5 #include "kerncompat.h"
7 #define BTRFS_MAGIC "_BtRfS_M"
8 #define BTRFS_BLOCKSIZE 1024
10 #define BTRFS_ROOT_TREE_OBJECTID 1
11 #define BTRFS_EXTENT_TREE_OBJECTID 2
12 #define BTRFS_FS_TREE_OBJECTID 3
15 * the key defines the order in the tree, and so it also defines (optimal)
16 * block layout. objectid corresonds to the inode number. The flags
17 * tells us things about the object, and is a kind of stream selector.
18 * so for a given inode, keys with flags of 1 might refer to the inode
19 * data, flags of 2 may point to file data in the btree and flags == 3
20 * may point to extents.
22 * offset is the starting byte offset for this key in the stream.
24 * btrfs_disk_key is in disk byte order. struct btrfs_key is always
25 * in cpu native order. Otherwise they are identical and their sizes
26 * should be the same (ie both packed)
28 struct btrfs_disk_key {
32 } __attribute__ ((__packed__));
38 } __attribute__ ((__packed__));
41 * every tree block (leaf or node) starts with this header.
44 u8 fsid[16]; /* FS specific uuid */
45 __le64 blocknr; /* which block this node is supposed to live in */
46 __le64 parentid; /* objectid of the tree root */
51 /* generation flags to be added */
52 } __attribute__ ((__packed__));
54 #define BTRFS_MAX_LEVEL 8
55 #define NODEPTRS_PER_BLOCK ((BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)) / \
56 (sizeof(struct btrfs_disk_key) + sizeof(u64)))
60 struct btrfs_root_item {
69 * in ram representation of the tree. extent_root is used for all allocations
70 * and for the extent tree extent_root root. current_insert is used
71 * only for the extent tree.
74 struct btrfs_buffer *node;
75 struct btrfs_buffer *commit_root;
76 struct btrfs_root *extent_root;
77 struct btrfs_root *tree_root;
78 struct btrfs_key current_insert;
79 struct btrfs_key last_insert;
81 struct radix_tree_root cache_radix;
82 struct radix_tree_root pinned_radix;
83 struct list_head trans;
84 struct list_head cache;
87 struct btrfs_root_item root_item;
88 struct btrfs_key root_key;
92 * the super block basically lists the main trees of the FS
93 * it currently lacks any block count etc etc
95 struct btrfs_super_block {
96 u8 fsid[16]; /* FS specific uuid */
97 __le64 blocknr; /* this block number */
105 } __attribute__ ((__packed__));
108 * A leaf is full of items. The exact type of item is defined by
109 * the key flags parameter. offset and size tell us where to find
110 * the item in the leaf (relative to the start of the data area)
113 struct btrfs_disk_key key;
116 } __attribute__ ((__packed__));
119 * leaves have an item area and a data area:
120 * [item0, item1....itemN] [free space] [dataN...data1, data0]
122 * The data is separate from the items to get the keys closer together
125 #define LEAF_DATA_SIZE (BTRFS_BLOCKSIZE - sizeof(struct btrfs_header))
127 struct btrfs_header header;
129 struct btrfs_item items[LEAF_DATA_SIZE/
130 sizeof(struct btrfs_item)];
131 u8 data[BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)];
133 } __attribute__ ((__packed__));
136 * all non-leaf blocks are nodes, they hold only keys and pointers to
140 struct btrfs_header header;
141 struct btrfs_disk_key keys[NODEPTRS_PER_BLOCK];
142 __le64 blockptrs[NODEPTRS_PER_BLOCK];
143 } __attribute__ ((__packed__));
146 * items in the extent btree are used to record the objectid of the
147 * owner of the block and the number of references
149 struct btrfs_extent_item {
152 } __attribute__ ((__packed__));
155 * btrfs_paths remember the path taken from the root down to the leaf.
156 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
157 * to any other levels that are present.
159 * The slots array records the index of the item or block pointer
160 * used while walking the tree.
163 struct btrfs_buffer *nodes[BTRFS_MAX_LEVEL];
164 int slots[BTRFS_MAX_LEVEL];
167 static inline u64 btrfs_extent_owner(struct btrfs_extent_item *ei)
169 return le64_to_cpu(ei->owner);
172 static inline void btrfs_set_extent_owner(struct btrfs_extent_item *ei, u64 val)
174 ei->owner = cpu_to_le64(val);
177 static inline u32 btrfs_extent_refs(struct btrfs_extent_item *ei)
179 return le32_to_cpu(ei->refs);
182 static inline void btrfs_set_extent_refs(struct btrfs_extent_item *ei, u32 val)
184 ei->refs = cpu_to_le32(val);
187 static inline u64 btrfs_node_blockptr(struct btrfs_node *n, int nr)
189 return le64_to_cpu(n->blockptrs[nr]);
192 static inline void btrfs_set_node_blockptr(struct btrfs_node *n, int nr,
195 n->blockptrs[nr] = cpu_to_le64(val);
198 static inline u16 btrfs_item_offset(struct btrfs_item *item)
200 return le16_to_cpu(item->offset);
203 static inline void btrfs_set_item_offset(struct btrfs_item *item, u16 val)
205 item->offset = cpu_to_le16(val);
208 static inline u16 btrfs_item_end(struct btrfs_item *item)
210 return le16_to_cpu(item->offset) + le16_to_cpu(item->size);
213 static inline u16 btrfs_item_size(struct btrfs_item *item)
215 return le16_to_cpu(item->size);
218 static inline void btrfs_set_item_size(struct btrfs_item *item, u16 val)
220 item->size = cpu_to_le16(val);
223 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
224 struct btrfs_disk_key *disk)
226 cpu->offset = le64_to_cpu(disk->offset);
227 cpu->flags = le32_to_cpu(disk->flags);
228 cpu->objectid = le64_to_cpu(disk->objectid);
231 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
232 struct btrfs_key *cpu)
234 disk->offset = cpu_to_le64(cpu->offset);
235 disk->flags = cpu_to_le32(cpu->flags);
236 disk->objectid = cpu_to_le64(cpu->objectid);
239 static inline u64 btrfs_key_objectid(struct btrfs_disk_key *disk)
241 return le64_to_cpu(disk->objectid);
244 static inline void btrfs_set_key_objectid(struct btrfs_disk_key *disk,
247 disk->objectid = cpu_to_le64(val);
250 static inline u64 btrfs_key_offset(struct btrfs_disk_key *disk)
252 return le64_to_cpu(disk->offset);
255 static inline void btrfs_set_key_offset(struct btrfs_disk_key *disk,
258 disk->offset = cpu_to_le64(val);
261 static inline u32 btrfs_key_flags(struct btrfs_disk_key *disk)
263 return le32_to_cpu(disk->flags);
266 static inline void btrfs_set_key_flags(struct btrfs_disk_key *disk,
269 disk->flags = cpu_to_le32(val);
272 static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
274 return le64_to_cpu(h->blocknr);
277 static inline void btrfs_set_header_blocknr(struct btrfs_header *h, u64 blocknr)
279 h->blocknr = cpu_to_le64(blocknr);
282 static inline u64 btrfs_header_parentid(struct btrfs_header *h)
284 return le64_to_cpu(h->parentid);
287 static inline void btrfs_set_header_parentid(struct btrfs_header *h,
290 h->parentid = cpu_to_le64(parentid);
293 static inline u16 btrfs_header_nritems(struct btrfs_header *h)
295 return le16_to_cpu(h->nritems);
298 static inline void btrfs_set_header_nritems(struct btrfs_header *h, u16 val)
300 h->nritems = cpu_to_le16(val);
303 static inline u16 btrfs_header_flags(struct btrfs_header *h)
305 return le16_to_cpu(h->flags);
308 static inline void btrfs_set_header_flags(struct btrfs_header *h, u16 val)
310 h->flags = cpu_to_le16(val);
313 static inline int btrfs_header_level(struct btrfs_header *h)
315 return btrfs_header_flags(h) & (BTRFS_MAX_LEVEL - 1);
318 static inline void btrfs_set_header_level(struct btrfs_header *h, int level)
321 BUG_ON(level > BTRFS_MAX_LEVEL);
322 flags = btrfs_header_flags(h) & ~(BTRFS_MAX_LEVEL - 1);
323 btrfs_set_header_flags(h, flags | level);
326 static inline int btrfs_is_leaf(struct btrfs_node *n)
328 return (btrfs_header_level(&n->header) == 0);
331 static inline u64 btrfs_root_blocknr(struct btrfs_root_item *item)
333 return le64_to_cpu(item->blocknr);
336 static inline void btrfs_set_root_blocknr(struct btrfs_root_item *item, u64 val)
338 item->blocknr = cpu_to_le64(val);
341 static inline u32 btrfs_root_refs(struct btrfs_root_item *item)
343 return le32_to_cpu(item->refs);
346 static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val)
348 item->refs = cpu_to_le32(val);
351 static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)
353 return le64_to_cpu(s->blocknr);
356 static inline void btrfs_set_super_blocknr(struct btrfs_super_block *s, u64 val)
358 s->blocknr = cpu_to_le64(val);
361 static inline u64 btrfs_super_root(struct btrfs_super_block *s)
363 return le64_to_cpu(s->root);
366 static inline void btrfs_set_super_root(struct btrfs_super_block *s, u64 val)
368 s->root = cpu_to_le64(val);
371 static inline u64 btrfs_super_total_blocks(struct btrfs_super_block *s)
373 return le64_to_cpu(s->total_blocks);
376 static inline void btrfs_set_super_total_blocks(struct btrfs_super_block *s,
379 s->total_blocks = cpu_to_le64(val);
382 static inline u64 btrfs_super_blocks_used(struct btrfs_super_block *s)
384 return le64_to_cpu(s->blocks_used);
387 static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s,
390 s->blocks_used = cpu_to_le64(val);
393 static inline u16 btrfs_super_blocksize(struct btrfs_super_block *s)
395 return le16_to_cpu(s->blocksize);
398 static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s,
401 s->blocksize = cpu_to_le16(val);
404 /* helper function to cast into the data area of the leaf. */
405 #define btrfs_item_ptr(leaf, slot, type) \
406 ((type *)((leaf)->data + btrfs_item_offset((leaf)->items + (slot))))
408 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root);
409 int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf);
410 int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks);
411 int btrfs_search_slot(struct btrfs_root *root, struct btrfs_key *key,
412 struct btrfs_path *p, int ins_len, int cow);
413 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
414 void btrfs_init_path(struct btrfs_path *p);
415 int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path);
416 int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *key,
417 void *data, int data_size);
418 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
419 int btrfs_leaf_free_space(struct btrfs_leaf *leaf);
420 int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap);
421 int btrfs_finish_extent_commit(struct btrfs_root *root);
422 int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key);
423 int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key,
424 struct btrfs_root_item *item);
425 int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key,
426 struct btrfs_root_item *item);
427 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
428 struct btrfs_root_item *item, struct btrfs_key *key);