offset = le64_to_cpu(disk->offset);
278 cpu->flags = le32_to_cpu(disk->flags);
279 cpu->objectid = le64_to_cpu(disk->objectid);
282 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
283 struct btrfs_key *cpu)
285 disk->offset = cpu_to_le64(cpu->offset);
286 disk->flags = cpu_to_le32(cpu->flags);
287 disk->objectid = cpu_to_le64(cpu->objectid);
290 static inline u64 btrfs_disk_key_objectid(struct btrfs_disk_key *disk)
292 return le64_to_cpu(disk->objectid);
295 static inline void btrfs_set_disk_key_objectid(struct btrfs_disk_key *disk,
298 disk->objectid = cpu_to_le64(val);
301 static inline u64 btrfs_disk_key_offset(struct btrfs_disk_key *disk)
303 return le64_to_cpu(disk->offset);
306 static inline void btrfs_set_disk_key_offset(struct btrfs_disk_key *disk,
309 disk->offset = cpu_to_le64(val);
312 static inline u32 btrfs_disk_key_flags(struct btrfs_disk_key *disk)
314 return le32_to_cpu(disk->flags);
317 static inline void btrfs_set_disk_key_flags(struct btrfs_disk_key *disk,
320 disk->flags = cpu_to_le32(val);
323 static inline u32 btrfs_key_type(struct btrfs_key *key)
325 return key->flags & BTRFS_KEY_TYPE_MASK;
328 static inline u32 btrfs_disk_key_type(struct btrfs_disk_key *key)
330 return le32_to_cpu(key->flags) & BTRFS_KEY_TYPE_MASK;
333 static inline void btrfs_set_key_type(struct btrfs_key *key, u32 type)
335 BUG_ON(type >= BTRFS_KEY_TYPE_MAX);
336 key->flags = (key->flags & ~((u64)BTRFS_KEY_TYPE_MASK)) | type;
339 static inline void btrfs_set_disk_key_type(struct btrfs_disk_key *key, u32 type)
341 u32 flags = btrfs_disk_key_flags(key);
342 BUG_ON(type >= BTRFS_KEY_TYPE_MAX);
343 flags = (flags & ~((u64)BTRFS_KEY_TYPE_MASK)) | type;
344 btrfs_set_disk_key_flags(key, flags);
349 static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
351 return le64_to_cpu(h->blocknr);
354 static inline void btrfs_set_header_blocknr(struct btrfs_header *h, u64 blocknr)
356 h->blocknr = cpu_to_le64(blocknr);
359 static inline u64 btrfs_header_parentid(struct btrfs_header *h)
361 return le64_to_cpu(h->parentid);
364 static inline void btrfs_set_header_parentid(struct btrfs_header *h,
367 h->parentid = cpu_to_le64(parentid);
370 static inline u16 btrfs_header_nritems(struct btrfs_header *h)
372 return le16_to_cpu(h->nritems);
375 static inline void btrfs_set_header_nritems(struct btrfs_header *h, u16 val)
377 h->nritems = cpu_to_le16(val);
380 static inline u16 btrfs_header_flags(struct btrfs_header *h)
382 return le16_to_cpu(h->flags);
385 static inline void btrfs_set_header_flags(struct btrfs_header *h, u16 val)
387 h->flags = cpu_to_le16(val);
390 static inline int btrfs_header_level(struct btrfs_header *h)
392 return btrfs_header_flags(h) & (BTRFS_MAX_LEVEL - 1);
395 static inline void btrfs_set_header_level(struct btrfs_header *h, int level)
398 BUG_ON(level > BTRFS_MAX_LEVEL);
399 flags = btrfs_header_flags(h) & ~(BTRFS_MAX_LEVEL - 1);
400 btrfs_set_header_flags(h, flags | level);
403 static inline int btrfs_is_leaf(struct btrfs_node *n)
405 return (btrfs_header_level(&n->header) == 0);
408 static inline u64 btrfs_root_blocknr(struct btrfs_root_item *item)
410 return le64_to_cpu(item->blocknr);
413 static inline void btrfs_set_root_blocknr(struct btrfs_root_item *item, u64 val)
415 item->blocknr = cpu_to_le64(val);
418 static inline u32 btrfs_root_refs(struct btrfs_root_item *item)
420 return le32_to_cpu(item->refs);
423 static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val)
425 item->refs = cpu_to_le32(val);
428 static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)
430 return le64_to_cpu(s->blocknr);
433 static inline void btrfs_set_super_blocknr(struct btrfs_super_block *s, u64 val)
435 s->blocknr = cpu_to_le64(val);
438 static inline u64 btrfs_super_root(struct btrfs_super_block *s)
440 return le64_to_cpu(s->root);
443 static inline void btrfs_set_super_root(struct btrfs_super_block *s, u64 val)
445 s->root = cpu_to_le64(val);
448 static inline u64 btrfs_super_total_blocks(struct btrfs_super_block *s)
450 return le64_to_cpu(s->total_blocks);
453 static inline void btrfs_set_super_total_blocks(struct btrfs_super_block *s,
456 s->total_blocks = cpu_to_le64(val);
459 static inline u64 btrfs_super_blocks_used(struct btrfs_super_block *s)
461 return le64_to_cpu(s->blocks_used);
464 static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s,
467 s->blocks_used = cpu_to_le64(val);
470 static inline u32 btrfs_super_blocksize(struct btrfs_super_block *s)
472 return le32_to_cpu(s->blocksize);
475 static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s,
478 s->blocksize = cpu_to_le32(val);
481 static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l)
483 return (u8 *)l->items;
485 /* helper function to cast into the data area of the leaf. */
486 #define btrfs_item_ptr(leaf, slot, type) \
487 ((type *)(btrfs_leaf_data(leaf) + \
488 btrfs_item_offset((leaf)->items + (slot))))
490 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root);
491 int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf);
492 int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks);
493 int btrfs_search_slot(struct btrfs_root *root, struct btrfs_key *key,
494 struct btrfs_path *p, int ins_len, int cow);
495 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
496 void btrfs_init_path(struct btrfs_path *p);
497 int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path);
498 int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *key,
499 void *data, u32 data_size);
500 int btrfs_insert_empty_item(struct btrfs_root *root, struct btrfs_path *path,
501 struct btrfs_key *cpu_key, u32 data_size);
502 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
503 int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf);
504 int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap);
505 int btrfs_finish_extent_commit(struct btrfs_root *root);
506 int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key);
507 int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key,
508 struct btrfs_root_item *item);
509 int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key,
510 struct btrfs_root_item *item);
511 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
512 struct btrfs_root_item *item, struct btrfs_key *key);
513 int btrfs_insert_dir_item(struct btrfs_root *root, char *name, int name_len,
514 u64 dir, u64 objectid, u8 type);
515 int btrfs_lookup_dir_item(struct btrfs_root *root, struct btrfs_path *path,
516 u64 dir, char *name, int name_len, int mod);
517 int btrfs_match_dir_item_name(struct btrfs_root *root, struct btrfs_path *path,
518 char *name, int name_len);