xref: /openbmc/linux/fs/btrfs/extent_map.h (revision b6bec26c)
1 #ifndef __EXTENTMAP__
2 #define __EXTENTMAP__
3 
4 #include <linux/rbtree.h>
5 
6 #define EXTENT_MAP_LAST_BYTE (u64)-4
7 #define EXTENT_MAP_HOLE (u64)-3
8 #define EXTENT_MAP_INLINE (u64)-2
9 #define EXTENT_MAP_DELALLOC (u64)-1
10 
11 /* bits for the flags field */
12 #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
13 #define EXTENT_FLAG_COMPRESSED 1
14 #define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
15 #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
16 #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
17 #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
18 
19 struct extent_map {
20 	struct rb_node rb_node;
21 
22 	/* all of these are in bytes */
23 	u64 start;
24 	u64 len;
25 	u64 mod_start;
26 	u64 mod_len;
27 	u64 orig_start;
28 	u64 orig_block_len;
29 	u64 block_start;
30 	u64 block_len;
31 	u64 generation;
32 	unsigned long flags;
33 	struct block_device *bdev;
34 	atomic_t refs;
35 	unsigned int in_tree;
36 	unsigned int compress_type;
37 	struct list_head list;
38 };
39 
40 struct extent_map_tree {
41 	struct rb_root map;
42 	struct list_head modified_extents;
43 	rwlock_t lock;
44 };
45 
46 static inline u64 extent_map_end(struct extent_map *em)
47 {
48 	if (em->start + em->len < em->start)
49 		return (u64)-1;
50 	return em->start + em->len;
51 }
52 
53 static inline u64 extent_map_block_end(struct extent_map *em)
54 {
55 	if (em->block_start + em->block_len < em->block_start)
56 		return (u64)-1;
57 	return em->block_start + em->block_len;
58 }
59 
60 void extent_map_tree_init(struct extent_map_tree *tree);
61 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
62 					 u64 start, u64 len);
63 int add_extent_mapping(struct extent_map_tree *tree,
64 		       struct extent_map *em);
65 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
66 
67 struct extent_map *alloc_extent_map(void);
68 void free_extent_map(struct extent_map *em);
69 int __init extent_map_init(void);
70 void extent_map_exit(void);
71 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
72 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
73 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
74 					 u64 start, u64 len);
75 #endif
76